Surgical fixes (each with a regression test that fails without the change):
mux/mkv.rs, mux/demux_sink.rs: drive the clip-boundary timeline epoch
off the resolved PRIMARY VIDEO track, not the literal stream index 0.
An M2TS/PMT title can list an audio ES before video, so streams[0] may
be audio; a non-video epoch driver ratchets the frontier and inflates
the timeline. mkv cluster-opening falls back to track 0 for audio-only
titles so they still open clusters.
mux/codec/ac3.rs: correct ACMOD_CHANNELS — acmod=5 (3/1) is 4 channels,
not 3 (was undercounting a 3/1 stream); fix the A/52 Table 5.8 doc.
disc/mod.rs: HDMV coding_type 0x91 (Interactive Graphics / menus) no
longer maps to PGS subtitle — it falls through to Unknown so the PMT/STN
walker drops it instead of surfacing a bogus subtitle track.
mux/videomap.rs + mux/mkv.rs: FVI colour now mirrors the MKV muxer's CICP
precedence (measured CICP authoritative; HDR-driven PQ/HLG transfer
override) via a shared cicp_for_video helper, so the two sinks can't
disagree (HDR10 BT.2020 no longer emits SDR transfer 14).
mux/mkvstream.rs: saturating_add on cluster_ts + rel_ts so an adversarial
CLUSTER_TIMESTAMP near i64::MAX can't overflow/panic before the existing
saturating_mul.
mux/timeline.rs: tighten the tail-straggler clamp so a normal new-epoch
non-video frame leading the sparse video frontier by >3s is not demoted
into the previous clip's epoch.
mux/m2ts_mux/mod.rs: re-stamp PCR per video TS packet (mid-PES), not only
at PES boundaries, so a large UHD I-frame can't open a multi-second PCR
gap; modular 33-bit PTS rebasing so a real 90 kHz clock wrap is not
collapsed to PTS 0 (pre-base frames still floor to 0).
io/byte_prefetcher.rs, sector/prefetched.rs: wrap the producer feed loop
in catch_unwind and emit a typed error sentinel on panic, so a mid-stream
producer panic is not read as a clean EOF at the demux boundary (which
would silently truncate the mux).
mux/codec/h264.rs: extend HIGH_PROFILES to the full ISO/IEC 14496-15 set
that mandates the avcC chroma/bit-depth extension (adds 244 et al.).
Doc/comment accuracy: css/mod.rs (50000 sectors, not scrambled-sectors),
aacs/decrypt.rs (decrypt_unit already-clear path), ifo.rs (TT_SRPT at
0xC4), css/lfsr.rs (LFSR0 24-bit; TAB1-then-XOR cipher; real scramble-flag
predicate), disc/read_error.rs (for_sweep does bounded transient retries).
Skipped: keydb.rs SSRF guard (low/latent, no live caller) — a hard
loopback block breaks an existing behavioral test that exercises the
header-EOF path over a loopback server; a clean fix needs a resolver test
seam beyond this surgical pass. The sibling keydb_fetch.rs comment fix is
out of scope (freemkv crate).
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.
- FieldOrder now derives from the bitstream's measured top_field_first
(Some(true)→TFF, Some(false)→BFF) instead of hardcoding TFF for all
interlaced content; falls back to TFF when unmeasured. Adds
VideoStream::top_field_first; DVD/BD scan sets None with a precise
TODO(spec) for parser→title plumbing.
- CICP (matrix/transfer/primaries/range) now prefers measured CICP from
the bitstream (VideoStream::measured_cicp) over the coarse ColorSpace
enum, so the container stops assuming a colour space the stream may
contradict. Enum remains the fallback.
- VobSub S_VOBSUB CodecPrivate now emits a `size: WxH` line ahead of the
palette per the .idx format so players place/scale subs correctly.
- SeekHead: when zero cues are written, the CUES Seek entry is Voided
instead of leaving a dangling pointer to the Cues offset (now Tags/EOF).
- AC-3 Channels back-patch offset is captured from the writer instead of
the hardcoded chan_elem_pos+2 (decoupled from the VINT width choice).
- Hoisted inline CICP codes and the dvcC fourcc to named constants citing
ITU-T H.273 / RFC 9559; fixed the stale FieldOrder comment.
- DefaultDuration vs pulldown: precise TODO(spec) left (needs the same
parser→title channel as top_field_first).
Tests: BFF-from-measured-flag, measured-CICP-overrides-enum, VobSub size:
line present/omitted, zero-cue SeekHead Void. precommit (1.86) green.
Delete re-implementations in the demux:// sink and wire to proven helpers;
keep only genuinely-new functionality.
- AnnexB reframing: delete the sink's local length_prefixed_to_annexb (it
break'd on a zero-length NAL, dropping the rest of the access unit) and
call the canonical append_length_prefixed_as_annex_b in mux::hevc, which
skips just the empty NAL.
- HEVC param sets: delete hvcc_param_sets; reuse hvcc_to_annex_b.
- avcC param sets: hoist as the new canonical avcc_to_annex_b in mux::hevc,
next to hvcc_to_annex_b (the symmetry point); the sink calls it.
- PGS .sup: emit a synthetic clear display set (empty PCS + END) at
pts + duration_ns so subtitles time out instead of lingering to EOF.
- TimelineContinuity: move verbatim into the shared mux::timeline module
(with the prev_offset straggler-remap intact) and use it from both the
MKV muxer and the demux sink; delete the sink's drifted TimelineRebase
copy (which lacked the straggler branch).
- VobSub .idx: emit the conventional 'id: <lang2>, index: 0' line mkvmerge
reads to assign the subtitle language; palette reuse unchanged.
- output(): seed DemuxOptions.base from title.playlist when non-empty.
New constants for the PGS clear-segment framing and avcC header cite the
public HDMV PGS (BD-ROM Part 3) and ISO/IEC 14496-15 specs.
Tests: a zero-length NAL mid-frame no longer truncates the AU; a frame with
duration_ns produces a .sup clear segment; existing demux tests stay green.
New write-only pes::Stream sink that taps the per-track PesFrame stream
(the seam right before MKV muxing) and writes each track to its own
elementary-stream file, plus chapters and per-audio-track delay metadata.
Purely additive — the MKV mux path is untouched.
- mux/demux_sink.rs: DemuxSink + EsWriter dispatch. Pass-through for
codecs whose Frame.data is already standalone ES (MPEG-2, VC-1, AC3/
E-AC3, DTS/DTS-HD, TrueHD, LPCM). Non-trivial writers:
- AnnexBWriter: reframes hvcC/avcC 4-byte-length-prefixed NALs to
Annex-B and prepends VPS/SPS/PPS parsed out of the codec_private
configuration record (HEVC .hevc / H.264 .h264).
- PgsSupWriter: rebuilds the HDMV 'PG' segment framing the parser
strips, with 90kHz PTS/DTS (.sup).
- VobSubWriter: writes raw SPUs to .sub and synthesizes the .idx
sidecar (palette + per-SPU timestamp/filepos).
- Delay-in-filename (mkvmerge-readable 'DELAY <n>ms') + chapter XML/OGM
export. TimelineRebase ports the MKV muxer's seamless-branch epoch
logic so per-track ES timestamps stay continuous across clip joins.
- mux/resolve.rs: StreamUrl::Demux variant + scheme/path_str/parse_url/
input(write-only)/output arms.
- mux/mod.rs: module + public type re-exports.
16 unit tests: Annex-B reframing, hvcC/avcC param extraction, delay
sign/rounding + mkvmerge-regex match, PGS .sup framing, VobSub .idx
synthesis, chapter XML/OGM, timeline rebase, and end-to-end file-keying
by track + track selection.
Matthew Jackson