Question

It seems like every time I split a .webm video, half or more of the frames are pixelated and distorted.

My configuration looks like the following:

FFmpeg version 0.6.6-4:0.6.6-0ubuntu0.11.04.1, Copyright (c) 2000-2010 the Libav developers
  built on Jun 12 2012 16:35:16 with gcc 4.5.2
  configuration: --extra-version=4:0.6.6-0ubuntu0.11.04.1 --prefix=/usr --enable-avfilter --enable-avfilter-lavf --enable-vdpau --enable-bzlib --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --enable-zlib --enable-libvpx --disable-stripping --enable-runtime-cpudetect --enable-vaapi --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --enable-libdc1394 --enable-shared --disable-static

Does anyone have any experience with something similar to this? When I play the same videos with a standard ffmpeg player on the same system, they look just fine.

Answer 1

If you’re just splitting a .webm file into 2 .webm files, then you need to add -vcodec copy -acodec copy to your command line, i.e. something like

ffmpeg -i input.webm -vcodec copy -acodec copy -ss 10 -t 10 output.webm

Otherwise ffmpeg will also transcode the video, using the default bitrate, which is low, and this causes the pixelation. Also, it makes the splitting much, much slower.