Recherche avancée

Sur d’autres sites (5682)

• Adaptive bit rate streaming of mp4 of different gop size using media source api

  25 décembre 2018, par wahab khurram

  I want the adaptive bitrate streaming of the mp4 video of different gop keyframe size.

  I know there are couple of options for multi bitrate streaming i.e hls, dash etc

  But I already uploaded the videos on the server each video have the 360p, 480p and 720p mp4 file and each video are having different keyframe intervals.

  So the real challenge is to make the own multi bitrate mp4 media player using the media source api

  I have brain storming all aspect.

  We can only cut the h264 at keyframe

  So my real challenge is to know the video each keyframe, the keyframe chunk duration, the offset duration and the offset byte position in the mp4 file.

  So my question is how I can get these following using ffmpeg, ffprobe or any other software.

  1- Keyframe chunk duration

  2- Offset video duration

  3- Offset byte position in video.

  The following ffprobe command give the detailed info of the each keyframe, maybe this will help

  ffprobe -i "1080p.mp4" -select_streams v -skip_frame nokey -show_frames

  Thanks !

• how to encode mp4 from movie content for wowza streaming ?

  15 juillet 2014, par lng0415

  i want to encode to mp4(h.264 codec) from avi,mpg..... for wowza streaming.

  encode mp4 using ffmpeg, jave.

  encode is success, but wowza streaming is not work on android and iphone OS.
  (it’s play successfully on my PC)

  please help me.

  thank you.

  ps. i’m sorry. i’m poor at english.

  [using jave]

  File source = new File("D://temp/20140704_163504.mp4");
  
  File target = new File("D://temp/jave.mp4");
  
  
  
  AudioAttributes audio = new AudioAttributes();
  
  audio.setCodec("libmp3lame");
  
  audio.setBitRate(new Integer(64000));
  
  audio.setChannels(new Integer(1));
  
  audio.setSamplingRate(new Integer(22050));
  
  
  
  VideoAttributes video = new VideoAttributes();
  
  video.setCodec("h263");
  
  video.setBitRate(new Integer(320000));
  
  video.setFrameRate(new Integer(15));
  
  video.setSize(new VideoSize(400, 300));
  
  
  
  EncodingAttributes attrs = new EncodingAttributes();
  
  attrs.setFormat("mp4");
  
  attrs.setAudioAttributes(audio);
  
  attrs.setVideoAttributes(video);
  
  Encoder encoder = new Encoder();
  
  encoder.encode(source, target, attrs);

• Scenecut detection and consistent GOP size - adaptive streaming

  24 mars 2014, par Tarun

  Sample Command :

  -map 0:0 -f mp4 -vcodec libx264 -preset slow -profile:v main -vf scale="640:trunc(ow/a/2)*2" -vb 700k -minrate 650k -maxrate 750k -bufsize 10000k -an -g 48 -x264opts keyint=48:min-keyint=10:scenecut=40 -flags +cgop -sc_threshold 40 -pix_fmt yuv420p -threads 0 -y

  There is as such no error in encoding, But I wanted to understand following points-

  1) the above command will ensure that range of GOP size is 10,48, and if any scene change value (frame1 to fame2) is >40%, then a keyframe is introduced there ?

  2) So that means in a 3 hours of source video, there is no guarantee that GOP size will remain same

  3) No consider, I am creating 7 MP4 files each with different bitrate and resolution. (These Mp4s will be encoded to smooth in later stage). Hence i am targeting adaptive streaming. But when I did that, I found that if GOP sizes were not consistent across each bitrates. What I mean by this is, for ex : if in Bitrate1 - GOP size is like 10, 20, 48 and so on, in other bitrates it wasnt in the same sequence. I hope my question makes sense.

  So is there a way to ensure that GOP size may vary across one single output. But it should be consistent across each bitrate provided that the source is same ?

  Also for adaptive streaming Is scenecut detection advisable ?