mirror of
https://github.com/freemkv/libfreemkv.git
synced 2026-10-07 18:13:10 +00:00
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.
39 lines
1.8 KiB
Markdown
39 lines
1.8 KiB
Markdown
# `PipelinedPesStream`
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The read-side of the freemkv mux highway. Given a `DemuxThread` (which has
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the producer + demux workers already spawned), a set of codec parsers, and
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the title metadata, this struct implements `crate::pes::Stream` by running
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codec parse on the caller's thread and emitting `PesFrame`s one at a time.
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## Threading
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The pipeline runs three threads in parallel:
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```text
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Thread A: read + decrypt (PrefetchedSectorSource / BytePrefetcher)
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Thread B: M2TS demux (DemuxThread)
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Thread C: codec parse (this struct, on the caller's thread)
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```
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Communication between A→B and B→C is via bounded channels with recycled
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buffer pools — no allocations or memcpys in the steady-state hot loop.
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This is the *only* read-side `Stream` impl in tree. Both the ISO file mux
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and the BD-TS (`m2ts://`) file mux input paths are built by
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`crate::mux::resolve` (`build_iso_pipeline` / the m2ts pipeline builder)
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and hand back a `PipelinedPesStream`; the differences are in how the
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producer thread (A) is configured — sector-aligned reads with AACS
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decrypt for ISO, raw byte reads for M2TS. (`crate::mux::M2tsStream`
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itself is a write-only sink and does not construct this type.)
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## DVD seek-index regression (highway-level test)
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The real CLI mux runs `PsDemuxer → PipelinedPesStream (codec parse) →
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frame out`, NOT the codec parser straight into the muxer. The keyframe
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flag and per-frame duration the `Mpeg2Parser` sets on each `Frame` must
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survive that path (`from_codec_frame`) so the muxer's cluster/cue logic
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— which opens a cluster + pushes a cue on `keyframe && track 0` —
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actually fires. If the highway dropped the keyframe flag, every video
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I-frame would arrive as a non-keyframe and the DVD MKV would get
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thousands of clusters with ZERO cues (chapter-seek only, no scrub).
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