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• ffmpeg converting video to images while video file is being written

  15 octobre 2015, par user3398227

  Hopefully an easy question for an ffmpeg expert !

  I’m currently converting large (+6GB) mpeg video into an image sequence - which is working well using the below ffmpeg command :

  ffmpeg -i "input.mpeg" -vf - fps=fps=2 -f image2 -qscale 1 -s 1026x768 "output%6d.jpg"

  however i have to wait for the file to finish being written to disk before i kick off ffmpeg - but this takes a good hour or so to finish writing, but what i’ve noticed is that ffmpeg can start reading the file while its being written to disk - the only snag here is it gets to the end of the file and stops before the file has finished being written...

  Question is, is there a way that ffmpeg can convert to an image sequence at the same pace the video is being written (and not exit out ?)... or know to wait for the next frame to be written from the source. (unfortunately the input doesn’t support streaming, I only get a network drive and file to work off.. ) I thought i read somewhere that ffmpeg can process at the video frame rate but cant seem to find this command for love or money in the doco !!

  Thanks !

• Demuxing .AVI Video Muxed using mpegts on 3 Video Streams

  11 juin 2022, par nwf1115

  I have output from a Python program that comes out as a single .AVI that contains 3 video streams, however, it seems that they are all combined. The videos are not concatenated, but they are interlaced. The code that produces it is pretty abstract and the only thing I can tell is that they used Gstreamer to combine the videos. I can pick out H.264 encoding and mpegts and output as an .AVI. Using ffprobe on the file I get the following output :

  


  Input #0, mpegts, from 'output.avi':
  Duration: 00:05:00.07, start: 12045.450000, bitrate: 33695 kb/s
  Program 1
    Stream #0:0[0xdd]: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(progressive), >1920x1080 [SAR 1:1 DAR 16:9], 15 fps, 15 tbr, 90k tbn, 30 tbc


  


  I'm needing to separate the videos contained in this .AVI file, but I'm having trouble doing so using ffmpeg since there are not separate streams for each video.

  


  Does anyone have any tips on how to do this using ffmpeg or gstreamer ?

  


  Update : Upon further experimentation, it does not seem that the frames are interlaced, rather the stream of data was in some way, combined in some manner.

  


• FFMPEG add audio to a video but clip it to the video length

  5 novembre 2011, par Daniel Lloyd-Wood

  I'm trying to create a video from an image sequence and add audio with FFMPEG

  The frame sequence is only 25 frames long but the audio is several minutes. I want FFMPEG to clip the audio to the length of the frame sequence.

  This is the command I have tried :

  ffmpeg -i input_images%04d.jpg -pix_fmt yuv420p -vcodec mjpeg -qmin 1 -qmax 1 -r 25 -i audio_file.mp3 -ar 22050 -ab 192k -aframes 25 output.mov

  This results in a video with the first image sequence but the full length audio. -aframes is ignored. Any ideas ?