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• How can I extract the characteristics of multimedia video stream while the video is streaming ?

  10 mai 2021, par Kai

  I have built adaptive video streaming ,DASH, over SDN network and was wondering if I can get some video characteristics while the video is streaming. I have used youtube_dl and was able to get the received video after the completion of the stream however, I want to get the video characteristics such as (stream size, bitrate, frame rate, resolution and etc.) while streaming. I hope that you can provide me with a script to extract and generate a file that contains such information.

  


• vcodec copy does not work when start/duration is messed up in video file

  25 janvier 2014, par anishsane

  My Video file shows below meta-data with ffprobe/ffmpeg :

  Duration: 00:44:27.52, start: 1333.760000, bitrate: 335 kb/s
  
    Stream #0.0(und): Video: h264 (Main), yuv420p, 640x480, 25 tbr, 90k tbn, 50 tbc

  Note : The file does not contain audio.

  I am trying to convert this video file to other video file, using ffmpeg/avconv.

  This works : (but encodes h.264 video to mpeg4)

  ffmpeg -i input.mp4 output.mp4

  & it generates output file of proper duration (44:27 - 1333 seconds = 22:14)

  This does not work :

  ffmpeg -i input.mp4 -vcodec copy output.mp4

  Generates file without video.

  The output contains :

  $ avconv -i input.mp4 -vcodec copy output.mp4
  
  
  
  avconv version 0.8.9-6:0.8.9-0ubuntu0.13.10.1, Copyright (c) 2000-2013 the Libav developers
  
    built on Nov  9 2013 19:09:46 with gcc 4.8.1
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  
    Metadata:
  
      major_brand     : dash
  
      minor_version   : 0
  
      compatible_brands: iso6avc1mp41
  
      creation_time   : 2014-01-19 22:43:21
  
    Duration: 00:44:27.52, start: 1333.760000, bitrate: 335 kb/s
  
      Stream #0.0(und): Video: h264 (Main), yuv420p, 640x480, 25 tbr, 90k tbn, 50 tbc
  
      Metadata:
  
        creation_time   : 2014-01-19 22:43:21
  
  Output #0, mp4, to 'output.mp4':
  
    Metadata:
  
      major_brand     : dash
  
      minor_version   : 0
  
      compatible_brands: iso6avc1mp41
  
      creation_time   : 2014-01-19 22:43:21
  
      encoder         : Lavf53.21.1
  
      Stream #0.0(und): Video: ![0][0][0] / 0x0021, yuv420p, 640x480, q=2-31, 90k tbn, 90k tbc
  
      Metadata:
  
        creation_time   : 2014-01-19 22:43:21
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
  Press ctrl-c to stop encoding
  
  frame=    0 fps=  0 q=-1.0 Lsize=       0kB time=10000000000.00 bitrate=   0.0kbits/s    
  
  video:0kB audio:0kB global headers:0kB muxing overhead inf%

• How to process and upload large video files directly to cloud with ffmpeg but without fragmented MP4 ?

  9 avril 2024, par volume one

  I am using ffmpeg via fluent-ffpmeg for Node.js to process videos uploaded by users.

  


  The problem I have is if a user uploades a huge movie file, say 8GB in size, then I don't want to store the file on the server as it will soon reach full capacity of space.

  


  I thought a way to tackle this was to stream the output from ffmpeg straight to cloud storage like AWS S3. The only way to do this (I believe) is using a PassThrough() stream :

  


  import PassThrough from 'node:stream' ;
import FFMpeg from 'fluent-ffmpeg' ;

  


  let PassThroughStream = new PassThrough() ;

  


           FFMpeg('/testvideo.mp4')
                .videoCodec('libx264')
                .audioCodec('libmp3lame')
                .size(`640x480`)
                // Stream input requires manually specifying input format
                .inputFormat('mp4')
                // Stream output requires manually specifying output formats
                .format('mp4')
                // Must be fragmented for stream to work. This causes duration problem.
                .outputOptions('-movflags dash')
                .pipe(PassThroughStream, {end: true})


  


  When the video is created using fragmented MP4, there is no duration associated with the file which means it has no length metadata. That makes playback difficult in a browser and is unacceptable :

  


  

  


  The only way I have been able to get a proper length property set in the file's metadata is by not using fragmented MP4 (that is the -movflags dash part in the code above). By not using this, I cannot stream the output directly to cloud storage - I have to save the file somewhere locally first.

  


  I think I am missing something but don't know what. How could this be solved ? I want to process and write the output to AWS S3 without storing the file locally without creating a fragmented MP4.