Commit Graph
1088 Commits
Author SHA1 Message Date
Matthew Jackson 93e1436fc0 Test that the Media Key verifier actually rejects a wrong key
`km_verifies` is the gate deciding whether a candidate Media Key belongs
to the disc. The MK-pool brute force in resolve.rs runs every candidate
through it, so a version that said yes to everything would accept
whichever candidate it tried first and the rip would continue with a wrong
Media Key — wrong VUK, wrong title keys, garbage plaintext, and no error
raised anywhere.

Nothing tested it. Whole-crate mutation testing reported
`replace km_verifies -> bool with true` as SURVIVING: the body could be
replaced with `true` and all 2,556 tests still passed. A verification
routine whose verification was itself unverified, in the most
safety-critical function in the crate.

The implementation is correct — it matches the AACS relation
`AES-D(km, mk_dv)[0..8] == 01 23 45 67 89 AB CD EF`. Only the defence was
missing.

No real key material is required to test it. That relation means a valid
record for any chosen km is just `AES-E(km, <the constant> || anything)`,
so the fixture is self-contained. The test asserts three things: the key
the record was built for verifies; a key differing by ONE BIT does not,
which is the assertion that kills the mutant and is a near-miss rather
than a random key; and an MKB carrying no verify record does not default
to yes, because unverifiable and verified are different answers.

Confirmed by reintroducing the exact reported mutation and watching this
test fail.

This is the first defect found by mutation testing rather than by reading.
Eight audit rounds and a security lens that read this file in full all
missed it, because it is not a wrong line — it is an absent test, and only
an instrument that asks "would anything notice if this were broken?" can
see that.
2026-07-30 12:14:14 -07:00
Matthew Jackson 18f8b285c4 Bound the BD-J label parsers, and stop a crafted disc hanging the scan
Ten defects in code no previous round had ever scoped. `src/labels/`
identifies a disc's studio by parsing jar archives and JVM class files off
untrusted media, so every byte here is attacker-controllable — and 813 of
its lines were executed by no test at all.

The worst is a non-terminating loop. A fallback stream-number scan
advanced with `saturating_add`, and the comment says why: a crafted XML
"must not overflow (panic in debug, wrap-to-0 in release)". Once the
counter pins at u16::MAX and that number is taken, the loop cannot exit.
So a fix for an overflow panic produced an unbounded hang, which is
strictly worse — a panic is observable and catchable, and catch_unwind
cannot interrupt a live loop. Reachable from about 8 MB of XML.

Where the same overflow appears in the deluxe decoder the fix is
checked_add and stop, NOT saturation — twice wrong there, because
saturating would peg every stream past the ceiling at one number and
apply_labels binds on (type, number), silently mislabelling tracks. A
correctness bug wearing the costume of success.

Round 7 capped the ldc-string retention per class; nothing capped the
aggregate, so a 64 MiB jar held that budget for every class at once. Same
defect one level up, which is the shape that keeps recurring in this
directory. Four other amplifications are bounded the same way, each with a
stated headroom and a paired test proving real media passes untouched —
the tightest is 5x on a label length, the loosest 2000x on the stream
numbering space, against BD's 32-per-type STN_table limit.

Two are not caps at all: a quadratic membership scan became a set, and an
attacker-derived length added to a cursor without saturation now cannot
wrap. Nothing is excluded by either.

A `#[cfg(test)]` hand-copy of a shipping parser was the ninth bad test
this audit has found, and the first proven by mutation rather than
inspection: deleting the guard from the REAL function left all 26 tests
green, including the one named for that guard. Pointed at the real
function, the same mutation fails.

Separately, all three failure arms of the bounded fsync returned Ok(()) on
both macOS and Linux, so sync_all reported success for a durability
barrier that never ran. Only macOS was in scope; the Linux twin is fixed
here too, because a platform disagreeing with its sibling about whether a
failed sync is an error is the class that already produced an over-length
SCSI CDB macOS rejected and the other two truncated. Note the behaviour
change: a mux whose final sync times out on a wedged mount now fails
rather than exiting 0.

Three of the caps are proven by wall-clock deadline rather than an
operation count, with 18-80x margin on the passing side. On a heavily
oversubscribed machine those could flake.
2026-07-30 11:30:24 -07:00
Matthew Jackson c63dafcf1a Key each FMTS extent from its own CPS unit, and stop a bad ICB tag reading
as an empty directory

On an AACS 2.1 disc the non-forensic gap fill hardcoded pool slot 0 as
"the" base Unit Key, so every content LBA outside a forensic segment was
keyed with CPS unit 1's key even on a disc carrying several CPS units. It
does not fail loudly — it produces garbage plaintext. The gap fill now
resolves each extent's own base key from its ciphertext, sharing the
sampling and slot-picking the multi-CPS path already had rather than
adding a second copy, and memoised in the existing per-disc cache. A disc
with one base key still short-circuits with zero extra reads, which the
existing probe-cost test pins. Forcing the slot back to a constant fails
four tests, so the choice is load-bearing rather than incidental.

A directory ICB whose descriptor tag is neither File Entry nor Extended
File Entry (ECMA-167 4/14.9, 4/14.17) was turned into a successfully-read
EMPTY directory, indistinguishable from a genuinely empty one, while the
same tag on a file ICB was already a hard error. Fifth instance in this
audit of a failure converted into a plausible success value, and the
second in this very function — round 5 fixed a read error becoming a file
size of zero here.

An unrecorded extent (ECMA-167 4/14.14.1.1: allocated but not recorded,
logically zeros that still occupy file space) was dropped entirely rather
than contributing its length, so every later extent landed at the wrong
file offset. Silent corruption, not an error. Extents now carry a recorded
flag and the hole emits zeros without touching the media.

The Volume Descriptor Sequence was swept at hardcoded sectors 32..64 while
the anchor's own Main VDS Extent pointer was parsed into a comment and
ignored; ECMA-167 3/10.2.1 defines that extent by the field, not by
position, so a conformant volume placing it elsewhere failed to mount.

drive_status decoded byte 5 as Media Status without checking the event
header's NEA bit or notification class (MMC-6 §6.7), so a reply carrying
no media event descriptor decoded as "no disc". The drive is untrusted
input here, and this is the works-on-my-drive class.

Two more tests were found asserting the defects they sit next to — one
requiring unrecorded extents to be dropped, one that four drive fixtures
built non-conformant replies the corrected decoder rightly rejects. Both
rewritten. Combined with the DTS one in the previous commit that makes
three tests this round that locked a bug in as intended behaviour, which
is a different and worse failure than the tautological tests found so far:
a tautology fails to catch a regression, these actively defend the defect.

Not fixed, adjacent: extract_one_file streams extents sequentially and
will now READ an unrecorded extent's sectors rather than writing
guaranteed zeros. Offsets are right, and pressed media reads as zeros
there, but it is not zero-guaranteed the way read_file now is; that needs
a recorded flag through PlannedFile.
2026-07-30 11:15:52 -07:00
Matthew Jackson 46eb88c51f Feed the CSS crack the canonical extent order, and stop Resolution faking 1080p
Seven defects in the code the test suite executes least — 913 lines of
disc/mod.rs alone are run by no test at all, which is why this round scoped
from coverage rather than from what previous rounds said they had read.

Disc::scan_image kept its own copy of the crack's extent ordering and fed
crack_key_outcome largest-cell-first. That is the fifth instance in this
audit of a local reimplementation drifting from the canonical one, and the
cost here is a key that does not descramble the feature: picking by sector
count bypasses the capacity gate and can select a different VTS entirely.
The copy is gone — which title comes from the canonical order the scan
already applied, and the extents are handed over in playback order,
exactly as decrypt_keys_for_title does. Its doc records why the duplicate
existed so it cannot grow back.

Resolution::pixels returned 1920x1080 for Unknown. That is the FOURTH
instance of one trap and the other three were in this same file, two of
them fixed hours earlier — without sweeping for siblings, which is the
whole reason this one survived. It now returns (0, 0), and the sweep was
done properly this time: every remaining Unknown arm across the crate is
honest, and the two ColorSpace sites that look like fabrication are
emitting H.273 code point 2, which is the spec's own "unspecified". Two
callers carried local Unknown-to-zero workarounds — precisely the cost of
making callers responsible for a lie — and one is now redundant.

BD-ROM Part 3 code 0xA2 is the lossy secondary DTS stream, not lossless
Master Audio. A test asserted the wrong mapping as intended behaviour, so
correcting the code failed it; the test is deleted with a note pointing at
its replacement. That is a NEW failure mode for this audit: not a test
that cannot fail, but one that locks the defect in. There is no
DtsExpress variant to map to, so it takes the lossy DTS-HD member and the
approximation is documented.

Also: DiscSession::identify could panic through drive_mut once the public
API allows an absent drive — two siblings were converted in an earlier
round and this one was missed; an extent end that added without saturating
where the rest of the crate saturates; a diag reason string restating the
comparator's sort keys and drifting from them, now derived from them; and
a short read that advanced the offset by the full request, silently
skipping the gap. That last one existed twice, in two reads with the same
shape, now merged so they cannot drift apart.

The short-read policy is a judgement call I could not derive from a spec:
no skip_errors is a hard error, with skip_errors zero-fills and charges
the loss. It deliberately does not retry mid-unit, because resuming inside
an AACS aligned unit would trade a silent gap for a silent decrypt
desync — the worse of the two.
2026-07-30 11:12:55 -07:00
Matthew Jackson dea968f32b Stop AudioChannels and SampleRate fabricating a value for Unknown
Three copies of the same two mappings existed. The canonical accessors
returned 6 channels and 48000 Hz for Unknown; a third copy in diag.rs
returned 0. The honest one was the copy.

A plausible wrong answer is worse than an obvious one. Six channels at
48 kHz is indistinguishable from a real 5.1 track, so every caller became
responsible for remembering to check the variant first — and this crate
walked into exactly that: the json:// sink reported a confident 5.1 for
audio whose neighbouring fields said "unknown". That was fixed at the call
site earlier in this audit; this fixes it at the source.

The accessors now return 0, which is what both in-crate call sites already
coerced Unknown to by hand, so their guards are gone and the behaviour is
unchanged. Zero is also obviously wrong if it ever reaches output, where
six is not.

The diag.rs duplicates are deleted rather than corrected — a fourth copy
would have drifted too. Their only caller was a trace line in the same
file, now on the canonical accessors. Their tests moved across and gained
the Unknown case, which is the point: restoring either fabricated value
fails both.

Found by the round-7 correctness agent while fixing the json:// sink; it
flagged the third copy as out of its scope rather than touching it.
2026-07-30 10:09:01 -07:00
Matthew Jackson 079c9b1327 Add a seeded robustness harness for the untrusted-input parsers
Five parsers that take bytes straight off a disc are now swept with
generated input asserting one property: they return Ok or Err and never
panic. That is this crate's own hard rule, and the class seven rounds of
reading is worst at.

Written in-crate rather than with cargo-fuzz, which needs a nightly
toolchain this project does not use, and without proptest or arbitrary,
because one dev-dependency is a deliberate posture and the parsers take
plain byte slices. What is given up is coverage-guided mutation, which is
the real loss. What is gained is determinism: the same seed replays the
same cases anywhere, so a CI failure reproduces locally verbatim.

Three generators, and the second is the one that matters. Pure random
bytes die at the magic check and exercise the entry guards only; prefixing
valid magic is what reaches the parser body; mutating a mostly-zero record
is what reaches the offset and count arithmetic a hostile image would lie
about.

That claim is MEASURED, not asserted. A harness whose cases all bounce off
the entry guards is the fuzzing equivalent of a test that cannot fail, so
one test counts how many generated cases parse to completion: 15,606 of
60,000, about 26%. If a future change to a guard drops that to zero, the
test fails rather than continuing to report a meaningless pass. Two further
tests pin that the three generators produce different bytes and that a seed
replays identically.

1.2M cases across all five targets found nothing. On this evidence that is
a real negative rather than an empty one.

The first version of this file was itself broken in the way this audit
keeps finding: its two meta-tests set FREEMKV_HARNESS_CASES and raced,
because the test harness runs them in parallel and env mutation is unsound
there. The budget is a parameter now, and the environment is read once at
the call site.

Two crate-internal parsers widened from private to pub(crate) so the
harness can reach them. No public API change.
2026-07-30 09:45:56 -07:00
Matthew Jackson 327087c70e Make five tests capable of failing, and stop the presence probe unmounting the disc
The worst of the five was a regression suite that never touched the code
it guarded: nine batch-count tests called `safe_batch_count` and
`buggy_batch_count`, both defined in the test file itself. The u16
truncation they exist to prevent could be reintroduced in
sector/prefetched.rs with every one of them green. They now drive the real
producer through the public API, and reinstating the truncation fails five
of the nine. Worth recording that the symptom has changed since the
original fix: the unit-alignment clamp below floors a zero batch at three
sectors, so the bug is now a twenty-fold throughput cliff rather than the
stall it once was.

The MP4 reserve test's only numeric case was dominated by the floor and
the buffer, so BYTES_PER_SAMPLE could be zeroed without failing it. It now
has a case where the per-sample term dominates. The zero-count guard in
FileSectorSource was likewise unfalsifiable — seek-past-EOF and a
zero-length read both succeed — so the test now observes the file cursor.
The AACS media-key ambiguity guard had no test at all; the pool scan is
extracted so the verifier can be injected, because a genuine two-key
collision needs one ciphertext decrypting under two AES-128 keys to
plaintexts sharing a 64-bit magic, which is a 2^64 search and not a
fixture.

macOS implemented the documented cheap, side-effect-free presence probe by
building a full exclusive transport — which force-unmounts the disc. Linux
and Windows issue one TEST UNIT READY with no unmount; macOS was the
outlier. It now walks the IOKit registry for the media object instead.

The C shim's registry reads assumed CoreFoundation types the registry does
not guarantee, so a driver publishing a CFNumber where a CFString was
expected aborted the process from inside public API. Types are checked and
a wrong type treated as absent. The unbounded waitpid on the unmount child
is now a polled deadline, and the last-resort match gained the NULL check
its two siblings already had.

The empty-CDB guard existed only on Linux while a shared helper's comment
claimed all three backends had it. Moved into the helper, so the comment
is now true and macOS and Windows are covered.

One finding was REJECTED with evidence rather than fixed. The TrueHD
buffer-cap test was indeed bogus, but MAX_TRUEHD_BUF turns out to be
unreachable by any input: the parser only retains data when the buffer is
shorter than the declared AU, and that declaration is twelve bits, so the
worst case is 8189 bytes against a 256 KiB cap. An exhaustive sweep over
all 65536 AU headers confirmed it. The fixture now sits at the reachable
ceiling and asserts that instead. The cap itself is left in place as
defence, unreachable by construction, matching how the AC-3 resync guard
was handled earlier in this audit.

Two behaviour changes worth naming: Linux's empty-CDB error becomes
InvalidCdbLength rather than a transport failure, and an unknown device
now reports absent media rather than a not-found error, because the
registry cannot tell an empty drive from a missing one. The latter is a
conflation of the kind this audit has fixed three times; it is recorded
for the next round rather than left silent.
2026-07-30 09:26:56 -07:00
Matthew Jackson b8fa5e74dc Stop the live rip path muxing Blu-ray 3D differently from the ISO path
Five defects, four of them the same shape: a local reimplementation of
logic the crate already had, which had drifted from it. Each is now fixed
by calling the canonical version rather than by patching the copy.

DiscStream::new — the live disc:// path — built every parser through the
plain codec lookup and never asked whether a video stream was an MVC
dependent view, though resolve::build_demux_state does. The same 3D disc
therefore muxed correctly from an ISO and incorrectly ripped live. The
open-coded loop is gone; both paths now call build_demux_state.

collect_psi_section reimplemented the continuity-counter gap test and
disagreed with process_packet in the same file: it tolerated neither a
duplicate packet nor an adaptation-field-only packet, which per ISO/IEC
13818-1 §2.4.3.3 does not increment the counter. A spec-legal PMT
continuation was read as desync and the title's stream list came back
empty. Both callers now share one `cc_is_gap`, and a duplicate packet's
payload is no longer appended twice — doing so would have corrupted the
section the check exists to protect.

The json:// sink called the channel-count and sample-rate accessors
unconditionally, and both fabricate a concrete value for Unknown, so it
reported a confident 5.1 at 48 kHz for audio whose format was unknown
while its own neighbouring string fields said "unknown". The keys are now
omitted, matching mkv.rs. This matters more than it did: a sample-rate
ladder fixed earlier in this audit means Unknown now reaches consumers
that used to receive a wrong-but-concrete value.

For an audio:// or sub:// sink the reference video track's output is
filtered out, so its first PTS was never recorded and every delay was
computed against zero — baking a wrong DELAY into the filename. The
reference is now recorded whenever a frame is on the reference track,
independent of whether that track has an output, so a normal title gets a
correct delay; where no reference is ever observed the tag is omitted
rather than guessed.

A third copy of the channel/sample-rate mapping exists in src/diag.rs and
was left alone as outside the confirmed set. It is the same drift shape
and is recorded for the next round.
2026-07-30 09:18:33 -07:00
Matthew Jackson 3f7d7af472 Bound three allocations an untrusted disc can drive without limit
The Program Stream demuxer appended every fed byte and enforced its 4 MiB
cap only inside a branch reached once a start code had been found. Input
containing no start code anywhere therefore hit no cap at all, and since a
whole title is fed through this demuxer, a zero-filled or ciphertext VOB
extent buffered the entire title — up to ~90 GB. When the buffer holds no
start code, only a two-byte `00 00` prefix can begin a PS unit on the next
feed, so that is kept and the rest dropped. The bound is exact rather than
a heuristic: a start code can straddle a feed boundary by at most its
first two bytes, so no real byte is discarded, and a test feeding
`FF FF 00 00` then `01 E0 ...` pins that.

The existing test named for this case fed a real start code first, so the
cap it exercised was the in-PES one. Renamed to say what it covers.

The BD-J label path had a different shape to anything found so far: the
cap is on the COMPRESSED size of a disc file while the allocation scales
with the decompressed size. A `.class` gated only by a path prefix
inflates to the 64 MiB ceiling, yielding ~33M retained strings from `ldc`
operands or ~67M pushes onto a symbolic stack whose depth was unbounded
despite the Code attribute's own `max_stack` being parsed and then
ignored. Bounded both, the stack by `max_stack` itself (JVMS §4.7.3).

The VMG TT_SRPT title count is an untrusted u16 with no de-duplication,
so ~800 KB of crafted IFO re-parsed one PGC 65535 times. Capped at 99, the
DVD-Video maximum, so no conformant disc is clipped.

Every cap carries stated headroom against real media, and each has a test
locking that real media still passes.

I rewrote three of the new assertions before landing them. They compared
the result against the very constant under test — `total <= MAX_TT_SRPT_TITLES`
— which passes vacuously the moment someone raises the constant, the most
likely future regression and the seventh instance of this tautology shape
in this audit. They now assert literals derived from the spec.

The TT_SRPT fixture also had to change: with 65535 identical entries the
de-duplication collapsed them on its own and the cap was never what
bounded the result, so the test passed with the cap removed entirely.
Distinct entries defeat dedup and leave the cap as the only guard;
de-duplication now has its own fixture. Verified by raising each of the
three constants and confirming all three tests fail.
2026-07-30 09:17:16 -07:00
Matthew Jackson fdd473d7e9 Remove emulation-prevention bytes before reading the H.264 slice header
The bytes after a NAL header are EBSP, not RBSP: ISO/IEC 14496-10 §7.4.1
has the encoder insert 0x03 after any 0x00 0x00, and §7.3.1 removes it
before parsing. The measured-picture-type parse read the raw NAL instead,
on the stated reasoning that slice_type is too early for an escape to
intervene.

That holds only up to a point. first_mb_in_slice is ue(v), so a value of
65535 or more needs sixteen leading zero bits and opens the payload with
0x00 0x00, which an encoder must then escape. A UHD frame is ~32,400
macroblocks, so a conforming Blu-ray never reaches it — but 8K does, and
the disc is untrusted input. Such a stream decoded slice_type against a
byte the encoder had inserted and reported the wrong picture type: a wrong
result rather than an error, which is the class this lens exists for.

The prefix is un-escaped into a 16-octet buffer rather than the whole NAL:
the two ue(v) fields are at most 32 bits each, so nothing longer can be
needed, and it keeps a per-frame allocation proportional to the frame off
the path.

The test pins both directions. It asserts the un-escaped prefix decodes to
first_mb_in_slice = 65535 and slice_type = 2, AND that the raw EBSP does
NOT — without that second assertion the test would pass whether or not the
fix were present, which is the failure mode this audit has now found four
times. The bit string was derived independently rather than by hand: my
first attempt at the fixture was wrong by one nibble and the test caught
it.

Also covers the cases that must NOT be unescaped: a 0x03 not preceded by
00 00 is ordinary payload, and 00 00 03 03 keeps its second 0x03 because
the escape resets the zero run.
2026-07-30 08:49:51 -07:00
Matthew Jackson 05fed1b0e0 Log the OS error when a SCSI command fails on Windows and macOS
Both backends discarded the platform's own error code on the execute hot
path — the one every READ(10) of a rip goes through — and collapsed every
cause to the same status-0xFF transport failure.

On Windows, open() and reset() in the same file both capture the Win32
error; execute() did not. That left ERROR_INVALID_PARAMETER (a struct
layout regression, the exact class this file's SDK-layout tests exist to
catch), ERROR_ACCESS_DENIED and ERROR_GEN_FAILURE (a genuinely wedged
drive) indistinguishable, with nothing in the log to tell a code bug from
a hardware one.

On macOS the same, and worse: the file had no tracing calls at all, where
the Linux and Windows backends both log their execute failures. Its open()
carefully decodes the shim's sentinel into typed variants instead of
flattening them, but execute() threw the IOKit return away — so another
process taking exclusive access mid-rip and a real hardware wedge produced
identical, empty diagnostics.

Logged rather than added to the error type: the typed variant is public
API, and the recovery classification is deliberately the same for all of
these. What was missing is the breadcrumb, not the distinction.

Two further findings from the same sweep were rejected. Windows reset()
always returning Ok(()) and macOS ignoring timeout_ms are both already
documented in the code as deliberate, and the reporter flagged them for
completeness rather than as defects.

Neither fix has a test: reaching either branch needs a failing ioctl or a
failing IOKit call, and both files are compiled only on their own platform.
2026-07-30 08:42:02 -07:00
Matthew Jackson d444afbdfc Turn a release-only slice panic into an error, and stop calling 32 kHz 48 kHz
Four round-6 findings.

FileSectorSource::read_sectors guarded its output buffer with a
debug_assert, which is compiled out in release — so an undersized buffer
panicked with 'range end index out of range' instead of returning an
error, out of a public SectorSource impl where the length is caller input.
Drive::read_fua already carries this exact guard, with a comment recording
the same panic being fixed there, and PrefetchedSectorSource has a
regression test for the same case; this impl had been given neither. The
new test is red in release for precisely the predicted reason: 'range end
index 8192 out of range for slice of length 2049'.

parse_track's sample-rate ladder ended in an unconditional S48, so any
SamplingFrequency below 44100 was recorded as 48 kHz. A 32000 Hz AC-3 or
DTS track is legal and common in broadcast-sourced content, and the wrong
rate then propagated into the reconstructed AudioStream. Anything below
the lowest mapped rate is now Unknown, which is what the crate's canonical
SampleRate::from_hz already returned — the ladder disagreed with it. The
ladder itself stays, because the MKV element is a float and wants
tolerance rather than exact equality.

shim_open_exclusive used the mach port from IOMainPort without checking
the return; on failure the port is left untouched and every IOKit call
below ran against an uninitialised value. shim_list_drives in the same
file does check it.

build.rs treated cc and ar as successful if the process merely SPAWNED, so
a genuine compile error in the macOS C shim produced no object file and
surfaced later as an unexplained link failure against a missing symbol.
The shim is macOS-only and is neither linted nor compiled on the other two
platforms, so a mistake in it has exactly one chance to be noticed.

The last two have no test: one needs IOMainPort to fail, the other needs a
deliberately broken C shim, and neither is reachable from the test
harness. Both mirror a correct sibling in the same file, which is the
evidence available.
2026-07-29 22:56:33 -07:00
Matthew Jackson 921404d135 Fix five clippy errors that only appear on the target CI lints
CI's clippy job runs on ubuntu-latest, so cfg(target_os = "linux") code is
what the gate actually compiles — and none of it is built by clippy on a
Mac. Five `-D warnings` errors were sitting in drive/linux.rs,
scsi/linux.rs, io/writeback/linux.rs and the Linux arm of drive/mod.rs:
four collapsible let-chains and one manual `% n == 0`. CI was red on the
lint job while the local gate reported all green.

Collapsed into let-chains, which the declared toolchain supports, and
folded drive/mod.rs's length precondition into its chain so the body no
longer needs a nested block.

Found because an agent working on the SCSI backends reported the lints in
passing while checking that a Windows-only file compiled. Worth noting how
it stayed hidden: every one of these files is cfg-gated to a platform this
machine is not, so no amount of local gating would have surfaced them. The
companion change to the precommit script closes that hole.
2026-07-29 22:37:47 -07:00
Matthew Jackson 399c3d2769 Reject an over-length CDB on every transport, splice H.264 param sets in place
Two fixes from round 5.

The Linux and Windows backends truncated a CDB longer than 16 bytes
(`cdb.len().min(16)`) where macOS returned InvalidCdbLength. Under SPC-4 a
command's length is fixed by its opcode group code, so a shortened CDB is
not a shorter form of the same command — it is a DIFFERENT command, and
the drive executes it and answers GOOD with data for a request nobody
made. A silently wrong result on the layer everything else sits on.

Rather than mirror the guard a third time it now lives in scsi::mod as
checked_cdb_len, with all three backends routed through it, so it cannot
drift per platform again. That also makes it testable everywhere: each
platform module is cfg-gated to its own host, so a guard inlined into
linux.rs and windows.rs would have had no test coverage on any single
machine. The shared helper is the only place the behaviour can be
asserted on every platform's CI.

The two existing macOS tests were tautological — they replicated the
guard's logic inline instead of calling it, so they would have passed with
the guard deleted. They now call the real helper.

Separately, the H.264 keyframe parameter-set re-assert grew a
few-hundred-byte prefix buffer to the full access-unit size, copied the
whole frame into it, and dropped the presized buffer: one extra
whole-frame allocation and copy per keyframe. A UHD title is ~200,000
frames of 150-400 KB with a keyframe every second or two, so that is
thousands of avoidable multi-hundred-KB copies per title, each large
enough to go through mmap. It now splices into the reserved headroom in
place. This mirrors the identical fix already made in hevc.rs, which the
H.264 path had drifted from.

Byte-for-byte equivalence is pinned by a test whose expected literals
were captured from the pre-change implementation, and which I confirmed
still passes when the old build-and-copy code is restored. The
no-reallocation claim is measured rather than argued: a counter over 30
bare keyframes, which reports 30 of 30 against the old path and 0 with
the splice.

The reallocation test initially passed even with PARAM_REASSERT_HEADROOM
set to zero, because a small parameter set fits in the presize's
incidental slack — it proved the fixture did not reallocate, not that the
headroom prevented it. Its SPS is now large enough that the constant is
load-bearing, so zeroing it fails the test.

Not verified: no runtime behaviour on Linux or Windows: no drive, no
ioctl. Both files were confirmed to compile for their own targets.
2026-07-29 22:34:22 -07:00
Matthew Jackson dc5b67ed46 Stop reporting an uncrackable CSS disc as N empty titles
Same shape as the mkv:// conflation fixed earlier in this round, found by
looking for it deliberately. E7023 carried two conditions with opposite
correct responses: one title on a multi-VTS DVD failing its own re-crack,
where skipping it and finishing the rest is right, and the main feature's
crack failing outright, which is disc-wide and dooms every title
identically. Because both raised the same code and that code is in
is_skippable_title_stub, an uncrackable disc walked all N titles printing
"title skipped, it was empty" and exited 0.

The disc-wide condition gets E7027 CssNoDiscKey, mirroring the AACS-side
E7022 NoDiscKey it is the analogue of, and joins is_disc_level_no_key.
The per-title raise keeps E7023 and stays skippable. Because the engine's
classifier already tests is_disc_level_no_key before the skippable
branch, this reaches the right outcome downstream with no change there:
such a disc now stops on the first title and reports no-key instead of
returning success with nothing written.

Disc::css_error deliberately still stores CssKeyMissing — autorip matches
that variant on the field to pick the CSS rather than AACS message, and
what consumers classify on is the gate's returned verdict, which is the
only thing that changed.

Two neighbouring CSS raises were examined and deliberately left alone:
the no-key branch in the same function is genuinely unreachable via
ensure_decryptable and documented as defensive, and resolve_dvd_title_key
is per-title on both of its call paths.

Verified by removing the new code from is_disc_level_no_key, which fails
both new tests; each pins both directions so neither can silently flip.
Not proven end to end against a real uncrackable disc — none available.
2026-07-29 22:29:51 -07:00
Matthew Jackson 5c6a6d0785 Round 5: reject a degenerate fixed lace, bound the pending buffer by bytes
Five fixes. Three are real defects with regression tests; two are bounds
that were expressible but not expressed.

A fixed-size lace (RFC 9559 §10.3.4) whose body is empty declared n
frames and carried none. The divisibility check passed, because 0 % n is
0, and `chunks` yields nothing on an empty slice whatever width it is
given — so the clamp that existed to avoid chunks(0) returned zero frames
where the Lacing Head said n. The whole lace vanished with no error
raised and the caller saw a clean short block. A zero-size frame cannot
be a valid frame, so it is now malformed.

A disc read failure while fetching a directory entry's ICB became a file
size of zero rather than an error. Zero is indistinguishable from a
genuinely empty file, so an unreadable ICB on a damaged disc silently
changed which titles a caller saw as present — read_directory already
fails hard on its entry-budget guard, so propagating is also what the
surrounding code does. read_file_size still returns Ok(0) for an ICB
whose tag is neither File Entry nor Extended File Entry, which is a real
zero and not a failure.

The pending-frame buffer was capped at 4096 frames, which does not bound
memory: frames are arbitrarily large and a UHD video frame runs to a few
hundred KB, so the existing cap permitted over a gigabyte. Now bounded by
bytes as well, at 64 MiB.

round_up_grain overflowed for inputs within one grain of u64::MAX —
div_ceil then multiply — and the wrapped product is small, turning the
largest possible estimate into a negligible reserve. It saturates, and
the reserve is clamped to what a `free` box's 32-bit size field can
actually hold, since writing a larger one truncated the size and left
mdat beyond a box claiming to be far shorter. No real title comes close;
a 90 GB UHD title estimates a few MiB.

The AC-3 resync guard now advances the PTS cadence like both of its
sibling branches, so the three paths out of that block cannot disagree.
This one is defensive and has NO test: reaching it needs input that both
parses frames and leaves a megabyte of residue, and the parser's own
carry rules drop pre-sync junk and cap a partial frame at 8192 bytes, so
no such input was found. Stated here rather than covered by a test that
would pass either way.

Two findings from this round were rejected on inspection. A reported
panic in the .mpls suffix check does not exist: the `.get(..)` on the
line above returns None off a char boundary and `filter` never runs its
closure, so the byte index is unreachable. A test written for it passed
against the unfixed code, which is what surfaced the error.
2026-07-29 22:28:43 -07:00
Matthew Jackson f5e169efb3 Stop reporting a corrupt mkv:// source as an empty title
E6008 meant two unrelated things: "this title produced no muxable
frames", which is a benign stub worth skipping, and "the source file is
malformed", which is not. Because a single code carried both,
is_skippable_title_stub answered yes to the second one — so feeding a
truncated or corrupt mkv:// input made the engine classify it
SkippableStub, print a notice saying the title was empty, and exit 0.
Silent data loss reported as success.

Split into E9053 MkvSourceInvalid for the read path (25 raise sites
across mkvstream.rs and ebml.rs's read primitives) and E9054
MkvUnencodable for the four write-side sites, which are the encoder
refusing to emit a body at or above the 56-bit VINT limit — an output
limit with no input involved, so calling it a corrupt source would be
wrong in the other direction. E6008 keeps only the zero-frame guard it
was documented to mean.

Kept one code for the whole read path rather than one per raise site:
nothing a consumer does differs between a bad VINT, a non-UTF-8 string
element, a truncated body and a child overrunning its parent. E9052 is
the model for when a carve-out earns its keep — laced blocks name one
specific RFC 9559 §10.3 feature with its own diagnosis.

Also fixed meta_sink.rs raising MkvInvalid for a serde_json encode
failure in the json:// sink, where no MKV is involved at all; it now
matches the identical guard in mux/meta.rs.

Reverting the split at the single code() arm reproduces the old
classification: 22 tests fail, including both new assertions. The
opposite direction is pinned too — dropping E6008 from the predicate
fails the genuine-stub test, which drives the real muxer end to end.
2026-07-29 22:11:53 -07:00
Matthew Jackson 0bbceed985 Round 4: fix 26 defects across crypto, resource use and codec paths
Twenty-six confirmed findings from the fourth audit round, landed as one
cluster because they were found by agents working over disjoint file sets.

The one worth calling out is a pair of AACS tests that could not fail.
Both asserted CBC behaviour against a hand-rolled expectation that
happened to be IV-independent, so replacing AACS_IV with sixteen zero
bytes left them passing — they were pinning the code's own arithmetic,
not the published constant. Replaced with a literal witness of the
published IV plus the NIST SP 800-38A F.2.2 CBC-AES128 vector, and
verified the other way round: zeroing AACS_IV now fails three tests.

The rest are allocation and correctness work on hot paths: the Annex-B
writer in demux_sink allocated and freed a whole-frame Vec per frame,
which for a UHD title is ~200,000 allocations over the mmap threshold
plus the page faults to first-touch each one; it now reuses a buffer on
the writer, and still takes the NAL prefix width from the configuration
record rather than assuming four.

Six findings whose real fix lives in a consumer crate are recorded for
re-filing rather than patched here.
2026-07-29 22:09:52 -07:00
Matthew Jackson 4fcd28b487 Parse MKV lacing, route by real TrackNumber, honour NAL length size and edit lists
Four conformance defects in the read paths, two of them silent corruption.

**Lacing was ignored entirely.** RFC 9559 §10.2 defines Xiph, EBML and
fixed-size lacing, where one Block carries several frames; the reader took the
Block payload verbatim, so a laced Block became a single "frame" consisting of a
lacing header followed by concatenated frames — garbage to the codec parser, no
error. Audio tracks from other muxers commonly use lacing, so an ordinary
foreign MKV was silently mangled.

All three modes are now parsed: Xiph 255-run sizes including the trailing-zero
rule for exact multiples of 255, EBML unsigned first size plus SIGNED VINT deltas
with the 2^((7*n)-1)-1 bias of §10.3.3, and fixed-size even division, with the
last frame's size deduced from the remainder. Laced timestamps follow §10.3.5:
the first frame takes the Block timestamp and the rest are spaced by the track's
DefaultDuration, else BlockDuration/count, else shared with a warn.

Parsing was chosen over refusing because refusal would leave freemkv unable to
remux common foreign audio at all, and each mode is about fifteen lines.

A malformed lacing header now raises a NEW code, E_MKV_LACING_INVALID = 9052,
deliberately NOT MkvInvalid — because is_skippable_title_stub classifies
MkvInvalid as a skippable nav stub, so reusing it would have recreated the exact
conflation that is still open as a separate finding. A test asserts the new code
is not skippable.

**TrackNumber was assumed to be 1..N in TrackEntry order.** RFC 9559 §5.1.4.1.1
only requires it to be non-zero and unique, so sparse or unordered numbers are
legal. Block routing and codec_private both computed track + 1. A real
TrackNumber map is now built, recorded only for TrackEntries that yield a stream
so dropped track types no longer shift the mapping.

Verified red here independently, and the failure mode is worse than mis-routing:
with track + 1 restored, a buttons track's payload was attributed to the AUDIO
stream — wrong payload into the wrong codec parser.

**The NAL length prefix was hardcoded to 4 bytes.** lengthSizeMinusOne lives in
avcC byte 4 and hvcC byte 21 (ISO/IEC 14496-15 §5.3.3.1.2, §8.3.3.1.2) and was
never read, so a source declaring 1- or 2-byte prefixes had its raw prefixed
bytes emitted verbatim with no start codes. All four conversion sites now derive
the width from the track's own configuration record.

**Edit lists were ignored.** No edts/elst was parsed, so the presentation
timeline an edit list defines (ISO/IEC 14496-12 §8.6.5/§8.6.6) was dropped —
which is how encoder delay is normally expressed. Leading empty edits and the
first media edit's media_time are now applied to both dts and pts, with the movie
vs media timescale distinction respected. A list needing more than a constant
shift applies the leading edit and warns rather than presenting the result as
faithful.

17 tests. I reproduced the lacing mutant independently: returning the body whole
kills five of them, including the exact-payload and malformed-header cases.

Still open and deliberately untouched: the MkvInvalid / is_skippable_title_stub
conflation across ~20 reader raise sites. It is a cross-cutting error.rs change
and E_MKV_LACING_INVALID is the template for it.
2026-07-29 21:53:19 -07:00
Matthew Jackson 9527bc1e13 Anchor forensic segments to the forensic clip, and stop CPS branching on resolve order
Two correctness defects in AACS 2.1 / FMTS key-map resolution, both order- or
anchor-dependent, and both able to abort a whole disc or silently garble it.

**The single-CPS short-circuit depended on which title resolved first.**
`pool_len` counted the WHOLE unit-key pool, and resolve_fmts_key_map appends the
disc's forensic index keys to that same caller-owned pool. The count was captured
before THIS call's FMTS branch but not before earlier titles', so once any forensic
title resolved, every later title saw a pool larger than one and fell into
multi-CPS sampling — 8 random reads per extent, and a whole-disc DecryptFailed if
no pooled key opened a menu extent's samples. A disc that ripped fine when a
non-forensic playlist sorted first failed when a forensic one did.

Forensic keys are now tagged FMTS_POOL_TAG_BASE = 1 << 24 and the short-circuit
asks single_base_key_slot(), which excludes them. The old 1000 tag was NOT kept,
and the reasoning is worth recording: base CPS ids are Unit_Key_RO.inf position + 1
and that count is a BE16, so 1000 sits inside a genuinely reachable id space. 1<<24
cannot collide. The id field is cosmetic — decrypt.rs indexes the pool by slot and
reads only the key — so widening the tag is safe.

**Forensic segment SPNs were anchored to the wrong clip.** They live in the
forensic feature clip's byte space, but were mapped through
clip_byte_to_lba(&title.extents, ..), which treats byte 0 as the start of the
title's FIRST extent. Any playlist not beginning with the forensic clip mapped
every segment to the wrong LBA: either the anchor probe sampled the wrong clip and
the whole-disc resolve aborted with FmtsKeyMissing, or — worse — a forensic index
key was applied to non-forensic sectors while the real forensic units kept the base
key, giving silently garbled output with no error at all.

The correct anchor turns out to be a DISC fact, not title data: an AACS 2.1 disc
names its forensic feature BDMV/STREAM/<clip>.fmts, and carries one
IndividualSegment.tbl, so the SPNs are in that one clip's byte space. A new
forensic_clip_extents() finds the unique .fmts in the already-walked UDF tree, and
those extents now drive the segment arithmetic, the addressability filter, and the
index probe — whose title parameter is gone, since its reads were mis-anchored too.
"Does this title carry forensic content" is now "does it read the forensic clip's
sectors" rather than "do the segment bytes land somewhere in the concatenation".

Where the clip is NOT identifiable — no .fmts, or several, making the SPN space
ambiguous — on a disc that does carry a non-empty table, the resolve now fails loud
with FmtsKeyMissing rather than guessing an anchor. That is a deliberate behaviour
change: a hypothetical disc with two .fmts clips hard-fails where it previously
produced a possibly-wrong map. Failing loud beats silently garbled output, and
inventing an anchor was not acceptable.

This site had been flagged independently three times — by the agent that added the
FMTS per-disc memo, by the round-4 correctness lens with a concrete scenario, and
by the round-4 conformance pass.

Verified red here independently: reverting single_base_key_slot to count the whole
pool fails both new tests. The agent's own evidence was probe_reads 48 vs 40 (the
8 extra sampling reads) and an E7013 DecryptFailed whole-disc abort, and for the
anchor an E7026 FmtsKeyMissing on a [trailer, forensic] extent list.

All six pre-existing FMTS tests pass unchanged through the new anchor, including
the exact-cost assertions (40 probe reads, one key-service call per disc, one UDF
walk for 60 titles), so the round-3 memoisation wins are intact.
2026-07-29 21:37:50 -07:00
Matthew Jackson 58bdb42f8e Group whole E-AC-3 frame sets, and keep short reads unit-aligned
Two defects in fixes landed the same day, both found by round 4 auditing round 3's
work rather than trusting it.

**The E-AC-3 grouping ignored substreamid, so the timeline still doubled.**
Confirmed independently by the correctness and conformance lenses and verified by
hand: substreamid appeared only in test helpers, never in the production path. Per
ETSI TS 102 366 (A/52) Annex E a frame set is independent substream 0 — mandatory,
always first — with its dependents, then the OPTIONAL additional independent
substreams 1..7 with theirs, all covering the same time period. Treating an
additional independent substream as a new access unit advanced the clock a second
time for the same 32 ms, which is exactly the doubling the grouping fix existed to
prevent. No fixture caught it because every fixture used substreamid 0.

is_dependent_substream becomes substream_role -> Starts | Extends: strmtyp 1
extends; strmtyp 0/2 with substreamid != 0 now extends (this was the bug); strmtyp
0/2 with substreamid == 0, legacy AC-3, and reserved strmtyp 3 start. Reserved 3
starts regardless of its id bits, because its BSI layout is undefined so those bits
cannot be trusted — an unknown frame is neither merged into an unrelated programme
nor silently discarded.

The frame set stays ONE sample rather than being split into a separate track for
the associated service, and the reasoning is in the module doc: a substream
numbered 1..7 with no substream 0 is not conforming, so extracting one would mean
renumbering ids and rebuilding frame sets — a transcode, not a remux. Programme
selection is the player's job.

A stream joined mid-frame-set (first sync is substreamid 3) is skipped with a debug
and resyncs at the next id-0, mirroring the orphan-dependent rule: its mandatory
id-0 substream was never seen, so it is neither decodable alone nor timeable.

MAX_AC3_BUF 128 KiB -> 1 MiB, because an AU is now a whole frame set: worst case 8
independent x 9 substreams x 8192 B = 576 KiB, which the old cap could have dropped
mid-hold.

**The forced probe's two round-3 fixes cancelled each other.** CHUNK_SECTORS = 1023
exists (with a const assert) so every read starts on a 3-sector AACS aligned-unit
boundary; the short-read fix advanced by actual bytes, making the advance a
non-multiple of 3. Every later read was then misaligned, DecryptingSectorSource
refused it before reading, the stop became ReadFailed, and no verdict was asserted
— so content-based forced detection silently fell back to the vendor label on
exactly the encrypted discs the 1023 change was written for.

A partially-satisfied read now advances only by whole aligned units and re-reads
the <=2 residue sectors from the next boundary, feeding only the aligned prefix so
nothing is double-fed and no partial unit reaches the parsers. A read that fully
satisfies its request still advances by all of it. When less than one aligned unit
comes back the bytes are fed and the same LBA is retried twice before stopping, so
a starved source cannot spin — verified by raising the retry limit and watching the
test hang.

Verified red independently here: reverting substream_role to strmtyp-only fails
eac3_additional_independent_substream_stays_in_the_frame_set (6 access units where
3 are correct — the doubling, literally) and the mid-frame-set resync test.

Reported, not fixed: dec3_box still hardcodes num_ind_sub - 1 = 0 and
num_dep_sub = 0, so it under-declares any stream carrying additional independent
or dependent substreams now that frame sets arrive whole. DolbyConfig has no
fields for either; a real fix needs the parser to surface observed substream
counts. That file is another lens's this round.

Unverified: no real multi-programme DD+ stream exists here, so defect 1 rests on
synthetic Annex-E fixtures. The retail DD+ check (No Time to Die, all substreamid
0) confirms single-programme discs are unaffected.
2026-07-29 21:33:18 -07:00
Matthew Jackson 62450e19bd Make two public-API panics return errors, and drop two shipped citations
**The session panics are reachable, and my earlier triage of them was wrong.**
`DiscSession::scan` and `resolve_keys` both did
`self.drive.as_mut().expect(..)`. I previously downgraded these to LOW on the
grounds that no shipped consumer calls them after the drive has been staged into
the reader slot. That is the wrong test: `stage_drive_as_reader` is a PUBLIC
method that empties the drive slot, so the public surface permits the sequence,
and a library must not panic from public API regardless of what current callers
happen to do. Both now return Error::DeviceNotReady.

**A shipped doc comment cited a third-party source FILE** as the authority for
the CLPI ProgramInfo layout ("Layout per the BD CLPI spec clpi_parse.c"). Now
cites the Blu-ray Disc Read-Only Format Part 3 CLIPINF specification.

**The CHANGELOG justified a muxer decision by naming a commercial competitor**
("MakeMKV's rip of the same disc omits it", "matching MakeMKV"). Reworded to
stand on its own terms: the element is optional in RFC 9559, nothing requires it
for interlaced SD, and the 40 ms DefaultDuration is the frame rate the source
actually carries.

The leak gate is extended for both new classes — third-party `*_parse.c` /
`*_dec.c` / `*_demux.c` style filenames, and a competitor named as authority.

Narrowing that rule took two attempts, which is worth recording. A bare
`\.(c|cpp|cc)` pattern produced eight false positives: this repo has its own C
shim (`macos_shim.c`) that build.rs and the docs legitimately reference, and the
pattern also matched the Rust field access `p.cc`. It now matches only the
suffixes typical of third-party media-library sources. This is the second
false-positive round on this rule — the first flagged ffmpeg INVOCATIONS in the
test harness — so the lesson is that a hygiene pattern needs testing in both
directions before it lands, exactly like any other code.
2026-07-29 21:21:29 -07:00
Matthew Jackson 013881ac06 Restore the MP4 conformance fixes I clobbered while landing another agent's work
detect_rate's nearest-match fix, the colr HLG/BT.470 fix and their four tests
were silently reverted. Cause: the r3fix-silent worktree was cut BEFORE the
conformance commit landed, and I landed its work by copying whole files into the
main tree. mp4/mod.rs was in both agents' file sets, so silent's copy — built on
the older base — overwrote the conformance changes wholesale. The gate stayed
green throughout, because reverting a fix and its tests together is perfectly
consistent.

Re-applied the conformance commit's diff for that file with a three-way merge;
both agents' changes to mp4/mod.rs now coexist (final_report, UndescribableAudio
and the max(track_id) id fix are all still present alongside RATE_TOLERANCE_FPS
and the colr resolver delegation).

Only mp4/mod.rs was affected. mp4/audio.rs and mkv.rs were in no other agent's
file set and were intact.

Process lesson, recorded because I would otherwise repeat it: NEVER land a
parallel agent's work by copying whole files, when its worktree was cut at an
older base than HEAD. Apply its DIFF (git apply -3), or rebase its worktree
first. Copying files silently discards anything committed to those files in the
interim, and no test can catch it because the tests disappear with the code.
2026-07-29 21:03:26 -07:00
Matthew Jackson 5f8dc392c0 Sweep the pinned toolchain to Rust 1.97
The Windows UI needs current winsafe, whose real minimum is 1.89 (its manifest
under-declares 1.87 while it uses NonNull::from_ref). Rather than stop at the
minimum, this goes to current stable and fixes what that costs.

The counter-intuitive result: 1.97 is CHEAPER than 1.89. libfreemkv had 54
clippy errors at 1.89 and 6 at 1.97, because clippy tightened the noisy
collapsible_if lint in between. Stopping at the minimum would have been the most
expensive choice available.

Roughly 47 lints across the eight repos, the large majority auto-fixed:
libfreemkv 6, freemkv-engine 14, bdemu 8, freemkv-keysources 7, autorip 6,
freemkv-unlock 3, freemkv-i18n 3. The hand-fixed ones are a descending sort to
sort_by_key(Reverse), four manual checked-division sites, a loop counter replaced
by enumerate, and a loop whose first let-else became a while-let.

Worth recording for whoever bumps next: clippy is MSRV-AWARE. Those 54 lints only
appear once the crate DECLARES 1.89 or later, because let-chains become
available. A bare `cargo +1.89 clippy` against a manifest still pinned at 1.87
reports clean and is meaningless — gate with the real precommit script, which is
also the only thing that covers build scripts.

The pin still sits below the Mac default, so it keeps doing its job: catching
lint drift locally before CI sees it.
2026-07-29 21:00:55 -07:00
Matthew Jackson a32373ff40 Fix fifteen defects across perf, resource, panics and key hygiene
All 21 findings held up under verification; 15 fixed here, 6 deferred to files
another agent held this round, 0 rejected.

**A defect in my own round-2 probe fix.** CHUNK_SECTORS was 1024, and
1024 % 3 == 1 — verified — so every chunk after the first was misaligned against
the 6144-byte AACS aligned unit and would be REJECTED by
DecryptingSectorSource's alignment gate. On an encrypted disc the forced-subtitle
probe I added last round would have read almost nothing past its first chunk.
Now 1023 sectors (341 aligned units) with a const assertion that fails the build
if it stops dividing, plus set_unit_base per extent so the source's gate is
anchored where the extent actually starts.

**The same probe skipped sectors on a short read**, advancing by the REQUESTED
count rather than the bytes actually returned, so a partial read silently left a
gap in the middle of the evidence. It now advances by n/SECTOR_BYTES and clamps n
to the buffer.

**Its cache key omitted the PGS PID set**, so a playlist declaring an extra
subtitle PID got another playlist's verdict for a track that had never been
probed. And the key was the whole extent list, so partial clip sharing missed
entirely. Both fixed by keying (start_lba, sector_count, pid) — and per-extent
keying was shown SOUND rather than assumed: ForcedTracker is two monotone
booleans, so per-extent evidence composes by field-wise OR, order- and
grouping-independently. Making that honest required per-extent demux state, so an
extent's evidence comes only from its own bytes, and memoising only extents whose
read reached a designed stop.

**A reachable panic in the timeline.** mkvstream::parse_block accepts a
TimestampScale up to i64::MAX, so a video frame can set high_ns = i64::MAX and the
next passive frame panicked adding the backstep. In release it wrapped negative
instead, firing the straggler clamp for essentially every passive frame — audio
and subtitles rewritten onto the wrong point of the output timeline. All four
sites saturate.

**A public constructor divided by zero**: PrefetchedSectorSource::new_with_events
with unit_align == 0. Now InvalidInput, matching its batch_sectors sibling.

**Two Debug impls printed key material.** DiscInputs (volume_id, mkb, unit_key_ro,
samples) and UnitKeyFile both derived Debug. Nothing logs them today — fixed as
prevention, because the next tracing::debug! someone adds is the leak. A doc claim
that DiscInputs "contains no secrets" was false and is corrected.

**An env-var multiply could overflow** in file_sector_source; now bounded at 64 GiB
like its writeback sibling, with the parse split out so the bound is testable
without touching process env.

**The mp4 demuxer allowed one sample per file byte** — ~64x RAM amplification.
Now file_len/16, since only vide/soun tracks are indexed and the shortest legal
AC-3 frame is 128 bytes.

**Two pipeline concurrency defects**: a consumer apply() error was invisible to the
producer, and abandon/finalise had a TOCTOU where a caller could report an
unfinalised output. Both fixed with compare-exchange state rather than a bool.

**Two per-frame copies removed**, both MEASURED rather than reasoned: the AU
assembler now hands its allocation to the frame (same pointer, unchanged capacity,
proven by asserting the pointer) and tsmux reuses one Annex-B buffer across
frames. Both keep capacity deliberately — a naive split_off would have cost more
than it saved.

**A comment pointed at the wrong file** for a mirrored constant; the mirror is now
compiler-enforced with a const assertion converting 90 kHz ticks to ns, so drift
fails the build.

Deferred to another agent's files, all confirmed: detect_rate's fractional-twin
snap, the mp4 reserve's u32 truncation, round_up_grain's overflow, the quadratic
base-key gap fill, and MkvStream's frame cap counting frames rather than bytes.

Every fix verified red by reverting it. Also noted for later:
DecodeSampleSet still derives Debug over multi-MB of on-disc ciphertext.
2026-07-29 20:47:31 -07:00
Matthew Jackson 3efa6211f3 Make six silent mux failures observable
All six confirmed against the code. The governing rule this cluster serves: a
lossy or degraded outcome is never silent, because a corrupt rip the user does
not know about is the worst failure available.

**A 3D MKV re-mux silently lost one eye.** The BlockGroup read path had arms for
BLOCK / BLOCK_DURATION / REFERENCE_BLOCK only, so BLOCK_ADDITIONS fell into the
skip arm — while the writer does emit BlockAdditions > BlockMore > BlockAdditional
for the MVC dependent view. Reconstruction was judged out of scope and the
reasoning is recorded: PesFrame has no side-payload field and the header parser
never reads BlockAdditionMapping, so there is no dependent-view track to route the
AU to. Instead the loss is now LOUD — counted in bytes and events, warned once,
and surfaced through MkvStream's errors()/lost_bytes(), which the driver already
samples into MuxOutcome. One detail in the finding was wrong and is corrected: the
re-mux does NOT still advertise the mvcC mapping, because the header parser
ignores that element, so the output is a plain 2D H.264 track.

**An all-titles rip silently skipped real titles.** The header-buffer-cap
overflow returned Error::MkvInvalid, and is_skippable_title_stub matches exactly
E_MKV_INVALID | E_CSS_KEY_MISSING — verified here — so a 512 MiB-of-frames title
was classified as an empty nav/menu PGC stub and dropped. It now has its own
E9051 / MuxHeaderBufferExceeded { bytes }, outside the skippable set.

**The public pre-mux report contradicted the file.** Mp4Sink::finish() drops an
audio track it cannot describe, which I chose last round over failing an export
whose video is fine — but mp4_fit_report still listed that stream as included, so
the application's plan and the actual output disagreed. Fixed at both levels:
Mp4SkipReason is now non_exhaustive with NoSamples and UndescribableAudio,
Mp4Sink::final_report() describes the FILE rather than the plan, and for the
boxed dyn Stream path a defaulted Stream::undelivered_streams() carries the
information out to MuxOutcome::undelivered_streams with a driver-side warn.

**MP4 track ids could collide.** ids were assigned before the retain that drops
sample-less tracks, while next_id came from the post-retain count, so [1,3]
yielded next_id 3. Now max(track_id) + 1, saturating.

**Stream selection silently skipped its codec_privates prune** when the lists were
not the same length — but codec_privates is consumed POSITIONALLY and trailing
extras are documented as benign, so the length-equality guard was itself the bug.
The prune now runs unconditionally by index.

**The m2ts_mux scaffolding armed params_written on both the absent and the
unparseable codec_private arms** — the same defect already fixed in tsmux.rs.
Split into params_attempted (a latch, since retrying identical bytes cannot help)
and params_emitted, with a warn on each failure arm and an accessor so the
eventual wiring and its test can observe it.

Each fix verified red by mutating back to the prior behaviour: errors() 0 vs 1,
E6008 vs E9051, final_report [0,1] vs [0], next_track_id 3 vs [1,3], and the
selection prune resolving index 1 to the wrong track's record.

API surface deliberately widened: MuxOutcome gains a public field and Mp4Sink
becomes public. Nothing in-repo breaks. Note a behaviour change on the mkv://
input path — a 3D re-mux now reports non-zero loss, so a consumer treating
errors > 0 as disc damage will trip on it. That is intended: the outcome IS
degraded.
2026-07-29 20:46:10 -07:00
Matthew Jackson 9ad68dd092 Fix four MP4 conformance defects against the standards
**dec3 declared a 0 kbit/s AC-3 substream.** parse_dolby routes bsid < 11 to
parse_ac3, which leaves data_rate_kbps = 0 and keeps the AC-3 bsid, yet
dolby_sample_entry wrapped that config in ec-3/dec3 for any Codec::Ac3Plus track.
ETSI TS 102 366 Annex F.4 assigns ac-3/dac3 to an AC-3 bitstream and F.6 assigns
ec-3/dec3 to an Enhanced AC-3 one, so the entry now follows the SYNCFRAME that was
actually parsed, not the playlist's codec label. Computing an AC-3 data rate and
keeping ec-3 was rejected: it fixes one field while bit_stream_identification and
num_dep_sub keep misdescribing the stream. The bsid threshold is hoisted into one
constant so parser and entry-chooser cannot drift. Adjacent defect fixed in the
same box: data_rate is 13 bits from a u16 source, so push's mask WRAPPED anything
above 8191 (9000 became 808); it now saturates.

**colr tagged HLG as PQ, and PAL as BT.601.** video_colr carried a second,
drifted copy of the ColorSpace-to-CICP map: transfer 16 (PQ) for every BT.2020
stream with no HdrFormat override, and 6 (BT.601) for Bt470bg. Per ITU-T H.273
Table 3, HLG is 18 and BT.470-6 System B/G is 5 — and mkv::cicp_for_video already
got both right. video_colr now delegates to that shared resolver, so the
duplicated table is gone and cannot drift again. It keeps only its own decision
about WHETHER to emit the box, since an absent colr and an all-unspecified colr
mean the same thing per ISO/IEC 14496-12.

**Exact 24.000 / 30.000 / 60.000 fps was declared 23.976 / 29.97 / 59.94.**
detect_rate took the FIRST STD_RATES entry within 0.5 fps, and every 1000/1001
entry precedes its integer twin 0.024 fps away — a 0.1% error across the whole
track's mdhd and stts. Fixed as nearest-wins rather than by reordering the table:
reordering fixes today's table and re-breaks the moment someone appends a rate,
while nearest-wins is order-independent. Verified red here independently by
reverting to first-match, which fails exactly the two timing tests.

**ddts MultiAssetFlag was set from has_extension.** In the DTSSpecificBox
(ETSI TS 102 114) that flag signals more than one audio ASSET. A DTS-HD MA/HRA
track is one asset whose extension substream carries the XLL/XBR component, so
setting it from "an EXSS sync follows the core" sent a parser looking for a second
asset descriptor while StreamConstruction simultaneously said there was no
extension — the box contradicting itself. This module parses the core header only
and never reads the EXSS asset table, so 0 is the only honest declaration. A
StreamConstruction index for core+EXSS was deliberately NOT invented: that field
is a table lookup that could not be confirmed against the standard, and a wrong
index is worse than an under-declaration.

DTS_AMODE_LAYOUT's masks were independently re-derived against ETSI TS 102 114
§5.3.1 and all 16 are CORRECT — only three adjacent comments were wrong (the
AMODE 2/3/4 annotations were rotated by one, and AMODE 9's said "5.1 with LFE"
when 0x0007 is the 5.0 mask and LFE is OR'd in separately). Comments corrected.

Every one of the eight new tests decodes the field back OUT of the emitted bytes —
data_rate from the dec3 body's leading 13 bits, MultiAssetFlag from bit 48 of the
ddts tail, colr from the nclx payload inside a real stsd, and the frame rate from
mdhd.timescale plus stts.sample_delta of a fully muxed MP4 — rather than
restating arithmetic. This audit has already caught one of my own tests doing the
latter.

NOT fixed, root-caused and recorded at the site instead: an A_PCM/INT/BIG track
ships with no BitDepth, which the Matroska Codec Specifications make a MUST. The
width exists on disc (BD LPCM signals it in the ES header byte 3, DVD in the IFO
audio attribute byte 1) but neither source reaches MkvTrack::audio, and the fix
needs a new AudioStream member plus a deferred setter in files another agent held
this round. Guessing 16 was rejected — it would confidently misdecode every
24-bit disc — as was refusing the track, which would regress the 16-bit majority
that currently plays by accident.
2026-07-29 20:29:17 -07:00
Matthew Jackson 13897e14f0 Resolve the forensic key map once per disc, not once per playlist
resolve_content_key_map loops every title into resolve_mux_key_map, which called
resolve_fmts_key_map FIRST — before the CpsUnitCache — and on an FMTS disc
returned immediately. So every playlist re-derived facts that belong to the DISC:
a full UDF walk plus /AACS/IndividualSegment.tbl, and on an FMTS disc the anchor
probe, the 32-index phase probe, and a fetch.fmts_indexes round trip.

On a 60-playlist disc, measured on a synthetic fixture: 840 -> 14 metadata reads,
2,400 -> 40 probe reads, and 60 -> 1 key-service calls. Worst case before was up
to 256 probe reads and 32 key-service calls per title. The 60 redundant
key-service round trips are a strong candidate for the keyserver storm seen in
the field.

Two memos behind a pub(crate) DiscKeyCache. The table memo (UDF walk + tbl parse)
is disc-invariant outright — nothing in that path mentions the title — and runs on
EVERY disc, so a plain BD benefits too. Only the deterministic negatives are
memoised as "not FMTS"; a DiscRead fault propagates uncached so a later title
retries.

A blind once-per-disc hoist of the PROBES was rejected as unsafe, and this is the
load-bearing reasoning: the title enters through clip_byte_to_lba, which decides
which segments are addressable and which LBA every probed clip byte reads from, so
two titles with different extent lists probe different physical bytes. A hoist
would serve title B an answer derived from title A's media and could silently turn
a per-title FmtsKeyMissing into a success. The extent list is the ONLY per-title
input, so keying on it is exactly sufficient — matching the ForcedProbeCache
precedent.

Result-identity was proved, not assumed: NEITHER probe reads the key pool.
Verified here independently — probe_fmts_index_keys takes no keys parameter at
all; index keys come from `fetch`, and the anchor's reply feeds the phase probe.
So the pool's growth across titles, the one thing that does change between calls,
cannot move a memoised value, and the result is order-independent. A test resolves
three titles through a shared memo and through fresh memos and asserts both the
per-title ranges and the final key pool (keys, slots, order) are identical.

Not memoised, deliberately: fail-loud FmtsKeyMissing, and any run where an index
hit a read fault — that is a property of a transient drive fault, not of the
extents, and caching it would spread one bad read across 59 playlists.

A fully-memoised title now does zero I/O, which made the old in-loop halt polls
unreachable for it, so a check_halt on entry was added with a test that cancels
after warming the memos.

Also corrects my own overstatement from last round: the CpsUnitCache doc now says
plainly that on an FMTS disc it removes NO reads, because this function returns
before the extent loop ever runs.

Five mutations, all verified red. Pre-existing bug flagged but not fixed:
filter_addressable_segments only checks that a segment's START byte maps to some
LBA in the title, so a play-all playlist can pass the filter while mapping segment
bytes into the wrong clip, whose anchor then returns empty and aborts the sweep.
2026-07-29 20:27:50 -07:00
Matthew Jackson b4bf0daa82 Group E-AC-3 dependent substreams into one access unit
The AC-3 parser's own module doc stated the assumption: "AC3 frames are
self-contained and always start with syncword 0x0B77". True for legacy AC-3,
false for E-AC-3 above 5.1. Per ETSI TS 102 366 (A/52) Annex E, byte 2 of an
E-AC-3 syncframe is strmtyp(2) | substreamid(3) | frmsiz[10:8], and an access
unit is one INDEPENDENT substream plus every DEPENDENT substream that follows it
until the next independent one. The parser emitted one PES frame per syncframe,
so a decoder saw each dependent substream as a standalone frame with no parent —
including the AC-3-core + E-AC-3-dependent form Blu-ray uses for Dolby Digital
Plus. The extra channels were lost and the timeline ran at 2x.

The bit position is cross-checked against code already in the tree: the existing
frmsiz parse takes byte2 & 0x07 as its high bits, which is only consistent with
strmtyp occupying byte2's top two bits. Legacy AC-3 is excluded by bsid < 11,
where byte 2 is crc1 and reading strmtyp there would be nonsense. Reserved
strmtyp 3 is treated as INDEPENDENT so an unknown type starts a fresh AU rather
than merging into an unrelated one.

The AU carries the INDEPENDENT substream's PTS, and only the independent
substream advances the clock — dependents cover the same time period and add zero
duration. That is what removes the doubled timeline.

A trailing AU that can still grow is HELD across the PES boundary, because the
boundary is unknowable until the next independent sync; the whole AU is re-scanned
next call, so there is no shift and no double-count in the loss tally. Plain AC-3
is never held, which keeps DVD/AC-3 latency and behaviour unchanged.

A latent pre-existing bug surfaced while testing this: a new PES's PTS was
re-stamping an AU that began in an earlier PES, a constant one-frame shift. Fixed
with a PtsAnchor so a PES timestamp applies to the first AU that STARTS in that
PES's own bytes, while a genuine PTS jump is still adopted.

Nine tests. Verified red against five mutations, each killing a specific set:
reverting to the pre-fix behaviour kills 8 while
plain_ac3_frames_are_not_grouped_or_delayed SURVIVES as the no-regression guard —
reproduced independently here. Stamping the dependent's PTS kills 6; not holding
across PES kills 4; holding plain AC-3 too kills 15; neutering the PTS anchor
kills exactly the 2 split-across-PES timing tests.

Three sibling defects found and deliberately NOT fixed, all in mp4/audio.rs:
dec3 hardcodes num_dep_sub = 0 (and a nonzero value changes the box LAYOUT, not
just a field, per Annex F/G); parse_eac3 ignores strmtyp/substreamid entirely;
and a 7.1 DD+ track is still labelled 5.1 because the channel count comes from
the independent substream while the extra channels are described by the
dependent's chanmap, which nothing parses.

Not verified: no real E-AC-3-with-dependents sample exists here, so all evidence
is synthetic frames plus the spec layout. The multi-independent-substream case
(num_ind_sub > 1, main + associated audio in one PID) is deliberately treated as
one AU per independent substream and is untested.
2026-07-29 20:26:51 -07:00
Matthew Jackson ef36b452ad Fix three defects in last round's own fixes
Round 3 audited the round-1/2 fix commits rather than trusting them, and found
three defects in that new code. This is why the pin moves each round.

1. LICENCE REGRESSION, and it was mine. Reverting the "distinguish a failed key
   source" commit also restored a verbatim reference-decoder table citation in
   src/mux/codec/dts.rs, because both changes were in that one commit. The MIT
   licence cleanup was silently undone at HEAD and nothing caught it.

   The citation is replaced with ETSI TS 102 114 §5.3.1 again, and — more
   importantly — the rule now lives in the leak gate instead of in my memory.
   scan-secrets.sh gains LICENCE_RE, which flags ff_dca*, dcadec, l-smash,
   libav*, and bare ffmpeg/FFmpeg as REF-IMPL-CITATION. `no ffmpeg` is
   explicitly allowed via negative lookbehind: stating what this project does
   NOT depend on carries no risk and is a genuine selling point. Verified by
   re-introducing the citation (gate fails) and removing it (gate clean).

2. TsMuxer armed params_written even when the avcC/hvcC parser returned None, so
   a track whose codec_private exists but will not parse was muxed to BD-TS with
   no VPS/SPS/PPS ever emitted — undecodable video, reported as success, with no
   log line. Last round's fix corrected WHICH parser is used and left this half
   untouched. Arming the flag is still right (retrying identical bytes cannot
   succeed) but it is no longer silent: it now warns with the track, codec and
   codec_private length.

3. test_aes_cbc_roundtrip defined a LOCAL fn aes_cbc_encrypt that SHADOWED the
   production primitive, so it round-tripped a copy of the algorithm against
   itself and never touched crypto::aes_cbc_encrypt — the function this cycle
   added. Any mutation to the shipped code passed it. The shadow is deleted and
   the test now calls the real primitive; verified by mutating
   crypto::aes_cbc_encrypt, which now fails it and previously would not have.
2026-07-29 20:08:09 -07:00
Matthew Jackson f338552969 Pin the toolchain to Rust 1.87
The Windows UI needs winsafe, whose current release requires rustc 1.87. The
alternative was pinning winsafe back to an older release, which would bake a
stale API surface into a brand-new UI permanently to dodge one minor version.

The pin's purpose is to sit BELOW the Mac default so clippy drift is caught
locally before CI, not to stay on 1.86 specifically, so 1.87 preserves the
discipline exactly.

Verified before moving anything, not after: `cargo +1.87 clippy -- -D warnings`
and `cargo +1.87 fmt --check` are clean across all eight repos, and the full
precommit gate (fmt + clippy + tests) passes on libfreemkv, autorip, bdemu,
freemkv-engine and freemkv-keysources. Zero new lints, zero formatting drift.
2026-07-29 20:02:02 -07:00
Matthew Jackson 38aa895038 Memoise multi-CPS key-map sampling per extent, not per title
resolve_content_key_map calls resolve_mux_key_map once per title, and on a
multi-CPS disc that path issues 8 random single-unit reads per extent. A disc's
playlists overwhelmingly reference the same few clips — main feature, play-all,
per-chapter and seamless-branch variants — so the same physical extents were
re-sampled from the drive once per playlist. On a 60-playlist / 15-clip disc
that is ~2,400 non-sequential 6144-byte reads, roughly 8 minutes of pure seeking
at 200 ms per seek, before the mux starts. Now ~600 reads.

Keyed per EXTENT — (format, start_lba, sector_count) — rather than per title's
whole extent list, which is finer-grained than the forced-subtitle probe's cache
and strictly better here: a play-all playlist sharing 4 of 5 extents with the
main feature still hits on those 4.

Why a cached pool index is provably identical to a recomputed one, verified
rather than assumed:

  * `pick` iterates the pool IN ORDER and returns the FIRST index whose key
    decrypts a sample to clean.
  * The pool is APPEND-ONLY. Checked across the whole crate: only `push`, with no
    insert/remove/clear/retain/sort/dedup/truncate/drain/swap/reverse anywhere.
    So appended keys can only land AFTER a matched index, and the first match for
    the same samples cannot shift.
  * The samples are a pure function of the three values in the key, read from
    read-only optical media.

Two outcomes are deliberately NOT cached, which is what makes this safe rather
than merely faster:

  * the inherited index (`None if samples.is_empty() => last_idx`) is per-TITLE
    state, not a property of the extent — caching it would let one title's
    carry-in index leak into another title's clear extent, i.e. a WRONG key;
  * the fail-loud DecryptFailed verdict, so a retry after a key source banks the
    missing key re-samples instead of inheriting a stale answer.

Halt is still polled before the cache lookup, so cancellation is unchanged.
resolve_mux_key_map keeps its exact signature and delegates with a fresh cache,
so there is no public API change. ContentFormat gains Eq + Hash (additive).

Four tests, and the two mutants that matter both verified red: disabling the
cache short-circuit fails the hit and recompute-equivalence tests, and wrongly
caching the inherited index fails multi_cps_inherited_index_is_not_cached.
2026-07-29 19:49:55 -07:00
Matthew Jackson e3676e7cdf Build BlockGroups in memory so the hot path never seeks
Every BlockGroup frame back-patched its element size via ebml::end_master, which
does two stream_position() calls and two real seeks. BufWriter does not override
Seek::stream_position, so each position query is seek(Current(0)) = flush_buf +
lseek — and each of those flushed the 4 MiB BufWriter while every position-moving
seek reset WritebackPipeline::last_flush_pos. The buffer never got to do its job.

An MPEG-2 title takes this path for EVERY frame (the parser stamps a per-frame
duration, so I, P and B all become BlockGroups) — roughly 350,000 per feature.

A BlockGroup's size is knowable before writing, so there is no need to back-patch
at all. New seek-free twins start_master_buf / end_master_buf patch a placeholder
by buffer INDEX instead of file offset, and build_block_group assembles the whole
element into a persistent buffer that write_block_group and its MVC sibling take,
fill, write once, and hand back — including on the error path — so the allocation
is made once rather than per frame.

Measured with a counting writer that, like BufWriter, does not override
stream_position, over 200 frames:

              seek calls   position-moving
  plain   before 912              451
  plain   after  112               51
  MVC     before 2516            1253
  MVC     after  116               53

Per-frame cost is now zero; the residual is the header, the per-cluster
back-patch and Cues. For 350k BlockGroups that is 1.4M seek calls removed on the
plain path, 4.2M on an MVC title.

end_master is deliberately NOT changed for its other callers. The Cluster master
genuinely streams — frames are appended to an open cluster over time, so its body
cannot be buffered without holding a whole cluster in memory — and the rest
(EBML header, Tracks, Info, Chapters, Cues) run once, not per frame.

Byte-identity is the safety property, and it is structural: end_master always
patches a FIXED-width 8-byte VINT, and the buffered pair writes and patches
exactly that same placeholder, so the encodings cannot differ. Verified by
capture-then-compare over 200 frames (17 keyframes / 183 non-keyframes, multiple
clusters, BlockDuration present and absent, both reference branches) — output
byte-for-byte identical.

Three tests now pin it permanently: buffered vs seeking output byte-for-byte for
empty/tiny/multi-byte bodies, the same for NESTED masters (the MVC path nests
BlockAdditions > BlockMore, where an index-arithmetic slip would surface), and
end_master_buf erroring rather than panicking on a position outside the buffer.
All three verified red against a deliberately divergent placeholder width.

A note on verifying this kind of change: comparing emitted MKV across two
worktrees at different commits shows a spurious 14-byte difference, because
MuxingApp/WritingApp embed the build's git SHA twice. Compare at the same base.
2026-07-29 19:33:31 -07:00
Matthew Jackson 807eb053ca Only assert a forced-subtitle verdict the read actually supports
probe_and_set_forced broke out of its read loop on a read error but still
applied whatever partial observation it had accumulated as an authoritative
verdict, overwriting the vendor-label-derived forced flag. A disc that faults
early could have a correct flag replaced by a guess from a fraction of the data.

The file already got the zero-observation case right — it deliberately leaves
the vendor flag alone rather than "assert not-forced from having seen nothing".
The defect was that a PARTIAL observation cut short by a fault was treated as
complete.

The fix rests on the two verdicts not being symmetric evidence.
settled_not_forced() is POSITIVE evidence — a non-forced display set was
actually seen, and no unread data can retract it. is_forced() is an ABSENCE
claim — display sets were seen and none was non-forced — which is only sound if
the read got far enough for the absence to mean something.

So every loop exit now yields a named StopReason, and absence claims are
asserted only for a designed stop:

  * Exhausted / Budget → conclusive. The budget is deliberately conclusive: the
    natural exit is "every track settled not-forced", which a genuinely forced
    track never satisfies, so the budget is the ONLY path by which a real forced
    verdict is ever reached. Treating it as inconclusive would disable forced
    detection entirely.
  * Halted / ReadFailed → inconclusive. A cancelled probe's cut-off point is as
    arbitrary as a faulted one, so its absence claim is worth no more.

Evaluated per track, matching the existing observed() gate: a track that already
saw a non-forced set keeps its sound verdict even on a truncated run, while a
forced-so-far sibling keeps the vendor flag.

An inconclusive run is also NOT memoised. The cache key is the extent list and a
disc's playlists share clips, so caching a truncated run would replay one read
fault onto every playlist referencing those extents and deny any later title the
chance to re-read them.

Four tests; three of them verified red by forcing absence_is_conclusive() back
to always-true (the old semantics), while the budget test correctly stays green
either way — confirming the guard was not over-corrected.

Also moves the function doc comment back onto probe_and_set_forced; the earlier
probe commit left it attached to the ForcedProbeCache type alias.
2026-07-29 19:26:58 -07:00
Matthew Jackson 7322f4dd8a Record that the failed-vs-absent key source arm is unreachable
The `Ok(_) | Err(_)` arm in resolve_and_apply_traced conflates "this source
had no entry for the disc" with "this source failed", and reports both as
KeyNode::NoEntry. An operator whose key server is returning 502s is therefore
told their disc is not in the database.

The conflation is real but LATENT, and fixing it here would change nothing an
operator can see, because no shipped KeySource ever returns Err:
KeydbSource::get_unit_keys maps a load/parse failure to Ok(Vec::new()),
OnlineSource::get_unit_keys is Ok(self.query(ctx)) where query returns empty on
transport error, HTTP status, oversize body and bad JSON alike, and MultiSource
discards inner Errs. Only test doubles return Err. FetchOutcome::errored in
drive_unit_keys / drive_fmts_indexes is dead for the same reason — the right
contract, honoured by no source.

autorip already works around the missing signal by re-probing the service over
HTTP (probe_online_reachability / key_service_transient_status), and its own
comment names the incident: "the online keysource swallows every failure
(transport error, 502, timeout)".

So the fix belongs at the source boundary in freemkv-keysources, with
Disc::aacs_error as the channel the operator actually reads — not in this
trace. Documented here so the next reader does not assume the arm works, and
does not "fix" a dead path as I nearly did twice.
2026-07-29 19:24:58 -07:00
Matthew Jackson 4ed245868e Revert "Distinguish a failed key source from one with no entry"
This reverts commit 22a3e3fd01.
2026-07-29 19:15:21 -07:00
Matthew Jackson 50f37462db Remove reference-decoder citations from a public MIT-licensed repo
This crate is MIT licensed. Comments citing another decoder's internal symbols
and reproducing its tables verbatim create licence risk that no engineering
benefit justifies, so every such citation is replaced with the primary source:
ETSI TS 102 114 §5.3.1.

Eleven sites across src/mux/codec/dts.rs and src/mux/mp4/audio.rs. The technical
substance is unchanged in every case — the deficit-sample-count semantics, the
reserved-field skips, the invalid LFF value, and the 16 legal AMODE codes are all
spec facts and are now attributed as such. Four CHANGELOG entries that named a
validator are reworded; the "no a reference decoder" dependency claim stays, since stating
what this project does NOT depend on carries no risk.

I initially argued this was a false positive on the grounds that the project's
hygiene rules name internal infrastructure and reverse-engineering material, not
open-source citations, and that a channel-count table from a standard is fact
rather than expression. That reasoning missed the point: the exposure is MIT
distributing text derived from GPL/LGPL sources, and that is the maintainer's
risk to weigh, not mine. Reversed in full.
2026-07-29 19:09:10 -07:00
Matthew Jackson 22a3e3fd01 Distinguish a failed key source from one with no entry
resolve_and_apply_traced collapsed `Ok(_) | Err(_)` into a single
KeyNode::NoEntry step, so a key source that FAILED — server unreachable, keydb
unreadable, malformed entry — was recorded identically to one that simply had no
entry for this disc. The front-end renders that trace, so it told the operator
their disc is not in the database when the real cause was a fixable
infrastructure problem. drive_unit_keys and drive_fmts_indexes were refactored
this cycle to preserve exactly this distinction; this path had not been.

KeyNode gains a SourceFailed variant and the two arms are split. freemkv's
trace renderer matches KeyNode exhaustively with no catch-all, so its arm is
added in the same change — otherwise the consumer would not build.

Also made ETSI TS 102 114 the primary authority for DTS_AMODE_COUNT's comment
rather than a reference decoder internal symbol, and pointed it at this
crate's own cross-checked DTS_AMODE_LAYOUT / DTS_AMODE_CH tables.

A round-2 finding asked for every a reference decoder and a reference decoder citation in the DTS parser
to be stripped as a public-repo hygiene violation. Rejected: the project's rules
(scan-secrets.sh, CLAUDE.md) prohibit internal infrastructure references and
reverse-engineering material, and a reference-decoder citation is neither. The
AMODE channel-count table is a factual table from the standard, not expression
copied from an implementation. Citing the spec plus a corroborating
implementation is how a decodability gate should be justified.
2026-07-29 19:07:15 -07:00
Matthew Jackson 99c5fd3500 Reference keyframes per track, size the DTS reserve, correct two claims
The ReferenceBlock offset was computed for ANY video track, but the keyframe tick
it measures against was recorded in a single global slot gated to the PRIMARY
video track. On a title with two video tracks — an MVC base plus secondary view,
or a multi-angle disc — a secondary track's non-keyframe therefore referenced a
keyframe on a different track, or 0 (a self-reference) when the primary had not
produced one yet. The tick is now recorded per track, so a non-keyframe can only
reference a keyframe on its own track.

The faststart moov-hole estimate modelled every audio track as (E-)AC-3 at 1536
samples per frame. 1.6.0 added DTS to the writer's carried set, and a DTS core AU
is commonly 512 samples — a third of that — so a DTS track's sample table was
under-reserved threefold and the mux fell back to moov-at-end, losing faststart
on exactly the files 1.6.0 newly supports.

mvc_frame_emits_blockgroup_additional_and_reference asserted only that the
non-keyframe's ReferenceBlock was Some(_). Its non-MVC sibling, added in the same
commit, pins the exact offset; this one now does too, so a mutant emitting a
constant or wrong-signed offset no longer passes.

The comment above the mp4 sample budget claimed file_len stops a crafted file
inflating allocations "past the file's own size". Each indexed sample costs ~52
bytes, so the real ceiling is ~52x file_len (still capped by MAX_SAMPLE_COUNT).
The bound is real; the comment overstated how tight it is.
2026-07-29 19:03:59 -07:00
Matthew Jackson d4c913e0d3 Validate stream-selection PIDs per class, not across both
StreamSelection::apply validated a listed PID by scanning ALL streams, so a PID
named in the wrong class's filter passed validation — an audio filter listing a
subtitle PID, say. `keeps` then matched it against the audio streams only, so
the requested track was silently absent from the output. That is precisely the
outcome this validation documents itself as preventing: "fail loud rather than
silently emit an MKV missing a requested track".

Each filter is now checked against its own stream class. The `listed_pids`
helper existed only for the cross-class scan and is removed rather than left
behind as dead code.

Test covers both directions plus the sanity case, and asserts a rejected
selection leaves the title unpruned.
2026-07-29 19:00:53 -07:00
Matthew Jackson 0e23a6b291 Halve the per-frame allocation and copy on the m2ts NAL video path
The NAL path called length_prefixed_to_annex_b, which allocates a whole-frame
Vec of its own, then copied the result into a second whole-frame Vec — two
full-frame allocations and two full-frame copies per video frame. The crate
already has append_length_prefixed_as_annex_b, which writes the conversion
straight into a destination buffer; it is the same code path with the
intermediate removed.

The destination is also sized once up front instead of starting from Vec::new(),
which re-grew from zero capacity inside every conversion.

On a UHD HEVC title muxed to m2ts:// — ~200k video frames averaging ~310 KB of
ES at 60 Mb/s — that removes roughly 62 GB of allocation and 62 GB of memcpy.

Behaviour is unchanged: the existing tsmux conversion tests, including the
non-NAL passthrough and Annex-B default pair added last round, all still pass.

A first attempt reused a persistent scratch buffer across frames, which does not
work: the buffer is handed out as Cow::Owned and so can never be returned. A
right-sized single allocation gets most of the win without restructuring the
function around the borrow.
2026-07-29 18:58:39 -07:00
Matthew Jackson bcf47cc4ca Fix ddts numeric truncation and the decrypt pool's poison asymmetry
ddts CoreSize wrapped to zero on a maximum-size core. core_size is FSIZE + 1 and
FSIZE is itself 14 bits, so the maximum is 16384 — one past what the 14-bit
CoreSize field holds — and push()'s mask turned that into 0, declaring an empty
core frame. Clamped to 16383 instead: one byte short beats telling a decoder
there is no core. Proven red first (the field read back as 0).

ddts avg/max bitrate under-declared every non-integral frame rate. It computed
sample_rate / frame_samples first, so a 512-sample core at 48 kHz truncated
93.75 frames/s to 93. Multiplying before dividing, with round-to-nearest, keeps
the precision.

set_decrypt_threads skipped the pool swap on a poisoned lock while
DECRYPT_THREADS had already been updated, so the new thread count was reported
as taking effect while the stale pool kept serving. decrypt_pool() deliberately
recovers from poisoning for exactly this reason; the setter now does the same.
The pool Arc is immutable once stored, so a prior panic cannot have left it
half-written.

The CoreSize test decodes the value back out of the emitted box rather than
restating the clamp — a first draft asserted the clamp arithmetic against
itself, which would have passed against the unfixed writer.
2026-07-29 18:56:48 -07:00
Matthew Jackson a9dc3d7244 Make encrypt_unit report a refused slice, and expand its key once
Two defects in the encrypt_unit promoted to public API last round, both found by
round 2 auditing that new code.

It returned silently without encrypting when the slice was shorter than
ALIGNED_UNIT_LEN. Its own contract requires the caller to set the container's
encrypted flag BEFORE calling — the header is the key seed — so a silent no-op
leaves a unit advertised as encrypted while still carrying plaintext, with
nothing for an authoring caller to check. It now returns bool and is
#[must_use], so ignoring the refusal is a compile-time warning; every call site
was updated to assert on it.

bool rather than Result deliberately: a wrong buffer length is a programming
error at a library boundary, not a disc condition, and a new Error variant would
mean a new numeric code plus its rendering in another repo.

It also drove CBC from the single-block aes_ecb_encrypt, rebuilding the AES key
schedule for each of the 383 blocks in a unit — an order of magnitude slower
than its inverse, which expands the key once via aes_cbc_decrypt. The missing
counterpart aes_cbc_encrypt now exists alongside it, and encrypt_unit calls it,
so the two directions are symmetric in structure as well as in result. For an
authoring caller encrypting a 90 GB image that removes ~5.6 billion redundant
key expansions.

New test pins the boundary: ALIGNED_UNIT_LEN - 1 returns false and leaves the
buffer byte-identical, ALIGNED_UNIT_LEN succeeds. The existing round-trip and
padding-asymmetry tests still pass, so the CBC rewrite is provably the same
transform.
2026-07-29 18:54:19 -07:00
Matthew Jackson 94a876664b Correct six stale comments and doc claims
All six describe code that does something different from what they say, which
is the class of defect that gets a maintainer to write a bug on purpose.

docs/clpi.md presented the CLPI stream-PID entry as byte-aligned 2/2/2/4/4-byte
fields with a 32-bit fine-entry count. It is one 80-bit packed block —
reserved(10) + EP_stream_type(4) + num_EP_coarse(16) + num_EP_fine(18) +
EP_map_start_address(32) — and num_EP_fine is 18 bits. Anyone parsing to the
doc's offsets would read garbage. Replaced with the real bit layout.

docs/udf.md said read_directory()'s recursion cap is 3; MAX_DIR_DEPTH is 8.

TROUBLESHOOTING.md called Pass 1 `recovery::copy`. The engine's `sweep` is
documented as "Pass 1 of a multipass rip"; `copy` is the dispatch verb that
chooses between sweep and patch. This inconsistency was mine, introduced in the
1.6.0 doc rewrite. docs/drive-access.md already said `sweep` and was right — a
round-2 finding claimed the opposite on the grounds that `recovery::sweep`
appears nowhere else in this crate, which it cannot, being in another crate.

io/pipeline.rs cited `disc::patch` as WRITE_THROUGH_DEPTH's caller; that moved
to freemkv-engine in 1.6.0 and no `patch` exists here.

truehd.rs's doc on mlp_major_sync_crc_ok said the trailer is compared
big-endian while the body compares u16::from_le_bytes — and a big-endian
compare was the bug the function was fixed for, so the comment described the
defect rather than the code.

sector/decrypting.rs claimed the decorator owns "the only mutable state (its
call-count cap and spent flag)". DecryptingSectorSource has no such fields and
no KeyFetch field at all in this revision.
2026-07-29 18:50:53 -07:00
Matthew Jackson 7030de4ec9 Apply stream selection on the live path, and treat a halt as a clean stop
Three defects around MuxOptions in the mux driver.

MuxInput::Live never applied MuxOptions.selection, so a caller's audio/subtitle
selection was silently ignored on the live-drive path while the field's own
documentation said it was applied before the demux pipeline is built. The Iso
and Session arms both apply it; Live now does the same, in the same place —
before resolve_inline_base_map, which is keyed on extents and so unaffected by
pruning the stream list.

The header gate returned Error::MkvInvalid whenever headers had not resolved.
On the prefetch-highway path a halt landing while the pump is blocked in a read
can end the stream as Ok(None) rather than Err(Halted), so the loop breaks with
headers unresolved through no fault of the data. Reporting that as MkvInvalid
tells the consumer its disc is malformed and skips the stop-preserves-staging
path that a clean completed=false triggers. The gate now re-checks halt first.

MuxOptions.selection's doc claimed it was applied without naming the one input
it is not applied to. That exception lived only in an internal comment at the
Url match arm, where a caller reading the public field docs would never see it.
It is now on the field, pointing at InputOptions::selection instead.
2026-07-29 18:48:51 -07:00
Matthew Jackson c0434e87de Fix the DVD MPEG-audio codec mapping and the fabricated AACS docs
parse_audio_attr mapped DVD audio_coding_mode 2 to Codec::Mpeg1 — the MPEG-1
VIDEO variant. Codec::kind() reports Video for it, so a DVD MPEG-audio stream
was classified and handled as video everywhere downstream. Modes 2 and 3 are
both MPEG audio Layer II (3 adds the MPEG-2 multichannel extension), so both
map to Codec::Mp2. A test now walks every coding mode and asserts each result's
kind() is Audio, so no mode can map to a non-audio codec again.

docs/aacs.md documented an entire keydb-resolving API that does not exist:
ScanOptions::with_keydb, Disc::open_title, reader.read_unit(). None of those
symbols appear anywhere in the crate, and ScanOptions has no keydb field — its
own doc comment says "libfreemkv is lookup-free — it resolves no keys". A
reader following that page would conclude the library reads keydb.cfg, which
inverts the actual design: the caller resolves keys out-of-band through a
KeySource and applies them with Disc::decrypt_with.

The section is rewritten against the real API, and the AacsState table's
`key_source` type corrected from KeySource to KeyOrigin.

Worth recording: the first replacement example I wrote was itself wrong. It
used `input("disc://...")`, which resolve.rs explicitly rejects with
Error::DiscUrlNotDirect — live disc must go through Drive::open + Disc::scan +
DiscStream::new. Every symbol and signature in the committed example was
checked against the source rather than assumed.
2026-07-29 18:47:06 -07:00
Matthew Jackson ec5cd31ae1 Stop Mp4Sink losing audio frames and writing an empty sample entry
Mp4Sink::write returned Ok(()) without recording the sample whenever an audio
track's frame would not parse into a sample entry. Two consequences, both
silent: leading audio frames were lost until one frame parsed, and a track
whose frames never parsed disappeared from the output entirely — finish()'s
retain() removed the sample-less trak and the run reported success. That
contradicts this crate's stated policy that a skipped track is never silently
dropped.

The drop was never necessary. audio_entry is read in exactly one place,
build_trak, reached only from build_moov inside finish() — nothing on the write
path consumes it. So write() now records every sample and derives the entry
opportunistically from whichever frame parses first.

That makes build_trak's `audio_entry.unwrap_or_default()` reachable, which
would emit an stsd declaring entry_count=1 around an EMPTY sample entry: a
structurally invalid mp4 returned as success. finish() therefore drops any
audio track it cannot describe, with a tracing::warn! naming the codec and
sample count.

Dropping rather than erroring is deliberate. It matches finish()'s existing
treatment of sample-less tracks, keeps an export whose video is fine from
failing outright, and needs no new error code — a new code would mean a new
i18n key across 29 locale files in another repo, which is not this change's
scope. The track's bytes stay unreferenced in mdat: wasted space in a valid
file, which is the cheaper failure.

Test pins both halves — moov describes only the video track, and the
unparseable audio bytes still reach mdat rather than being discarded at write
time.
2026-07-29 18:44:49 -07:00
Matthew Jackson a1304f9e78 Stop the mp4 demuxer dropping tracks silently or inventing sample offsets
Three defects in the mp4:// read path, all of the same family: a damaged
source was remuxed minus a track, or with fabricated data, and the run
reported success.

Silent drops. Eight paths dropped a whole track on malformed input with no
report of any kind, so an mp4:// source missing its audio looked like a clean
run. Each now emits a tracing::warn! naming the track and the missing or
inconsistent table (tracing English is permitted in this crate; the numeric
error codes are unchanged). The non-A/V handler case is debug!, since skipping
a timecode or hint track is normal.

Fabricated offsets. sample_offsets ended with a `while offsets.len() <
sizes.len()` loop that packed unplaced samples after the last known offset.
Those samples have no known location, so the invented offsets made the reader
pull frame data from arbitrary file bytes — the exact "emit garbage" outcome
the stco/stsc presence guards refuse. It now returns the short list and the
caller drops the track.

Short stts. `durations.get(i).unwrap_or(0)` gave every sample past the end of a
short stts a duration of 0, collapsing the whole tail onto one timestamp. That
is the same degenerate timing the `durations.is_empty()` guard was written to
refuse, so the guard now refuses both cases.

Two shared test fixtures were internally inconsistent and only passed because
the reader was lenient: stsz declared 3 samples while stsc placed 1, and the
hostile-stsz fixture's stsc/stts covered a single sample. Both are now
consistent. The hostile fixture keeps its lying stsz count — that lie is what
it tests — but its stsc and stts now cover whatever count survives the
file_len bound, so it exercises the allocation bound rather than the
inconsistency guards.

Two new tests pin the new refusals by mutating the consistent fixture: an stsc
that places 1 of 3 samples, and an stts that covers 1 of 3.
2026-07-29 18:42:38 -07:00
Matthew Jackson a39045adf1 Bound the forced-subtitle probe, make it cancellable, and stop re-reading clips
The probe's only natural exit was "every PGS track has shown a non-forced
display set". A genuinely FORCED track never satisfies that, so on the common
authoring — a forced-narrative track for foreign dialogue — the loop read the
title's entire extent set at 2 MiB per call with no byte cap, no time cap and
no halt check. It was also invoked once per title rather than once per distinct
clip, and a disc's playlists overwhelmingly reference the same few clips (main
feature, play-all, seamless-branch variants), so the same physical extents were
re-read 30-150 times. The two defects multiplied: tens of GB, times the
playlist count, off an optical drive.

Reached via ScanOptions::probe_forced_subtitles, whose only consumer is
`freemkv info -v` (freemkv/src/disc_info.rs). The rip path leaves it off. So
the symptom is `info -v` never returning on an ordinary UHD, not a corrupt rip.

Three changes:

  * PROBE_BUDGET_SECTORS caps a probe at 256 MiB. A forced track's display sets
    appear throughout the title, so a bounded prefix classifies it; the budget
    only decides how long we keep looking for a non-forced set before accepting
    the forced verdict.
  * ScanOptions::halt is now plumbed in and checked per chunk, so `info -v` is
    cancellable. The probe previously took no halt at all.
  * A ForcedProbeCache memoises verdicts against the title's exact extent list.
    Keying on byte-identical input means a hit cannot change any result — it
    only removes the re-read.

Verdict application is factored into apply_verdicts so the cached and freshly
probed paths cannot diverge.

Three tests pin the behaviour, each against a reader that counts sectors and
never ends: the budget stops at exactly PROBE_BUDGET_SECTORS, a cancelled halt
reads zero sectors, and a second title with identical extents costs no further
reads while a different extent list still misses the cache.

Also worth recording: the CLI acceptance harness never exercised `info -v`
against an optical drive — it reads ISOs from local SSD, where a full-extent
read is fast enough to hide both defects.
2026-07-29 18:38:25 -07:00
Matthew Jackson ea72e6df5f Give every audio and video codec its own registered Matroska CodecID
MkvTrack::audio's catch-all was `_ => CODEC_AC3`, and ebml.rs defined no
A_AAC, A_MPEG/L2, A_MPEG/L3, A_FLAC or A_OPUS constant at all. A CodecID
names the payload, so any of those codecs was written into the MKV declaring
AC-3 while carrying something else — a player either refuses the track or
decodes noise.

Reachable through two ordinary paths, both verified: ifo.rs:577 maps DVD
audio_coding_mode 3 to Codec::Mp2, so a DVD with MPEG audio muxed to mkv://
produced a track declaring A_AC3 over MP2 bytes; and mp4/read.rs:479 maps the
`mp4a` sample entry to Codec::Aac for an mp4:// source. codec/mod.rs already
has working parsers for MP2, MP3, AAC, FLAC and Opus, so the pipeline carried
these codecs end to end and only the container label was wrong.

MkvTrack::video had the same shape: `_ => CODEC_MPEG2` announced Codec::Mpeg1
and Codec::Av1 as MPEG-2 video. V_MPEG1 and V_AV1 added.

Both catch-alls stay, because MkvTrack::audio/video return Self and have no
error channel, but they are now reachable only by a non-audio/non-video or
Unknown codec routed there in error. Two tests enumerate every real codec of
each kind and cross-check each against Codec::kind(), so a codec added to the
enum later cannot silently inherit another codec's ID.

Both proven red first: Aac declared A_AC3 before the fix.
2026-07-29 18:34:53 -07:00