Usefull snippets to work with video under Linux

video-snippet.sh

# cut video
## mencoder (bad way)
## http://www.misterhowto.com/?category=Computers&subcategory=Video&article=trim_or_split_with_mencoder
mencoder -endpos 00:01:32 -ovc copy -oac copy MVI_0587.MOV -o cutted2.mov

## ffmpeg (cut better)
## from 00:00 to 00:01:32 to separete file
ffmpeg -i MVI_0587.MOV -c:v -acodec copy -ss 00:00:00 -t 00:01:32 cutted.mov

# concatenate (ok)
# http://www.misterhowto.com/index.php?category=Computers&subcategory=Video&article=join_with_mencoder
mencoder -oac copy -ovc copy -idx -o output.avi video1.avi video2.avi video3.avi

* The -oac copy option tells mencoder to just copy the audio stream (no reencoding). -ovc copy does the same with the video stream.
* The -idx option asks mencoder to build the index if none was found. This makes searching inside the video easier.
-o stands for "output" and specifies the output file.
* The last few parameters are the input video files.
* You can join as many files as you like. This will work for videos of the same resolution, and using the same codec, but any video format that mencoder recognizes is fine.

# convert to other codec (ok)
mencoder inputfile.MOV -o out.mkv -oac mp3lame -ovc x264
avconv -r 30 -i out.h264 -vcodec h264 out-avconv-h264.mp4

for vi in $(ls *.MOV) ;
do 
  echo "$vi"; 
  mencoder -quiet "$vi" -o "${vi//MOV/mkv}" -oac mp3lame -ovc x264; 
done

# convert and cut (ok)
mencoder MVI_0587.MOV -o out.mkv -oac mp3lame -ovc x264 -endpos 00:01:32

# ---
# video recoding from webcam

# get supported resolution
$ ffmpeg -f v4l2 -list_formats all -i /dev/video0

# record with sound
$ arecord -l
# remember magic name from output
# https://arashafiei.wordpress.com/2012/10/12/capture-video-and-audio-from-webcam-using-ffmpeg/
$ ffmpeg -f video4linux2 -r 25 -i /dev/video0 -f alsa -i plughw:U0x46d0x824,0 -ar 22050 -ab 128k -b:v 600K -strict experimental -acodec aac -vcodec mpeg4 -y webcam.mp4