Recherche avancée

Sur d’autres sites (9375)

• avcodec_send_packet causing memory leak

  23 juin 2020, par AleksaJanjatovic

  I'm trying to fetch a frame from an Rtsp stream, but it seems that I'm forgetting to free some element, causing my RAM to rapidly fill. Here are the code snippets :

  


  Here is the initialization before frame fetching

  


  bool CRtspStream::Init(void* _userData) {
    InitParam* param = (CBaseStream::InitParam*)_userData;
    m_InputPath = param->m_InputPath;
    m_OutputPath = param->m_OutputPath;
    m_Logger.SetLogLevel(param->m_LoggerLevel);

    av_register_all();
    avformat_network_init();

    int ffmpegFatalLogLevel = 8;
    av_log_set_level(ffmpegFatalLogLevel);

    AVCodec* codec = avcodec_find_decoder(param->m_CodecID);
    if(!codec)
        throw DetectionUtility::StreamException("Unable to open codec.");

    m_FormatContext = avformat_alloc_context();
    m_CodecContext = avcodec_alloc_context3(codec);

    if(avformat_open_input(&m_FormatContext, param->m_InputPath.c_str(), nullptr, nullptr) < 0)
        throw DetectionUtility::StreamException("Unable to open stream: " + param->m_InputPath);

    if(avformat_find_stream_info(m_FormatContext, nullptr) < 0)
        throw DetectionUtility::StreamException("Unable to get stream info into format context.");

    for(unsigned int i = 0;i < m_FormatContext->nb_streams; i++){
        if(m_FormatContext->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
            m_VideoStreamIndex = i;
    }

    if (avcodec_open2(m_CodecContext, codec, nullptr) < 0)
        throw DetectionUtility::StreamException("Unable to open codec.");

    return m_InitSuccesful = true;
}


  


  And here is the actual frame fetching, i made sure that retVal frame is being freed afterward. Main evidence that this is what causes memory leaks is that valgrind is also pointing to the avcodec_send_packet() line : valgrind_results

  


  AVFrame* CRtspStream::RequestNewFrame() {
    AVPacket packet;
    AVFrame* retVal = av_frame_alloc();
    bool frameAvailable = false;

//    avformat_flush(m_FormatContext);
//    avcodec_flush_buffers(m_CodecContext);
    av_read_play(m_FormatContext);
    int readFrameRes;
    while(!frameAvailable) {
        if((readFrameRes = av_read_frame(m_FormatContext, &packet)) >= 0) {
            if(packet.stream_index == m_VideoStreamIndex) {
                int res = 1;
                if((res = avcodec_send_packet(m_CodecContext, &packet)) < 0) {
                    av_packet_unref(&packet);
                    continue;
                }
                av_packet_unref(&packet);
                res = 1;
                while(res > 0) {
                    res = avcodec_receive_frame(m_CodecContext, retVal);
                    if(res == AVERROR(EAGAIN)) {
                        break;
                    } else if (res < 0) {
                        throw DetectionUtility::StreamException("Unable to receive a frame from the codec.");
                    } else {
                        frameAvailable = true;
                    }
                }
            }
        }
        av_packet_unref(&packet);
    }

    if(readFrameRes < 0) {
        av_frame_free(&retVal);
        av_packet_unref(&packet);
        throw DetectionUtility::StreamException("Unable to fetcha a new frame.");
    } else {
        try {
            if(CheckOutputSupported())
                DetectionUtility::AVFrameHelper::SaveFrame(retVal, "Rtsp" + m_OutputPath, m_CurrentFrameNumber);
            ++m_CurrentFrameNumber;
        } catch (const Utility::BaseException& e) {
            m_Logger.Error(e.GetMessage());
        }
    }
    return retVal;
}


  


• Encoding raw YUV420P to h264 with AVCodec on iOS

  4 janvier 2013, par Wade

  I am trying to encode a single YUV420P image gathered from a CMSampleBuffer to an AVPacket so that I can send h264 video over the network with RTMP.

  The posted code example seems to work as avcodec_encode_video2 returns 0 (Success) however got_output is also 0 (AVPacket is empty).

  Does anyone have any experience with encoding video on iOS devices that might know what I am doing wrong ?

  - (void) captureOutput:(AVCaptureOutput *)captureOutput
  
   didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
  
          fromConnection:(AVCaptureConnection *)connection {
  
  
  
    // sampleBuffer now contains an individual frame of raw video frames
  
    CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
  
  
  
    CVPixelBufferLockBaseAddress(pixelBuffer, 0);
  
  
  
    // access the data
  
    int width = CVPixelBufferGetWidth(pixelBuffer);
  
    int height = CVPixelBufferGetHeight(pixelBuffer);
  
    int bytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0);
  
    unsigned char *rawPixelBase = (unsigned char *)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
  
  
  
  
  
    // Convert the raw pixel base to h.264 format
  
    AVCodec *codec = 0;
  
    AVCodecContext *context = 0;
  
    AVFrame *frame = 0;
  
    AVPacket packet;
  
  
  
    //avcodec_init();
  
    avcodec_register_all();
  
    codec = avcodec_find_encoder(AV_CODEC_ID_H264);
  
  
  
    if (codec == 0) {
  
      NSLog(@"Codec not found!!");
  
      return;
  
    }
  
  
  
    context = avcodec_alloc_context3(codec);
  
  
  
    if (!context) {
  
      NSLog(@"Context no bueno.");
  
      return;
  
    }
  
  
  
    // Bit rate
  
    context->bit_rate = 400000; // HARD CODE
  
    context->bit_rate_tolerance = 10;
  
    // Resolution
  
    context->width = width;
  
    context->height = height;
  
    // Frames Per Second
  
    context->time_base = (AVRational) {1,25};
  
    context->gop_size = 1;
  
    //context->max_b_frames = 1;
  
    context->pix_fmt = PIX_FMT_YUV420P;
  
  
  
    // Open the codec
  
    if (avcodec_open2(context, codec, 0) < 0) {
  
      NSLog(@"Unable to open codec");
  
      return;
  
    }
  
  
  
  
  
    // Create the frame
  
    frame = avcodec_alloc_frame();
  
    if (!frame) {
  
      NSLog(@"Unable to alloc frame");
  
      return;
  
    }
  
    frame->format = context->pix_fmt;
  
    frame->width = context->width;
  
    frame->height = context->height;
  
  
  
  
  
    avpicture_fill((AVPicture *) frame, rawPixelBase, context->pix_fmt, frame->width, frame->height);
  
  
  
    int got_output = 0;
  
    av_init_packet(&packet);
  
    avcodec_encode_video2(context, &packet, frame, &got_output)
  
  
  
    // Unlock the pixel data
  
    CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
  
    // Send the data over the network
  
    [self uploadData:[NSData dataWithBytes:packet.data length:packet.size] toRTMP:self.rtmp_OutVideoStream];
  
  }

  Note : It is known that this code has memory leaks because I am not freeing the memory that is dynamically allocated.

  UPDATE

  I updated my code to use @pogorskiy method. I only try to upload the frame if got output returns 1 and clear the buffer once I am done encoding video frames.

• FFmpeg on Xcode

  4 octobre 2013, par user2741735

  I'm developing an app for ios which uses IP Camera to stream live videos to the user. I installed macports and ffmpeg using terminal on my mac. I have taken the IP Camera output and converted into .ts file using ffmpeg on terminal. Now I want the procedure to do the same using Xcode i.e. writing code in xcode to convert IP Camera output to .ts files.
  Thanks in advance.