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• How to extract a video snippet from a video file that is being written in by ffmpeg in realtime

  26 février 2015, par alex.b

  At the moment i am recording a LIVE stream video from youtube with youtube-dl (https://github.com/rg3/youtube-dl)

  The command i use for this :

  youtube-dl --id -f 92 https://www.youtube.com/watch?v=VYlQJbsVs48

  92 is a format code that i got after executing a command to get the formats, that gave me this list :

  format code  extension  resolution note
  
  140          m4a        audio only DASH audio  144k , m4a_dash container, aac  @128k (48000Hz)
  
  141          m4a        audio only DASH audio  272k , m4a_dash container, aac  @256k (48000Hz)
  
  160          mp4        256x144    DASH video  124k , 15fps, video only
  
  133          mp4        426x240    DASH video  258k , 30fps, video only
  
  134          mp4        640x360    DASH video  616k , 30fps, video only
  
  135          mp4        854x480    DASH video 1116k , 30fps, video only
  
  136          mp4        1280x720   DASH video 2216k , 30fps, video only
  
  137          mp4        1920x1080  DASH video 4141k , 30fps, video only
  
  151          mp4        72p        HLS
  
  132          mp4        240p       HLS
  
  92           mp4        240p       HLS
  
  93           mp4        360p       HLS
  
  94           mp4        480p       HLS
  
  95           mp4        720p       HLS
  
  96           mp4        1080p      HLS  (best)

  This is creating a file called VYlQJbsVs48.mp4.part that gets bigger and bigger of course.

  Is there a way to extract a video snippet from that live stream or form the part file ? Or maybe there is a better way of doing this ?

  What i have noticed is that if i force quit iTerm2 while youtube-dl is running the .part file it creates wont contain any index information (something to do with an moov atom not being present in the mp4 file - which is the information about the number of frames and other things - metadata i think), so it makes me think i cannot extract from the file.

  Maybe if there would be a way that youtube-dl can write the index information at all times or maybe another way that i can record the live stream and get video snippets while its recording.

  I forgot to mention i am doing this on OSX Yosemite. I have FFMPEG installed with homebrew and youtoube-dl

  I am more than happy to try stuff on UBUNTU if there is a solution.

  Any help would be greatly appreciated.

  Thank you.

  Alex

• How to extract a video snippet from a video file that is being written in by ffmpeg in realtime

  31 juillet 2020, par alex.b

  At the moment i am recording a LIVE stream video from youtube with youtube-dl (https://github.com/rg3/youtube-dl)

  



  The command i use for this :

  



  youtube-dl --id -f 92 https://www.youtube.com/watch?v=VYlQJbsVs48


  



  92 is a format code that i got after executing a command to get the formats, that gave me this list :

  



  format code  extension  resolution note
140          m4a        audio only DASH audio  144k , m4a_dash container, aac  @128k (48000Hz)
141          m4a        audio only DASH audio  272k , m4a_dash container, aac  @256k (48000Hz)
160          mp4        256x144    DASH video  124k , 15fps, video only
133          mp4        426x240    DASH video  258k , 30fps, video only
134          mp4        640x360    DASH video  616k , 30fps, video only
135          mp4        854x480    DASH video 1116k , 30fps, video only
136          mp4        1280x720   DASH video 2216k , 30fps, video only
137          mp4        1920x1080  DASH video 4141k , 30fps, video only
151          mp4        72p        HLS
132          mp4        240p       HLS
92           mp4        240p       HLS
93           mp4        360p       HLS
94           mp4        480p       HLS
95           mp4        720p       HLS
96           mp4        1080p      HLS  (best)


  



  This is creating a file called VYlQJbsVs48.mp4.part that gets bigger and bigger of course.

  



  Is there a way to extract a video snippet from that live stream or form the part file ? Or maybe there is a better way of doing this ?

  



  What i have noticed is that if i force quit iTerm2 while youtube-dl is running the .part file it creates wont contain any index information (something to do with an moov atom not being present in the mp4 file - which is the information about the number of frames and other things - metadata i think), so it makes me think i cannot extract from the file.

  



  Maybe if there would be a way that youtube-dl can write the index information at all times or maybe another way that i can record the live stream and get video snippets while its recording.

  



  I forgot to mention i am doing this on OSX Yosemite. I have FFMPEG installed with homebrew and youtoube-dl

  



  I am more than happy to try stuff on UBUNTU if there is a solution.

  



  Any help would be greatly appreciated.

  



  Thank you.

  



  Alex

  


• Android, fast video processing

  27 avril 2016, par Ilja Kosynkin

  I have troubles in my current project which requires video processing. Basically crop function (video should be squared), trimming (video shouldn’t be longer than 30 seconds) and quality reduction (bitrate should be equal 713K).
  I’ve succesfully embedded FFmpeg into application, all functions are working quite fine except one major detail - processing as per my boss is taking too long time. For video that have around 52 MB for 36 seconds it’s taking 50 seconds to perforn all the operations (I’m trimming video to 30 seconds before any other operation obviously). The problem is that on parallel project on iOS video processing takes like 10-15 seconds for greater files. I assume that it’s related to fact that they’re using Apple QuickTime format which obviusly was developed by Apple so it’s not surprising that it’s working quite fast.
  So well, it was introduction, now my question : is there any way for Android to process any video in any quality (for now we can assume that all videos are in h264) in time of 10-15 seconds (not more then in 30 seconds, as my boss said) ? Some alternative to FFmpeg, that can perform operations faster ? I’nm pretty sure that there is no possibility to perform such work in a such short time, since I already feel like I searched thought while Internet, but I want to make sure that there is really no possibility to do such work. If anyone can provide me links to solution more faster than FFmpeg or confirm that there is no such solution, I will be very gratefull.

  Update
  Thanks to Alex Cohn I’ve resolved this with MediaCodec. After a while, I got 20 seconds processing on 52MB video with cropping to square and lowering bitrate. For any future Googlers out of here I can suggest to take a look at this respository :
  Many stuff about MediaCodec
  and more precisely at this file : Extract, edit and encode again, video and audio