[FFmpeg-user] How to split webm files quickly?

[Peng Yu]

Hi,

I am trying to split a webm file of 01:26:49.148000000 into chunks of
15 minutes each.

Output #0, webm, to 'input.webm':
  Metadata:
    encoder         : Lavf60.3.100
  Stream #0:0(eng): Video: vp9, yuv420p(tv, bt709, progressive),
1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 23.98 fps, 1k tbn (default)
    Metadata:
      DURATION        : 01:26:49.120000000
      encoder         : Lavc60.3.100 libvpx-vp9
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
  Stream #0:1(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
    Metadata:
      DURATION        : 01:26:49.148000000
frame= 4087 fps=4.8 q=30.0 size=   14848kB time=00:02:52.02 bitrate=
707.1kbits/s speed=0.202x


I currently use these commands to split it. But it is very slow. I
have waited for 15 minutes without getting the first chunk finished.
What is the fastest way to split a video file like this? Thanks.

f=input.webm
ffmpeg -i "$f" -acodec copy -ss 00:00:00 -t 00:15:00 0.webm
ffmpeg -i "$f" -acodec copy -ss 00:15:00 -t 00:30:00 1.webm
ffmpeg -i "$f" -acodec copy -ss 00:30:00 -t 00:45:00 2.webm
ffmpeg -i "$f" -acodec copy -ss 00:45:00 -t 01:00:00 3.webm
ffmpeg -i "$f" -acodec copy -ss 01:00:00 -t 01:15:00 4.webm
ffmpeg -i "$f" -acodec copy -ss 01:15:00                  5.webm

-- 
Regards,
Peng