[FFmpeg-user] MPEGTS with multiple audio streams containing discrete audio channels to AC3

[Casey Nielson]

On Aug 13, 2014, at 8:20 AM, Casey Nielson <caseyn at grumpy.com> wrote:

> Trying to convert a MPEGTS file with multiple audio streams to mp4 with AC3 audio. I’ve tried map_channel and filter_complex but I can’t make it work (due to my misunderstanding I’m sure).
> 
> Output from ffprobe
> Input #0, mpegts, from ‘mpegts_test.ts':
>  Duration: 01:03:01.93, start: 0.313956, bitrate: 21811 kb/s
>  Program 1 
>    Stream #0:0[0x1e1]: Video: mpeg2video
>    Stream #0:1[0x1e2]: Audio: s302m 
>    Stream #0:2[0x1e3]: Audio: s302m
>    Stream #0:3[0x1e4]: Audio: s302m
> 
> 
> Stream 0:1 contains LF and RF
> Stream 0:2 contains C and LFE
> Stream 0:3 contains LS and RS
> 
> I’m trying to create a mp4 file with the video and a ac3 audio stream.
> 
> I’ve tried this but I don’t understand how the filter graph is supposed to work.
> 
> ffmpeg -i mpegts_test.ts -strict experimental -filter_complex "[0:1][0:2][0:3]amerge=inputs=6[aout]" -map "[aout]" -c:v libx264 -crf 20 -c:a ac3 -b:a 384k -t 30 output.mp4
> 
> Any help greatly appreciated.


Can anyone provide guidance? Restating the use case: I would like to transcode a mpegts file with three audio streams (two channels each) to an output with a single audio stream of AC3. I’m not sure how to configure the map or the filter in a filter_complex.