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• save sequence of frame as BMP not PNG

  27 décembre 2013, par user2922938

  I extract 100 frames from video file and i save each frame as (.bmp) but i found that each frame format is PNG not BMP , how can I save sequence of frame (format as BMP not PNG as show in picture)in C# ?

  string name;            
  
  for ( int i = 0; i < 100; i++ )
  
  {
  
      Bitmap videoFrame = video.ReadVideoFrame( );  
  
      name = (i).ToString().PadLeft(5, '0');
  
      videoFrame.Save(@"D:\frames\" + name  + ".bmp");
  
      videoFrame.Dispose( );
  
  }
  
  
  
  video.Close( );
  
  MessageBox.Show(" Complete Convert video to sequence of image","Convert");

  

• How do I correctly convert .avi to .flv with ffmpeg ? [closed]

  25 septembre 2012, par terbooter

  UPDATE
  Shame on me )
  I chacked red5 logs again and found that I placed converted files to wrong place.
  Now all works fine

  I have two red5 apps.

  1. Recorder. It can record live stream and save it to flv file to disk

     private void startRecord(String uid, String name, IConnection connection) {
     
         // Get a reference to the current broadcast stream.
     
         ClientBroadcastStream stream = (ClientBroadcastStream) this.getBroadcastStream(
     
                 connection.getScope(), name);
     
         try {
     
             // Save the stream to disk.
     
             String path = uid + "/" + name;
     
             stream.saveAs(path, true);
     
     
     
             System.out.println("file..:" + stream.getSaveFilename());
     
     
     
         } catch (Exception e) {
     
             System.out.println("Error while saving stream: " + name + e);
     
         }
     
     }
     
     
     
     private void stopRecord(String name) {
     
         IConnection conn = Red5.getConnectionLocal();
     
         System.out.println("Stop recording show for: {}" + conn.getScope().getContextPath());
     
     
     
         ClientBroadcastStream stream = (ClientBroadcastStream) this.getBroadcastStream(conn.getScope(), name);
     
         // Stop recording.
     
         if (stream != null) {
     
             stream.stopRecording();
     
         }
     
     }

  2. Second red5 app (Chat) streams recorded flv file to flash client

     public static String serverStreamCreate(String path, String streamName) {
     
     
     
         IServerStream serverStream = StreamUtils.createServerStream(Red5.getConnectionLocal().getScope(), streamName);
     
         SimplePlayItem item = SimplePlayItem.build(path);
     
     
     
         IPlaylistController controller = new MyPlayListController();
     
     
     
         serverStream.setPlaylistController(controller);
     
         serverStream.setRepeat(false);
     
         serverStream.addItem(item);
     
         serverStream.addItem(item);
     
         serverStream.start();
     
         return streamName;
     
     }

  If I record stream from flash client to flv file with Recorder and after that stream this flv file back to client with Chat, all works fine.

  Now I want to convert avi file to flv and stream it from red5 app to flash client.
  I used ffmpeg

  ffmpeg -i 24.avi -ar 22050 -an -f flv -b 500k -s 320x240 -y 24_c.flv

  But if I stream 24_c.flv from Chat app flash client have no video.
  24_c.flv cant be playd by VLC player and have same code information as flv file created by Recorder red5 app.

  I really dont know where to dig.

• ffmpeg get RGB values ?

  13 novembre 2012, par Nav

  I've seen this, this and this but I still can't figure out how to get the RGB values from the tutorial code.

  if(avcodec_open(pCodecCtx, pCodec)<0) {_getch();return -1;}
  
  pFrame = avcodec_alloc_frame();
  
  pFrameRGB=avcodec_alloc_frame();
  
  if(pFrameRGB==NULL)    {_getch();return -1;}
  
  numBytes=avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width, pCodecCtx->height);
  
  buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
  // Assign appropriate parts of buffer to image planes in pFrameRGB
  
  avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24, pCodecCtx->width, pCodecCtx->height);
  
  
  
  i=0;
  
  int framecounter=0;
  
  while(av_read_frame(pFormatCtx, &packet)>=0) 
  
  {
  
    if(packet.stream_index==videoStream) 
  
      {
  
        // Decode video frame
  
        //int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture, int *got_picture_ptr, const AVPacket *avpkt);
  
        avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
  
  
  
        if(frameFinished) 
  
        {
  
           // Convert the image from its native format to RGB
  
       //img_convert((AVPicture *)pFrameRGB, PIX_FMT_RGB24, (AVPicture*)pFrame, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height);
  
           if(++i<=5)  {SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, i);}
  
        }
  
      }
  
    av_free_packet(&packet);
  
  }

  Since img_convert wasn't available, I took it from here but it threw an unhandled exception error. Why is the RGB format so tough to understand ? Why assign zero to G and B of RGB, as shown here ?

  How can I get my RGB values as a simple R, G and B which spans between 0 and 255 ? Also, I don't understand the use of x and y, when video width and height are already given. y is an increment of height, but what about x ?

  Can anyone please show me a complete working code of obtaining rgb values from a video or at least explain how data and linesize help in storing RGB info ? The lack of tutorials is appalling and the complexity of the API is surprising, after having worked on Processing videos.