[FFmpeg-devel] FFmpeg TC input needed

Kieran Kunhya kierank at obe.tv
Sat Feb 17 14:01:51 EET 2024


On Sat, 17 Feb 2024, 11:46 Gyan Doshi, <ffmpeg at gyani.pro> wrote:

> Issue:
>
> Patch: avcodec/s302m: enable non-PCM decoding
> URL:
>
> https://patchwork.ffmpeg.org/project/ffmpeg/patch/20240127103854.9971-1-ffmpeg@gyani.pro/
>
> The issue needing resolution is whether the patch should be added to the
> existing s302m decoder or should that decoder
> be removed and all old and new patched features inlined into the mpeg-ts
> demuxer.
>

Additional comments:

Dolby E can exist in any PCM container (wav, MP4). S302M just happens to be
a tricky one.

Whilst s302m multiple substreams I haven't seen, Dolby E streams internally
contain multiple programs, often 5.1 and a 2.0 downmix.

Strictly speaking you have to handle the case where the Dolby E frame is
misaligned and spans two S302M packets which does exist (and there is
ambiguity about the PTS).

There is a 3x3 matrix of flavours between coded Dolby E and the carriage
PCM (16-bit, 20-bit, 24-bit).

Kieran


More information about the ffmpeg-devel mailing list