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• split video (avi/h264) on keyframe

  30 novembre 2012, par m.sr

  Hallo.

  I have a big video file. ffmpeg, tcprobe and other tool say, it is an h264-stream in an AVI-container.

  Now i'd like to cut out small chunks form the video.

  1. Problem : The index of the video seam corrupted/destroyed. I kind of fixed this via mplayer -forceidx -saveidx <indexfile> <bigvideofile></bigvideofile></indexfile>. The Problem here is, that I'm now stuck with mplayer/mencoder which can use this index file via -loadidx <indexfile></indexfile>. I have tried correcting the index like described in man aviindex (mplayer -frames 0 -saveidx mpidx broken.avi ; aviindex -i mpidx -o tcindex ; avimerge -x tcindex -i broken.avi -o fixed.avi), but this didn't fix my video - meaning that most tools i've tested couldn't search in the video file.

  2. Problem : I cut out parts of the video via following command : mencoder -loadidx in.idx -ss 8578 -endpos 20 -oac faac -ovc x264 -sws 9 -lavfopts format=mp4 -x264encopts <lotsofopts> -of lavf -vf scale=800:-10,harddup in.avi -o out.mp4</lotsofopts>. Now here the problem is, that some videos are corrupted at the beginning. I think this is because the fact, that i do not necessarily cut at keyframe.

  Questions :

  1. What is the best way to fix the index of an avi "inline" so that every tool can again work as expected with it ?

  2. How can i split at the keyframes ? Is there an mencoder-option for this ?

  3. Are Keyframes coming in a frequency ? How to find out this frequency ? (So with a bit of math it should be possible to calculate the next keyframe and cut there)

  4. Is ther perhaps some completely other way to split this movie ? Doing it by hand is no option, i've to cut out 1000+ chunks ...

  Thanks a lot !

• x264 rate control set

  2 juillet 2015, par chinayin

  I have been learning x264 encode for months. What I need is to control the rate and get an average bitrate. Following is my set, I got an average bitrate but the picture quality is bad, so I need your suggestion or something that can help me learn more about x264.

  Params.rc.i_rc_method = X264_RC_ABR ;
  
  Params.rc.i_bitrate = nBitRate*0.65/1000  ;
  
  Params.rc.i_vbv_buffer_size = nBitRate/1000;
  
  Params.rc.i_vbv_max_bitrate = nBitRate*0.65/1000 ;
  
  Params.rc.f_vbv_buffer_init = 1.0 ;
  
  Params.rc.f_rate_tolerance = 1.0 ;                              
  
  Params.i_fps_num =  ParamIn.dFrameRate*0.6 ;
  
  Params.i_fps_den = 1 ;
  
  Params.i_width = ParamIn.nWidth ;
  
  Params.i_height = ParamIn.nHeight ;

• Playing RTSP stream in Android

  9 décembre 2014, par Kamil

  I’m trying to play video stream on Android device. Unfortunatelly I still get the same problem with MediaPlayer/VideoView. I’m searching for a few days, but still haven’t found any working solution.
  For test purposes I’m using MediaPlayer app from API Demos (API Demos/Media/MediaPlayer/Play Streaming Video).
  Here is code snippet for playing stream

  mMediaPlayer = new MediaPlayer();
  
  mMediaPlayer.setDataSource(path);
  
  mMediaPlayer.setDisplay(holder);
  
  mMediaPlayer.prepare();
  
  mMediaPlayer.setOnBufferingUpdateListener(this);
  
  mMediaPlayer.setOnCompletionListener(this);
  
  mMediaPlayer.setOnPreparedListener(this);
  
  mMediaPlayer.setOnVideoSizeChangedListener(this);

  When I try to play stream I get this info from logcat
  http://pastebin.com/5Uib5CH5

  This is configuration of ffserver streaming the video

  Port 8090
  
  BindAddress 0.0.0.0
  
  
  
  RTSPPort 7654
  
  RTSPBindAddress 0.0.0.0
  
  
  
  MaxHTTPConnections 2000
  
  MaxClients 1000
  
  MaxBandwidth 10000
  
  
  
  CustomLog -
  
  NoDaemon
  
  <Feed feed1.ffm>
  
  
  
  File /tmp/feed1.ffm
  
  FileMaxSize 5M
  
  
  
  Launch ffmpeg -i mmsh://tempserv.cam/vid1
  
  
  
  ACL allow 127.0.0.1
  
  
  
  </Feed>
  
  
  
  <Stream rat1.mpg>
  
  Feed feed1.ffm
  
  Format rtp
  
  NoAudio
  
  VideoBitRate 56k
  
  VideoBufferSize 40
  
  VideoFrameRate 12
  
  VideoSize 176x144
  
  VideoGopSize 12
  
  VideoCodec libx264
  
  AVPresetVideo baseline
  
  </Stream>

  If anyone can advise me how to fix it, or at least indicate an mistake, I will be grateful.