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• Ffmpeg AVAudioFifo memory leak

  10 août 2020, par Expressingx

  I'm encoding audio to AAC with encoder. Because it requires I'm using AVAudioFifo following https://ffmpeg.org/doxygen/4.0/transcode_aac_8c-example.html

  


  Everything works, but I can see my memory slowly growing up. If I comment out PushToFifo() no memory leaks. And not sure why. I've profiled the app with ANTS Profiler and I can see a lot of unmanaged memory allocated by avutil-x.dll.

  


  while (ffmpeg.av_read_frame(_inputContext.InputFormatContext, pkt) >= 0)
{
   // decode
   int ret = ffmpeg.avcodec_send_packet(decCtx, pkt);

        if (ret < 0)
        {
            ffmpeg.av_packet_unref(pkt);
            return;
        }

        while (ret >= 0)
        {
            ret = ffmpeg.avcodec_receive_frame(decCtx, frame);

            if (ret == ffmpeg.AVERROR(ffmpeg.EAGAIN) || ret == ffmpeg.AVERROR_EOF)
            {
                return;
            }
            
            // push to fifo
            PushToFifo();
            TryFlushSamples();
        }
}


  


  PushToFifo()

  


              byte* samples = null;

            if (ffmpeg.av_samples_alloc(&samples, null, _outputContext->channels, inputFrame->nb_samples, _outputContext->sample_fmt, 0) < 0)
            {
              ffmpeg.av_freep(&samples[0]);
              ffmpeg.av_free(samples);
              // throw
            }

            if (ffmpeg.swr_convert(_resamplerCtx, &samples, inputFrame->nb_samples, inputFrame->extended_data, inputFrame->nb_samples) < 0)
            {
              throw new Exception();
            }

            if (ffmpeg.av_audio_fifo_realloc(AudioFifo, ffmpeg.av_audio_fifo_size(AudioFifo) + inputFrame->nb_samples) < 0)
            {
              throw new Exception();
            }

            if (ffmpeg.av_audio_fifo_write(AudioFifo, (void**)&samples, inputFrame->nb_samples) < 0)
            {
               throw new Exception();
            }


  


  And in TryFlushSamples();

  


          while (ffmpeg.av_audio_fifo_size(_audioFifo.AudioFifo) >= _outputContext.AudioEncodeContext->frame_size)
        {
            int fifoSize = ffmpeg.av_audio_fifo_size(_audioFifo.AudioFifo);
            int frameSize = fifoSize > _outputContext.AudioEncodeContext->frame_size
                ? _outputContext.AudioEncodeContext->frame_size
                : fifoSize;

            var outputContext = _outputContext.AudioEncodeContext;
            var frame = ffmpeg.av_frame_alloc();
            frame->nb_samples = frameSize;
            frame->channel_layout = outputContext->channel_layout;
            frame->format = (int)outputContext->sample_fmt;
            frame->sample_rate = outputContext->sample_rate;

            if (ffmpeg.av_frame_get_buffer(frame, 0) < 0)
                ffmpeg.av_frame_free(&frame);

            // read frame
            if (ffmpeg.av_audio_fifo_read(_audioFifo.AudioFifo, (void**)&frame->data, frameSize) < frameSize)
            {
                ffmpeg.av_frame_free(&frame);
                return;
            }

            frame->pts = _audioFrameCount;
            _audioFrameCount += frame->nb_samples;

            // send to encoder 

            ffmpeg.av_frame_free(&frame);
        }


  


• Ffmpeg H.264 encode video is sped up if camera capture with low light

  10 août 2020, par Expressingx

  I'm encoding everything to H.264. If h264_qsv is available I'm using it, else libx264. Works fine, but I noticed that if the camera is recording in low light, the video saved is sped up like x2 or x3. And I'm not sure where the problem is. Creating the input format context :

  


      private AVFormatContext* CreateFormatContext()
    {
        AVDictionary* options = null;

        ffmpeg.av_dict_set(&options, "packet-buffering", "0", 0);
        ffmpeg.av_dict_set(&options, "sync", "1", 0);
        ffmpeg.av_dict_set(&options, "rtsp_transport", "tcp", 0);
        ffmpeg.av_dict_set(&options, "reconnect", "1", 0);
        ffmpeg.av_dict_set(&options, "analyzeduration", "2000000", 0);
        ffmpeg.av_dict_set(&options, "probesize", (16384 * 16).ToString(), 0);
        ffmpeg.av_dict_set(&options, "max_delay", "0", 0);
        ffmpeg.av_dict_set(&options, "reorder_queue_size", "0", 0);
        ffmpeg.av_dict_set(&options, "skip_frame", "8", 0);
        ffmpeg.av_dict_set(&options, "skip_loop_filter", "48", 0);
        ffmpeg.av_dict_set(&options, "rtbufsize", "1000M", 0);

        AVFormatContext* pInputFmtCtx = ffmpeg.avformat_alloc_context();

        AVInputFormat* inputFormat = null;

        if (!string.IsNullOrEmpty(_format))
        {
            inputFormat = ffmpeg.av_find_input_format(_format);

            if (inputFormat == null)
            {
                //throw
            }
        }

        int ret = ffmpeg.avformat_open_input(&pInputFmtCtx, _streamUrl, inputFormat, &options);

        if (ret != 0)
        {
            //throw
        }

        return pInputFmtCtx;
    }


  


  video decoder

  


      private void CreateVideoDecoder()
    {
        AVStream* videoStream = InputFormatContext->streams[VideoStreamIndex];
        AVCodecParameters* videoCodecParams = videoStream->codecpar;
        AVCodec* videoDecoder = ffmpeg.avcodec_find_decoder(videoCodecParams->codec_id);

        VideoDecodeContext = ffmpeg.avcodec_alloc_context3(videoDecoder);

        if (ffmpeg.avcodec_parameters_to_context(VideoDecodeContext, videoCodecParams) < 0)
        {
            //throw
        }

        if (ffmpeg.avcodec_open2(VideoDecodeContext, videoDecoder, null) < 0)
        {
            //throw
        }
    }


  


  and the h264 encoder

  


  private void CreateH264Encoder(AVStream* inputStream, AVStream* outputStream)
    {
        AVRational framerate = ffmpeg.av_guess_frame_rate(_inputContext.InputFormatContext, inputStream, null);

        AVCodec* videoEncoder = ffmpeg.avcodec_find_encoder_by_name("h264_qsv");
        if (videoEncoder == null)
        {
            videoEncoder = ffmpeg.avcodec_find_encoder_by_name("libx264");
            PixelFormat = AVPixelFormat.AV_PIX_FMT_YUV420P;
        }

        if (videoEncoder == null)
        {
            //throw
        }

        VideoEncodeContext = ffmpeg.avcodec_alloc_context3(videoEncoder);

        if (VideoEncodeContext == null)
        {
            //throw
        }

        VideoEncodeContext->width = _inputContext.VideoDecodeContext->width;
        VideoEncodeContext->height = _inputContext.VideoDecodeContext->height;
        VideoEncodeContext->pix_fmt = PixelFormat;
        VideoEncodeContext->bit_rate = 2 * 1000 * 1000;
        VideoEncodeContext->rc_buffer_size = 4 * 1000 * 1000;
        VideoEncodeContext->rc_max_rate = 2 * 1000 * 1000;
        VideoEncodeContext->rc_min_rate = 3 * 1000 * 1000;
        VideoEncodeContext->framerate = framerate;
        VideoEncodeContext->max_b_frames = 0;
        VideoEncodeContext->time_base = ffmpeg.av_inv_q(framerate);
        VideoEncodeContext->flags |= ffmpeg.AV_CODEC_FLAG_GLOBAL_HEADER;

        ffmpeg.av_opt_set(VideoEncodeContext->priv_data, "preset", "slow", 0);
        ffmpeg.av_opt_set(VideoEncodeContext->priv_data, "vprofile", "baseline", 0);

        if (ffmpeg.avcodec_open2(VideoEncodeContext, videoEncoder, null) < 0)
        {
            //throw
        }

        ffmpeg.avcodec_parameters_from_context(outputStream->codecpar, VideoEncodeContext);
    }


  


  I'm using ffmpeg 4.0.1, so I'm decoding/encoding with the new format API which I'll skip to share for now because its nothing more than following the link : https://ffmpeg.org/doxygen/3.3/group__lavc__encdec.html

  


• ffmpeg streaming of audio and video using rtmp

  30 juillet 2020, par weicheng.yu

  开发包

  


  I want to stream some videos (a dynamic playlist managed by a python script) to a RTMP server, and i'm currently doing something quite simple : streaming my videos one by one with FFMPEG to the RTMP server, however this causes a connection break every time a video end, and the stream is ready to go when the next video begins.

  


  I would like to stream those videos without any connection breaks continuously, then the stream could be correctly viewed.

  


  I use this command to stream my videos one by one to the server

  


   while (CanRun)
        {
            try
            {
                do
                {
                    // 读取一帧未解码数据
                    error = ffmpeg.av_read_frame(pFormatContext, pPacket);
                    // Console.WriteLine(pPacket->dts);
                    if (error == ffmpeg.AVERROR_EOF) break;
                    if (error < 0) throw new ApplicationException(GetErrorMessage(error));

                    if (pPacket->stream_index == pStream->index) { }
                    else if (pPacket->stream_index == aStream->index)
                    {
                        AVPacket* aVPacket = ffmpeg.av_packet_clone(pPacket);
                        if (Aqueue.Count > 49) Aqueue.Dequeue();
                        Aqueue.Enqueue(*aVPacket);

                        ++AframeNumber;
                        continue;
                    }
                    else
                    {
                        ffmpeg.av_packet_unref(pPacket);//释放数据包对象引用
                        continue;
                    }

                    // 解码
                    error = ffmpeg.avcodec_send_packet(pCodecContext, pPacket);
                    if (error < 0) throw new ApplicationException(GetErrorMessage(error));
                    // 解码输出解码数据
                    error = ffmpeg.avcodec_receive_frame(pCodecContext, pDecodedFrame);
                } while (error == ffmpeg.AVERROR(ffmpeg.EAGAIN) && CanRun);
                if (error == ffmpeg.AVERROR_EOF) break;
                if (error < 0) throw new ApplicationException(GetErrorMessage(error));
                if (pPacket->stream_index != pStream->index) continue;

                AVFrame* aVFrame = ffmpeg.av_frame_clone(pDecodedFrame);
                if (Vqueue.Count > 49) Vqueue.Dequeue();
                Vqueue.Enqueue(*aVFrame);
            }
            finally
            {
                ffmpeg.av_packet_unref(pPacket);//释放数据包对象引用
                ffmpeg.av_frame_unref(pDecodedFrame);//释放解码帧对象引用
            }

            VframeNumber++;
            FFmpeg_Manager.ShowMessage = string.Format(ProgramInfo, VframeNumber, AframeNumber, exhibitionNum, effectiveNum);
        }