[FFmpeg-user] Problem with combining a video and an audio stream from USB device

FHoevi fhoevi at fullbeamahead.com
Sun Feb 2 11:50:16 EET 2020

Dear Carl Eugen,
thanks for your immediate reply. I got Raspbian Buster freshly installed with ffmpeg included. Building all this from Git head code base would potentially be one of the next steps but only if anything else won't work. All streams below do show no errors at all, therefore I have decided to not disclose them, mea culpa. And, sorry, I'm certainly not a video expert like you obviously are and thus haven't been aware of the fact that mjpeg and mpegts may not work with each other by design. I simply would like to use what I have in the most efficient way and just tried to get potential aid by ffmpeg experts.

Perhaps let me ask this question: Given that I have an incoming mjpeg video stream as well as an incoming mp2 audio stream which kind of container format (ok, it's obviously not mpegts) is the most appropriate one for combined streaming across my LAN or even into a pipe for further processing? Believe me, I tried my very best over a couple of hours to find out how to proceed but with no success. At least to my humble knowledge there is nothing such like a table providing answers to questions of that kind.

Perhaps another hint, with the same kind of hardware setup I can do this

cvlc -vvv v4l2:///dev/video0 --input-slave=alsa://plughw:1,0 --sout='#transcode{acodec=mpga,ab=128}:std{access=http,mux=asf,dst=:Port}'

So, here my understanding is that video gets passed on unchanged (mjpeg) and audio gets transcoded via vlc's mpga which presumably corresponds to mp2 for ffmpeg. The container format is asf, but I was not able to get that running with ffmpeg for no obvious reason. Anyway, picking up this vlc broadcast stream via http://StreamingMachine:Port on any other machine in my network is working well. But how to achieve that with ffmpeg directly and potentially not as http:// but udp:// or pipe stream?

Thx in advance

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