[Ffmpeg-devel] [BUG] slowness and/or memory leak with adpcm_ima_qt .mov files

Allan Hsu allan
Fri Jan 26 21:39:53 CET 2007

I've run across what looks like a major memory leak caused by  
adpcm_ima_qt audio track decoding. ffmpeg output doesn't look out of  
the ordinary, but it is much slower than it should be (kind of slow  
on a PPC OS X machine, but *super slow* on a x86_64 linux machine).  
I've uploaded a sample to the FTP site as "shuffle-ima41.mov". Here  
is the ffmpeg output, killed because it was taking up too much memory:

./ffmpeg -i ~/Desktop/shuffle-ima41.mov -acodec pcm_s16le -vcodec  
mpeg4 -b 768k ~/Desktop/shuffle.avi
FFmpeg version SVN-r7718, Copyright (c) 2000-2006 Fabrice Bellard, et  
   configuration:  --enable-gpl --enable-x264 --enable-xvid --enable- 
mp3lame --extra-cflags=-I/Users/allan/code/usr/include --extra- 
   libavutil version: 49.2.0
   libavcodec version: 51.29.0
   libavformat version: 51.8.0
   built on Jan 26 2007 10:46:06, gcc: 4.0.1 (Apple Computer, Inc.  
build 5367)

Seems stream 1 codec frame rate differs from container frame rate:  
1000.00 (1000/1) -> 23.98 (24000/1001)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/allan/Desktop/shuffle- 
   Duration: 00:00:30.0, start: 0.000000, bitrate: 1184 kb/s
   Stream #0.0(eng): Audio: adpcm_ima_qt, 44100 Hz, stereo
   Stream #0.1(eng): Video: mpeg4, yuv420p, 212x120, 23.98 fps(r)
File '/Users/allan/Desktop/shuffle.avi' already exists. Overwrite ?  
[y/N] y
Output #0, avi, to '/Users/allan/Desktop/shuffle.avi':
   Stream #0.0: Video: mpeg4, yuv420p, 212x120, q=2-31, 768 kb/s,  
23.98 fps(c)
   Stream #0.1: Audio: pcm_s16le, 44100 Hz, stereo, 1411 kb/s
Stream mapping:
   Stream #0.1 -> #0.0
   Stream #0.0 -> #0.1
Press [q] to stop encoding
Killed   68 q=2.0 size=     767kB time=2.8 bitrate=2214.7kbits/s


Allan Hsu <allan at counterpop dot net>
1E64 E20F 34D9 CBA7 1300  1457 AC37 CBBB 0E92 C779

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