ffmpeg RTSP stream decoding memory leak - qt

Question

I need to decode rtsp stream from Ip camera using ffmpeg, below is the code for decoder
ffmpeg_decoder.h
class ffmpeg_decoder
{
public:
ffmpeg_decoder();
int initial(QString & url);
int h264Decodec();
void close_stream();
virtual ~ffmpeg_decoder();
AVPicture picture;
int width;
int height;
QMutex mutex;
QImage imageDecoded;
private:
AVFormatContext *pFormatCtx;
AVCodecContext *pCodecCtx;
AVFrame *pFrame;
AVPacket packet;
SwsContext * pSwsCtx;
int videoStream;
QString rtspURL;
};
ffmpeg_decoder.cpp
ffmpeg_decoder::ffmpeg_decoder()
{
pCodecCtx = NULL;
videoStream=-1;
}
ffmpeg_decoder::~ffmpeg_decoder()
{
sws_freeContext(pSwsCtx);
}
int ffmpeg_decoder::initial(QString & url)
{
int err;
rtspURL=url;
AVCodec *pCodec;
av_register_all();
avformat_network_init();
pFormatCtx = avformat_alloc_context();
pFrame = av_frame_alloc();
err = avformat_open_input(&pFormatCtx, rtspURL.toStdString().c_str(), NULL,
NULL);
if (err < 0)
{
printf("Can not open this file");
return -1;
}
if (avformat_find_stream_info(pFormatCtx,NULL) < 0)
{
printf("Unable to get stream info");
return -1;
}
int i = 0;
videoStream = -1;
for (i = 0; i < pFormatCtx->nb_streams; i++)
{
if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
{
videoStream = i;
break;
}
}
if (videoStream == -1)
{
printf("Unable to find video stream");
return -1;
}
pCodecCtx = pFormatCtx->streams[videoStream]->codec;
width=pCodecCtx->width;
height=pCodecCtx->height;
avpicture_alloc(&picture,PIX_FMT_RGB24,pCodecCtx->width,pCodecCtx->height);
pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
pSwsCtx = sws_getContext(width, height, PIX_FMT_YUV420P, width,
height, PIX_FMT_RGB24,
SWS_BICUBIC, 0, 0, 0);
if (pCodec == NULL)
{
printf("Unsupported codec");
return -1;
}
printf("video size : width=%d height=%d \n", pCodecCtx->width,
pCodecCtx->height);
if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0)
{
printf("Unable to open codec");
return -1;
}
printf("initial successfully");
return 0;
}
int ffmpeg_decoder::h264Decodec()
{
int frameFinished=0;
// while (av_read_frame(pFormatCtx, &packet) >= 0)
if(av_read_frame(pFormatCtx, &packet) >= 0)
{
if(packet.stream_index==videoStream)
{
avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
if (frameFinished)
{
printf("***************ffmpeg decodec*******************\n");
mutex.lock();
int rs = sws_scale(pSwsCtx, (const uint8_t* const *) pFrame->data,
pFrame->linesize, 0,
height, picture.data, picture.linesize);
imageDecoded = QImage();
imageDecoded= QImage(this->picture.data[0],this->width,this->height,QImage::Format_RGB888);
//imageDecoded = imageDecoded.copy();
mutex.unlock();
if (rs == -1)
{
printf("__________Can open to change to des imag_____________e\n");
return -1;
}
}
}
}
av_free_packet(&packet);
av_frame_unref(pFrame);
av_packet_unref(&packet);
avpicture_free(&picture);
return 1;
}
void ffmpeg_decoder::close_stream(){
/*if (pFrame)
av_free(&pFrame);*/
if (pCodecCtx)
avcodec_close(pCodecCtx);
if (pSwsCtx)
sws_freeContext(pSwsCtx);
avpicture_free(&picture);
if (pFormatCtx)
avformat_close_input(&pFormatCtx);
}
Below is the main thread which do the decoding.
I am using Qt for creating thread and do decoding
ffmpeg_decoder * ffmpeg = new ffmpeg_decoder();;
if(ffmpeg->initial(rtspURL)==0){
while (1) {
ffmpeg->h264Decodec();
//get frame and do processing right now it disabled, and still see the memory leak.
.......
if(stopFlg.load()==1)
break;
}
//close stream if break
ffmpeg->close_stream();
}
else {
ffmpeg->close_stream();
}
When I run 36 thread with different URL I can see the memory usage of the program increase over time.
I have used valgrind to detect the leak, and here is the relevant part of the log
This is the first memory leak location
=14402== by 0x692017F: av_malloc (in /usr/lib/x86_64-linux-gnu/libavutil-ffmpeg.so.54.31.100)
==14402== by 0x692048D: av_mallocz (in /usr/lib/x86_64-linux-gnu/libavutil-ffmpeg.so.54.31.100)
==14402== by 0x691915E: av_frame_alloc (in /usr/lib/x86_64-linux-gnu/libavutil-ffmpeg.so.54.31.100)
==14402== by 0x419663: ffmpeg_decoder::initial(QString&) (ffmpeg_decoder.cpp:24)
==14402== by 0x41ABEC: RTSP_Player_Object::run() (rtsp_player_object.cpp:15)
Another
==14402== 2,176 bytes in 16 blocks are indirectly lost in loss record 23,113 of 23,379
==14402== at 0x4C2E0EF: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14402== by 0x7780A4E: QImageData::create(unsigned char*, int, int, int, QImage::Format, bool, void (*)(void*), void*) (in /home/vapplica/Qt5.11.1/5.11.1/gcc_64/lib/libQt5Gui.so.5.11.1)
==14402== by 0x7780C30: QImage::QImage(unsigned char*, int, int, QImage::Format, void (*)(void*), void*) (in /home/vapplica/Qt5.11.1/5.11.1/gcc_64/lib/libQt5Gui.so.5.11.1)
==14402== by 0x419B21: ffmpeg_decoder::h264Decodec() (ffmpeg_decoder.cpp:96)
I have check the documentation and sample on ffmpeg site, and I think I am releasing the allocated memory, but still I can see the memory leak when I run the program.