[Libav-user] (AVStream *)av_malloc(sizeof(AVStream)) crashed the application

Chandranath Bhattacharyya cbhattac at adobe.com
Tue Oct 30 12:28:06 CET 2012

>> Hi Chandranath

>> Thanks!

>> But I already allocated memory for the pointer *ic_enc_mjpeg
                OK. Sorry. I did not realize you meant the crash occurred even after allocation.

>> AVFormatContext *ic_enc_mjpeg;
>> ic_enc_mjpeg = (AVFormatContext *)av_malloc(sizeof(AVFormatContext));

>> Then I tried to allocate the memory for ic_enc_mjpeg->streams[0], then it crashed.

streams variable inside AVFormatContext is AVStream **. So the allocation of AVFormatContext using av_malloc is not supposed to initialize/allocate it. Hence the crash.

Check the documentation in header avformat.h for more info.

The crash can be fixed by the following code.

AVFormatContext *ic_enc_mjpeg;
ic_enc_mjpeg = (AVFormatContext *)av_malloc(sizeof(AVFormatContext));
ic_enc_mjpeg->streams = (AVStream **)av_malloc(sizeof(AVStream *)); // <== DO THIS.
ic_enc_mjpeg->nb_streams = 1; // OR WHATEVER.
ic_enc_mjpeg->streams[0] = (AVStream *)av_malloc(sizeof(AVStream));


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