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• WebRTC Detect Orientation from Peer Video Stream

  30 mars 2018, par Daryl

  Using RecordRTC and WebRTC I am able to save a Peer MediaStream as a webm/video file. The orientation of the file differs based on the peer device. Meaning a 640x480 video is rotated clockwise or counter clockwise.

  To re-orient the recorded video, some of the videos need to be rotated "clockwise" and others need to be rotated "counter clockwise". I need a way to determine which direction to rotate the video. Otherwise, some videos will be right side up and others upside down.

  I attempted to look up the orientation, using ffprobe. However, the videos created do not have the "rotate" tag in the metadata.

  I have also been unable to find the orientation in the Peer video stream of the WebRTC object.

  I really thought that since the Video Element has the WebRTC Peer Stream displayed correctly in it, that I should be able to get the orientation from it.

• Display ffmpeg frames on opgel texture

  21 mars 2018, par naki

  I am using Dranger tutorial01 (ffmpeg) to decode the video and get AVI frames. I want to use OpenGL to display the video.

  http://dranger.com/ffmpeg/tutorial01.html

  The main function is as follows :

  int main (int argc, char** argv) {
  
  // opengl stuff
  
  glutInit(&argc, argv);
  
  glutInitDisplayMode(GLUT_RGBA);
  
  glutInitWindowSize(800, 600);
  
  glutCreateWindow("Hello GL");
  
  
  
  glutReshapeFunc(changeViewport);
  
  glutDisplayFunc(render);
  
  
  
  GLenum err = glewInit();
  
  if(GLEW_OK !=err){
  
      fprintf(stderr, "GLEW error");
  
      return 1;
  
  }
  
  
  
  glClear(GL_COLOR_BUFFER_BIT);
  
  
  
  
  
  glEnable(GL_TEXTURE_2D);
  
  GLuint texture;
  
  glGenTextures(1, &texture); //Make room for our texture
  
  glBindTexture(GL_TEXTURE_2D, texture);
  
  
  
  //ffmpeg stuff
  
  
  
   AVFormatContext *pFormatCtx = NULL;
  
   int             i, videoStream;
  
   AVCodecContext  *pCodecCtx = NULL;
  
   AVCodec         *pCodec = NULL;
  
   AVFrame         *pFrame = NULL; 
  
   AVFrame         *pFrameRGB = NULL;
  
   AVPacket        packet;
  
   int             frameFinished;
  
   int             numBytes;
  
   uint8_t         *buffer = NULL;
  
  
  
   AVDictionary    *optionsDict = NULL;
  
  
  
  
  
   if(argc < 2) {
  
  printf("Please provide a movie file\n");
  
  return -1;
  
   }
  
   // Register all formats and codecs
  
  
  
  av_register_all();
  
  
  
   // Open video file
  
   if(avformat_open_input(&pFormatCtx, argv[1], NULL, NULL)!=0)
  
     return -1; // Couldn't open file
  
  
  
  // Retrieve stream information
  
  
  
  if(avformat_find_stream_info(pFormatCtx, NULL)<0)
  
  return -1; // Couldn't find stream information
  
  
  
  // Dump information about file onto standard error
  
   av_dump_format(pFormatCtx, 0, argv[1], 0);
  
  
  
  // 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)
  
  return -1; // Didn't find a video stream
  
  
  
   // 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);
  
   if(pCodec==NULL) {
  
     fprintf(stderr, "Unsupported codec!\n");
  
     return -1; // Codec not found
  
   }
  
   // Open codec
  
  if(avcodec_open2(pCodecCtx, pCodec, &optionsDict)<0)
  
     return -1; // Could not open codec
  
  
  
   // Allocate video frame
  
   pFrame=av_frame_alloc();
  
  
  
   // Allocate an AVFrame structure
  
  pFrameRGB=av_frame_alloc();
  
  if(pFrameRGB==NULL)
  
  return -1;
  
  
  
   // Determine required buffer size and allocate buffer
  
   numBytes=avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width,
  
                pCodecCtx->height);
  
   buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
  
  
  struct SwsContext      *sws_ctx = sws_getContext(pCodecCtx->width,
  
             pCodecCtx->height, pCodecCtx->pix_fmt, 800,
  
             600, PIX_FMT_RGB24, SWS_BICUBIC, NULL,
  
             NULL, NULL);
  
  
  
  
  
   // 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, buffer, PIX_FMT_RGB24,
  
       pCodecCtx->width, pCodecCtx->height);
  
  
  
   // Read frames and save first five frames to disk
  
   i=0;
  
   while(av_read_frame(pFormatCtx, &packet)>=0) {
  
  
  
  
  
  // Is this a packet from the video stream?
  
  if(packet.stream_index==videoStream) {
  
    // Decode video frame
  
    avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, 
  
             &packet);
  
  
  
    // Did we get a video frame?
  
    if(frameFinished) {
  
  // Convert the image from its native format to RGB
  
    /*  sws_scale
  
      (
  
          sws_ctx,
  
          (uint8_t const * const *)pFrame->data,
  
          pFrame->linesize,
  
          0,
  
          pCodecCtx->height,
  
          pFrameRGB->data,
  
          pFrameRGB->linesize
  
      );
  
     */
  
  sws_scale(sws_ctx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);
  
    // additional opengl
  
      glBindTexture(GL_TEXTURE_2D, texture);
  
  
  
          //gluBuild2DMipmaps(GL_TEXTURE_2D, 3, pCodecCtx->width, pCodecCtx->height, GL_RGB, GL_UNSIGNED_INT, pFrameRGB->data[0]);
  
     // glTexSubImage2D(GL_TEXTURE_2D, 0, 0,0, 840, 460, GL_RGB, GL_UNSIGNED_BYTE, pFrameRGB->data[0]);
  
  
  
          glTexImage2D(GL_TEXTURE_2D,                //Always GL_TEXTURE_2D
  
              0,                            //0 for now
  
              GL_RGB,                       //Format OpenGL uses for image
  
              pCodecCtx->width, pCodecCtx->height,  //Width and height
  
              0,                            //The border of the image
  
              GL_RGB, //GL_RGB, because pixels are stored in RGB format
  
              GL_UNSIGNED_BYTE, //GL_UNSIGNED_BYTE, because pixels are stored
  
                              //as unsigned numbers
  
              pFrameRGB->data[0]);               //The actual pixel data
  
    // additional opengl end   
  
  
  
  // Save the frame to disk
  
  if(++i<=5)
  
    SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, 
  
          i);
  
    }
  
  }
  
  
  
  glColor3f(1,1,1);
  
  glBindTexture(GL_TEXTURE_2D, texture);
  
  glBegin(GL_QUADS);
  
      glTexCoord2f(0,1);
  
      glVertex3f(0,0,0);
  
  
  
      glTexCoord2f(1,1);
  
      glVertex3f(pCodecCtx->width,0,0);
  
  
  
      glTexCoord2f(1,0);
  
      glVertex3f(pCodecCtx->width, pCodecCtx->height,0);
  
  
  
      glTexCoord2f(0,0);
  
      glVertex3f(0,pCodecCtx->height,0);
  
  
  
  glEnd();
  
  // Free the packet that was allocated by av_read_frame
  
  av_free_packet(&packet);
  
   }
  
  
  
  
  
    // Free the RGB image
  
   av_free(buffer);
  
   av_free(pFrameRGB);
  
  
  
   // Free the YUV frame
  
   av_free(pFrame);
  
  
  
   // Close the codec
  
   avcodec_close(pCodecCtx);
  
  
  
   // Close the video file
  
   avformat_close_input(&pFormatCtx);
  
  
  
   return 0;
  
  }

  Unfortunately i could not find my solution here

  ffmpeg video to opengl texture

  The program compiles but does not show any video on the texture. Just a OpenGL window is created.

• Rotating videos with FFmpeg [closed]

  14 juin 2023, par jocull

  I have been trying to figure out how to rotate videos with FFmpeg. I am working with iPhone videos taken in portrait mode. I know how to determine the current degrees of rotation using MediaInfo (excellent library, btw) but I'm stuck on FFmpeg now.

  



  From what I've read, what you need to use is a vfilter option. According to what I see, it should look like this :

  



  ffmpeg -vfilters "rotate=90" -i input.mp4 output.mp4


  



  However, I can't get this to work. First, -vfilters doesn't exist anymore, it's now just -vf. Second, I get this error :

  



  No such filter: 'rotate'
Error opening filters!


  



  As far as I know, I have an all-options-on build of FFmpeg. Running ffmpeg -filters shows this :

  



  Filters:
anull            Pass the source unchanged to the output.
aspect           Set the frame aspect ratio.
crop             Crop the input video to x:y:width:height.
fifo             Buffer input images and send them when they are requested.
format           Convert the input video to one of the specified pixel formats.
hflip            Horizontally flip the input video.
noformat         Force libavfilter not to use any of the specified pixel formats
 for the input to the next filter.
null             Pass the source unchanged to the output.
pad              Pad input image to width:height[:x:y[:color]] (default x and y:
 0, default color: black).
pixdesctest      Test pixel format definitions.
pixelaspect      Set the pixel aspect ratio.
scale            Scale the input video to width:height size and/or convert the i
mage format.
slicify          Pass the images of input video on to next video filter as multi
ple slices.
unsharp          Sharpen or blur the input video.
vflip            Flip the input video vertically.
buffer           Buffer video frames, and make them accessible to the filterchai
n.
color            Provide an uniformly colored input, syntax is: [color[:size[:ra
te]]]
nullsrc          Null video source, never return images.
nullsink         Do absolutely nothing with the input video.


  



  Having the options for vflip and hflip are great and all, but they just won't get me where I need to go. I need to the ability to rotate videos 90 degrees at the very least. 270 degrees would be an excellent option to have as well. Where have the rotate options gone ?