Memory leak while opening encoders in ffmpeg - ffmpeg

Question

I'm getting memory leaks in avcodec_find_encoder. Although I'm cleaning the resources properly
still I'm not able to get rid of the leak. By successive commenting the code I found that memory leaks happen only after the call of avcodec_find_encoder(). I've tried my code with different video files and I found that memory leaks blocks are always same. Also if I open only audio or video then I get just one memory leaks block.
Below is the part of Init and Clean-up code from the application.
Note that this is just part of code which contains initialization and resource release.
AVFormatContext *m_informat;
AVFormatContext *m_outformat;
AVStream *m_in_vid_strm, *m_out_vid_strm;
AVStream *m_in_aud_strm, *m_out_aud_strm;
int VideoClipper::Init(const wxString& filename)
{
int ret = 0;
char errbuf[64];
av_register_all();
if ((ret = avformat_open_input( &m_informat, filename.mb_str(), 0, 0)) != 0 )
{
av_strerror(ret,errbuf,sizeof(errbuf));
PRINT_VAL("Not able to Open file;; ", errbuf)
ret = -1;
return ret;
}
else
{
PRINT_MSG("Opened File ")
}
if ((ret = avformat_find_stream_info(m_informat, 0))< 0 )
{
av_strerror(ret,errbuf,sizeof(errbuf));
PRINT_VAL("Not Able to find stream info:: ", errbuf)
ret = -1;
return ret;
}
else
{
PRINT_MSG("Got stream Info ")
}
for(unsigned int i = 0; i<m_informat->nb_streams; i++)
{
if(m_informat->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
{
PRINT_MSG("Found Video Stream ")
m_in_vid_strm_idx = i;
m_in_vid_strm = m_informat->streams[i];
}
if(m_informat->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO)
{
PRINT_MSG("Found Audio Stream ")
m_in_aud_strm_idx = i;
m_in_aud_strm = m_informat->streams[i];
}
}
AVOutputFormat *outfmt = NULL;
std::string outfile = std::string(filename) + "clip_out.avi";
outfmt = av_guess_format(NULL,outfile.c_str(),NULL);
if(outfmt == NULL)
{
ret = -1;
return ret;
}
else
{
m_outformat = avformat_alloc_context();
if(m_outformat)
{
m_outformat->oformat = outfmt;
_snprintf(m_outformat->filename, sizeof(m_outformat->filename), "%s", outfile.c_str());
}
else
{
ret = -1;
return ret;
}
}
AVCodec *out_vid_codec,*out_aud_codec;
out_vid_codec = out_aud_codec = NULL;
if(outfmt->video_codec != AV_CODEC_ID_NONE && m_in_vid_strm != NULL)
{
out_vid_codec = avcodec_find_encoder(outfmt->video_codec);
if(NULL == out_vid_codec)
{
PRINT_MSG("Could Not Find Vid Encoder")
ret = -1;
return ret;
}
else
{
PRINT_MSG("Found Out Vid Encoder ")
m_out_vid_strm = avformat_new_stream(m_outformat, out_vid_codec);
if(NULL == m_out_vid_strm)
{
PRINT_MSG("Failed to Allocate Output Vid Strm ")
ret = -1;
return ret;
}
else
{
PRINT_MSG("Allocated Video Stream ")
if(avcodec_copy_context(m_out_vid_strm->codec, m_informat->streams[m_in_vid_strm_idx]->codec) != 0)
{
PRINT_MSG("Failed to Copy Context ")
ret = -1;
return ret;
}
}
}
}
if(outfmt->audio_codec != AV_CODEC_ID_NONE && m_in_aud_strm != NULL)
{
out_aud_codec = avcodec_find_encoder(outfmt->audio_codec);
if(NULL == out_aud_codec)
{
PRINT_MSG("Could Not Find Out Aud Encoder ")
ret = -1;
return ret;
}
else
{
PRINT_MSG("Found Out Aud Encoder ")
m_out_aud_strm = avformat_new_stream(m_outformat, out_aud_codec);
if(NULL == m_out_aud_strm)
{
PRINT_MSG("Failed to Allocate Out Vid Strm ")
ret = -1;
return ret;
}
else
{
if(avcodec_copy_context(m_out_aud_strm->codec, m_informat->streams[m_in_aud_strm_idx]->codec) != 0)
{
PRINT_MSG("Failed to Copy Context ")
ret = -1;
return ret;
}
}
}
}
if (!(outfmt->flags & AVFMT_NOFILE))
{
if (avio_open2(&m_outformat->pb, outfile.c_str(), AVIO_FLAG_WRITE,NULL, NULL) < 0)
{
PRINT_VAL("Could Not Open File ", outfile)
ret = -1;
return ret;
}
}
/* Write the stream header, if any. */
if (avformat_write_header(m_outformat, NULL) < 0)
{
PRINT_VAL("Error Occurred While Writing Header ", outfile)
ret = -1;
return ret;
}
else
{
PRINT_MSG("Written Output header ")
m_init_done = true;
}
return ret;
}
Here is the Clean-up part
void VideoClipper::ReleaseResource(void)
{
if(m_in_aud_strm && m_in_aud_strm->codec)
{
avcodec_close(m_in_aud_strm->codec);
PRINT_MSG("Closed Input Audio Codec ")
}
if(m_in_vid_strm && m_in_vid_strm->codec)
{
avcodec_close(m_in_vid_strm->codec);
PRINT_MSG("Closed Input Video Codec ")
}
if(m_informat)
{
avformat_close_input(&m_informat);
PRINT_MSG("Freed Input Format Contex ")
}
if(m_out_aud_strm && m_out_aud_strm->codec)
{
avcodec_close(m_out_aud_strm->codec);
PRINT_MSG("Closed Output Audio Codec ")
}
if(m_out_vid_strm && m_out_vid_strm->codec)
{
avcodec_close(m_out_vid_strm->codec);
PRINT_MSG("Closed Output Audio Codec ")
}
if(m_outformat)
{
avformat_close_input(&m_outformat);
m_outformat = NULL;
PRINT_MSG("Closed Output Format ")
}
}
Memory Leaks message
Detected memory leaks!
Dumping objects ->
{13691} normal block at 0x01046A60, 4479 bytes long.
Data: < > CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD CD
{13685} normal block at 0x01043FD0, 10831 bytes long.
Data: < ? > CD CD CD CD CD CD CD CD D0 3F 04 01 ED ED ED ED
Object dump complete.
I'm using latest version of ffmpeg on Visual Studio 2012.
Please suggest where I'm missing.
Thanks
Pradeep

Answer 1

There are lots of thing that matters here
first you need to close io
if (!(fmt->flags & AVFMT_NOFILE))
{
/* Close the output file. */
avio_close(ctx->oc->pb);
}
you should also call
avformat_free_context(ctx->oc);
There is always 24 bytes memory leakage at my system due to allocation pthread_mutex in libavcodec/utils.c of ffmpeg, and there is no way to free that memory.atleast till I or someone fix the code.