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• Is there any control property to fix video playback speed problem when using ffmpeg to decode in Qt platform ?

  16 février 2019, par SoloWang

  I want to play local video file in Qt platform using ffmpeg to decode.Everything is OK except that play speed is as twice as normal.
  The first thing I think about is that there must be a sampling frequency involved.But to be a new to ffmpeg,I don’t know how to fix this problem.
  Above is my code to read frame,is anyone can tell me what’s wrong with the code ?

  void VideoThread::run()
  
  {
  
      m_pInFmtCtx = avformat_alloc_context(); //ini struct
  
      char path[] = "d:/test.mp4";
  
      // open specific file
  
      if(avformat_open_input(&m_pInFmtCtx, *path, NULL, NULL)){ 
  
      {
  
          qDebug()<<"get rtsp failed";
  
          return;
  
      }
  
      else
  
      {
  
          qDebug()<<"get rtsp success";
  
      }
  
  
  
  
  
      if(avformat_find_stream_info(m_pInFmtCtx, NULL) < 0)
  
      {
  
          qDebug()<<"could not find stream information";
  
          return;
  
      }
  
      int nVideoIndex = -1;
  
      for(int i = 0; i < m_pInFmtCtx->nb_streams; i++)
  
      {
  
          if(m_pInFmtCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
  
          {
  
              nVideoIndex = i;
  
              break;
  
          }
  
      }
  
      if(nVideoIndex == -1)
  
      {
  
          qDebug()<<"could not find video stream";
  
          return;
  
      }
  
  
  
      qDebug("---------------- File Information ---------------");
  
      m_pCodecCtx = m_pInFmtCtx->streams[nVideoIndex]->codec;
  
      m_pCodec = avcodec_find_decoder(m_pCodecCtx->codec_id);
  
      if(!m_pCodec)
  
      {
  
          qDebug()<<"could not find codec";
  
          return;
  
      }
  
      //start Decoder
  
      if (avcodec_open2(m_pCodecCtx, m_pCodec, NULL) < 0) {
  
          qDebug("Could not open codec.\n");
  
          return;
  
      }
  
  
  
  
  
      //malloc space for stroring frame
  
      m_pFrame     = av_frame_alloc();
  
      m_pFrameRGB  = av_frame_alloc();
  
      m_pOutBuf = (uint8_t*)av_malloc(avpicture_get_size(AV_PIX_FMT_RGB32, m_pCodecCtx->width, m_pCodecCtx->height));
  
      avpicture_fill((AVPicture*)m_pFrameRGB, m_pOutBuf, AV_PIX_FMT_RGB32, m_pCodecCtx->width, m_pCodecCtx->height);
  
  
  
      //for color switch,from YUV to RGB
  
      struct SwsContext *pImgCtx = sws_getContext(m_pCodecCtx->width, m_pCodecCtx->height, m_pCodecCtx->pix_fmt,
  
                                                  m_pCodecCtx->width, m_pCodecCtx->height, AV_PIX_FMT_RGB32, SWS_BICUBIC, NULL, NULL, NULL);
  
  
  
  
  
      int nSize = m_pCodecCtx->width * m_pCodecCtx->height;
  
      m_pPacket = (AVPacket *)av_malloc(sizeof(AVPacket));
  
      if(av_new_packet(m_pPacket, nSize) != 0)
  
      {
  
          qDebug()<<"new packet failed";
  
      }
  
  
  
      //isInterruptionRequested is a flag,determine whether the thread is over
  
      // read each frame from specific video file
  
      while (!isInterruptionRequested())
  
      {
  
          int nGotPic = 0;
  
          if(av_read_frame(m_pInFmtCtx, m_pPacket) >= 0)
  
          {
  
              if(m_pPacket->stream_index == nVideoIndex)
  
              {
  
                  //avcodec_decode_video2()transform from packet to frame
  
                  if(avcodec_decode_video2(m_pCodecCtx, m_pFrame, &nGotPic, m_pPacket) < 0)
  
                  {
  
                      qDebug()<<"decode failed";
  
                      return;
  
                  }
  
                  if(nGotPic)
  
                  {   // transform to RGB color
  
                      sws_scale(pImgCtx, (const uint8_t* const*)m_pFrame->data,
  
                                m_pFrame->linesize, 0, m_pCodecCtx->height, m_pFrameRGB->data,
  
                                m_pFrameRGB->linesize);
  
                      // save to QImage,for later use
  
                      QImage *pImage = new QImage((uchar*)m_pOutBuf, m_pCodecCtx->width, m_pCodecCtx->height, QImage::Format_RGB32);
  
                  }
  
  
  
              }
  
          }
  
  
  
          av_free_packet(m_pPacket);
  
          msleep(5);
  
      }
  
      exec();
  
  }

• Merging videos. multiple overlays and audio in one step

  3 février 2019, par user14567

  I have a process that I run hourly to update a 60 sec weather video.

  I combine a background video with a generated m4a audio track, scrolling text and separate top and bottom overlays.

  I need all of this in an mp4 and in a TLS (m3u8) format.

  Right now I do this 3 ffmpeg consecutive sessions and end up with a rendered 720p mp4.

  Then I run a 4th ffpmeg session to convert the the mp4 to a TLS version (I need both mp4 and m3u8.)

  I am doing this in 4 ffmpeg runs because I haven’t figured out how to combine the filters and do it in less.

  When I try an combine this, I lose either the overlays or the text. I can’t get it all to come out in one session. I’ve tried comma separating within the filters but I haven’t found the right combination.

  Any assistance in showing me how to combine this work and reduce the number of runs would be greatly appreciated.

  This runs on a Centos 7 box with ffmpeg version 3.4.1.

  #
  
  # Step 1: Combine background video with audio and scrolling text
  
  #
  
  ffmpeg -i /video/weather/media/sunnybeach.mp4 \
  
  -i /video/weather/prod/currentweather.m4a \
  
  -i /video/weather/media/weather-lower-third1.png \
  
  -map 2:v:0 -map 1:a:0 -strict -2 \
  
  -filter_complex  "[0]split[txt][orig];[txt]drawtext=fontfile=/var/www/vhosts/30a.tv/httpdocs/openx/lib/pear/Image/Canvas/Fonts/arial.ttf:fontsize=80:fontcolor=white:x=(w-text_w)/2+20:y=h-70*t:textfile=/video/weather/prod/currentweather.txt:bordercolor=black:borderw=2[txt];[orig]crop=iw:50:0:0[orig];[txt][orig]overlay” \
  
  -t 60 -c:v libx264 -y -s hd720  -loglevel quiet /video/weather/prod/currentweather.mp4 2>&1 >> /dev/null
  
  
  
  if [ $? != 0 ]; then echo fail step 1; exit 1;fi
  
  
  
  #
  
  # Step 2: now overlay current lowerthird
  
  #
  
  ffmpeg -i /video/weather/prod/currentweather.mp4 \
  
  -i /video/weather/media/weather-lower-third1.png \
  
  -strict -2 -filter_complex  "[0:v][1:v]overlay" -c:a copy -y  \
  
  -loglevel quiet $FKWI/currentweather1.mp4 2>&1 >> /dev/null
  
  
  
  if [ $? != 0 ]; then echo fail step 2; exit 1;fi
  
  
  
  #
  
  # Step 3: now overlay current topbanner
  
  #
  
  ffmpeg -i $FKWI/currentweather1.mp4 \
  
  -i /video/weather/media/weather-top-banner.png \
  
  -strict -2 -filter_complex  "[0:v][1:v]overlay" -c:a copy -y  \
  
  -loglevel quiet $FKWI/currentweather.mp4 2>&1 >> /dev/null
  
  
  
  if [ $? != 0 ]; then echo fail step 3; exit 1;fi
  
  
  
  #
  
  # Step 4: Now make TLS version
  
  #
  
  
  
  cd $FKWI/httpdocs/weather
  
  RES1=`/usr/bin/ffmpeg -i $FKWI/httpdocs/currentweather.mp4 \
  
  -profile:v baseline -level 3.0 -s 1280x720 \
  
  -c:a aac -ar 48000 -g 60 -start_number 0 \
  
  -hls_time 6 -hls_list_size 0 -f hls \
  
  -hls_base_url "http://$URL.com/weather/" \
  
  -hls_segment_filename "video%04d.ts" \
  
  -strict -2   -loglevel quiet "currentweather.m3u8" 2>&1>>/dev/null `
  
  
  
  if [ $? != 0 ]; then echo fail step 4; exit 1;fi

  This code yields both videos fine, but it takes 4 runs and I need it to happen in less runs.

• avcodec/mips : [loongson] enable MSA optimization for loongson platform.

  17 décembre 2018, par Shiyou Yin

  avcodec/mips : [loongson] enable MSA optimization for loongson platform.
  Set initialization order of MSA after MMI to make it work on loongson platform(msa is supported by loongson2k、3a4000 etc.).
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/mips/blockdsp_init_mips.c
  • [DH] libavcodec/mips/h264chroma_init_mips.c
  • [DH] libavcodec/mips/h264dsp_init_mips.c
  • [DH] libavcodec/mips/h264pred_init_mips.c
  • [DH] libavcodec/mips/h264qpel_init_mips.c
  • [DH] libavcodec/mips/hpeldsp_init_mips.c
  • [DH] libavcodec/mips/idctdsp_init_mips.c
  • [DH] libavcodec/mips/mpegvideo_init_mips.c
  • [DH] libavcodec/mips/pixblockdsp_init_mips.c
  • [DH] libavcodec/mips/vp8dsp_init_mips.c