Hi Carl, I am unable to recreate the results you are describing here.
Starting with the sample.ac3 file I posted a copy of earlier: https://www.dropbox.com/s/ripe53oci6wz7t6/sample.ac3?dl=0 Packaging it with smpte 337M: ffmpeg -i sample.ac3 -acodec ac3 -f spdif sample.ac3.spdif Gives this file: https://www.dropbox.com/s/zksgfvavopi4qdq/sample.ac3.spdif?dl=0 It looks correct, it has SMPTE377 headers wrapped around AC3 frames with lots of null space in between, as I would expect. Converting this to a WAV file using your command as an example: ffmpeg -f s16le -ac 2 -ar 192k -i sample.ac3.spdif -acodec copy sample.ac3.spdif.wav Creates this wav file: https://www.dropbox.com/s/awoqe8l078ppezm/sample.ac3.spdif.wav?dl=0 That WAV file looks correct - it is more or less identical to the ones in the Dolby SDK sample files, however it appears to have a little bit of extra information in the WAV header that is not present in the Dolby version. Attempting to play this with mplayer doesn't work - it treats the input as if it were PCM so you hear garbage: *Playing Desktop/sample.ac3.spdif.wav.* *libavformat version 54.20.4 (external)* *Mismatching header version 54.20.3* *Audio only file format detected.* *Load subtitles in Desktop/* *==========================================================================* *Opening audio decoder: [pcm] Uncompressed PCM audio decoder* *AUDIO: 192000 Hz, 2 ch, s16le, 6144.0 kbit/100.00% (ratio: 768000->768000)* *Selected audio codec: [pcm] afm: pcm (Uncompressed PCM)* *==========================================================================* *AO: [pulse] 192000Hz 2ch s16le (2 bytes per sample)* *Video: no video* So I am guessing that the SPDIF decoding is not being done by mplayer, it is in the ALSA drivers you have on your system - and maybe specific to the hardware they are driving. Does this sound as though it is the likely reason for me not seeing your results? And can I replicate your configuration with the proper installation of alsa drivers? ------------------------------------------------------------------------------ Mark Nelson – ma...@ieee.org - http://marknelson.us On Mon, Dec 28, 2015 at 1:34 PM, Carl Eugen Hoyos <ceho...@ag.or.at> wrote: > Mark Nelson <markn <at> ieee.org> writes: > > > Same file wrappred in SMPTE-377M headers and packaged > > in a WAV file as if it were 1536 kbps PCM: > > > > https://www.dropbox.com/s/tec7al5bcmihwey/sample.eac3.337.wav > > Is this really valid? > My receiver cannot play this, the following plays as > expected here (showing that eac3-over-spdif works > fine on my equipment): > $ ffmpeg -i input -acodec eac3 -f spdif out > $ ffmpeg -f s16le -ac 2 -ar 192k -i out -acodec copy out.wav > $ mplayer out.wav -ao alsa:device=hw=1.7 > > I can make your file play but I wonder if I should... > (And yes, I do remember that this isn't your issue > but I would still like to understand the issue first.) > > Carl Eugen > > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user