1

For the project that I'm working on I have to cut some parts of same video with some subtitles. So I made a bash file that executes multiple ffmpeg commands like this.

ffmpeg -i input.mp4 -vf scale="w=640:h=-2",drawtext="fontfile=/usr/share/fonts/truetype/msttcorefonts/verdana.ttf: textfile='1.txt': fontcolor=white: fontsize=20: box=1: boxcolor=black@0.5: boxborderw=5: x=(w-text_w)/2: y=((h-text_h)/2)+90:" -ss 00:00:45.674 -to 00:00:50.093 -async 1 ./out/1.mp4

ffmpeg -i input.mp4 -vf scale="w=640:h=-2",drawtext="fontfile=/usr/share/fonts/truetype/msttcorefonts/verdana.ttf: textfile='2.txt': fontcolor=white: fontsize=20: box=1: boxcolor=black@0.5: boxborderw=5: x=(w-text_w)/2: y=((h-text_h)/2)+90:" -ss 00:00:49.344 -to 00:00:52.971 -async 1 ./out/2.mp4

but it fast for first times (start) of the input file, it gets slower if I want to start seeking from middle or near end of input. So it gets nearly 7-8 minutes for 22. minute of the input file...

ffmpeg -i input.mp4 -vf scale="w=640:h=-2",drawtext="fontfile=/usr/share/fonts/truetype/msttcorefonts/verdana.ttf: textfile='226.txt': fontcolor=white: fontsize=20: box=1: boxcolor=black@0.5: boxborderw=5: x=(w-text_w)/2: y=((h-text_h)/2)+90:" -ss 00:22:23.345 -to 00:22:25.846 -async 1 ./out/226.mp4

Anybody knows better way to do that? Can I do that without seeking file each time? (Because it seems this is a seeking problem to me....)

2

Use ss/to as input options. This seeks at the demuxer stage, which is much faster.

ffmpeg -ss 00:22:23.345 -to 00:22:25.846 -i input.mp4 ...

You'll need a very recent build of ffmpeg (> Nov 19 2017)

| improve this answer | |
  • I have already, should I move them before input file as parameter to executable? – tanaydin Jan 4 '18 at 15:48
  • -ss must be before the input file to be applied at the read-stage like the example shows – sebix Jan 4 '18 at 15:51
  • I'll try to build with recent source... Current ffmpeg under ubuntu is not accepting like this. – tanaydin Jan 4 '18 at 15:53
  • -ss as demuxer option is old, but -to wasn't implemented till the date stated. – Gyan Jan 4 '18 at 16:02
  • 1
    Use the git version from johnvansickle.com/ffmpeg – Gyan Jan 4 '18 at 16:31

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