Script for encoding web video with FFMPEG.

encode_web.sh

# This script transcodes a single MP4 video to WebM and Theora and
# creates a still for the video after 2 seconds

# Inspiration: http://johndyer.name/ffmpeg-settings-for-html5-codecs-h264mp4-theoraogg-vp8webm/

INFILE=$1
FORMAT=$2
BASENAME="${INFILE%.*}"

VIDEO_BITRATE="1500k"
AUDIO_BITRATE="160000"

if ! [[ -r $INFILE ]]; then
    echo "Input file '$INFILE' not readable. Exiting."
    echo "Usage: $0 <filename> <mp4|webm|theora|still>"
    exit -1
fi

# MP4/AAC
if [[ $FORMAT == 'mp4' ]]; then
    ffmpeg -i $INFILE \
        -vcodec libx264 -vpre slow -vpre baseline -b:v $VIDEO_BITRATE \
        -b:a $AUDIO_BITRATE \
        -g 30 $BASENAME.mp4

        exit 0
fi

# WebM
if [[ $FORMAT == 'webm' ]]; then
    echo 'Encoding WebM'
    ffmpeg -i $INFILE \
        -vcodec libvpx -b:v $VIDEO_BITRATE \
        -acodec libvorbis -b:a $AUDIO_BITRATE \
        -f webm -g 30 $BASENAME.webm

    exit 0
fi

# Theora
if [[ $FORMAT == 'theora' ]]; then
    echo 'Encoding Theora'
    ffmpeg -i $INFILE \
        -vcodec libtheora -b:v $VIDEO_BITRATE \
        -acodec libvorbis -b:a $AUDIO_BITRATE \
        -g 30 $BASENAME.ogv

    exit 0
fi

# Grabbing a still
if [[ $FORMAT == 'still' ]]; then
    echo 'Grabbing a still'
    ffmpeg -i $INFILE \
        -ss 00:02 -vframes 1 -r 1 \
        -f image2 $BASENAME.jpg

    exit 0

fi

echo 'Unknown format specifed.'
echo "Usage: $0 <filename> <mp4|webm|theora|still>"
exit -1