Dolby-E decoding

[smallishzulu]

Hello,

Does FFmpeg support Dolby-E decoding ?
I have attached 2 files:

a) Dolby-E data with SMPTE-337
b) Dolby-E data

Kind Regards,

[smallishzulu]

Dolby-E Data

[smallishzulu]

Dolby-E Data with SMPTE 337

[Carl Eugen Hoyos]

A more useful sample is in ​http://samples.ffmpeg.org/ffmpeg-bugs/trac/ticket3890/
Using that sample, this maybe isn't just an enhancement request: Audio is incorrectly identified.

[Elon Musk]

Fixed in 930fe4b1f75d4176a7226fccdcbd6c68b816a1b7.

[cepesh]

Replying to richardpl:

Fixed in 930fe4b1f75d4176a7226fccdcbd6c68b816a1b7.

Thank you very much. Would you please be so kind and clarify whether Dolby E can now be detected by ffmpeg and ffprobe?

On the example TS file from one of the comments in this thread I get this:

[s302m @ 000000000033b9e0] S302 non PCM mode with data type 28 not supported
[mpeg2video @ 00000000006dd740] Invalid frame dimensions 0x0.
[s302m @ 000000000033b9e0] S302 non PCM mode with data type 28 not supported
    Last message repeated 175 times
[mpegts @ 000000000033a6c0] decoding for stream 3 failed
[mpegts @ 000000000033a6c0] PES packet size mismatch
    Last message repeated 2 times
[mpegts @ 000000000033a6c0] Could not find codec parameters for stream 3 (Audio: s302m (BSSD / 0x44535342), stereo, s32 (20 bit), 2304 kb/s): unspecified sample rate
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, mpegts, from 'C:\Temp\20170807\ffmpeg isnt able to demux video stream.ts':
  Duration: 00:00:19.96, start: 32171.787089, bitrate: 20976 kb/s
  Program 1
    Stream #0:0[0x200]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv, bt709, bottom first), 1920x1080 [SAR 1:1 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0:1[0x1010](eng): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, s16p, 384 kb/s
    Stream #0:2[0x1020](eng): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, s16p, 384 kb/s
    Stream #0:3[0x1030](eng): Audio: s302m (BSSD / 0x44535342), stereo, s32 (20 bit), 2304 kb/s

And I'm not sure how to work with those .bin files from the other comments. Are we supposed to inform ffprobe/ffmpeg that input codec is Dolby E? Can you please supply an example?

Thanks in advance.

[Balling]

You still did not add on the fly support for 28 type. Why is that? Also, I have a file where 28 type is not somehow recognized. Again, why? Using standard ffmpeg -non_pcm_mode copy -i "file.ts" -map 0:2 -vn -c:a pcm_s24le -f s24le "out.dat" and ffplaying out.dat works though thanks to new patches even with actual seek.

[Elon Musk]

because your behaviour here is unacceptable.

[Balling]

Replying to richardpl:

because your behaviour here is unacceptable.

What is unacceptable is that there is a workaround like that:

ffmpeg -non_pcm_mode copy -i file.ts -vn -map 0:2 -c:a pcm_s24le -f s24le - | ffmpeg -i - -ar 48000 -f WAV - | ffmpeg -i - -i file.ts -map 0:a -c:a copy -map 1:v -c:v copy -copyts -f matroska - | ffplay -

Why it cannot work without this?
P.S. If you think my behaviour is unacceptable (I read you on mailing lists BTW, it is funny coming from you, though you are usually right) what do you think about this guy in #3785?
P.S.2 Also, I still do not get whether -ar 48000 is needed. I mean there is no such sample rate internally, if you look in fr_code variable.

[Balling]

There is now this (on the fly support for 28 type): ​https://patchwork.ffmpeg.org/project/ffmpeg/patch/20240127103854.9971-1-ffmpeg@gyani.pro/

But still not pushed, why is that? Is Dolby threatening you or something? LOL!

[Gyan]

A dev objected to the approach of decoding in-place, wanted the embedded stream to be unwrapped in the demuxer itself; I referred it to the Technical Committee, where the patch was rejected.

When I have enough time, I may try the demuxer approach.