Matthew Jackson
b8f0af9ef5
Relicensed from AGPL-3.0 to MIT, effective 1.3.1 (<=1.3.0 remain AGPL). The CSS content cipher and Stevenson title-key attack are attributed to their published cryptanalysis (not libdvdcss); all libaacs/libbluray/libdvdread/libdvdnav name references were dropped from comments while keeping the standard format/spec descriptions. Also bumps to 1.3.1.
50 lines
2.2 KiB
Rust
50 lines
2.2 KiB
Rust
//! DVD-Video navigation — read-only resolver for the **main-feature start
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//! point** (issue #40). Mirrors what a DVD player's nav VM resolves: First-Play
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//! → menu "Play" → title dispatch → the first cell of the feature, so the rip
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//! starts at the movie rather than at raw cell 0 (e.g. skipping a leading
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//! logo/warning segment when the disc's own navigation does).
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//!
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//! Byte layout follows the DVD-Video specification (VMGI/VTSI headers,
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//! PGC/cell tables, PCI/HLI button packets); the VM command decoder is
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//! verified against real discs.
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//!
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//! Current contents: [`vmcmd`] — the VM command decoder (proven against the
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//! SOTL/Greenland test discs). The IFO/PCI parsing and the navigation executor
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//! that resolves the start cell build on top of this.
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pub mod vmcmd;
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use crate::sector::SectorSource;
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/// Resolve the feature title's **true start cell** (0-based index into the
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/// title PGC's cell list) by following the disc's own navigation — First-Play →
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/// menu "Play" → title dispatch — the way a player reaches the movie. This is
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/// what lets the rip begin at the feature instead of at raw cell 0 when the
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/// disc's nav enters the title past a leading logo/warning segment (e.g. a
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/// disc whose "Play" resolves to a later cell than cell 0).
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///
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/// Returns `None` when navigation cannot be resolved, so the caller falls back
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/// to the structural leading-cell filter (today's behaviour, ≈ cell 0 / 0:00).
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///
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/// TODO(#40): the IFO/PCI parsing + nav executor (built on [`vmcmd`]) land
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/// incrementally. Until the executor is complete this returns `None`, so wiring
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/// it in is behaviour-neutral; improvements to the resolver take effect here
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/// without touching the call site.
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pub fn resolve_feature_start(
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reader: &mut dyn SectorSource,
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udf: &crate::udf::UdfFs,
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vtsn: u16,
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vts_ttn: u16,
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) -> Option<usize> {
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// `reader`/`udf` are the seam inputs the nav executor will consume to read
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// VIDEO_TS.IFO + the VTS IFOs/menu VOBs. Reserved until that lands.
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let _ = (reader, udf);
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tracing::trace!(
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target: "freemkv::dvdnav",
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vtsn,
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vts_ttn,
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"nav start-cell resolver: unresolved — caller falls back to leading-cell filter"
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);
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None
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}
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