mux: keyframe-align MKV clusters + SeekHead; set TS RAI on keyframe PES

MKV: cluster boundaries now require a video keyframe in addition to the
5s minimum, so every cluster has a CuePoint at its start. Pre-first-
keyframe frames are dropped. Adds a SeekHead at Segment start with
fixed-width back-patched SeekPositions for Info/Tracks/Chapters/Cues.

Before this change a 2h26m UHD rip had 52 CuePoints across ~1750
clusters and a 16.5-minute gap between adjacent seek entries; players
seeking inside that gap had to scan from the prior cue. After, one
CuePoint per cluster.

TS (tsmux production path + m2ts_mux): PesFrame.keyframe is plumbed
end-to-end. Codec-private parameter sets are prepended on the first
keyframe (not the first frame); non-key video before any keyframe is
dropped. The first TS packet of a keyframe video PES carries an
adaptation field with random_access_indicator=1. m2ts_mux previously
hardcoded RAI=1 on every PCR packet; that is now gated on the current
PES being a keyframe video PES, combining correctly with PCR when both
land on the same packet.

Adds 17 tests covering keyframe alignment, cue count/position/timing,
SeekHead correctness, RAI set/clear, codec_private gating, non-key drop,
and PCR+RAI combination.

This commit is contained in:

MattJackson

2026-05-17 15:31:16 -07:00

parent b08662f95c

commit 2a31a47434

5 changed files with 1051 additions and 63 deletions

									
										src/mux/ebml.rs
									
		+6
		
												View File
												
				@@ -321,6 +321,12 @@ pub const EBML_DOC_TYPE_READ_VERSION: u32 = 0x4285;

				// Segment

				pub const SEGMENT: u32 = 0x1853_8067;

				// SeekHead

				pub const SEEK_HEAD: u32 = 0x114D_9B74;

				pub const SEEK: u32 = 0x4DBB;

				pub const SEEK_ID: u32 = 0x53AB;

				pub const SEEK_POSITION: u32 = 0x53AC;

				// Segment Info

				pub const INFO: u32 = 0x1549_A966;

				pub const TIMESTAMP_SCALE: u32 = 0x2A_D7B1;