[FFmpeg-user] ffmpeg to stream an already h.264 encoded stream

Moritz Barsnick barsnick at gmx.net
Tue Sep 10 23:02:53 EEST 2019

On Tue, Sep 10, 2019 at 17:25:43 +0200, Verachten Bruno wrote:
> ffmpeg -i rtmp:// -thread_queue_size
> 2048 -f pulse -i
> alsa_input.usb-Focusrite_Scarlett_2i4_USB-00.analog-stereo -c:v copy
> -map 0:v:0 -map 1:a:0 -f tee "[f=flv:onfail=ignore]$YOUTUBE_URL/$KEY"
> Automatic encoder selection failed for output stream #0:1. Default
> encoder for format tee (codec none) is probably disabled. Please
> choose an encoder manually.
> Error selecting an encoder for stream 0:1
> I had other outputs for the tee, but as it was not working, I removed
> them. There must be something important that I missed in that tee
> format...
> Please let me know.

Yes, you missed the actual error message. ;-)

The tee muxer, unlike the flv muxer, doesn't have useful defaults for
codecs. You are only specifying the video codec ("-c:v copy"), you also
need to specify an audio codec. AFAICT, flv defaults to mp3, so if you
want that, you should add "-c:a libmp3lame" to your command line.

Hope this helps,

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