Matthew Jackson
6e14fc0c0c
Security - Remove the unsafe Vec::set_len over recycled sector buffers — UB reachable from safe code (GHSA-j8ww-f5fg-9pmh, low). Uses Vec::resize; pooling unchanged. CI / tooling - clippy on stable with the MSRV single-sourced from Cargo.toml; cargo-deny dependency-audit gate with first-party git sources allowed (#15); audience-based comment-guard (#17). Docs - README (keydb ownership, BD-J parser count), drive-access transport/reset notes, mux timeline module-doc links.
3.1 KiB
diag.rs — scan diagnostics rationale
Why this module exists
A bug report log must be self-diagnosing: everything needed to explain why
freemkv made the choices it did at scan must be in the log, in a compact,
machine-parseable form. diag.rs emits one terse line per row (title, cell,
stream, decision) under the tracing target freemkv::diag, which the CLI
routes to log.txt when --log-level 3 (debug) is set.
Format conventions (stable, greppable)
- Every line is prefixed by a
tag=so a log scraper can filter (disc,title,dvd.cell,dvd.vattr,dvd.aattr,bd.clip,bd.mark,aacs,stream,decision). - Raw bytes are shown as
0xNNnext to their decode so a wrong decode is obvious against the raw value. - This module only READS already-parsed scan state — it never re-reads the disc and never mutates anything.
DVD per-cell table vs. Disc-level dump
The DVD per-cell table (with the raw cell-category byte) is emitted from the
IFO scan itself (dump_dvd_cells), because the per-cell ifo::DvdCell detail
is lowered away before the Disc is built. The Disc-level dump
(dump_disc) covers everything that survives lowering: titles, streams, the
picked main feature, and AACS state.
dump_dvd_substream_probe
Emits the ACTUAL per-physical-sub-stream AC-3 channel counts read off the VOB
during the mux-time sub-stream probe (the Silence-of-the-Lambs wrong-stream
fix). This is the ground truth the IFO nibble is compared against: each row is
sub_id=0x8x channels=N for a physical private_stream_1 AC-3 sub-stream
whose first frame was decoded. An empty probe (scrambled / unreadable / short
VOB) logs a single probed=0 line so the absence is explicit in a bug log.
Self-sufficiency: with tag=dvd.aattr (the IFO's declared sub_id + claimed
channels) and these tag=dvd.substream rows (the physical reality), a bug log
alone shows whether the ordinal 0x80 actually carries the declared channel
layout — no disc needed to diagnose a wrong-substream rip.
dump_mkv_track
Emits the MKV TrackEntry elements the muxer is about to WRITE for one track
— the Windows-fps-class metadata (FlagInterlaced, FieldOrder,
DefaultDuration, DefaultDecodedFieldDuration, Display dims) plus the
codecPrivate as hex. With this row a bug log alone is enough to verify why
Windows Explorer reports a given frame rate for an interlaced SD track: the
container values that drive its fps derivation are all present, no disc and
no MediaInfo needed.
track_number is the 1-based MKV track number; track is the built
crate::mux::mkv::MkvTrack whose fields map one-to-one onto the emitted
elements (see MkvMuxer::new).
main_feature_reason
The reason= token on the main-feature decision row is DERIVED from
Disc::CANONICAL_TITLE_ORDER_KEYS, which lives beside the comparator that
actually implements them — never restated here. The previous hand-written
copy drifted (it advertised a fewest-clips key the comparator had replaced
with largest-physical-size), which made the self-diagnosing log explain the
pick with a rule the code does not apply. A diagnostic that disagrees with the
decision it documents is worse than no diagnostic.