Audio Stream Mixing in FFMPEG

[encodingmonkey]

Hi,

I have a video file that has 3 different audio streams:

put #0, mov,mp4,m4a,3gp,3g2,mj2, from '/media/local-trans02/PORTABLE28-B/mance/Men7_Textless_107.mov':
Metadata:
creation_time : 2012-09-27 18:35:06
timecode : 00:58:43;28
Duration: 00:47:27.04, start: 0.078078, bitrate: 143265 kb/s
Stream #0:0(eng): Video: prores (apcn / 0x6E637061), yuv422p10le, 1920x1080, 138631 kb/s, 29.97 fps, 29.97 tbr, 2997 tbn, 2997 tbc
Metadata:
creation_time : 2012-09-27 19:22:34
handler_name : Apple Alias Data Handler
Stream #0:1(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, mono, s32, 1152 kb/s
Metadata:
creation_time : 2012-09-27 19:22:34
handler_name : Apple Alias Data Handler
Stream #0:2(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, mono, s32, 1152 kb/s
Metadata:
creation_time : 2012-09-27 19:22:34
handler_name : Apple Alias Data Handler
Stream #0:3(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, stereo, s32, 2304 kb/s
Metadata:
creation_time : 2012-09-27 19:22:34
handler_name : Apple Alias Data Handler
Stream #0:4(eng): Data: none (tmcd / 0x64636D74)
Metadata:
creation_time : 2012-09-27 19:22:34
handler_name : Apple Alias Data Handler
timecode : 00:58:43;28
File '/media/local-trans02/PORTABLE08-STG/mance-transcode-050313-cds/Men7_Textless_107.mp3' already exists. Overwrite ? [y/N] y
Output #0, mp3, to '/media/local-trans02/PORTABLE08-STG/mance-transcode-050313-cds/Men7_Textless_107.mp3':
Metadata:
timecode : 00:58:43;28
TSSE : Lavf54.29.104
Stream #0:0(eng): Audio: mp3, 48000 Hz, mono, s32
Metadata:
creation_time : 2012-09-27 19:22:34
handler_name : Apple Alias Data Handler
Stream mapping:
Stream #0:1 -> #0:0 (pcm_s24le -> libmp3lame)
Press [q] to stop, [?] for help
size= 2344kB time=00:05:00.00 bitrate= 64.0kbits/s
video:0kB audio:2343kB subtitle:0 global headers:0kB muxing overhead 0.009793%

I'm having trouble converting it to mp4 because it ends up picking what I believe is steram 0:3, which is only music elements. The other two streams contain either narration or some other audio, but I need all three. Is there anyway to mix the audio? I once was able to somehow mix multiple audio streams into a wav file, before reburning with the mp4 as an aac. Sadly, I forgot to record the commands and was hoping someone here could help me out. Thanks!

[Baldrick]

Tried http://www.ffmpeg.org/ffmpeg-filters.html#amix ?

[Chris K]

If you clean up the FFmpeg log a bit from all the metadata it's easier to see what you've got ...

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/media/local-trans02/PORTABLE28-B/mance/Men7_Textless_107.mov':
  Duration: 00:47:27.04, start: 0.078078, bitrate: 143265 kb/s
    Stream #0:0(eng): Video: prores (apcn / 0x6E637061), yuv422p10le, 1920x1080, 138631 kb/s,
      29.97 fps, 29.97 tbr, 2997 tbn, 2997 tbc
    Stream #0:1(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, mono, s32, 1152 kb/s
    Stream #0:2(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, mono, s32, 1152 kb/s
    Stream #0:3(eng): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, stereo, s32, 2304 kb/s
    Stream #0:4(eng): Data: none (tmcd / 0x64636D74)

You could try this ...

ffmpeg -i INPUT.mov [video output commands] -filter_complex "[0:1][0:2][0:3]amerge=inputs=3" [audio output commands] -y OUTPUT.mp4

I tried this with success but the input streams were all stereo. I don't know what FFmpeg does with a mix of mono and stereo streams. Also wonder if this merging could lead to audio clipping?

http://ffmpeg.mplayerhq.hu/ffmpeg-filters.html#amerge