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• Is it possible to stream multi framerate videos using MPEG-DASH ?

  9 août 2018, par Suresh Murali

  I transcoded a mp4 video to several framerates like 5FPS, 10FPS .. 30FPS and used MP4Box to segment them to play in DASH IF player.

  FFMPEG Command to generate multi framerate videos with same resolution :

  ffmpeg -i fball.mp4 -f mp4 -vcodec libx264 -profile:v high -vf scale=1280 :-1 -b:v 2000k -minrate 2000k -maxrate 2000k -bufsize 2000k -nal-hrd cbr -g 120 -keyint_min 120 -r 60.0 -flags +cgop -sc_threshold 0 -pix_fmt yuv420p -threads 0 -x264opts keyint=120:min-keyint=120:sps-id=1 -an -y fball_720p_60fps.mp4

  ffmpeg -i fball.mp4 -f mp4 -vcodec libx264 -profile:v high -vf scale=1280 :-1 -b:v 1000k -minrate 1000k -maxrate 1000k -bufsize 1000k -nal-hrd cbr -g 60 -keyint_min 60 -r 30.0 -flags +cgop -sc_threshold 0 -pix_fmt yuv420p -threads 0 -x264opts keyint=60:min-keyint=60:sps-id=1 -an -y fball_720p_30fps.mp4

  FFMPEG command to extract audio :

  ffmpeg -i fball.mp4 -acodec aac -b:a 128k -vn -strict -2 -y fball_audio.mp4

  MP4Box command for segmentation :

  MP4Box -frag 2000 -dash 2000 -rap -base-url ./segments/ -profile main -segment-name /segments/%s_ -out dash/fball_dash.mpd fball_720p_24fps.mp4 fball_720p_30fps.mp4 fball_720p_60fps.mp4 fball_audio.mp4

  1. Segment Duration : 2 seconds

  2. GOP length : segment duration x FPS of video

  3. Resolution : 720p for all videos

  Result is VIDEO DECODE error or stalls while switching framerate.

  Am I making any mistake while transcoding ?
  Is it possible to stream Multi frame rate videos using MPEG DASH ?

• avformat/dashenc : Remove muxer overhead from Bandwidth field in DASH manifest

  4 septembre 2018, par Karthick Jeyapal

  avformat/dashenc : Remove muxer overhead from Bandwidth field in DASH manifest
  Fixes bug id #7386
  
  Muxer overhead calculations was intented for HLS playlist as Apple's mediastreamvalidator tests were failing.
  
  But applying the same fix for DASH manifest proved counterproductive, as Bandwidth can be used for segment name templates.
  

  • [DH] libavformat/dashenc.c

• Upload video and convert to MPEG-DASH [on hold]

  26 juin 2018, par Justin Rec

  Upload video and convert to MPEG-DASH I’m doing ...

  Upload file
  
  1. move_uploaded_file($_FILES['video']['tmp_name'], video.mp4);
  
  
  
  Converting video
  
  2.  ffmpeg -i video.mp4 -ac 2 -ab 128k -c:v libx264 -preset veryfast -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 3000k -maxrate 3000k -bufsize 1500k -vf "scale=-1:1080" video_1080.mp4
  
      ffmpeg -i video.mp4 -ac 2 -ab 128k -c:v libx264 -preset veryfast -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 1500k -maxrate 1500k -bufsize 1000k -vf "scale=-1:720"  video_720.mp4
  
      ffmpeg -i video.mp4 -ac 2 -ab 128k -c:v libx264 -preset veryfast -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 500k  -maxrate 500k  -bufsize 500k  -vf "scale=-1:480"  video_480.mp4
  
  
  
  From mp4 to MPEG-DASH
  
  3. MP4Box -dash 4000 -frag 4000 -rap -segment-name %s/segment_ -url-template -out manifest.mpd video_1080.mp4 video_720.mp4 video_480.mp4
  
  
  
  Delete mp4 videos
  
  4.  unlink('video_1080.mp4');
  
      unlink('video_720.mp4');
  
      unlink('video_480.mp4');

  Everything is working. But I’m not sure that this is the right decision. Is there a better solution ? Do I do everything right ?