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

[Allan Hsu]

On Jan 31, 2007, at 3:49 PM, Michael Niedermayer wrote:

[...]
>> 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
>
> does that also happen if you dont encode the video? -vn

Interesting results. The following command line does not seem to leak  
memory, but it doesn't ever seem to stop transcoding either:

./ffmpeg -i ~/Desktop/shuffle-ima41.mov -vn -b 768k -acodec pcm_s16le  
~/Desktop/shuffle.avi

I stopped ffmpeg by hitting 'q' after it had written over 1.5GB of  
data to shuffle.avi (the source movie is only 30 seconds long). I  
tried to play back this file in VLC and the audio doesn't seem to  
have survived. All I can hear is a periodic quiet clicking noise.

> and what if you just copy the audio -acodec copy?

I can't seem to find a muxer that will accept an adpcm_ima_qt stream.

[...]

Is there anything else I can do to help with this bug? As I mentioned  
in the first email, I've already uploaded my sample file to the ftp.

	-Allan
--
Allan Hsu <allan at counterpop dot net>
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