Recherche avancée

Sur d’autres sites (12067)

• Automate file spliting with FFMPEG

  10 novembre 2017, par JSawyer

  We currently use Wowza web streaming for events and would like to take the recorded streams and split them up based on events within the stream.

  My thought would be to upload a file with the times listed and then loop through those times using FFMPEG to split the file.

• Revision 5dd146cb26 : Added comment for vp9 only codec controls Comments are updated to reflect that

  13 mars 2015, par Yaowu Xu

  Changed Paths :
   Modify /vpx/vp8cx.h

  
  
  Added comment for vp9 only codec controls

  Comments are updated to reflect that these controls apply to VP9 only,
  thereby, to insure the document produced by doxygent to reflect the
  same fact too.

  Change-Id : Ic54c88ec066aa0ec4552d43dd4a7016e1f810f42

• How to use the ffmpeg library to transpose a video ?

  12 décembre 2013, par beni

  I'm trying to develop an video recorder and playback app in Android. So, I'm using the ffmpeg library and I've compiled the library to use in the project.

  I record a video and when I playback, in some devices don't recognize the orientation matrix, so I want to develop with the ffmpeg library a C method to do this order :

  ffmpeg -i f.mp4 -vf "transpose=1" -r 24 -sameq f2.mp4"

  I found this documentation but don't help me, because don't use the AVFilter and AVFilterContext classes.

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

  http://cekirdek.pardus.org.tr/ ismail/ffmpeg-docs/structAVFilterContext.html

  http://ffmpeg.org/doxygen/trunk/api-example_8c-source.html

  Now I only have the opening and closing video file

  Here my code :

  /*open the video file*/
  
  if ((lError = av_open_input_file(&gFormatCtx, gFileName, NULL, 0, NULL)) !=0 ) {
  
      LOGE(1, "Error open video file: %d", lError);
  
      return; //open file failed
  
  }
  
  /*retrieve stream information*/
  
  if ((lError = av_find_stream_info(gFormatCtx)) < 0) {
  
      LOGE(1, "Error find stream information: %d", lError);
  
      return;
  
  } 
  
  /*find the video stream and its decoder*/
  
  gVideoStreamIndex = av_find_best_stream(gFormatCtx, AVMEDIA_TYPE_VIDEO, -1, -1, &lVideoCodec, 0);
  
  if (gVideoStreamIndex == AVERROR_STREAM_NOT_FOUND) {
  
      LOGE(1, "Error: cannot find a video stream");
  
      return;
  
  } else {
  
  LOGI(10, "video codec: %s", lVideoCodec->name);
  
  }
  
  if (gVideoStreamIndex == AVERROR_DECODER_NOT_FOUND) {
  
      LOGE(1, "Error: video stream found, but no decoder is found!");
  
      return;
  
  }   
  
  /*open the codec*/
  
  gVideoCodecCtx = gFormatCtx->streams[gVideoStreamIndex]->codec;
  
  LOGI(10, "open codec: (%d, %d)", gVideoCodecCtx->height, gVideoCodecCtx->width);
  
  #ifdef SELECTIVE_DECODING
  
  gVideoCodecCtx->allow_selective_decoding = 1;
  
  #endif
  
  if (avcodec_open(gVideoCodecCtx, lVideoCodec) < 0) {
  
  LOGE(1, "Error: cannot open the video codec!");
  
      return;
  
  }
  
  LOGI(10, "get video info ends");

  How can I transpose the video using the ffmpeg library ?