FFmpeg error trying to convert audio in mp4

[Thunderhead2772]

im trying to convert audio in an mp4 video

the video is avc, the audio is ac3

im trying to get a new mp4 file with the same video codec, but converted audio to wav

i used this command

ffmpeg -i input.mp4 -vcodec copy -acodec pcm_s16le output.mp4

i get this error

Could not write header for output file #0 (incorrect codec parameters ?)

maybe i should give the whole command line output

FFmpeg version SVN-r18709, Copyright (c) 2000-2009 Fabrice Bellard, et al.
  configuration: --enable-memalign-hack --prefix=/mingw --cross-prefix=i686-ming
w32- --cc=ccache-i686-mingw32-gcc --target-os=mingw32 --arch=i686 --cpu=i686 --e
nable-avisynth --enable-gpl --enable-zlib --enable-bzlib --enable-libgsm --enabl
e-libfaac --enable-libfaad --enable-pthreads --enable-libvorbis --enable-libtheo
ra --enable-libspeex --enable-libmp3lame --enable-libopenjpeg --enable-libxvid -
-enable-libschroedinger --enable-libx264
  libavutil     50. 3. 0 / 50. 3. 0
  libavcodec    52.27. 0 / 52.27. 0
  libavformat   52.32. 0 / 52.32. 0
  libavdevice   52. 2. 0 / 52. 2. 0
  libswscale     0. 7. 1 /  0. 7. 1
  built on Apr 28 2009 04:04:42, gcc: 4.2.4

Seems stream 0 codec frame rate differs from container frame rate: 47.95 (48000/
1001) -> 23.98 (24000/1001)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'D:\Stuff\Toy Story 1995 2010 Trilogy Bl
uray 720p x264 ac3\Toy Story 1 1995.mp4':
  Duration: 01:21:03.44, start: 0.000000, bitrate: 2387 kb/s
    Stream #0.0(und): Video: h264, yuv420p, 1280x720, 23.98 tbr, 90k tbn, 47.95
tbc
    Stream #0.1(eng): Audio: ac3, 48000 Hz, stereo, s16
[mp4 @ 0x13acff0]track 1: could not find tag, codec not currently supported in c
ontainer
Output #0, mp4, to 'D:\Stuff\Toy Story 1995 2010 Trilogy Bluray 720p x264 ac3\to
ystory1.mp4':
    Stream #0.0(und): Video: libx264, yuv420p, 1280x720, q=2-31, 48k tbn, 23.98
tbc
    Stream #0.1(eng): Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Could not write header for output file #0 (incorrect codec parameters ?)

[Chris K]

You've missed a earlier message in the FFmpeg output ...

[mp4 @ 0x13acff0]track 1: could not find tag, codec not currently supported in container

This means PCM audio in mp4 container is not supported.

[Thunderhead2772]

what would be the best uncompressed audio format to convert to. i plan on editing the video in sony vegas, and when i imported the original video, only the video was imported.

[Chris K]

what would be the best uncompressed audio format to convert to. i plan on editing the video in sony vegas, and when i imported the original video, only the video was imported.

Only PCM audio is uncompressed. You could try to mux it in a mov container.

ffmpeg -i input.mp4 -vcodec copy -acodec pcm_s16le output.mov

You may need to update your FFmpeg version.

http://oss.netfarm.it/mplayer-win32.php

You also need to download the faac encoder dll (also on that webpage) and put it together with FFmpeg.

[saigone]

Thanks a lot Chris K.
your post helps me too much. thanks you. hope someone will be help.