pq/libfreemkv
1
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

v0.25.2: DTS-HD codec ID + PGS BlockDuration

Browse Source 
- MkvTrack::audio emits A_DTS/MA, A_DTS/HR, A_DTS per the DTS family
  instead of mislabelling everything as A_DTS. Plex transcoder and
  strict hardware decoders reject DTS-HD MA payload under a plain
  A_DTS track.
- PgsParser is now stateful: pairs display PCS with the following
  empty PCS to compute a duration. Frame::duration_ns + PesFrame::duration_ns
  carry it through; MkvMuxer::write_frame gains a final Option<u64>
  parameter that emits BlockGroup + BlockDuration when set. Fixes
  subtitle bitmaps lingering past their intended end-time.
This commit is contained in:
MattJackson
2026-05-19 16:11:54 -07:00
parent 7dcac44136
commit 1b95193517
24 changed files with 376 additions and 48 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/mux/mkv.rs
+70 -12
View File
@@ -87,11 +87,19 @@ impl MkvTrack {
}
pub fn audio(a: &AudioStream) -> Self {
// Codec ID strings must distinguish the DTS family — strict
// players (Plex transcoder, some hardware decoders, some AV
// receivers) reject lossless DTS-HD MA payload when the
// track advertises plain `A_DTS` because it implies the
// bitstream is the 1.5 Mbps "core" only. Fix is just to
// emit the right ID per BD-STN codec field.
let codec_id = match a.codec {
Codec::Ac3 => "A_AC3",
Codec::Ac3Plus => "A_EAC3",
Codec::TrueHd => "A_TRUEHD",
Codec::DtsHdMa | Codec::DtsHdHr | Codec::Dts => "A_DTS",
Codec::DtsHdMa => "A_DTS/MA",
Codec::DtsHdHr => "A_DTS/HR",
Codec::Dts => "A_DTS",
Codec::Lpcm => "A_PCM/INT/BIG",
_ => "A_AC3",
};
@@ -380,12 +388,19 @@ impl<W: Write + Seek> MkvMuxer<W> {
}
/// Write a single frame.
///
/// When `duration_ns` is `Some`, the frame is emitted as a
/// `BlockGroup` with `BlockDuration` so the player knows exactly
/// when to remove the on-screen artifact (the practical case is
/// PGS subtitles — without it, the last bitmap lingers until the
/// next display set replaces it). Otherwise a plain `SimpleBlock`.
pub fn write_frame(
&mut self,
track_idx: usize,
pts_ns: i64,
keyframe: bool,
data: &[u8],
duration_ns: Option<u64>,
) -> io::Result<()> {
let raw_ms = pts_ns / 1_000_000;
let base = *self.base_pts_ms.get_or_insert(raw_ms);
@@ -409,9 +424,16 @@ impl<W: Write + Seek> MkvMuxer<W> {
});
}
// Write SimpleBlock
let relative_ts = (pts_ms - self.cluster_ts_ms) as i16;
self.write_simple_block(track_idx + 1, relative_ts, keyframe, data)?;
match duration_ns {
Some(dur_ns) => {
let duration_ms = (dur_ns / 1_000_000).max(1);
self.write_block_group(track_idx + 1, relative_ts, keyframe, data, duration_ms)?;
}
None => {
self.write_simple_block(track_idx + 1, relative_ts, keyframe, data)?;
}
}
self.frame_count += 1;
Ok(())
@@ -510,6 +532,34 @@ impl<W: Write + Seek> MkvMuxer<W> {
Ok(())
}
fn write_block_group(
&mut self,
track_num: usize,
relative_ts: i16,
keyframe: bool,
data: &[u8],
duration_ms: u64,
) -> io::Result<()> {
let track_vint = if track_num < 0x80 {
vec![(track_num as u8) | 0x80]
} else {
vec![0x40 | ((track_num >> 8) as u8), track_num as u8]
};
let flags: u8 = if keyframe { 0x80 } else { 0x00 };
let block_size = track_vint.len() + 2 + 1 + data.len();
let bg_pos = ebml::start_master(&mut self.writer, ebml::BLOCK_GROUP)?;
ebml::write_id(&mut self.writer, ebml::BLOCK)?;
ebml::write_size(&mut self.writer, block_size as u64)?;
self.writer.write_all(&track_vint)?;
self.writer.write_all(&relative_ts.to_be_bytes())?;
self.writer.write_all(&[flags])?;
self.writer.write_all(data)?;
ebml::write_uint(&mut self.writer, ebml::BLOCK_DURATION, duration_ms)?;
ebml::end_master(&mut self.writer, bg_pos)?;
Ok(())
}
}
// ============================================================
@@ -619,7 +669,7 @@ mod tests {
let tracks = [make_video_track()];
let mut muxer = MkvMuxer::new(buf, &tracks, None, 60.0, &[]).unwrap();
muxer
.write_frame(0, 0, true, &[0xDE, 0xAD, 0xBE, 0xEF])
.write_frame(0, 0, true, &[0xDE, 0xAD, 0xBE, 0xEF], None)
.unwrap();
let data = muxer.writer.into_inner();
assert!(
@@ -657,7 +707,9 @@ mod tests {
let writer = SharedWriter(shared.clone());
let tracks = [make_video_track()];
let mut muxer = MkvMuxer::new(writer, &tracks, Some("Cue Test"), 60.0, &[]).unwrap();
muxer.write_frame(0, 0, true, &[0x01, 0x02, 0x03]).unwrap();
muxer
.write_frame(0, 0, true, &[0x01, 0x02, 0x03], None)
.unwrap();
muxer.finish().unwrap();
let data = shared.lock().unwrap().clone().into_inner();
@@ -673,13 +725,17 @@ mod tests {
let tracks = [make_video_track(), make_audio_track()];
let mut muxer = MkvMuxer::new(buf, &tracks, Some("Multi"), 120.0, &[]).unwrap();
// Write frames to both tracks
muxer.write_frame(0, 0, true, &[0x00, 0x00, 0x01]).unwrap();
muxer.write_frame(1, 0, false, &[0x0B, 0x77, 0x00]).unwrap();
muxer
.write_frame(0, 40_000_000, false, &[0x00, 0x00, 0x01])
.write_frame(0, 0, true, &[0x00, 0x00, 0x01], None)
.unwrap();
muxer
.write_frame(1, 32_000_000, false, &[0x0B, 0x77, 0x01])
.write_frame(1, 0, false, &[0x0B, 0x77, 0x00], None)
.unwrap();
muxer
.write_frame(0, 40_000_000, false, &[0x00, 0x00, 0x01], None)
.unwrap();
muxer
.write_frame(1, 32_000_000, false, &[0x0B, 0x77, 0x01], None)
.unwrap();
// Should not panic
let data = muxer.writer.into_inner();
@@ -694,10 +750,12 @@ mod tests {
// Record position before first frame
let pos_before_kf = muxer.writer.position();
muxer.write_frame(0, 0, true, &[0xAA]).unwrap();
muxer.write_frame(0, 0, true, &[0xAA], None).unwrap();
let pos_after_kf = muxer.writer.position();
muxer.write_frame(0, 1_000_000, false, &[0xBB]).unwrap();
muxer
.write_frame(0, 1_000_000, false, &[0xBB], None)
.unwrap();
let pos_after_nkf = muxer.writer.position();
let data = muxer.writer.into_inner();
@@ -942,7 +1000,7 @@ mod tests {
let writer = SharedWriter(shared.clone());
let mut muxer = MkvMuxer::new(writer, tracks, None, 0.0, chapters).unwrap();
for (t, pts, kf, data) in frames {
muxer.write_frame(*t, *pts, *kf, data).unwrap();
muxer.write_frame(*t, *pts, *kf, data, None).unwrap();
}
let frame_count = muxer.frame_count;
muxer.finish().unwrap();