3g2 Notes

Target device

• LG-VX8100

High-quality video

• video: mpeg4, 176x144 (qcif), 15 fps, bitrate 120 kbps
• audio: aac, 22050 Hz, stereo (2 channels), bitrate 60 kbps
• size: 90MB/hour
• sample ffmpeg command (includes offset and duration for extracting a piece):

    ffmpeg -ss 2664 -t 33 -i in.mpg -acodec aac -ab 60 -ar 22050 -vcodec mpeg4 -s qcif -b 120 -r 15 out.3g2
  

Standard video

• video: h263, 176x144 (qcif), 12 fps, bitrate 30 kB/sec
• audio: aac, 8000 Hz, mono (1 channel), bitrate 12 kB/sec
• size: 20MB/hour

Music

• ordinary mp3 files will do
• filename length limit: 47 characters including dot and extension
• to save space, first use mp3info -x to find out which files are encoded with unnecessarily high quality, then transcode like so:

     for f in *.mp3
     do 
       ffmpeg -f mp3 -i "$f" -ar 44100 -ab 128 new-"$f"
       mv new-"$f" "$f"
     done