video grabber script for PAL VHS video

grab.sh

#!/bin/bash
#
# record from video grabber

VIDEO=${VIDEO:-/dev/video1}
AUDIO=${AUDIO:-hw:1}
AUDIO_RATE=48000
VIDEO_IN="-f video4linux2 -video_size 720x576 -thread_queue_size 1024 -framerate 25 -i $VIDEO -vsync 1"
AUDIO_IN="-f alsa -sample_rate $AUDIO_RATE -channels 2 -thread_queue_size 2048 -itsoffset 0.3 -i $AUDIO"

AUDIO_FILTER="-af aresample=async=1000"
VIDEO_FILTER="-vf format=yuv420p,setdar=4/3"

ACODEC_MP3="-acodec mp3 -ar $AUDIO_RATE -ac 2 -b:a 128k $AUDIO_FILTER"
ACODEC_AAC="-acodec aac -ar $AUDIO_RATE -ac 2 -b:a 128k $AUDIO_FILTER"


function myffmpeg {
    /usr/bin/ffmpeg -hide_banner "$@"
}
    
function mpeg4 {
    output="$1" ; shift
    myffmpeg \
    $VIDEO_IN \
    $AUDIO_IN \
    -vcodec mpeg4 -b:v 3000k -r 25 $VIDEO_FILTER \
    $ACODEC_AAC \
    -movflags faststart "$output".mp4 \
    -pix_fmt yuv420p -f opengl live -f pulse $AUDIO_FILTER live "$@"
}

function dvd {
    output="$1" ; shift
    myffmpeg \
    $VIDEO_IN \
    $AUDIO_IN \
    -target pal-dvd -b:v 8000 $VIDEO_FILTER $AUDIO_FILTER \
    "$output".mpg \
    -pix_fmt yuv420p -f opengl live -f pulse $AUDIO_FILTER live "$@"
}


function h264 {
    output="$1" ; shift
    myffmpeg \
    $VIDEO_IN \
    $AUDIO_IN \
    -vcodec h264 -preset faster -profile:v high -level 4.2 -tune film -crf 18 $VIDEO_FILTER \
    $ACODEC_AAC \
    -movflags faststart "$output".mp4 \
    -f opengl $VIDEO_FILTER live -f pulse $AUDIO_FILTER live "$@"    
}

function h264_complex {
    output="$1" ; shift
    myffmpeg \
    $VIDEO_IN \
    $AUDIO_IN \
    -filter_complex "format=yuv420p,setdar=4/3,split=[file][screen];aresample=async=1000,asplit=[afile][ascreen]" \
    -map '[file]' -map '[afile]' \
        -vcodec h264 -preset faster -profile:v high -level 4.2 -tune film -crf 18 \
        -acodec aac -ar $AUDIO_RATE -ac 2 -b:a 128k \
        -movflags faststart "$output".mp4 \
    -map '[screen]' -an \
        -f opengl live \
    -map '[ascreen]' -vn \
        -f pulse live "$@"
}

function dv {
    output="$1" ; shift
    myffmpeg \
    $VIDEO_IN \
    $AUDIO_IN \
    -target pal-dv $VIDEO_FILTER $AUDIO_FILTER \
    "$output".dv \
    -pix_fmt yuv420p -f opengl live -f pulse $AUDIO_FILTER live "$@"
}

function watch {
    ffmpeg $VIDEO_IN $AUDIO_IN -pix_fmt yuv420p $VIDEO_FILTER -f opengl live -f pulse $AUDIO_FILTER live "$@"
}

#mode="$1" ; shift
mode=h264_complex
$mode "$@"