Commit Graph
34 Commits
Author SHA1 Message Date
Matthew Jackson f8ed0b99f4 Pin read_moov's box-size boundaries and MAX_ALLOC_BYTES exactly
read_moov's forward-progress guard (box_size < header_len, OR'd with the
EOF check) and the MAX_ALLOC_BYTES cap were only exercised on inputs well
away from their boundaries, so a mutation testing pass found the exact
edges unasserted: a size-8 (header-only) moov, a box that overruns the
file by exactly the amount the OR/AND distinction can see, and a payload
of precisely MAX_ALLOC_BYTES. Added a shared FakeBigReader (lifted out of
an existing test's local struct so a new test can reuse it) to exercise
the MAX_ALLOC_BYTES boundary without a multi-hundred-MiB backing file.
2026-08-01 14:39:39 -07:00
Matthew Jackson 8189da1b0c Document why audio.rs's bit-packing | mutants are equivalent
Every mutation-testing survivor in this file is a | with ^ flip inside a
bitstream packer: BitReader::read's accumulate step, the push closures in
dac3_box/dec3_box/ddts_box, and the multi-field extractions in parse_eac3
and parse_dts. All nine are the same shape: shift an accumulator left by
exactly the width of the next field, then OR it in, so the two operands
never share a set bit and | and ^ agree on every input. Confirmed by
running cargo-mutants against just these nine mutations after the existing
test suite (which already exercises each function's field values) - all
nine still survive, as expected for a genuinely equivalent mutant. Recorded
the reasoning once at BitReader::read so nobody spends time chasing it
site by site.
2026-08-01 14:24:47 -07:00
Matthew Jackson 698ba36ae4 Document the pack_language and detect_rate equivalent mutants
Three pack_language mutants and two detect_rate boundary mutants survive
mutation testing with no test able to close them, and it's not for lack
of trying: they're equivalent by construction. Recording the proofs next
to the code so nobody re-chases them:

- (b[0] - 0x60) as u16, shifted << 10 then truncated to u16, is congruent
  mod 65536 to (b[0] + 0x60) as u16 shifted the same way, because
  0x60 * 2 * 1024 is an exact multiple of 65536. The same swap on the
  second letter (shifted only << 5) is NOT equivalent, which is why only
  the first letter's mutant survives.
- The two | with ^ mutations that OR the three packed fields together
  are equivalent because the fields (a lowercase letter minus 0x60, so
  1..=26) always fit in 5 bits and never share a set bit once shifted
  into their 0/5/10 positions.
- detect_rate's tolerance and tie-break comparisons only diverge from
  their <= mutants on an exact 0.5 fps distance or an exact tie, and a
  brute-force search over every achievable integer-nanosecond median
  found no case that lands on either boundary bit-exactly.
2026-08-01 14:20:13 -07:00
Matthew Jackson 90a7fe2ff1 Assert the MP4 timing arithmetic, and name the faststart slack rule
MP4 track timing was numerically unasserted. Every operator in the
PTS-to-ticks, duration, tkhd_dur and ctts chain could be flipped and the
whole suite stayed green, because no test decoded an output file and checked
a concrete number — the existing tests assert box presence and gross
container shape only. That is the crate's worst failure mode: a title muxes
"successfully" with silently wrong A/V sync or total duration, and nothing
above can tell.

The new tests build tracks with known PTS deltas and compare the emitted
stts, ctts and tkhd.duration against computed values.

Also lifted the faststart slack rule out of the match guard into
faststart_fits(). A leftover hole of 1-7 bytes cannot be expressed as any
ISO-BMFF box, since a box header is 8 bytes, so finish() must fall back to
moov-at-end rather than write a free box that lies about its own size. The
condition now has a name and a test instead of being an unexplained
`g == 0 || g >= 8` inside a pattern guard.
2026-08-01 14:06:16 -07:00
Matthew Jackson 71686f1407 Lint the test code, and fix the 74 findings it had been hiding
Every other repo's CI now runs clippy with --all-targets. libfreemkv,
the crate the other seven build against and the one held up as the
reference workflow, was the last one still linting the library only — so
its ~3,000 tests, by far the largest body of test code in the project,
had never been linted at all. Turning the flag on surfaced 74 findings.

Most were mechanical and applied with clippy --fix. The rest, by hand:

- Four discarded Results in decrypt.rs. css::descramble_region returns a
  Result and four CSS tests threw it away, so a descramble that FAILED
  would have surfaced as a confusing buffer-comparison mismatch instead
  of the actual error. They expect() now.
- A dead `kp` field on the PlantedWalk fixture. The test deliberately
  asserts Kp as the explicit AES-G3(dk, 1) relation from [C] §3.2.4
  rather than against a stored value — its doc comment says so — which
  makes the field not just unused but a trap: the obvious "fix" of
  asserting against it would quietly weaken the test to comparing the
  fixture with itself. Removed.
- Two hand-rolled ICB counters in the HD-DVD fixtures, a needless mut,
  three vec!s that only ever needed arrays, a filter_map whose every arm
  was Some, and a Vec::new()+push chain.
- Doc list indentation in mkv.rs and mp4/read.rs, which was mis-rendering
  in the generated docs.
- A five-[u8; 16]-tuple return type named FourLevelParts.

Three lints are allowed at the specific sites, with reasons, because
they are wrong for this domain: the underscores in the bitstream-header
literals mark BITFIELD boundaries, not digit groups, so regrouping them
uniformly would satisfy the lint by destroying the only thing they
encode; and in three table-validation loops the loop variable is the
domain value under test (a DTS SFREQ code, an AMODE value, a palette
entry number), which is what the assertion messages name.
2026-07-31 15:08:37 -07:00
Matthew Jackson 42591c77fc test: constrain the AC-3/E-AC-3/DTS header decode and the boxes it emits
All 59 measured survivors in mp4/audio.rs: 50 killed, 9 proven
equivalent, none left unaddressed. No production change — every
extraction reads correct against ETSI TS 102 366 (5.3.2, 5.4.2, Annex
E.1.3, F.4, F.6.1) and TS 102 114 5.3.1.

It was a fixture gap, not a code defect, and a specific one: the
existing fixtures gave several fields the SAME value (fscod=0, bsmod=0,
lfeon=1, acmod=7) and asserted only derived channel counts. Nothing
asserted the emitted dac3/dec3/ddts payload BYTES at all, so the
packer's shifts and masks were entirely unconstrained. A wrong mask
there does not crash — it writes a box declaring the wrong channel
configuration, and a player believes it.

Several kills needed fixtures designed to discriminate rather than
merely exercise:

  the reduced-rate branch needed fscod == 3, which no test in the file
  reached — and `== -> !=` survived on an fscod=0 fixture only because
  the reduced table happens to return 48000 there too

  the DTS LFF mask needed a value where XOR and AND differ in MEANING:
  on the 5.1 fixtures LFF flips 1 -> 2 and BOTH codes mean "LFE present"

  the acmod mix-level skips needed three different acmods, because `^`
  is a no-op unless acmod == 4 exactly

  the ddts bitrate needed 44100/512, which does not divide evenly — at
  48000 the rounding is invisible and `/ -> %` on den/2 survives

The 9 equivalents are one pattern: OR-ing a shifted high part with a
masked low part on disjoint bit lanes, where the mask is on the same
line as the OR. Since cargo-mutants applies one mutation at a time, no
single mutant can break both. Each was applied and observed green.

FILED, not fixed: reserved sample-rate codes are silently guessed as
48 kHz (audio.rs:133, :20/:153) while a reserved DTS AMODE is refused
with a comment explaining why. Same silent-wrong-metadata class,
opposite answer. Refusing would make such a stream unmuxable, which is a
product call.
2026-07-30 21:51:26 -07:00
Matthew Jackson 9f25a4c454 fix(mp4): refuse a video track with no resolved dimensions
Resolution::pixels() returned (0, 0) for Unknown, and the MP4 sink wrote
it verbatim into tkhd (ISO/IEC 14496-12 8.3.2) and VisualSampleEntry
(12.1.3). Both fields are MANDATORY there, so unlike Matroska — which
omits the optional PixelWidth/PixelHeight elements — MP4 has nothing to
leave out. The result was a structurally complete file that passes every
container check, declares a 0x0 video track, cannot be rendered, and is
written with no error anywhere.

WHY IT WAS POSSIBLE, which is the part worth keeping:

pixels() previously fabricated 1920x1080 for Unknown. That was wrong but
playable, so this sink never needed a guard and the absence of one was
invisible. Changing the sentinel to (0, 0) moved the defect instead of
removing it — a zero PAIR still reads as a usable value, so the sink
stored it and serialised it.

The accessor's doc comment then ENUMERATED the callers it believed were
safe: "the Matroska sink omits the optional elements, the VobSub writer
omits its size: line, and no caller divides by either dimension." Two of
those three are true. MP4 was not on the list because MP4 has no guard
at all, and a prose list cannot enforce itself. mkv.rs's own comment
even states the principle — "the check belongs in the one accessor
rather than in each caller that remembered to write it" — and
labels/mod.rs still carried its own duplicate Unknown test long after
the accessor took that job over.

So: pixels() now returns Option. Not because Option is tidier, but
because every caller genuinely needs a DIFFERENT answer and the compiler
is the only thing that reliably makes them choose one. Matroska and the
metadata sinks take unwrap_or((0, 0)) with the reason stated at each
site; the VobSub path degrades to a palette-only .idx; MP4 fails with
E_MP4_UNKNOWN_RESOLUTION (9055).

Six call sites, not the five my first grep showed — I piped it through
`head` and acted on a truncated list. The compiler caught the sixth.
That is the same mistake as trusting a lens that reported silence.
2026-07-30 19:34:54 -07:00
Matthew Jackson 0bc8d7af9c test: constrain the AACS key-map gap fill, the PSI walk, and MP4 field offsets
Third pass over src/mux/. 40 survivors killed, no production change.

resolve.rs — the deleted-statement cluster is now fully constrained.
All 14 deletable statements probed; 9 were already caught, 5 survived:

  c.sort_unstable() in fill_base_key_gaps. Every existing case handed
  it cuts already in LBA order, but IndividualSegment.tbl is a record
  list. Verified on HEAD: deleting the sort passes all 54 resolve
  tests. The mutant lays a base-key fill straight over a forensic
  segment.

  last_idx = idx (FMTS gap fill) and last_idx = hit (multi-CPS cache
  hit). An extent with nothing to sample must inherit its neighbour's
  CPS unit; the mutants fall back to the first unit's key. Exactly the
  shape this file's own comments name — wrong key, no error,
  lost_bytes == 0.

  Both check_halt()? polls in probe_fmts_index_keys. These cannot be
  killed by outcome, since a later poll returns Halted too. The tests
  count reads instead, which is what the don't-hammer-a-struggling-
  drive rule actually says: after a Stop the drive is asked for zero
  content sectors.

The four unresolved += 1 arms each got a test, and deleting each fails
exactly one — one-to-one, so no fixture passes for the wrong reason. A
control test pins that the baseline table resolves, so an expect_err
cannot succeed for an unrelated reason.

ts.rs::scan_streams was never entered. Six killed, two of which return
wrong answers that look right: reading the PAT/PMT CRC as a table entry
invents a stream on PID 546 out of CRC bytes, and dropping the
ES_info_length skip decodes a descriptor as an entry and loses the one
after it. Every existing PMT fixture declares ES_info_length = 0; a
real BD PMT carries a registration descriptor on essentially every
entry. Also ISO/IEC 13818-1 2.4.4.3 program_number == 0 is the network
PID, not a program.

mp4/read.rs — 13. Height read as the width beside it; channelcount;
the 4-byte base-128 descriptor varint (every existing esds fixture uses
a single byte); all three optional ES_Descriptor fields, whose loss is
silent (an AAC track just loses its CodecPrivate); first-vs-last media
edit, which is A/V desync of the difference; and the version-1 mvhd
timescale offset, emitted by any writer whose duration exceeds 32 bits.

dts.rs — 7, from a real cargo-mutants run over the file rather than
guesswork. Including a buffer that IS the syncword, which is the state
a sync split across PES packets lands in the moment its last byte
arrives.

Equivalents proven by application, not argued: the sample_encrypted_units
guard pair is mutually redundant by construction (total*p/9 < total for
p <= 8), so either alone is equivalent and both together are not; the
PMT section_len guard is dead code where its PAT twin panics; three of
the seven EXSS_HEADER_MIN_BYTES arithmetic mutants still sum to 10.
2026-07-30 16:05:37 -07:00
Matthew Jackson 9de88969ca test: constrain the DiscStream loss surface and the empty-title guards
Second mutation pass over src/mux/. 26 survivors killed, no production
change. Verified on HEAD before landing: each mutation below passes all
1,237 mux tests unmutated-suite.

The priority item was the honest-loss-reporting surface. Both
DiscStream::errors and DiscStream::lost_bytes could return a constant
with nothing failing — a rip that lost sectors would report zero loss
to the caller. This project has already shipped one defect of that
shape (a total decryption failure reported as an empty title, exit 0).
Driven now through two short-read fills so both land on values that are
neither 0 nor 1 and differ from each other; no constant and no field
swap survives.

MkvStream::finish -> Ok(()) also survived. MkvMuxer::finish has the
zero-frame MkvInvalid guard and two tests cover it, but the Stream
wrapper above it could return Ok unconditionally and bypass the guard
entirely — the empty-title defence was one layer thinner than it looked.

au_assembly: pinned au_opener_from behaviourally to the normative byte
values for all four modes, with negative cases for codes that are
explicitly not openers (MPEG-2 slice 0x01..0xAF, user data 0xB2,
extension 0xB5, sequence end 0xB7 per 13818-2 Table 6-1; VC-1
0x0A/0x0B/0x0C; H.264 SPS/PPS/IDR-slice). au_assembly and codec/ hold
independent copies of these constants; they agree today, and comparing
constants would not catch logic drifting apart, so both sides are now
pinned to the spec instead of to each other.

demux_sink::sanitize: every filename component demux:// writes comes
from disc-controlled text, so the path-separator arm is a traversal
guard. Deleting it now fails, including an end-to-end case where
base = "../evil/Title" must produce exactly one file inside the
chosen directory.

stts_and_ctts_expand renamed to stts_expands_runs_to_per_sample_deltas_in_order
and given runs with distinct deltas AND distinct lengths. Its old name
claimed ctts coverage it never had, which is why the composition-time
chain went unconstrained for eight rounds; the doc comment now points
at the tests that do cover ctts.

Correction to the previous pass: codec/truehd.rs flush -> vec![] IS
equivalent. Applied it, full mux suite green. TrueHD buffers across PES
but parse emits every complete unit immediately, so a residual buffer
at EOF is a truncated access unit and is correctly discarded. The
vec![Default::default()] variants are genuinely different and are
killed.

Deliberately not constrained: mkv::set_opening_capture (diagnostics
behind a process-global tracing check, flaky under the parallel
runner), and the three stdio.rs header paths (StdioStream holds
concrete io::Stdin/Stdout and cannot be driven without a production
refactor to injectable Read/Write).
2026-07-30 14:13:33 -07:00
Matthew Jackson 170fd0c064 test: constrain MP4 composition timing, MLP substream directory, and codec-private absence
Mutation testing over src/mux/. No production change — 49 survivors
killed, all proven red before green.

The MP4 composition-time chain was entirely unconstrained: VideoTiming::ctts,
build_ctts and parse_ctts could each return a constant and the suite
stayed green. Confirmed on HEAD: build_ctts -> vec![] passes all 1,220
mux tests. A demuxed B-frame title presenting in decode order would
have shipped.

The cause is a test whose name asserts coverage its body does not
deliver — stts_and_ctts_expand builds an stts box and never touches
ctts, and write_then_read_round_trip asserts sample sizes and keyframe
flags but not one PTS. Same shape as the set_speed forwarding finding,
different disguise.

mlp_num_substreams / mlp_substr_header_size: every TrueHD fixture in
the crate uses one substream and no extraword, so both could return a
constant and agree with all of them. These position mlp_parity_ok's
window over the AU header, so a constant mis-windows the parity check
on exactly the multi-substream AUs that carry 7.1 and Atmos.

CodecPrivate absent vs empty: mkv.rs writes Some(bytes) verbatim and
omits the element on None (RFC 9559 5.1.4.1.24), so a zero-length Some
emits a track header asserting the config IS empty. Four parsers could
return Some(vec![]) before any frame.

Also: mandatory ISO/IEC 14496-12 boxes (tkhd, vmhd, smhd, dinf, mdhd)
could each build empty; HEVC num_extra_slice_header_bits (H.265 7.3.2.3)
was never non-zero in any fixture, so the slice-type offset skip was
unexercised; chapter names from the disc go straight into
<ChapterString> and the & escape must run first; a stray 0x47 in a
payload must not latch a TS resync.

Documented as equivalent rather than killed: CodecParser::flush and the
three parser flush bodies that differ from the mutant only by a tracing
call, and DropTally::log_summary.
2026-07-30 13:39:02 -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 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 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 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 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 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 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 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 f76688a0dc Make the ddts speaker mask agree with its own channel count
The ddts box declares both a channel count and a 16-bit speaker mask, and
a decoder may trust either. dts_channel_layout ended in a `_ => 0x0007`
catch-all describing five speakers (C + L/R + Ls/Rs), so for AMODE 6, 7,
and 10 through 15 the box contradicted the count DTS_AMODE_CH declared
alongside it — provoking a downmix or an outright decode error.

AMODE 6 (L + R + S) is the reachable case: its S is a single
centre-surround, not the Ls/Rs pair, so it is three channels and 0x0012,
not four and 0x0006. AMODE 13/14/15 do not occur on retail media, which
ships a 5.1 AMODE-9 core plus an extension substream.

Replace the catch-all with the full 16-entry ETSI TS 102 114 mask table.
Every entry is cross-checked against DTS_AMODE_CH by counting the
speakers its bits imply: sixteen independent constraints, all satisfied,
and that table is itself pinned to the per-AMODE channel counts in ETSI TS 102 114.

AMODE is a 6-bit field, so the reserved 16..=63 are reachable from a
malformed stream. The old `unwrap_or(6)` invented a channel count for
them that no mask could match; parse_dts now refuses those frames rather
than guessing a layout it cannot name.

One existing fixture placed the ext-sync pattern at f[4..8], which
incidentally set f[7]=0x25 → AMODE 20. That test is about where the
pattern sits, not about AMODE, so the frame is now spec-legal (AMODE 9,
48 kHz) with the pattern moved into the payload proper.
2026-07-29 17:43:38 -07:00
Matthew Jackson b79ff71b43 Fix read-fault misclassification, DTS AMODE channel table, and untestable guards
- resolve_fmts_key_map: distinguish a genuinely-not-FMTS disc from a
  transient live-drive read fault. read_filesystem now returns the new
  Error::UdfNotFilesystem for a deterministic tag/format mismatch (no AVDP,
  no partition descriptor, no FSD); resolve maps only UdfNotFilesystem (fs)
  and UdfNotFound (.tbl absent) to Ok(None), and PROPAGATES DiscRead / other
  I/O faults so a marginal AACS 2.1 disc fails loud instead of silently
  dropping forensic content under a base-Unit-Key-only map.

- DTS_AMODE_CH (mp4/audio.rs): extend 10→16 entries
  {1,2,2,2,2,3,3,4,4,5,6,6,6,7,8,8} (the spec per-AMODE channel table / ETSI TS 102 114) so
  the spec-legal high AMODEs that now pass the decodability gate declare
  their true channelcount (AMODE 13→7, 14/15→8) instead of a truncated 6.

- session.rs resolve_keys "called before scan" guard is now testable:
  from_parts_for_test takes Option<Disc>; added a test that a disc-less
  session returns a clean DeviceNotReady Err rather than panicking.

- mp4/read.rs: a track with samples but a missing/malformed stts (mandatory
  per ISO/IEC 14496-12) is dropped rather than emitting all-zero timestamps,
  matching the existing stco/stsc guards; all-tracks-dropped → Mp4Invalid.

- Remove the inert MuxInput::Iso.key_map field (the Iso path re-derives its
  map inside build_iso_pipeline); the live path keeps Live.key_map.

All four fixes are mutation-verified.
2026-07-24 09:59:33 -07:00
Matthew Jackson 3bd2fd23b0 Fix audit findings: DTS AMODE bound, key-fetch negative memoization, PGS probe coverage
- dts: accept all 16 legal AMODE channel-arrangement codes (0-15), not just
  0-9. Per ETSI TS 102 114 the 6-bit AMODE field has 16 defined arrangements;
  only 16-63 are reserved. a reference decoder the spec per-AMODE channel table confirms 10-15 are
  decodable 6/7/8-channel layouts. The old bound of 10 dropped spec-legal
  multichannel core frames as undecodable, silencing recoverable audio. Add a
  regression test (literal 0..16 range) that fails if the bound reverts to 10.

- keysource: only memoize a NEGATIVE (empty) key-fetch result when every source
  genuinely ran and none held the key — never when a source Err'd (network down,
  unreachable). A transient outage was being cached as a permanent "no key" for
  the fingerprint, permanently dropping a unit that could be recovered once the
  source came back. Thread an `errored` flag out of the drivers and gate the
  cache insert on it. Tests cover both the recover-after-outage case and that a
  genuine absence is still memoized.

- pgs_forced_probe: add happy-path coverage feeding real synthetic BD-TS PGS
  display sets through the full demux -> parse -> observe -> apply path, both a
  forced verdict landing and a non-forced verdict clearing a vendor flag.

- mp4: correct fit_report doc (audio carried is AC-3/E-AC-3 AND DTS/DTS-HD).

- scan_iso test: add independent fixture expectations (volume id) so the parity
  test is no longer purely tautological against a re-run of the same composition.
2026-07-24 08:32:37 -07:00
Matthew Jackson b9568242df libfreemkv: 10-phase release audit fixes (v1.5.2..HEAD)
Multi-round audit of the decrypt/AACS/mux-codec refactor. Fixes, in
descending severity:

- mux/mp4/read.rs: bound untrusted-input allocations. `sample_budget`
  now also capped by file_len (a fixed-size stsz claiming count=u32::MAX
  can't inflate the Vec<SampleRef> past the file's own size); trak scan
  capped at MAX_TRACKS matches; find_box() takes only the first match
  (cap=1) instead of materializing every match. Removes dead find_boxes
  wrapper.
- disc/mod.rs: merge_content_key_ranges now UNIONS same-key overlapping
  ranges (coverage-preserving) instead of dropping the non-overlapping
  tail, which silently left encrypted LBAs uncovered -> ciphertext
  passthrough in the whole-disc sweep/patch map. Different-key overlap
  (malformed) still dropped to keep the set disjoint.
- sector/decrypting.rs: remove dead unit_key_idx field + with_unit_key_idx
  setter (vestigial from the pre-keymap trial-decrypt design; AACS is
  map-only now). Fix stale docs.
- decrypt.rs / resolve.rs / error.rs / extract.rs: doc/comment drift from
  the refactor (AacsKeyMap positive-map semantics, resolve_mux_key_map doc
  reattachment, decrypt_sectors_in_content legacy-alias, E_MP4_INVALID
  meaning, multi-CPS orphan by-design note).

Test coverage (all mutation-verified real):
- DTS NeedMore force-flush buffer bound; FLAC/MPEG-audio PTS carry-forward;
  mp4 mdhd timescale=0 divide-by-zero guard, MAX_TRACKS cap, sample-count
  file_len bound, MAX_ALLOC_BYTES cap under inflated file_len.
- resolve_fmts_key_map: extracted filter_addressable_segments,
  resolve_tie_phase, fill_base_key_gaps as pure behavior-preserving
  helpers, each unit-tested (segment filter, phase-tie arms, gap-fill
  gaplessness over every extent).
2026-07-23 22:09:04 -07:00
Matthew Jackson 1eb6910bdb Harden mux + decrypt paths; fail-loud on unresolvable keys
mp4 demuxer (untrusted input): bound every allocation sized from a box
field (stsz/stco/stsc counts, stts/ctts run-lengths, per-sample and moov
sizes, plus an absolute cap so a sparse file can't inflate file_len);
guard the parse_stsd slice and a zero mdhd timescale; cap track count so
the per-track PID can't overflow; rewrite read_moov to handle size==0 /
size<8 / 64-bit largesize; parse esds/AudioSpecificConfig for AAC; write
tkhd duration in the movie timescale.

decrypt: resolve_mux_key_map now fails loud on an extent no key can
classify instead of inheriting the previous extent's key, so a keymap
never silently carries a wrong key; the sweep/patch key-fetch recovery
fails loud when a unit is still unresolved after the retry.

AACS: reject inverted forensic segments in both range builders; compare
the forensic index in u16 space so an out-of-range value can't truncate
onto a valid u8 index. RECOVERED_ERROR no longer latches the damage zone,
preserving the 30s wedge cooldown for a following hard error.

audio: AAC/MP2/MP3/FLAC carry the last PTS across a PES with no timestamp;
the DTS-HD extension-sync search is bounded to after the core; the MP4
16.16 sample-rate field saturates. demux_sink records the video reference
before the kind filter so audio:// / sub:// keep multi-clip PTS continuity
and the DELAY tag.

Remove a dead error variant and the AACS-unsupported-video code; codec
comments cite the primary format specs; assorted doc/naming fixes and
regression tests throughout.
2026-07-23 12:02:43 -07:00
Matthew Jackson f7edd4e6a9 mux/mp4: DTS audio (dtsc/dtsh + ddts)
Parse the DTS core header (SFREQ/AMODE/RATE/LFF/NBLKS/FSIZE) → a ddts box
(sample rate, channel layout mask, core size, computed bitrate, LFE);
whole access units (core + DTS-HD extension substreams) pass through, so
an HD decoder finds the extension. dtsh when an extension sync follows the
core, else dtsc. Fit oracle now carries DTS / DTS-HD MA / DTS-HD HR.

Validated on 300 (real DTS-HD MA 7.1): freemkv's mp4 DTS track is
byte-identical to ffmpeg -c copy under ffprobe (dts / 48000 / 8ch / 7.1)
and decodes clean (exit 0). Channel layout correct.
2026-07-18 22:18:35 -07:00
Matthew Jackson a947439171 mux/mp4: faststart on by default (reserve-and-fill)
moov now precedes mdat. At create() reserve a moov-sized hole (a free
box) between ftyp and mdat: reserve = round_up_4MB(16 B/sample ×
est_samples) + 4MB buffer, floored at 8MB. Because the hole precedes
mdat, sample offsets are fixed from the start — no rewrite, no offset
patch. finish() writes moov into the hole and pads the slack with a free
box; if the estimate is blown it falls back to moov-at-end. Streams over
HTTP without a pre-fetch. Reserve-math + box-order tests added.
2026-07-18 21:43:44 -07:00
Matthew Jackson 8f55cb78d2 mux/mp4: MP4 demuxer — mp4:// as a source
Read side of mp4://: parse moov/trak/stbl (stsd codecs+hvcC/avcC/channel
info, stsz/stco/co64+stsc → per-sample offsets, stts+ctts → decode/
composition timing, stss → sync), rebuild a DiscTitle, and emit samples
as PesFrames in global decode order. Video NALs are length-prefixed in
MP4 — the exact framing the MKV muxer wants — so no reframing. Wired into
input() so mp4:// flows to every sink (mkv://, audio://, json://, …).
In-memory write→read round-trip test proves symmetry (streams, hvcC,
sample sizes survive). Progressive MP4 only; fragmented (moof) is future.
2026-07-18 21:10:15 -07:00
Matthew Jackson 65e14fe3b7 mux/mp4: route through WritebackFile (bounded-cache writeback)
Make Mp4Sink generic over a seekable writer; the CLI output() arm wraps
the file in WritebackFile (as mkv:// does) so a UHD-scale mux to slow /
NFS staging avoids the dirty-page burst. The mdat backpatch is an
ordinary seek WritebackFile already handles (seek_then_patch_roundtrip).
Tests switched to in-memory Cursor writers.
2026-07-18 20:57:44 -07:00
Matthew Jackson 0c9d375548 mux/mp4: M2 — audio tracks + fit oracle (multi-track)
Generalize the sink to N tracks: one video + every MP4-mappable audio
track. Audio sample entries built from the first frame's bitstream —
AC-3 (ac-3/dac3) and E-AC-3 (ec-3/dec3), parsing the (E-)AC-3 BSI for
fscod/bsid/bsmod/acmod/lfeon and the data rate. Per-sample audio
durations from PTS deltas (no reorder → no ctts, all sync). Fit oracle
(mp4_fit_report, exported): video HEVC/H264, audio AC-3/E-AC-3;
TrueHD/DTS/LPCM and bitmap subs are excluded with a typed reason so the
CLI can report exclusions — never a silent drop.

Verified vs ffmpeg -c copy on real discs: AVC+AC3 and HEVC(HDR10)+AC3
both frame-exact on every track (video 2650/4270, audio 5567/3454),
duration and colour identical, clean decode. On a pathological 4-clip
title ffmpeg's OWN output emits the same DTS-monotonicity warnings (more
of them) — source-inherent, not a muxer defect.
2026-07-18 20:37:10 -07:00
Matthew Jackson 8aff7fe708 mux: native progressive MP4 muxer (mp4://) — M1 video track
New mux/mp4: writes ftyp+mdat+moov (moov-at-end), streaming samples into
a 64-bit mdat and building the sample tables in memory, patched at
finish(). Video track (HEVC/AVC): passthrough length-prefixed NALs
(already MP4 framing), full stts/stsz/stsc/co64/stss and signed ctts,
CFR-derived decode timeline (pipeline carries presentation PTS only), and
a colr box for HDR10 colour signalling. hvc1/avc1 sample entry from the
hvcC/avcC codec_private. Fail-loud on codecs with no MP4 mapping.

Verified against ffmpeg -c copy on real discs: AVC-SDR (300) and
HEVC-HDR10 UHD (Dune) both frame-exact (8159 / 8160 frames), colour-exact
(bt2020/smpte2084/bt2020nc), and clean-decoding. Audio + fit oracle land
in M2.
2026-07-18 20:16:19 -07:00