FFMPEG: how to encode audio for a target duration?

[marcorocchini]

Dear Cats,

I have try this wrong commandline

ffmpeg.exe -y -i "V:\100 GOPRO\GOPR2887.MP4" -af "pan=stereo:c0=c0:c1=c1,volume=1.5" -shortest -af apad=whole_len=100000000 -c:a pcm_s16le -ar 48000 out.wav

trying to encode the audio part only of a gopro audio/video file but I need to encode for a specific duration.

For example the original duration of my GOPR2887.MP4 is and 27s 27ms (mediainfo) but we suppose that I want encode to a target duration of 0:00:09.480000 seconds OR 525 [correspondant framecount value @ 25fps]

The original duration have to be fit exactly the target-duration: if necessary ffmpeg should insert silence or have to cut the original audio file to fit for the new duration,

how can I do?

Thanks

ps: please consinder I'm a cat already in a batch file.
Probably I need to extract the duration from a video (video-only) .avs file and fit tha audio file of the exactly duration of video file

[poisondeathray]

-t is duration in ffmpeg, hh:mms.ms

-t 00:00:09.480

A video only avs would be the same length of the video. So if you use trim(0,524) it would be 525 frames . -shortest in ffmpeg will cut to the shortest input length

[mulvya]

As I told you in the last thread, you should only use one filterchain for audio, so

ffmpeg.exe -y -i "V:\100 GOPRO\GOPR2887.MP4" -af "pan=stereo:c0=c0:c1=c1,volume=1.5,apad" -c:a pcm_s16le -ar 48000 -t 9.480 out.wav

(Unless your source has more than 2 channels, that pan command is redundant)