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• avcodec/mjpegdec : dont try to combine fields for decimated multiscope 2 material

  21 juin 2015, par Michael Niedermayer

  avcodec/mjpegdec : dont try to combine fields for decimated multiscope 2 material
  Fixes Ticket4535
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavcodec/mjpegdec.c
  • [DH] libavcodec/mjpegdec.h

• conversion from cv::mat to avframe, encode in h264 dont writing correctly [on hold]

  15 novembre 2014, par danics

  i create a method for converting between cv::mat to avframe with PIX_FMT_YUV420P format (oframe format) but _convCtx always return null, whats wrong ? thanks in advance ! ((i solve this)) but i have another probelm in end of this question please

  void processToFrame(cv::Mat* _mat, AVFrame* oframe)
  
    {
  
        // Create and allocate the conversion frame.
  
        if (_oframe == nullptr) {
  
            _oframe = avcodec_alloc_frame();  
  
            if (_oframe == nullptr)
  
                throw std::runtime_error("Matrix Converter: Could not allocate the output frame.");
  
  
  
            avpicture_alloc(reinterpret_cast(_oframe), 
  
                PIX_FMT_BGR24, _mat->cols, _mat->rows);             
  
        }
  
  
  
        avpicture_fill(reinterpret_cast(_oframe),
  
            (uint8_t *)_mat->data,
  
            AV_PIX_FMT_BGR24,
  
            _mat->cols,
  
            _mat->rows);
  
  
  
        // Convert the image from its native format to BGR.
  
        if (_convCtx == nullptr) {
  
            _convCtx = sws_getContext(
  
                oframe->width, oframe->height, (enum AVPixelFormat) oframe->format, 
  
                _oframe->width, _oframe->height, PIX_FMT_BGR24, 
  
                SWS_BICUBIC, nullptr, nullptr, nullptr);
  
        }
  
        if (_convCtx == nullptr)
  
            throw std::runtime_error("Matrix Converter: Unable to initialize the conversion context.");   
  
  
  
        // Scales the source data according to our SwsContext settings.
  
        if (sws_scale(_convCtx,
  
            _oframe->data, _oframe->linesize, 0, _oframe->height,
  
            oframe->data, oframe->linesize) < 0)
  
            throw std::runtime_error("Matrix Converter: Pixel format conversion not supported.");
  
    }

  create oframe

  void createVideoFile(const char* filename, int w, int h, int codec_id, int fps)
  
    {
  
        /* find the mpeg1 video encoder */
  
        if(codec == nullptr) 
  
        {
  
            /* find the mpeg1 video encoder */
  
            codec = avcodec_find_encoder((AVCodecID)codec_id);
  
            if (!codec) {
  
                throw std::runtime_error("codec not found\n");
  
            }
  
        }
  
  
  
        if(c == nullptr)
  
        {
  
            c = avcodec_alloc_context3(codec);
  
            if(!c)
  
            {
  
                throw std::runtime_error("Could not allocate video codec context\n");
  
            }
  
            /* put sample parameters */
  
            c->bit_rate = 400000;
  
            /* resolution must be a multiple of two */
  
            c->width = 2 * (w / 2);
  
            c->height = 2 * (h / 2);
  
            /* frames per second */
  
            AVRational ar;
  
            ar.den = 1;
  
            ar.num = fps;
  
  
  
            c->time_base= ar; //(AVRational){1,25};
  
            c->gop_size = 10; /* emit one intra frame every ten frames */
  
            c->max_b_frames=1;
  
            c->pix_fmt = PIX_FMT_YUV420P;
  
  
  
            if(codec_id == AV_CODEC_ID_H264)
  
                av_opt_set(c->priv_data, "preset", "slow", 0);
  
  
  
            /* open it */
  
            if (avcodec_open2(c, codec, NULL) < 0) {
  
                throw std::runtime_error("Could not open codec\n");
  
            }
  
  
  
            f = fopen(filename, "wb");
  
            if (!f) {
  
                throw std::runtime_error("could not open file\n");
  
            }
  
  
  
            frame = avcodec_alloc_frame();
  
            if (!frame) {
  
                throw std::runtime_error("Could not allocate video frame\n");
  
            }
  
            frame->format = c->pix_fmt;
  
            frame->width  = c->width;
  
            frame->height = c->height;
  
  
  
            /* the image can be allocated by any means and av_image_alloc() is
  
             * just the most convenient way if av_malloc() is to be used */
  
  
  
            int ret = av_image_alloc(frame->data, frame->linesize, c->width, c->height, c->pix_fmt, 32);
  
  
  
            if (ret < 0) {
  
                throw std::runtime_error("Could not allocate raw picture buffer\n");
  
            }
  
        }
  
  }

  read mat images

  void video_encode_example(const cv::Mat& fin)
  
  {
  
      AVPacket pkt;
  
      /* encode 1 second of video */
  
      av_init_packet(&pkt);
  
      pkt.data = NULL;    // packet data will be allocated by the encoder
  
      pkt.size = 0;
  
  
  
      fflush(stdout);
  
  
  
      cv::Mat res;
  
      cv::resize(fin, res, cv::Size(c->width, c->height));
  
  
  
      processToFrame(&res, frame);
  
      frame->pts = i;
  
  
  
      /* encode the image */
  
      int ret = avcodec_encode_video2(c, &pkt, frame, &got_output);
  
      if (ret < 0) {
  
      throw std::runtime_error("Error encoding frame\n");
  
      }
  
  
  
      if (got_output) {
  
          printf("Write frame %3d (size=%5d)\n", i, pkt.size);
  
          fwrite(pkt.data, 1, pkt.size, f);
  
          av_free_packet(&pkt);
  
      }
  
      i++;
  
  }

  update :

  i can solve the conversion problem by setting of _oframe.width = _mat.cols and _oframe.height = _mat.rows, avpicture_alloc dont set this value itself.

  now i have the other problem my videowriting class seems write ok because windows slideshow show one of frames, but i cant view video in my players, this is my release function, i dont know whats wrong endcoding or endcoder structure parameter like pts and else.

  void video_release()
  
      {
  
          /* get the delayed frames */
  
          for (got_output = 1; got_output; i++) {
  
              fflush(stdout);
  
  
  
              int ret = avcodec_encode_video2(c, &pkt, NULL, &got_output);
  
              if (ret < 0) {
  
                  throw std::runtime_error("Error encoding frame\n");
  
              }
  
  
  
              if (got_output) {
  
                  printf("Write frame %3d (size=%5d)\n", i, pkt.size);
  
                  fwrite(pkt.data, 1, pkt.size, f);
  
                  av_free_packet(&pkt);
  
              }
  
          }
  
  
  
          uint8_t endcode[] = { 0, 0, 1, 0xb7 };
  
  
  
          /* add sequence end code to have a real mpeg file */
  
          fwrite(endcode, 1, sizeof(endcode), f);
  
          fclose(f);
  
  
  
          avcodec_close(c);
  
          av_free(c);
  
          av_freep(&frame->data[0]);
  
          avcodec_free_frame(&frame);
  
  
  
          c = nullptr;
  
          codec = nullptr;
  
          frame = nullptr;
  
  
  
          if (_convCtx)
  
              sws_freeContext(_convCtx);
  
  
  
          if (_oframe) {
  
              //if (_oframe->data)
  
                  //av_free(_oframe->data[0]);
  
              av_free(_oframe);
  
          }
  
  
  
          _oframe = nullptr;
  
          _convCtx = nullptr;
  
      }

• find text cointain in folder name and skip it's

  27 février 2014, par pasaico

  for subdir in */ ; do
  
  cd $subdir
  
  ffmpeg -i mycode

  how do I exclude the ffmpeg command if the folder name contains foo ?

  i use command find, is correctly ?

  find . -name *foo* -print

  but I can not implement it in bash for loop.

  I tried this code :

  for subdir in */ ; do
  
  foo=$(find -type d -name '*foo*')
  
  if [[ $subdir =~ $foo ] ; then
  
      echo yes
  
      ffmpeg -i mycode
  
  else
  
      echo no
  
  fi
  
  done