Hi I need to extract frames from videos using ffmpeg.. Is there a faster way to do it than this:
ffmpeg -i file.mpg -r 1/1 $filename%03d.jpg
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Came across this question, so here's a quick comparison. Compare these two different ways to extract one frame per minute from a video 38m07s long:
time ffmpeg -i input.mp4 -filter:v fps=fps=1/60 ffmpeg_%0d.bmp
1m36.029s
This takes long because ffmpeg parses the entire video file to get the desired frames.
time for i in {0..39} ; do ffmpeg -accurate_seek -ss `echo $i*60.0 | bc` -i input.mp4 -frames:v 1 period_down_$i.bmp ; done
0m4.689s
This is about 20 times faster. We use fast seeking to go to the desired time index and extract a frame, then call ffmpeg several times for every time index. Note that -accurate_seek
is the default
, and make sure you add -ss
before the input video -i
option.
Note that it's better to use -filter:v -fps=fps=...
instead of -r
as the latter may be inaccurate. Although the ticket is marked as fixed, I still did experience some issues, so better play it safe.