[FFmpeg-user] Selecting MPEG TS child streams for filter_complex

Moritz Barsnick barsnick at gmx.net
Mon Mar 16 10:27:38 EET 2020

On Mon, Mar 16, 2020 at 09:21:56 +0100, Michael Fladischer wrote:
> But there was no syntax error:
> $ ffmpeg -f -i file.ts -filter_complex '[i:0x101][i:0x103]amix=inputs=2' -vn -c:a flac /tmp/auphonic-input-m2s6wfy8.flac
> Invalid file index 0 in filtergraph description [i:0x101][i:0x103]amix=inputs=2.

Yeah, interesting. It's due to the the fact that the "-i" get swallowed
as an option to "-f", and you therefore have no input files specified,
and therefore the filtergraph cannot be set up.

With loglevel verbose, I get:
> Reading option '-f' ... matched as option 'f' (force format) with argument '-i'.

I wonder why ffmpeg doesn't trip over this first. Whatever.


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