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• How can I mux H.264 RTP output into a container using FFMPEG ?

  23 septembre 2013, par Grad

  I am working on the effects of network losses in video transmission. In order to simulate the network losses I use a simple program which drops random RTP packets from the output of H.264 RTP encoding.

  I use Joint Model (JM) 14.2 in order to encode the video. However, I don't use AnnexB format as my output, instead I choose the output as RTP packets. The JM output is generated as RTP packets with RTP headers and payload as a sequence. After that, some of RTP packets are dropped by using a simple program. Then, I decode the output by using also JM and it's error concealment methods. That gives me a YUV file as output. The format of the output is as follows :

       ----------------------------------------------------------------------
  
       | RTP Header #1 | RTP Payload #1 | RTP Header #2 | RTP Payload #2 |...
  
       ----------------------------------------------------------------------

  I want to make a subjective test with these bitstreams and it's very inconvenient to crowdsource this subjective test with GBs of video data. So, I want to mux these bitstreams into a container (i.e. AVI) by using FFMPEG. I have tried to decode these bitstreams with FFMPEG and FFPLAY ; however, both of them didn't work. I also tried the following command and it didn't work, either.

      ffmpeg - f h264 -i  -vcodec copy -r 25 out.avi

  Which format or muxer should I use ? Do I need to convert these files to any other format ?

• ffmpegthumbnailer error with carrierwave-video-thumbnailer

  30 janvier 2014, par scientiffic

  I am getting the error "No such file or directory" when I try to run ffmpegthumbnailer using the carrierwave-video-thumbnailer gem.

  I confirmed that ffmpegthumbnailer is working correctly on my computer since I can generate a thumbnail image from a video straight from the command line.

  From my logs, it looks like my app thinks that it has generated a thumbnail image. However, when I look in the directory, there is no file tmpfile.png, and my app fails with the error.

  Has anyone successfully used the carrierewave-video-thumbnailer gem to create thumbnails, and if so, what am I doing wrong ? Alternatively, if there is some way I can just run ffmpegthumbnailer within my model, I could do that too.

  Here are my logs :

  Running....ffmpegthumbnailer -i /Users/.../Website/public/uploads/tmp/1380315873-21590-2814/thumb_Untitled.mov -o /Users/.../Website/public/uploads/tmp/1380315873-21590-2814/tmpfile.png -c png -q 10 -s 192 -f
  
  Success!
  
  Errno::ENOENT: No such file or directory - (/Users/.../Website/public/uploads/tmp/1380315873-21590-2814/tmpfile.png, /Users/.../Website/public/uploads/tmp/1380315873-21590-2814/thumb_Untitled.mov)

  video_path_uploader.rb

  class VideoPathUploader < CarrierWave::Uploader::Base
  
    include CarrierWave::Video
  
    include CarrierWave::Video::Thumbnailer
  
  
  
    process encode_video: [:mp4]
  
  
  
    # Include RMagick or MiniMagick support:
  
    # include CarrierWave::RMagick
  
    include CarrierWave::MiniMagick
  
  
  
    # Choose what kind of storage to use for this uploader:
  
    # storage :file
  
    storage :fog
  
  
  
    # Override the directory where uploaded files will be stored.
  
    # This is a sensible default for uploaders that are meant to be mounted:
  
    def store_dir
  
      "#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  
    end
  
  
  
     version :thumb do
  
        process thumbnail: [{format: 'png', quality: 10, size: 192, strip: true, logger: Rails.logger}]
  
        def full_filename for_file
  
          png_name for_file, version_name
  
        end
  
    end
  
  
  
      def png_name for_file, version_name
  
        %Q{#{version_name}_#{for_file.chomp(File.extname(for_file))}.png}
  
      end
  
  
  
  end

  Video.rb

  class Video < ActiveRecord::Base
  
    # maybe we should add a title attribute to the video?
  
    attr_accessible :position, :project_id, :step_id, :image_id, :saved, :embed_url, :thumbnail_url, :video_path
  
    mount_uploader :video_path, VideoPathUploader
  
  ...
  
  end

• FFmpeg avcodec_decode_video2 decode RTSP H264 HD-video packet to video picture with error

  29 mai 2018, par Nguyen Ba Thi

  I used FFmpeg library version 4.0 to have simple C++ program, in witch is a thread to receive RTSP H264 video data from IP-camera and display it in program window.

  Code of this thread is follow :

  DWORD WINAPI GrabbProcess(LPVOID lpParam)
  
  // Grabbing thread
  
  {
  
    DWORD i;
  
    int ret = 0, nPacket=0;
  
    FILE *pktFile;
  
    // Open video file
  
    pFormatCtx = avformat_alloc_context();
  
    if(avformat_open_input(&pFormatCtx, nameVideoStream, NULL, NULL)!=0)
  
        fGrabb=-1; // Couldn't open file
  
    else
  
    // Retrieve stream information
  
    if(avformat_find_stream_info(pFormatCtx, NULL)<0)
  
        fGrabb=-2; // Couldn't find stream information
  
    else
  
    {
  
        // Find the first video stream
  
        videoStream=-1;
  
        for(i=0; inb_streams; i++)
  
          if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO)
  
          {
  
            videoStream=i;
  
            break;
  
          }
  
        if(videoStream==-1)
  
            fGrabb=-3; // Didn't find a video stream
  
        else
  
        {
  
            // Get a pointer to the codec context for the video stream
  
            pCodecCtxOrig=pFormatCtx->streams[videoStream]->codec;
  
            // Find the decoder for the video stream
  
            pCodec=avcodec_find_decoder(pCodecCtxOrig->codec_id);
  
            if(pCodec==NULL)
  
                fGrabb=-4; // Codec not found
  
            else
  
            {
  
                // Copy context
  
                pCodecCtx = avcodec_alloc_context3(pCodec);
  
                if(avcodec_copy_context(pCodecCtx, pCodecCtxOrig) != 0)
  
                    fGrabb=-5; // Error copying codec context
  
                else
  
                {
  
                    // Open codec
  
                    if(avcodec_open2(pCodecCtx, pCodec, NULL)<0)
  
                        fGrabb=-6; // Could not open codec
  
                    else
  
                    // Allocate video frame for input
  
                    pFrame=av_frame_alloc();
  
                    // Determine required buffer size and allocate buffer
  
                    numBytes=avpicture_get_size(pCodecCtx->pix_fmt, pCodecCtx->width,
  
                        pCodecCtx->height);
  
                    buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
                    // Assign appropriate parts of buffer to image planes in pFrame
  
                    // Note that pFrame is an AVFrame, but AVFrame is a superset
  
                    // of AVPicture
  
                    avpicture_fill((AVPicture *)pFrame, buffer, pCodecCtx->pix_fmt,
  
                        pCodecCtx->width, pCodecCtx->height);
  
  
  
                    // Allocate video frame for display
  
                    pFrameRGB=av_frame_alloc();
  
                    // Determine required buffer size and allocate buffer
  
                    numBytes=avpicture_get_size(AV_PIX_FMT_RGB24, pCodecCtx->width,
  
                        pCodecCtx->height);
  
                    bufferRGB=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
                    // Assign appropriate parts of buffer to image planes in pFrameRGB
  
                    // Note that pFrameRGB is an AVFrame, but AVFrame is a superset
  
                    // of AVPicture
  
                    avpicture_fill((AVPicture *)pFrameRGB, bufferRGB, AV_PIX_FMT_RGB24,
  
                        pCodecCtx->width, pCodecCtx->height);
  
                    // initialize SWS context for software scaling to FMT_RGB24
  
                    sws_ctx_to_RGB = sws_getContext(pCodecCtx->width,
  
                        pCodecCtx->height,
  
                        pCodecCtx->pix_fmt,
  
                        pCodecCtx->width,
  
                        pCodecCtx->height,
  
                        AV_PIX_FMT_RGB24,
  
                        SWS_BILINEAR,
  
                        NULL,
  
                        NULL,
  
                        NULL);
  
  
  
                    // Allocate video frame (grayscale YUV420P) for processing
  
                    pFrameYUV=av_frame_alloc();
  
                    // Determine required buffer size and allocate buffer
  
                    numBytes=avpicture_get_size(AV_PIX_FMT_YUV420P, pCodecCtx->width,
  
                        pCodecCtx->height);
  
                    bufferYUV=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
                    // Assign appropriate parts of buffer to image planes in pFrameYUV
  
                    // Note that pFrameYUV is an AVFrame, but AVFrame is a superset
  
                    // of AVPicture
  
                    avpicture_fill((AVPicture *)pFrameYUV, bufferYUV, AV_PIX_FMT_YUV420P,
  
                        pCodecCtx->width, pCodecCtx->height);
  
                    // initialize SWS context for software scaling to FMT_YUV420P
  
                    sws_ctx_to_YUV = sws_getContext(pCodecCtx->width,
  
                        pCodecCtx->height,
  
                        pCodecCtx->pix_fmt,
  
                        pCodecCtx->width,
  
                        pCodecCtx->height,
  
                        AV_PIX_FMT_YUV420P,
  
                        SWS_BILINEAR,
  
                        NULL,
  
                        NULL,
  
                        NULL);
  
                  RealBsqHdr.biWidth = pCodecCtx->width;
  
                  RealBsqHdr.biHeight = -pCodecCtx->height;
  
                }
  
            }
  
        }
  
    }
  
    while ((fGrabb==1)||(fGrabb==100))
  
    {
  
        // Grabb a frame
  
        if (av_read_frame(pFormatCtx, &packet) >= 0)
  
        {
  
          // Is this a packet from the video stream?
  
          if(packet.stream_index==videoStream)
  
          {
  
              // Decode video frame
  
              int len = avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
  
              nPacket++;
  
              // Did we get a video frame?
  
              if(frameFinished)
  
              {
  
                  // Convert the image from its native format to YUV
  
                  sws_scale(sws_ctx_to_YUV, (uint8_t const * const *)pFrame->data,
  
                      pFrame->linesize, 0, pCodecCtx->height,
  
                      pFrameYUV->data, pFrameYUV->linesize);
  
                  // Convert the image from its native format to RGB
  
                  sws_scale(sws_ctx_to_RGB, (uint8_t const * const *)pFrame->data,
  
                      pFrame->linesize, 0, pCodecCtx->height,
  
                      pFrameRGB->data, pFrameRGB->linesize);
  
                  HDC hdc=GetDC(hWndM);
  
                  SetDIBitsToDevice(hdc, 0, 0, pCodecCtx->width, pCodecCtx->height,
  
                      0, 0, 0, pCodecCtx->height,pFrameRGB->data[0], (LPBITMAPINFO)&RealBsqHdr, DIB_RGB_COLORS);
  
                  ReleaseDC(hWndM,hdc);
  
                  av_frame_unref(pFrame);
  
              }
  
          }
  
          // Free the packet that was allocated by av_read_frame
  
          av_free_packet(&packet);
  
        }
  
     }
  
     // Free the org frame
  
    av_frame_free(&pFrame);
  
    // Free the RGB frame
  
    av_frame_free(&pFrameRGB);
  
    // Free the YUV frame
  
    av_frame_free(&pFrameYUV);
  
  
  
    // Close the codec
  
    avcodec_close(pCodecCtx);
  
    avcodec_close(pCodecCtxOrig);
  
  
  
    // Close the video file
  
    avformat_close_input(&pFormatCtx);
  
    avformat_free_context(pFormatCtx);
  
  
  
    if (fGrabb==1)
  
        sprintf(tmpstr,"Grabbing Completed %d frames", nCntTotal);
  
    else if (fGrabb==2)
  
        sprintf(tmpstr,"User break on %d frames", nCntTotal);
  
    else if (fGrabb==3)
  
        sprintf(tmpstr,"Can't Grabb at frame %d", nCntTotal);
  
    else if (fGrabb==-1)
  
        sprintf(tmpstr,"Couldn't open file");
  
    else if (fGrabb==-2)
  
        sprintf(tmpstr,"Couldn't find stream information");
  
    else if (fGrabb==-3)
  
        sprintf(tmpstr,"Didn't find a video stream");
  
    else if (fGrabb==-4)
  
        sprintf(tmpstr,"Codec not found");
  
    else if (fGrabb==-5)
  
        sprintf(tmpstr,"Error copying codec context");
  
    else if (fGrabb==-6)
  
        sprintf(tmpstr,"Could not open codec");
  
    i=(UINT) fGrabb;
  
    fGrabb=0;
  
    SetWindowText(hWndM,tmpstr);
  
    ExitThread(i);
  
    return 0;
  
  }
  
  // End Grabbing thread  

  When program receive RTSP H264 video data with resolution 704x576 then decoded video pictures are OK. When receive RTSP H264 HD-video data with resolution 1280x720 it look like that first video picture is decoded OK and then video pictures are decoded but always with some error.

  Please help me to fix this problem !

  Here is problems brief :
  I have an IP camera model HI3518E_50H10L_S39 (product of China).
  Camera can provide H264 video stream both at resolution 704x576 (with RTSP URI "rtsp ://192.168.1.18:554/user=admin_password=tlJwpbo6_channel=1_stream=1.sdp ?real_stream") or 1280x720 (with RTSP URI "rtsp ://192.168.1.18:554/user=admin_password=tlJwpbo6_channel=1_stream=0.sdp ?real_stream").
  Using FFplay utility I can access and display them with good picture quality.
  For testing of grabbing from this camera, I have a simple (above mentioned) program in VC-2005. In "Grabbing thread" program use FFmpeg library version 4.0 for opening camera RTSP stream, retrieve stream information, find the first video stream... and prepare some variables.
  Center of this thread is loop : Grab a frame (function av_read_frame) - Decode it if it’s video (function avcodec_decode_video2) - Convert to RGB format (function sws_scale) - Display to program window (GDI function SetDIBitsToDevice).
  When proram run with camera RTSP stream at resolution 704x576, I have good video picture. Here is a sample :
  704x576 sample
  When program run with camera RTSP stream at resolution 1280x720, first video picture is good :
  First good at res.1280x720
  but then not good :
  not good at res.1280x720
  Its seem to be my FFmpeg function call to avcodec_decode_video2 can’t fully decode certain packet for some reasons.