Closes the three residual holes where a concealed/lost gap could still let
a dangling-reference frame reach the muxer (degraded/undecryptable-disc
path only; clean rips are byte-identical and untouched). Root cause: the
discontinuity signal was reconstructed from the 4-bit continuity counter
and applied per-PES, both of which are lossy.
Three coordinated changes:
1. CC-INDEPENDENT marker. fill_null_ts_unit now tags its NULL packets with
an adaptation-field discontinuity_indicator; the demuxer recognises a
0x1FFF packet carrying it as a concealed gap and forces a discontinuity
on every tracked PID (the lost unit's PID is unknowable). This survives
a loss that is an exact multiple of 16 packets (CC aliases to in-sequence
— hole 3) and a loss at a PID's very start (no prior CC — hole 4); it
also drops any open, potentially-truncated partial PES.
2. PUSI ATTRIBUTION. A gap landing on a PES boundary now flags the PES
STARTING after it, not the one flushed at the boundary (hole 1) —
stamping the pre-gap frame could arm-then-disarm the gate on a keyframe
and admit the real post-gap inter frame.
3. PER-FRAME signal. codec::Frame gains `discontinuity`; each parser
propagates it onto the first post-gap frame. MPEG-2 buffers whole GOPs
asynchronously, so it associates the gap by ES OFFSET (like PTS/source),
landing it on the exact post-gap picture mid-GOP (hole 2) — a per-PES
flag stamped the previous picture. consume_ts (and the EOF flush drain)
gate on frame.discontinuity.
Tests: CC-independent marker with in-sequence CC + leading-loss; PUSI
attribution flags the post-gap PES; MPEG-2 offset-mark stamps the post-gap
picture through GOP reorder, not the previous one. Existing B1 gate + EOF
tests still green (2270 lib tests).
Pairs with A2 (read-path NULL-TS concealment). When the demux assembler
sees a TS continuity gap it now stamps `discontinuity` on the next
completed PES; the codec-parse stage carries that onto a per-track
ResyncGate. After a gap on an inter-coded video track the gate drops
forward to the next IRAP/IDR keyframe so no frame with a dangling
reference reaches the muxer (an ffmpeg deep scan would otherwise report
a missing-reference / non-existing-PPS error). Audio and subtitle tracks
have no cross-frame references, so the gate is a no-op there.
- ts.rs: PesPacket gains `discontinuity`; PesAssembler tracks a sticky
pending_discontinuity flag set on CC gap / discontinuity_indicator and
carried to the next completed/flushed PES.
- resync.rs (new): ResyncGate — per-track arm-on-gap, drop non-keyframes
until the next keyframe disarms and resumes. Logs the resync + drop
count once at the keyframe.
- pipelined_stream.rs: precompute per-track is_video, apply the gate in
consume_ts. Out-of-range track index emits as-is (defensive).
Tests: ResyncGate unit tests; ts.rs gap-stamps-discontinuity; end-to-end
B1 video-drops-to-keyframe and audio-never-drops through PipelinedPesStream.
Parse the two HDR10 HEVC SEI messages and emit the corresponding
Matroska Colour metadata, only when actually present in the bitstream
(SDR / no-SEI tracks omit it; nothing is fabricated).
Parse (Rec. ITU-T H.265 Annex D):
- Mastering Display Colour Volume SEI, payloadType 137 (D.2.28):
display_primaries_x/y[3] (SEI order G,B,R), white_point_x/y
(0.00002 units), max/min_display_mastering_luminance (0.0001 cd/m²).
- Content Light Level Info SEI, payloadType 144 (D.2.35):
MaxCLL / MaxFALL (cd/m² integers).
HevcParser::scan_sei walks the sei_rbsp ff-extension payloadType/
payloadSize coding and de-emulates (00 00 03) before reading, reusing
the existing strip_emulation_prevention helper. Both SEI are required
before any metadata is surfaced; SEI NALs still pass through unchanged.
Carry: the measured Hdr10Metadata rides PictureInfo (the same per-coded-
picture seam FieldOrder uses), flowing through from_codec_frame onto
PesFrame.coding to the deferred-muxer activate path, where
apply_coding_to_track stamps it on the video track before the header is
written. Set only when both SEI were seen.
Emit (RFC 9559 / Matroska): new Colour children in ebml.rs
(MasteringMetadata 0x55D0, Primary R/G/B + WhitePoint chromaticity
0x55D1..0x55D8, Luminance max/min 0x55D9/0x55DA, MaxCLL 0x55BC,
MaxFALL 0x55BD). write_hdr10 converts chromaticity SEI int × 0.00002 →
Matroska float, luminance SEI int × 0.0001 → cd/m² float; MaxCLL/MaxFALL
are uints verbatim. SEI primary index 0/1/2 (G/B/R) mapped to the
Matroska R/G/B element layout. Emitted only when hdr10 is present.
Tests: SEI parse with exact raw values, requires-both-SEI, SDR omission,
and emulation-prevention stripping (hevc.rs); muxer emit with exact unit
scaling + SDR omission of MasteringMetadata/MaxCLL/MaxFALL (mkv.rs);
apply_coding_to_track HDR10 plumbing (mkvstream.rs).
Carry per-picture truth and byte-exact source provenance THROUGH the stream so
the muxer (and the upcoming video index) read MEASURED facts instead of
assuming them. Honest data in, honest data out.
- codec/coding.rs: codec-agnostic PictureInfo (CodingType / FieldOrder + the
accessors field_order/coding_type/nb_fields/progressive/keyframe). Each codec
folds its raw signals in; consumers use only accessors, never branch on codec.
- mpeg2: builds PictureInfo from the picture coding extension and carries it +
SourcePos (source_marks, parallel to pts_marks) on every emitted frame.
- pes / codec::Frame: additive `coding` + `source`, forwarded through the
highway; None for audio/subtitle and the network/stdio deserialize hop.
- mkvstream: DEFER muxer construction until the first coded picture, set the
video track's FieldOrder from the MEASURED value, THEN write the header —
right the first time, no guess, no seek-back. An interlaced track that arrives
with no measured order is LOGGED loudly and left UNDETERMINED, never faked.
- mkv: MkvTrack::video no longer guesses TFF (a bitstream property the scan
cannot know is UNDETERMINED at build). Removed VideoStream::top_field_first
(the dead scan-time guess) crate-wide.
- Tests: parser population (every PictureInfo facet + per-PES source carry) and
mux-stream consumption (measured -> correct; missing -> UNDETERMINED, not
faked). Two obsolete tests updated only after confirming (their own comments)
they existed to enforce the deleted hardcoded-TFF.
Library-wide review-and-fix pass: tightened AACS keydb/handshake/variant
handling and trailing-partial-unit policy, corrected MPLS mark offset and
added UDF allocation bounds, hardened the mux/codec framing and M2TS paths,
guarded SCSI READ CAPACITY short transfers and unified error mapping, added
overflow guards on untrusted disc input, and made prefetch shutdown
deterministic. Release profile now builds with thin LTO + single codegen unit.
Audit-driven fixes (rounds 1–3):
- hevc: correct hvcC profile/level SPS offsets (HEVC has a 2-byte NAL header)
- mkv: map all DTS variants to the registered A_DTS codec id; force a new
cluster before the i16 cluster-relative timestamp can overflow
- ebml/mkvstream: bound untrusted EBML sizes (no multi-GB allocs); reject
uint>8 (was an OOB panic) and non-{0,4,8} float widths (were a desync)
- ts: skip PES-header bytes that span a TS packet boundary; add the PMT
section_len/prog_info_len bounds the PAT parser already had
- ac3: preserve a 0x0B77 syncword split across a PES boundary; cap buffer
- dts: validate each next-core boundary by decoded core size (a 0x7FFE8001
pattern inside XLL payload no longer false-splits/drops the lossless
extension); reject sub-minimum core frames; fix forced-emit PTS base
- lpcm: DVD program-stream PCM no longer double-strips the BD LPCM header
- vc1/mpeg2: do not emit a parameter-set-only PES as a standalone frame
- pgs/truehd: cap the pending reassembly buffer (parity with ac3/dts)
- aacs: ts_syncs_intact uses the exact packet count
- prefetched: capacity-guard the recycled-buffer set_len
- Cargo.toml: exclude project docs from the published crate
Convergence: a third independent audit pass found no remaining material
(CRITICAL/HIGH/MEDIUM) issues. Full precommit (fmt + clippy -D + tests,
Rust 1.86) green.
DTS-HD MA/HRA access units on Blu-ray are a DTS core frame (sync
0x7FFE8001) followed by one or more DTS extension substreams (sync
0x64582025) carrying the lossless audio. Ground-truthing the Dunkirk
ISO showed the m2ts demuxer hands these out as SEPARATE PES packets on
the same PID: one core PES (exactly core-sized, nothing trailing), then
the extension substreams in following PES packets with their own later
PTS.
The old DtsParser emitted one frame per PES the moment a core frame was
complete, and dropped any PES with no core sync. So every core became a
core-only (lossy) frame and the extension PES packets were discarded as
junk -- silently downgrading the track to lossy DTS core (1557 kb/s CBR,
16-bit) instead of DTS-HD MA (VBR, 24-bit lossless).
Rewrite the parser to assemble across PES boundaries: an access unit
runs from its core sync up to (but not including) the NEXT core sync, so
the core plus every following extension substream stays together. Add a
CodecParser::flush() (default empty) called at end-of-stream by both the
pipelined and inline DiscStream mux paths to drain the final buffered
unit. A 64 KiB cap guarantees forward progress and never stalls if a
boundary can't be found.
Validated on the rip1 testbed: Dunkirk eng+ger and Fight Club eng main
audio now ffprobe as profile=DTS-HD MA (Fight Club eng at 24-bit), with
VBR packet sizes (~2716-2788 B) well above the old fixed 2012 B lossy
core. Genuinely-lossy DTS dub tracks are left untouched.
- MkvTrack::audio emits A_DTS/MA, A_DTS/HR, A_DTS per the DTS family
instead of mislabelling everything as A_DTS. Plex transcoder and
strict hardware decoders reject DTS-HD MA payload under a plain
A_DTS track.
- PgsParser is now stateful: pairs display PCS with the following
empty PCS to compute a duration. Frame::duration_ns + PesFrame::duration_ns
carry it through; MkvMuxer::write_frame gains a final Option<u64>
parameter that emits BlockGroup + BlockDuration when set. Fixes
subtitle bitmaps lingering past their intended end-time.
Matthew Jackson