#!/bin/bash

function _help() {
	echo "command"
	echo -e "\t split | merge | transition | compress"
	echo "param"
	echo -e "\t-f split or merge data file"
	echo -e "\t-i input video file"
	echo -e "\t-h help"
	exit 1
}

# 获取前缀
function _prefix() {
	[ "$DATA"x == ""x ] && _help
	PREFIX=`echo $DATA |cut -f1 -d'.'`
}

function _checkInput() {
	[ "$INPUT"x == ""x ] && _help
	FORMAT=`echo $INPUT |awk -F'.' '{print $NF}'`
	NAME=`echo $INPUT |awk -F'.' '{print $1}'`	
}

# 将使用win10 创建的转场动画转为 4k 分辨率，和 GeForce Experience 保持一致
function _transition() {
	_checkInput
	ffmpeg.exe -y -i $INPUT -s 3840x2160 -r 60 -video_track_timescale 90k $NAME-4k.$FORMAT
}

# DATA 格式
# 开始时间 持续时长，如：
# 00:00:00 00:00:10
function _split() {
	_checkInput
	_prefix
	[ ! -d $PREFIX ] && mkdir $PREFIX
	echo -n "" > $PREFIX/list.txt

	# 保证数据文件结尾换行
	cp $DATA $PREFIX/tmp.txt
	echo "" >> $PREFIX/tmp.txt

	ID=1
	while read line;do
		START=`echo $line |awk '{print $1}'`
		LENGTH=`echo $line |awk '{print $2}'`
		[ "$START"x == ""x ] && continue
		ffmpeg.exe -y -ss $START -t $LENGTH -accurate_seek -i $INPUT -codec copy  -avoid_negative_ts 1 $PREFIX/$ID.$FORMAT
		echo "file $ID.$FORMAT" >> $PREFIX/list.txt
		((ID=ID+1))
	done < $PREFIX/tmp.txt
	rm -f $PREFIX/tmp.txt
}

function _merge() {
	_prefix
	FORMAT=`head -n1 $DATA |awk -F'.' '{print $NF}'`
	ffmpeg.exe -y -f concat -i $DATA -c copy $PREFIX-merge.$FORMAT
}

function _compress() {
	_checkInput
	ffmpeg.exe -y -i $INPUT -r 30 -vf scale=-2:1080 $NAME-1080p.$FORMAT
	ffmpeg.exe -y -i $INPUT -r 30 -vf scale=-2:720 $NAME-720p.$FORMAT
}

COMMAND=$1

for i in "$@"
do
	key=$1
	case $key in
	-f) DATA=$2; shift 2;;
	-i) INPUT=$2; shift 2;;
	-h) _help;;
	*) shift;;
	esac
done

# 功能
case $COMMAND in
	"split") _split;;
	"transition") _transition;;
	"merge") _merge;;
	"compress") _compress;;
	*) _help;;
esac