Recherche avancée

Sur d’autres sites (10464)

• libopusenc : Add channel mapping family argument

  15 juin 2016, par Michael Graczyk

  libopusenc : Add channel mapping family argument
  The default value of -1 indicates that ffmpeg should determine the channel
  
  mapping automatically, which was the behavior before this commit.
  Unless the -mapping_family argument is provided, behavior is unchanged.
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] doc/encoders.texi
  • [DH] libavcodec/libopusenc.c

• FFMPEG, leaking memory

  8 juin 2016, par Nyaruko

  I use the following code to open a MP4 file. Each time the MP4 file is opened successfully by calling QVideoDecoder::openFile(QString filename).
  The initCode is called at the beginning of the program.

  However, each time I run the openFile(QString filename) function on the same file. There are some memory leak. What is wrong with my code ?

  void QVideoDecoder::InitVars()
  
  {
  
      //Input
  
      //-------------------
  
      ok = false;
  
      pFormatCtx = 0;
  
      pCodecCtx = 0;
  
      pCodec = 0;
  
      pFrame = 0;
  
      pFrameRGB = 0;
  
      buffer = 0;
  
      img_convert_ctx = 0;
  
      th = 0;
  
  }
  
  
  
  void QVideoDecoder::close()
  
  {
  
     // Free the RGB image
  
     if(buffer)
  
        delete [] buffer;
  
  
  
     // Free the YUV frame
  
     if(pFrame)
  
        av_free(pFrame);
  
  
  
     // Free the RGB frame
  
     if(pFrameRGB)
  
        av_free(pFrameRGB);
  
  
  
     // Close the codec
  
     if(pCodecCtx)
  
        avcodec_close(pCodecCtx);
  
  
  
     // Close the video file
  
     if(pFormatCtx)
  
         avformat_close_input(&pFormatCtx);
  
  
  
     // Close the timeout handler
  
     if (th)
  
         delete th;
  
  
  
     InitVars();
  
  }
  
  
  
  bool QVideoDecoder::initCodec()
  
  {
  
  
  
     ffmpeg::avcodec_register_all();
  
     ffmpeg::av_register_all();
  
     ffmpeg::avdevice_register_all();
  
     ffmpeg::avformat_network_init();
  
  
  
     printf("License: %s\n",ffmpeg::avformat_license());
  
     printf("AVCodec version %d\n",ffmpeg::avformat_version());
  
     printf("AVFormat configuration: %s\n",ffmpeg::avformat_configuration());
  
  
  
     return true;
  
  }
  
  
  
  bool QVideoDecoder::openFile(QString filename)
  
  {
  
      // Close the last video
  
      //----------------------------------------------
  
      close();
  
  
  
      // Initialize the params
  
      // ---------------------------------------------
  
      ffmpeg::AVInputFormat *iformat = NULL;
  
      ffmpeg::AVDictionary *opts = NULL;           
  
      ffmpeg::av_dict_set(&opts, "rtsp_transport", "tcp", NULL);
  
      ffmpeg::av_dict_set(&opts, "rtbufsize", "102400", NULL);
  
      ffmpeg::av_dict_set(&opts, "allowed_media_types", "video", NULL);
  
  
  
  
  
      //set the timeout handler for pFormatCtx
  
      //----------------------------------------------
  
      pFormatCtx = ffmpeg::avformat_alloc_context();
  
      th = new timeout_handler(3000000);
  
      pFormatCtx->interrupt_callback.opaque = (void*)th;
  
      pFormatCtx->interrupt_callback.callback = &timeout_handler::check_interrupt;
  
  
  
      // Open video file
  
      //---------------------------------------------
  
      th->reset(3000000);
  
      avformat_open_input(&pFormatCtx, filename.toStdString().c_str(), iformat, &opts) != 0)
  
      av_dict_free(&opts);
  
  
  
      // Retrieve stream information
  
      //---------------------------------------------
  
      th->reset(3000000);
  
      avformat_find_stream_info(pFormatCtx, NULL);
  
  
  
      // Dump information about file onto standard error
  
      //---------------------------------------------
  
      av_dump_format(pFormatCtx, 0, filename.toStdString().c_str(), false);
  
  
  
      // Find the first video stream
  
      //---------------------------------------------
  
      for (unsigned i = 0; i < pFormatCtx->nb_streams; i++)
  
      {
  
          if (pFormatCtx->streams[i]->codec->codec_type == ffmpeg::AVMEDIA_TYPE_VIDEO)
  
          {
  
              videoStream = i;
  
              break;
  
          }
  
      }
  
  
  
      // Get a pointer to the codec context for the video stream
  
      //--------------------------------------------
  
      pCodecCtx = pFormatCtx->streams[videoStream]->codec;
  
  
  
      // Find the decoder for the video stream
  
      //--------------------------------------------
  
      pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
  
  
  
      // Set thread type to 0 seems decrease the amount of delay
  
      //--------------------------------------------
  
      pCodecCtx->thread_type = 0;
  
  // Open codec
  
  //--------------------------------------------
  
  avcodec_open2(pCodecCtx, pCodec, NULL);
  
  
  
  // Allocate video frame
  
  //--------------------------------------------
  
  pFrame = ffmpeg::avcodec_alloc_frame();
  
  
  
  // Allocate an AVFrame structure
  
  //--------------------------------------------
  
  pFrameRGB = ffmpeg::avcodec_alloc_frame();
  
  
  
  // Determine required buffer size and allocate buffer
  
  //--------------------------------------------
  
  numBytes = ffmpeg::avpicture_get_size(ffmpeg::PIX_FMT_RGB24, pCodecCtx->width, pCodecCtx->height);
  
  buffer = new uint8_t[numBytes];
  
  
  
  // Assign appropriate parts of buffer to image planes in pFrameRGB
  
  //--------------------------------------------
  
  avpicture_fill((ffmpeg::AVPicture *)pFrameRGB, buffer, ffmpeg::PIX_FMT_RGB24,
  
      pCodecCtx->width, pCodecCtx->height);
  
  
  
  return true;
  
  }

• Losing quality when encoding with ffmpeg

  22 mai 2016, par lupod

  I am using the c libraries of ffmpeg to read frames from a video and create an output file that is supposed to be identical to the input.
  However, somewhere during this process some quality gets lost and the result is "less sharp". My guess is that the problem is the encoding and that the frames are too compressed (also because the size of the file decreases quite significantly). Is there some parameter in the encoder that allows me to control the quality of the result ? I found that AVCodecContext has a compression_level member, but changing it that does not seem to have any effect.

  I post here part of my code in case it could help. I would say that something must be changed in the init function of OutputVideoBuilder when I set the codec. The AVCodecContext that is passed to the method is the same of InputVideoHandler.
  Here are the two main classes that I created to wrap the ffmpeg functionalities :

  // This class opens the video files and sets the decoder
  
  class InputVideoHandler {
  
  public:
  
    InputVideoHandler(char* name);
  
    ~InputVideoHandler();
  
    AVCodecContext* getCodecContext();
  
    bool readFrame(AVFrame* frame, int* success);
  
  
  
  private:
  
    InputVideoHandler();
  
    void init(char* name);
  
    AVFormatContext* formatCtx;
  
    AVCodec* codec;
  
    AVCodecContext* codecCtx;
  
    AVPacket packet;
  
    int streamIndex;
  
  };
  
  
  
  void InputVideoHandler::init(char* name) {
  
    streamIndex = -1;
  
    int numStreams;
  
  
  
    if (avformat_open_input(&formatCtx, name, NULL, NULL) != 0)
  
      throw std::exception("Invalid input file name.");
  
  
  
    if (avformat_find_stream_info(formatCtx, NULL)<0)
  
      throw std::exception("Could not find stream information.");
  
  
  
    numStreams = formatCtx->nb_streams;
  
  
  
    if (numStreams < 0)
  
      throw std::exception("No streams in input video file.");
  
  
  
    for (int i = 0; i < numStreams; i++) {
  
      if (formatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
  
        streamIndex = i;
  
        break;
  
      }
  
    }
  
  
  
    if (streamIndex < 0)
  
      throw std::exception("No video stream in input video file.");
  
  
  
    // find decoder using id
  
    codec = avcodec_find_decoder(formatCtx->streams[streamIndex]->codec->codec_id);
  
    if (codec == nullptr)
  
      throw std::exception("Could not find suitable decoder for input file.");
  
  
  
    // copy context from input stream
  
    codecCtx = avcodec_alloc_context3(codec);
  
    if (avcodec_copy_context(codecCtx, formatCtx->streams[streamIndex]->codec) != 0)
  
      throw std::exception("Could not copy codec context from input stream.");
  
  
  
    if (avcodec_open2(codecCtx, codec, NULL) < 0)
  
      throw std::exception("Could not open decoder.");
  
  }
  
  
  
  // frame must be initialized with av_frame_alloc() before!
  
  // Returns true if there are other frames, false if not.
  
  // success == 1 if frame is valid, 0 if not.
  
  bool InputVideoHandler::readFrame(AVFrame* frame, int* success) {
  
    *success = 0;
  
    if (av_read_frame(formatCtx, &packet) < 0)
  
      return false;
  
    if (packet.stream_index == streamIndex) {
  
      avcodec_decode_video2(codecCtx, frame, success, &packet);
  
    }
  
    av_free_packet(&packet);
  
    return true;
  
  }
  
  
  
  // This class opens the output and write frames to it
  
  class OutputVideoBuilder{
  
  public:
  
    OutputVideoBuilder(char* name, AVCodecContext* inputCtx);
  
    ~OutputVideoBuilder();
  
    void writeFrame(AVFrame* frame);
  
    void writeVideo();
  
  
  
  private:
  
    OutputVideoBuilder();
  
    void init(char* name, AVCodecContext* inputCtx);
  
    void logMsg(AVPacket* packet, AVRational* tb);
  
    AVFormatContext* formatCtx;
  
    AVCodec* codec;
  
    AVCodecContext* codecCtx;
  
    AVStream* stream;
  
  };
  
  
  
  void OutputVideoBuilder::init(char* name, AVCodecContext* inputCtx) {
  
    if (avformat_alloc_output_context2(&formatCtx, NULL, NULL, name) < 0)
  
      throw std::exception("Could not determine file extension from provided name.");
  
  
  
    codec = avcodec_find_encoder(inputCtx->codec_id);
  
    if (codec == nullptr) {
  
      throw std::exception("Could not find suitable encoder.");
  
    }
  
  
  
    codecCtx = avcodec_alloc_context3(codec);
  
    if (avcodec_copy_context(codecCtx, inputCtx) < 0)
  
      throw std::exception("Could not copy output codec context from input");
  
  
  
    codecCtx->time_base = inputCtx->time_base;
  
    codecCtx->compression_level = 0;
  
  
  
    if (avcodec_open2(codecCtx, codec, NULL) < 0)
  
      throw std::exception("Could not open encoder.");
  
  
  
    stream = avformat_new_stream(formatCtx, codec);
  
    if (stream == nullptr) {
  
      throw std::exception("Could not allocate stream.");
  
    }
  
  
  
    stream->id = formatCtx->nb_streams - 1;
  
    stream->codec = codecCtx;
  
    stream->time_base = codecCtx->time_base;
  
  
  
  
  
  
  
    av_dump_format(formatCtx, 0, name, 1);
  
    if (!(formatCtx->oformat->flags & AVFMT_NOFILE)) {
  
      if (avio_open(&formatCtx->pb, name, AVIO_FLAG_WRITE) < 0) {
  
        throw std::exception("Could not open output file.");
  
      }
  
    }
  
  
  
    if (avformat_write_header(formatCtx, NULL) < 0) {
  
      throw std::exception("Error occurred when opening output file.");
  
    }
  
  
  
  }
  
  
  
  void OutputVideoBuilder::writeFrame(AVFrame* frame) {
  
    AVPacket packet = { 0 };
  
    int success;
  
    av_init_packet(&packet);
  
  
  
    if (avcodec_encode_video2(codecCtx, &packet, frame, &success))
  
      throw std::exception("Error encoding frames");
  
  
  
    if (success) {
  
      av_packet_rescale_ts(&packet, codecCtx->time_base, stream->time_base);
  
      packet.stream_index = stream->index;
  
      logMsg(&packet,&stream->time_base);
  
      av_interleaved_write_frame(formatCtx, &packet);
  
    }
  
    av_free_packet(&packet);
  
  }

  This is the part of the main function that reads and write frames :

   while (inputHandler->readFrame(frame,&gotFrame)) {
  
  
  
      if (gotFrame) {
  
        try {
  
          outputBuilder->writeFrame(frame);
  
        }
  
        catch (std::exception e) {
  
          std::cout << e.what() << std::endl;
  
          return -1;
  
        }
  
      }
  
    }