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• Revision ccef8842d2 : Allow full coeff probability model and cost update This commit moves the simpli

  13 août 2014, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_speed_features.c

  
  
  Allow full coeff probability model and cost update

  This commit moves the simplified coefficient probability model
  and costing update to speed 4, and turns on chessboard pattern
  mode search for sub 720p sequences. The overall coding performance
  of speed 3 is improved :
  derf 0.889%
  stdhd 1.744%

  The speed 3 runtime for test sequences are improved :
  bus cif at 1000 kbps 9823 ms -> 9642 ms
  pedestrian 1080p 2000 kbps 189559 ms -> 183284 ms

  Change-Id : Iecbc7496a68f31fd49fb09f8dfd97c028d675a5d

• Revision 1e30547984 : Skip mode search based on reference frame consistency This commit enables the e

  12 août 2014, par Jingning Han

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

  
  
  Skip mode search based on reference frame consistency

  This commit enables the encoder to skip NEARMV and ZEROMV if the
  above and left blocks have identical reference frame, and the
  current reference is different from that. It reduces the runtime
  of speed 3 for test sequences :
  bus cif at 1000 kbps 10064 ms -> 9823 ms
  pedestrian 1080p at 2000 kbps 193078 ms -> 189559 ms

  The compression performance is changed by
  derf -0.085%
  stdhd -0.103%

  Change-Id : If304f26d42e6412152a84c3dd7b02635c38444f4

• 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.