video-transcode

#!/bin/bash
# Copyright (C) 2009-2013, Kees Cook <kees@outflux.net>
# License: GPLv3
#
# For 1080i might need hack for http://bugzilla.mplayerhq.hu/show_bug.cgi?id=798
# http://forum.doom9.org/archive/index.php/t-124528.html
#
# Use differently compiled mencoder via $MENCODER environment variable.
# Use additional mencoder options via $MENCODER_OPTS environment variable.
set -e

res="$1"
shift || true

out="$1"
shift || true

if [ -z "$out" ] || [ -z "$1" ]; then
    echo "Usage: $0 res DEST SOURCE..." >&2
    echo "Examples" >&2
    echo "  $0 output.avi dvd://3 -dvd-device TITLE_S1_D4 -aid 128" >&2
    exit 1
fi

if [ -f "$out" ]; then
    echo "Not overwriting existing file '$out'" >&2
    exit 1
fi

mplayer_info=$($(dirname $0)/video-info "$@")

# Attempt to detect busted 1080 demuxer.
video_height=$(echo "$mplayer_info" | grep ^ID_VIDEO_HEIGHT | tail -n1 | cut -d= -f2- | cut -d. -f1)
demuxer=""
if [ "$video_height" -eq 1088 ]; then
    demuxer="-demuxer lavf"
    mplayer_info=$($(dirname $0)/video-info $demuxer "$@")
fi

# Examine info (with potentially adjusted demuxer) for actionable information.
video_height=$(echo "$mplayer_info" | grep ^ID_VIDEO_HEIGHT | tail -n1 | cut -d= -f2- | cut -d. -f1)
video_fps=$(echo "$mplayer_info" | grep ^ID_VIDEO_FPS | tail -n1 | cut -d= -f2- | cut -d. -f1)
vcodec=$(echo "$mplayer_info" | grep ^ID_VIDEO_CODEC | tail -n1 | cut -d= -f2-)
audio_format=$(echo "$mplayer_info" | grep ^ID_AUDIO_FORMAT | tail -n1 | cut -d= -f2- | cut -d. -f1)

# Detect uncopyable audio formats and force encoding.
oac=copy
if [ "$audio_format" = "twos" ] || [ "$audio_format" = "MP4A" ]; then
    oac=mp3lame
fi

# By default, disable subtitle handling.
subs="-nosub"

# Is there an existing EDL? Use it during encode.
edl=""
if [ -r "$1".edl ]; then
    edl="-edl $1.edl -hr-edl-seek -quiet"
fi

remux=""
deint=""
bitrate=""

case $res in
    480p)
        bitrate=1750
        ;;

    480|480i)
        bitrate=1750

        if [ "$video_fps" = "29.970" ]; then
            deint="-vf filmdint=io=29970:23976/fast=0,softskip -fps 30000/1001 -ofps 24000/1001"
        fi
        ;;

    720)
        # At 30fps, lower bit rate
        bitrate=2400

        if [ $video_fps -gt 30 ]; then
            # Broadcast 60/1001 fps

            # Works, but needs playback with -mc 1
            bitrate=4800
            deint="-mc 10 -noskip"
        fi
        ;;

    1080)
        # Resize to 720p!
        bitrate=2400
        scale=",scale=-2:720"

        # Resize to 480p ...
        #bitrate=800
        #scale=",scale=-2:480"

        # Leave at 1080...
        #bitrate=4000
        #scale=""

        if [ "$video_fps" = "29.970" ]; then
            # Default 29.97fps to 23.976fps deinterlacing
            deint="-vf filmdint=io=29970:23976/fast=0,softskip${scale} -fps 30000/1001 -ofps 24000/1001"
            # Hack for cropping!
            #deint="-vf filmdint=crop=1424:808:248:128 -fps 30000/1001 -ofps 24000/1001"
        fi

        # Try different deinterlacing?
        #deint="-vf yadif=1,framestep=2,filmdint=dint_thres=256,scale=-2:720 -fps 30000/1001 -ofps 24000/1001"

        if [ $video_fps -gt 30 ]; then
            # In the 59.94 fps case, tricking filmdint seems to help, but
            # then the A/V is wildly out of sync, so it needs a remuxing
            # as the final step, but that doesn't really work either.
            deint="-vf filmdint=io=29970:23976/fast=0,softskip${scale} -fps 60000/1001 -ofps 24000/1001"
            remux=1
        fi

        ;;

    crazy1080p)
        bitrate=4800

        if [ $video_fps -gt 30 ]; then
            # Works, untested, but I suspect it needs playback with -mc 1
            bitrate=6400
            deint="-mc 10 -noskip"
        fi
        ;;
    *)
        echo "Unknown video height $video_height" >&2
        exit 1
        ;;
esac

log=$(mktemp -t divxlog-XXXXXX)
opts="$edl $demuxer $subs $deint -oac $oac -passlogfile $log -ovc lavc -lavcopts vcodec=mpeg4:vhq:v4mv:vqmin=2:autoaspect=1:vbitrate=$bitrate"
opts_pass1="$opts:vpass=1"
opts_pass2="$opts:vpass=2"

set -x
${MENCODER:-mencoder} $MENCODER_OPTS $opts_pass1 "$@" -o /dev/null
${MENCODER:-mencoder} $MENCODER_OPTS $opts_pass2 "$@" -o "$out"

if [ -n "$remux" ]; then
    mv "$out" "$out".avi
    ffmpeg -i "$out".avi -i "$out".avi -vcodec copy -acodec copy -map 0.0 -map 1.1 "$out"
fi
rm -f $log