Re: libraries for processing video

[Benjamin Lau <benjamin.a.lau@gmail.com>]

Why not wrap avconv and ffmpeg using the Python sh module[1]?

I was kind of curious about the problem myself so I did an
implementation of the thumbnail extraction using ffprobe and ffmpeg
(attached).[2]

[1] python-pbs pre-jessie, python-sh in jessie and sid
https://github.com/amoffat/sh
[2] based on this answer from SU: http://superuser.com/a/821680

On Sat, Mar 21, 2015 at 3:20 AM, Etienne Millon <me@emillon.org> wrote:
> * Brian May <brian@microcomaustralia.com.au> [150321 11:07]:
>> I need to be able to generate a thumbnail of designated size and
>> also tell what the width and height in pixels of the video; Being
>> able to scale the video would be even better, but optional, I
>> currently use avconv to do this.
>
> You should be able to get metadata using python-enzyme ; not sure
> about what's best to actually extract the thumbnail.
>
> --
> Etienne Millon
>
>
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from sh import ffmpeg,ffprobe
import sys
import json
movie = sys.argv[1]
frames = int(sys.argv[2])
videometadata = ffprobe("-v", "quiet",
                        "-print_format", "json",
                        "-show_format",
                        "-show_streams",
                        movie)
videometadata = json.loads(videometadata.stdout)
duration = float(videometadata['format']['duration'])
print "Generating %d thumbnails for %s" % (frames,movie)
for x in range(1,frames+1):
    timepoint = int( (x - 0.5) * duration / frames)
    print "    Extracting thumbnail %d/%d @ %d" % (x,frames,timepoint)
    ffmpeg('-y', '-v', 'quiet',
           '-ss', timepoint,
           '-i', '%s' % movie,
           '-vframes', '1',
           'image%d.jpg' % x)