I'm trying to transcode a video with help of libavcodec. On transcoding big video files(hour or more) i get huge memory leaks in avcodec_encode_video. I have tried to debug it, but with different video files different functions produce leaks, i have got a little bit confused about that :). [Here] (http://stackoverflow.com/questions/4201481/ffmpeg-with-qt-memory-leak) is the same issue that i have, but i have no idea how did that person solve it. QtFFmpegwrapper seems to do the same i do(or i missed something). my method is lower. I took care about aFrame and aPacket outside with av_free and av_free_packet. int Videocut::encode( AVStream *anOutputStream, AVFrame *aFrame, AVPacket *aPacket ) { AVCodecContext *outputCodec = anOutputStream->codec; if (!anOutputStream || !aFrame || !aPacket) { return 1; /* NOTREACHED */ } uint8_t * buffer = (uint8_t *)malloc( sizeof(uint8_t) * _DefaultEncodeBufferSize ); if (NULL == buffer) { return 2; /* NOTREACHED */ } int packetSize = avcodec_encode_video( outputCodec, buffer, _DefaultEncodeBufferSize, aFrame ); if (packetSize < 0) { free(buffer); return 1; /* NOTREACHED */ } aPacket->data = buffer; aPacket->size = packetSize; return 0; }