1

Being on an Ubuntu 10.04 server i installed the ffmpeg packages with apt. ffmpeg is working afterwards, and doing as it should. Almost.

For testing purposes i uploaded a few audiofiles. One of them, an aif file, is not being correctly interpreted. While on my workhorse (Mac SnowLeopard) ffmpeg tells the format as

Stream #0.0: Audio: pcm_s24be, 44100 Hz, 2 channels, s32, 2116 kb/s

my Ubuntu server says it is:

Stream #0.0: Audio: pcm_s24be, 44100 Hz, stereo, s16, 2116 kb/s

which is the wrong bitdepth. Ubuntu then fails to convert the file with the error message 

[pcm_s24be @ 0xcd4b580]invalid PCM packet
Error while decoding stream #0.0

which certainly is not true. The file is perfectly valid.

Are there any know issues for ffmpeg interpreting the aif format? How can i find out which version of the aif-codec ffmpeg is using? Any ideas how to approach this issue?

ffprobe output:

FFprobe version SVN-r20090707, Copyright (c) 2007-2009 Stefano Sabatini
  libavutil     49.15. 0 / 49.15. 0
  libavcodec    52.20. 0 / 52.20. 1
  libavformat   52.31. 0 / 52.31. 0
  built on Jan 20 2010 00:13:01, gcc: 4.4.3 20100116 (prerelease)
Input #0, aiff, from 'testfile.aif':
  Duration: 00:00:04.00, start: 0.000000, bitrate: 2117 kb/s
    Stream #0.0: Audio: pcm_s24be, 44100 Hz, stereo, s16, 2116 kb/s

update 2: Forcing the conversion with -sample_fmt s32 doesn't change anything.

Strange thing is: Even without using -sample_fmt s32 i just realized that the conversion is working and creates valid audiofiles. There just is the error message from above.

marue
  • 111
  • 1
  • 4
  • How did you copy the file to your Ubuntu box? Can you show us the output from `ffprobe`? – Alastair McCormack Oct 27 '12 at 20:06
  • File was copied with scp. Added ffprobe output, it misinterprets the aif file information as well (s16 instead of the correct s32) – marue Oct 27 '12 at 21:48
  • As AIF is just the container I believe this may be a bug in the PCM analysis. You could prove this by re-muxing it on your Mac into a .wav container or as raw pcm. Have you tried using `-sample_fmt s32` to force it? – Alastair McCormack Oct 27 '12 at 22:17

1 Answers1

0

Yes, it is. According to information from the ffmpeg usergroup there has been an ongoing "war" between maintainers of ffmpeg and libav. And someone at the Ubuntu development team seems to have taken the libav side, providing intentionally broken packages for ffmpeg.

Don't know if this is all true, but at least i know that installing ffmpeg using apt does not work, while building from the sources does.

A summary of the topic can be found here:

http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html

allthough it just is the ffmpeg side of the story.

marue
  • 111
  • 1
  • 4