Using ffmpeg to cut up video

Question

I am using ffmpeg to cut out a section of a large file like this:

ffmpeg -i input.wmv -ss 60 -t 60 -acodec copy -vcodec copy output.wmv

The -ss part works fine but the -t is ignored. It correctly removes the initial specified seconds specified with -ss but then keeps going to the end of the input with the copy.

Is there a way to use ffmpeg to cut off the end of a video without recoding it?

Answer 1

It needs to be in HH:MM:SS.xxx format. The following worked for me to clip the first 30 seconds, and then clip everything that is 10 seconds after that:

-ss 00:00:30.0 -t 00:00:10.0 

The full command might look like:

ffmpeg -ss 00:00:30.0 -t 00:00:10.0 -i input.wmv -acodec copy -vcodec copy -async 1 output.wmv

Answer 2

I can cut video files as below:

$ ffmpeg  -t 00:00:10 -vcodec copy -acodec copy -i 5.mpg test.mpg

FFmpeg version 0.6.2, Copyright (c) 2000-2010 the FFmpeg developers
  built on Apr 26 2011 18:20:20 with gcc 4.2.1 (Apple Inc. build 5664)
  configuration: --prefix=/opt/local --enable-gpl --enable-postproc --enable-swscale --enable-avfilter --enable-avfilter-lavf --enable-libmp3lame --enable-libvorbis --enable-libtheora --enable-libdirac --enable-libschroedinger --enable-libfaac --enable-libfaad --enable-libxvid --enable-libx264 --enable-libvpx --enable-libspeex --enable-nonfree --mandir=/opt/local/share/man --enable-shared --enable-pthreads --disable-indevs --cc=/usr/bin/gcc-4.2 --arch=x86_64
  libavutil     50.15. 1 / 50.15. 1
  libavcodec    52.72. 2 / 52.72. 2
  libavformat   52.64. 2 / 52.64. 2
  libavdevice   52. 2. 0 / 52. 2. 0
  libavfilter    1.19. 0 /  1.19. 0
  libswscale     1.11. 0 /  1.11. 0
  libpostproc   51. 2. 0 / 51. 2. 0
[mpeg @ 0x12180c800]max_analyze_duration reached
Input #0, mpeg, from '5.mpg':
  Duration: 00:01:32.68, start: 0.500000, bitrate: 1559 kb/s
    Stream #0.0[0x1e0]: Video: mpeg1video, yuv420p, 384x288 [PAR 1:1 DAR 4:3], 104857 kb/s, 25 fps, 25 tbr, 90k tbn, 25 tbc
    Stream #0.1[0x1c0]: Audio: mp2, 44100 Hz, 2 channels, s16, 128 kb/s
Output #0, mpeg, to 'test.mpg':
  Metadata:
    encoder         : Lavf52.64.2
    Stream #0.0: Video: mpeg1video, yuv420p, 384x288 [PAR 1:1 DAR 4:3], q=2-31, 104857 kb/s, 90k tbn, 25 tbc
    Stream #0.1: Audio: mp2, 44100 Hz, 2 channels, 128 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Press [q] to stop encoding
frame=  249 fps=  0 q=-1.0 Lsize=    1672kB time=10.00 bitrate=1369.7kbits/s    
video:1503kB audio:156kB global headers:0kB muxing overhead 0.790309%

Answer 3

Does using a unit work? (works here)

ffmpeg -i input.wmv -ss 60s -t 60s -acodec copy -vcodec copy output.wmv

Answer 4

what I ended up having to do was put the -t option after the input file: ffmpeg -ss 10s -i input.flv -t 5s output.flv

technically this was avconv not the original ffmpeg but perhaps it works with ffmpeg as well.

Answer 5

For me -t option didn't work, but -vframes worked. I prefer using #frames, since I would rather cut at I-Frames and I found out GOP for video using ffprobe.

The command line that worked for me is:

ffmpeg -ss 60s -i input.wmv -vframes 1800 -acodec copy -vcodec copy output.wmv

By the way, putting -ss in the front of -i makes a big difference in execution time.