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• Bitmap images to WEBM video encoding

  21 novembre 2013, par Ankush

  I am trying to encode bitmap images to webm video,but generated video is not playable
  Here is code I am using,code works fine for H624.
  While encoding console windows shows : [libvpx @ 009b2f60] v1.2.0
  there is no webm string in produced video file. Any clue ? ( I am newbie for FFMPEG API )

  void create_from_bmp()
  
  {
  
  CFile file[5];  
  
  BYTE *szTxt[5];  
  
  
  
  int nWidth = 0;  
  
  int nHeight= 0;  
  
  
  
  int nDataLen=0;  
  
  
  
  int nLen;  
  
  
  
  CString csFileName;  
  
  for (int fileI = 1; fileI <= 5; fileI ++)  
  
  {
  
    csFileName.Format("e:\\pics\\%d.bmp",fileI);  
  
    file[fileI - 1].Open(csFileName,CFile::modeRead | CFile::typeBinary);  
  
    nLen = file[fileI - 1].GetLength();  
  
  
  
    szTxt[fileI -1] = new BYTE[nLen];  
  
    file[fileI - 1].Read(szTxt[fileI - 1], nLen);  
  
    file[fileI - 1].Close();  
  
  
  
    //BMP bmi;//BITMAPINFO bmi;  
  
    //int nHeadLen = sizeof(BMP);  
  
    BITMAPFILEHEADER bmpFHeader;  
  
    BITMAPINFOHEADER bmpIHeader;  
  
    memcpy(&bmpFHeader,szTxt[fileI -1],sizeof(BITMAPFILEHEADER));  
  
  
  
    int nHeadLen = bmpFHeader.bfOffBits - sizeof(BITMAPFILEHEADER);  
  
    memcpy(&bmpIHeader,szTxt[fileI - 1]+sizeof(BITMAPFILEHEADER),nHeadLen);  
  
  
  
    nWidth = bmpIHeader.biWidth;// 464;// bmi.bmpInfo.bmiHeader.biWidth;// ;  
  
    nHeight = bmpIHeader.biHeight;//362;// bmi.bmpInfo.bmiHeader.biHeight;// ;  
  
  
  
    szTxt[fileI - 1] += bmpFHeader.bfOffBits;  
  
    nDataLen = nLen-bmpFHeader.bfOffBits;  
  
  }  
  
  
  
  av_register_all();  
  
  avcodec_register_all();  
  
  AVFrame *m_pRGBFrame =  new AVFrame[1];  //RGB    
  
  AVFrame *m_pYUVFrame = new AVFrame[1];;  //YUV
  
  AVCodecContext *c= NULL;  
  
  AVCodecContext *in_c= NULL;  
  
  AVCodec *pCodecH264;
  
  uint8_t * yuv_buff;//  
  
  
  
  pCodecH264 = avcodec_find_encoder(CODEC_ID_VP8);  
  
  if(!pCodecH264)  
  
  {  
  
    fprintf(stderr, "h264 codec not found\n");  
  
    exit(1);  
  
  }  
  
  
  
  c= avcodec_alloc_context3(pCodecH264);  
  
  c->bit_rate = 3000000;// put sample parameters   
  
  c->width =nWidth;//   
  
  c->height = nHeight;//  
  
  
  
  // frames per second   
  
  AVRational rate;  
  
  rate.num = 1;  
  
  rate.den = 5;  //5 frames per sec
  
  c->time_base= rate;//(AVRational){1,25};  
  
  c->gop_size = 10; // emit one intra frame every ten frames   //emit one iframe per sec
  
  c->max_b_frames=0;  //
  
  c->thread_count = 1;  
  
  c->pix_fmt = PIX_FMT_YUV420P;//PIX_FMT_RGB24;  
  
  c->codec_id=CODEC_ID_VP8;
  
  
  
  //av_opt_set(c->priv_data, /*"preset"*/"libvpx-1080p.ffpreset", /*"slow"*/NULL, 0);  
  
  if(avcodec_open2(c,pCodecH264,NULL)<0)  
  
    printf("Cant open codec");
  
  
  
  int size = c->width * c->height;  
  
  
  
  yuv_buff = (uint8_t *) malloc((size * 3) / 2); // size for YUV 420    
  
  
  
  uint8_t * rgb_buff = new uint8_t[nDataLen];  
  
  
  
  int outbuf_size=400000;  
  
  uint8_t * outbuf= (uint8_t*)malloc(outbuf_size);   
  
  int u_size = 0;  
  
  FILE *f=NULL;   
  
  char * filename = "e:\\pics\\myData.h264";  
  
  f = fopen(filename, "wb");  
  
  if (!f)  
  
  {  
  
    printf( "could not open %s\n", filename);  
  
    exit(1);  
  
  }  
  
  
  
  //SwsContext  
  
  SwsContext * scxt = sws_getContext(c->width,c->height,PIX_FMT_BGR24,c->width,c->height,PIX_FMT_YUV420P,SWS_POINT,NULL,NULL,NULL);  
  
  
  
  AVPacket avpkt;  
  
  
  
  //AVFrame *pTFrame=new AVFrame  
  
  for (int i=0;i<60;++i)  
  
  {  
  
    //AVFrame *m_pYUVFrame = new AVFrame[1];  
  
  
  
    int index = (i / 5) % 5;  
  
    memcpy(rgb_buff,szTxt[index],nDataLen);  
  
  
  
    avpicture_fill((AVPicture*)m_pRGBFrame, (uint8_t*)rgb_buff, PIX_FMT_RGB24, nWidth, nHeight);  
  
  
  
    avpicture_fill((AVPicture*)m_pYUVFrame, (uint8_t*)yuv_buff, PIX_FMT_YUV420P, nWidth, nHeight);  
  
  
  
    m_pRGBFrame->data[0]  += m_pRGBFrame->linesize[0] * (nHeight - 1);  
  
    m_pRGBFrame->linesize[0] *= -1;                     
  
    m_pRGBFrame->data[1]  += m_pRGBFrame->linesize[1] * (nHeight / 2 - 1);  
  
    m_pRGBFrame->linesize[1] *= -1;  
  
    m_pRGBFrame->data[2]  += m_pRGBFrame->linesize[2] * (nHeight / 2 - 1);  
  
    m_pRGBFrame->linesize[2] *= -1;  
  
  
  
  
  
    sws_scale(scxt,m_pRGBFrame->data,m_pRGBFrame->linesize,0,c->height,m_pYUVFrame->data,m_pYUVFrame->linesize);  
  
  
  
    int got_packet_ptr = 0;  
  
    av_init_packet(&avpkt);  
  
    avpkt.data = outbuf;  
  
    avpkt.size = outbuf_size;  
  
    u_size = avcodec_encode_video2(c, &avpkt, m_pYUVFrame, &got_packet_ptr);  
  
    if (u_size == 0)  
  
    {  
  
     fwrite(avpkt.data, 1, avpkt.size, f);  
  
    }  
  
  } 
  
  
  
  fclose(f);   
  
  delete []m_pRGBFrame;  
  
  delete []m_pYUVFrame;  
  
  delete []rgb_buff;  
  
  free(outbuf);  
  
  avcodec_close(c);  
  
  av_free(c);  
  
  }

  I want to use this code to record screen by encoding screenshots. what fps,gop size or other parameters i can use to reduce size of video.

• Revision 5c808ba13a : Add max burst bitrate control. Applies an upper limit on burst bitrate for any

  10 janvier 2014, par Paul Wilkins

  Changed Paths :
   Modify /vp9/encoder/vp9_firstpass.c

  
   Modify /vp9/encoder/vp9_onyx_if.c

  
   Modify /vp9/encoder/vp9_onyx_int.h

  
   Modify /vp9/encoder/vp9_ratectrl.c

  
  
  Add max burst bitrate control.

  Applies an upper limit on burst bitrate for any
  frame. This is to insure that typical encodes for YT
  do not produce frames that are so large that they
  risk stalling HW implementations. Such frames
  could also cause playback problems in SW.

  For now the limit is set at 250 bits per MB for 1080P
  and larger (with the 1080P limit used for smaller frames).

  Setting maxQ, constant quality mode or targeting a
  very high bandwidth will have precedence over this limit.

  Change-Id : Ie6f776c38b06ac7cec043d034085f4b79ee46a38

• Revision 4282955ee1 : Skip intra mode tests depending on inter residuals This commit allows encoder t

  29 août 2014, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_rdopt.c

  
   Modify /vp9/encoder/vp9_speed_features.c

  
   Modify /vp9/encoder/vp9_speed_features.h

  
  
  Skip intra mode tests depending on inter residuals

  This commit allows encoder to skip intra coding mode test, when
  the known inter residual is less than the source variance. It
  reduces the runtime of speed 3 for test clips :
  bus cif 1000 kbps : 8587 ms -> 8260 ms, 3.8% speed-up
  pedestrian 1080p 2000 kbps : 161381 ms -> 155241 ms, 3.7% speed-up.

  The compression performance is down by
  derf -0.36%
  stdhd -0.25%

  Change-Id : I75ce1e035b4da2153cb1ac14111d1a07c05a735d