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• How to encode Planar 4:2:0 (fourcc P010)

  20 juillet 2021, par DennisFleurbaaij

  I'm trying to recode fourcc V210 (which is a packed YUV4:2:2 format) into a P010 (planar YUV4:2:0). I think I've implemented it according to spec, but the renderer is giving a wrong image so something is off. Decoding the V210 has a decent example in ffmpeg (defines are modified from their solution) but I can't find a P010 encoder to look at what I'm doing wrong.

  


  (Yes, I've tried ffmpeg and that works but it's too slow for this, it takes 30ms per frame on an Intel Gen11 i7)

  


  Clarification (after @Frank's question) : The frames being processed are 4k (3840px wide) and hence there is no code for doing the 128b alignment.

  


  This is running on intel so little endian conversions applied.

  


  Try1 - all green image :

  


  The following code

  


  #define V210_READ_PACK_BLOCK(a, b, c) \
    do {                              \
        val  = *src++;                \
        a = val & 0x3FF;              \
        b = (val >> 10) & 0x3FF;      \
        c = (val >> 20) & 0x3FF;      \
    } while (0)

#define PIXELS_PER_PACK 6
#define BYTES_PER_PACK (4*4)

void MyClass::FormatVideoFrame(
    BYTE* inFrame,
    BYTE* outBuffer)
{
    const uint32_t pixels = m_height * m_width;

    const uint32_t* src = (const uint32_t *)inFrame);

    uint16_t* dstY = (uint16_t *)outBuffer;

    uint16_t* dstUVStart = (uint16_t*)(outBuffer + ((ptrdiff_t)pixels * sizeof(uint16_t)));
    uint16_t* dstUV = dstUVStart;

    const uint32_t packsPerLine = m_width / PIXELS_PER_PACK;

    for (uint32_t line = 0; line < m_height; line++)
    {
        for (uint32_t pack = 0; pack < packsPerLine; pack++)
        {
            uint32_t val;
            uint16_t u, y1, y2, v;

            if (pack % 2 == 0)
            {
                V210_READ_PACK_BLOCK(u, y1, v);
                *dstUV++ = u;
                *dstY++ = y1;
                *dstUV++ = v;

                V210_READ_PACK_BLOCK(y1, u, y2);
                *dstY++ = y1;
                *dstUV++ = u;
                *dstY++ = y2;

                V210_READ_PACK_BLOCK(v, y1, u);
                *dstUV++ = v;
                *dstY++ = y1;
                *dstUV++ = u;

                V210_READ_PACK_BLOCK(y1, v, y2);
                *dstY++ = y1;
                *dstUV++ = v;
                *dstY++ = y2;
            }
            else
            {
                V210_READ_PACK_BLOCK(u, y1, v);
                *dstY++ = y1;

                V210_READ_PACK_BLOCK(y1, u, y2);
                *dstY++ = y1;
                *dstY++ = y2;

                V210_READ_PACK_BLOCK(v, y1, u);
                *dstY++ = y1;

                V210_READ_PACK_BLOCK(y1, v, y2);
                *dstY++ = y1;
                *dstY++ = y2;
            }
        }
    }

#ifdef _DEBUG

    // Fully written Y space
    assert(dstY == dstUVStart);

    // Fully written UV space
    const BYTE* expectedVurrentUVPtr = outBuffer + (ptrdiff_t)GetOutFrameSize();
    assert(expectedVurrentUVPtr == (BYTE *)dstUV);

#endif
}

// This is called to determine outBuffer size
LONG MyClass::GetOutFrameSize() const
{
    const LONG pixels = m_height * m_width;

    return
        (pixels * sizeof(uint16_t)) +  // Every pixel 1 y
        (pixels / 2 / 2 * (2 * sizeof(uint16_t)));  // Every 2 pixels and every odd row 2 16-bit numbers
}


  


  Leads to all green image. This turned out to be a missing bit shift to place the 10 bits in the upper bits of the 16-bit value as per the P010 spec.

  


  Try 2 - Y works, UV doubled ?

  


  Updated the code to properly (or so I think) shifts the YUV values to the correct position in their 16-bit space.

  


  #define V210_READ_PACK_BLOCK(a, b, c) \
    do {                              \
        val  = *src++;                \
        a = val & 0x3FF;              \
        b = (val >> 10) & 0x3FF;      \
        c = (val >> 20) & 0x3FF;      \
    } while (0)


#define P010_WRITE_VALUE(d, v) (*d++ = (v << 6))

#define PIXELS_PER_PACK 6
#define BYTES_PER_PACK (4 * sizeof(uint32_t))

// Snipped constructor here which guarantees that we're processing
// something which does not violate alignment.

void MyClass::FormatVideoFrame(
    const BYTE* inBuffer,
    BYTE* outBuffer)
{   
    const uint32_t pixels = m_height * m_width;
    const uint32_t aligned_width = ((m_width + 47) / 48) * 48;
    const uint32_t stride = aligned_width * 8 / 3;

    uint16_t* dstY = (uint16_t *)outBuffer;

    uint16_t* dstUVStart = (uint16_t*)(outBuffer + ((ptrdiff_t)pixels * sizeof(uint16_t)));
    uint16_t* dstUV = dstUVStart;

    const uint32_t packsPerLine = m_width / PIXELS_PER_PACK;

    for (uint32_t line = 0; line < m_height; line++)
    {
        // Lines start at 128 byte alignment
        const uint32_t* src = (const uint32_t*)(inBuffer + (ptrdiff_t)(line * stride));

        for (uint32_t pack = 0; pack < packsPerLine; pack++)
        {
            uint32_t val;
            uint16_t u, y1, y2, v;

            if (pack % 2 == 0)
            {
                V210_READ_PACK_BLOCK(u, y1, v);
                P010_WRITE_VALUE(dstUV, u);
                P010_WRITE_VALUE(dstY, y1);
                P010_WRITE_VALUE(dstUV, v);

                V210_READ_PACK_BLOCK(y1, u, y2);
                P010_WRITE_VALUE(dstY, y1);
                P010_WRITE_VALUE(dstUV, u);
                P010_WRITE_VALUE(dstY, y2);

                V210_READ_PACK_BLOCK(v, y1, u);
                P010_WRITE_VALUE(dstUV, v);
                P010_WRITE_VALUE(dstY, y1);
                P010_WRITE_VALUE(dstUV, u);

                V210_READ_PACK_BLOCK(y1, v, y2);
                P010_WRITE_VALUE(dstY, y1);
                P010_WRITE_VALUE(dstUV, v);
                P010_WRITE_VALUE(dstY, y2);
            }
            else
            {
                V210_READ_PACK_BLOCK(u, y1, v);
                P010_WRITE_VALUE(dstY, y1);

                V210_READ_PACK_BLOCK(y1, u, y2);
                P010_WRITE_VALUE(dstY, y1);
                P010_WRITE_VALUE(dstY, y2);

                V210_READ_PACK_BLOCK(v, y1, u);
                P010_WRITE_VALUE(dstY, y1);

                V210_READ_PACK_BLOCK(y1, v, y2);
                P010_WRITE_VALUE(dstY, y1);
                P010_WRITE_VALUE(dstY, y2);
            }
        }
    }

#ifdef _DEBUG

    // Fully written Y space
    assert(dstY == dstUVStart);

    // Fully written UV space
    const BYTE* expectedVurrentUVPtr = outBuffer + (ptrdiff_t)GetOutFrameSize();
    assert(expectedVurrentUVPtr == (BYTE *)dstUV);

#endif
}


  


  This leads to the Y being correct and the amount of lines for U and V as well, but somehow U and V are not overlaid properly. There are two versions of it seemingly mirrored through the center vertical. Something similar but less visible for zeroing out V. So both of these are getting rendered at half the width ? Any tips appreciated :)

  


  Fix :
Found the bug, I'm flipping VU not per pack but per block

  


  if (pack % 2 == 0)


  


  Should be

  


  if (line % 2 == 0)


  


• ffmpeg moving text drawtext

  5 juillet 2021, par BOB

  I'm using ffmpeg library to draw text on video in specific time and i'm success to do that Now i need to move the text from position to another and i can't do that so can any one suggest me how to do that

  



  i'm using this command to move text from top to down but i can't determine the x and Y to move from the x,y to specific x,y

  



  ffmpeg -i VideoInput.mp4 -vf "drawtext=enable='between(t,12,14)':fontfile=myfont.otf:text='Test test':x=(w-text_w)/2:y=w/50\*mod(t\,2):fontsize=65" -acodec copy outputVideo.mp4


  


• Display ffmpeg frames on opgel texture

  24 octobre 2014, 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.