Bash脚本:自动化mpeg-dash的ffmpeg编码 [英] Bash script: automate ffmpeg encoding for mpeg-dash
问题描述
我正在编写一个bash文件，以创建视频编码和串联，以用于破折号实时流媒体使用， 基本上，它会读取输入视频文件夹，将所有视频编码为三种分辨率格式，然后将它们连接起来以创建三个适应集.
I'm writing a bash file to create video encoding and concatenation for dash live streaming use, Basically it read an input video folder, encodes all videos into three resolution formats, after that it concatening them to create three adaption sets.
图:
此脚本检查fps一致性，
This script checks for fps conformance,
力/缩放分辨率，
插入频道徽标png，
剪切所有视频输入的末尾以使它们以闭合的gop结束，以确保不存在音频和视频轨道长度不同的视频.
Cut the end of all videos input in order to make them finish with closed gop, this to ensure that there are not videos with audio and video track with different lenght.
问题:
实际上，我不确定连接过程是否遵循编码后的封闭GOP对齐方式. 我也尝试削减连接结果的末尾，以使其在封闭的gop上也没有小数结束，但是我无法从总持续时间中擦除所有小数:
Actually I'm not sure that the concatenation process respects the closed GOP alignment as it after the encoding.. I try to cut also the end of the concatenation result in order to make it finish without decimals on a closed gop too, but im unable to erase all decimals from the total duration:
total duration in seconds: 826.795000
total duration corrected in seconds: 826
但是ffprobe测量的实际持续时间是
But the real duration measured by ffprobe is
824.044000
我尝试用mp4box检查关键帧的对齐方式，如果它们没有任何结果的话:
I try to check keyframes alignment with mp4box has they teach without any result:
MP4Box -info TRACK_ID source1.mp4 2>&1 | grep GOP
这是我第一次使用视频脚本"，可能我不知道要为TRACK_ID提供什么输入
This is the first time that i work with "video scripts" and probably i don't know what input to give for TRACK_ID
BASH脚本:
#!/bin/bash
#CANCAT 0.2
cd input
times=()
fps=()
for f in *.mp4; do
_t=$(ffprobe -i "$f" -show_entries format=duration -v quiet -of csv="p=0")
times+=("$_t")
_f=$(ffmpeg -i "$f" 2>&1 | sed -n "s/.*, \\(.*\\) fp.*/\\1/p")
fps+=("$_f")
done
#SUM ALL DURATIONS
TOTALDURATION=$( echo "${times[@]}" | sed 's/ /+/g' | bc )
#DELETE DECIMAL
DURROUND=$(echo "$TOTALDURATION" | cut -d'.' -f1)
#GET REST OF DIVISION BY 2 AS GOP
TOTDELTA="$((DURROUND%2))"
#SUBTRACT DELTA FROM TOTAL DURATION
TOTDUR="$(($DURROUND-$TOTDELTA))"
#GET NUMBER OF ELEMENTS IN FPS ARRAY
tLen=${#fps[@]}
#CHECK FPS EQUALITY
for tLen in "${fps[@]:1}"; do
if [[ $tLen != ${fps[0]} ]]; then
printf "WARNING: VIDEO’S FRAME-RATE ARE NOT EQUALS, THE PROCESS CAN’T START."
printf "%s\\0" "${fps[@]}" |
sort -zu |
xargs -0 printf " %s"
printf "\\n"
exit 1
fi
done
for f in *.mp4; do
#GET DURATION OF EACH VIDEO
DUR="$(ffprobe -i "$f" -show_entries format=duration -v quiet -of csv="p=0")"
DUR=$(echo "$DUR" | cut -d'.' -f1) # DELETE DECIMAL
#GET FPS OF EACH VIDEO
FPS="$(ffmpeg -i "$f" 2>&1 | sed -n "s/.*, \(.*\) fp.*/\1/p")"
#ROUND FPS OF EACH VIDEO
FPSC=$( echo "($FPS+0.5)/1" | bc )
#REMOVE EXTENSION FROM VIDEO FILE NAME
NAME=$(echo "$f" | cut -d'.' -f1)
#GET GOP
GOP="$((FPSC*2))"
DELTADUR="$((DUR%2))"
DUR="$(($DUR-$DELTADUR))"
#ENCODE 1080p
ffmpeg -y -i "$f" -i ../logo/logo.png -c:a aac -b:a 384k -ar 48000 -ac 2 -async 1 -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -r $FPSC -b:v 4800k -maxrate 4800k -bufsize 3000k -profile:v main -crf 22 -t $DUR -filter_complex "[0:v][1:v]overlay=main_w-overlay_w-10:10,scale=1920:1080,setsar=1" ../buffer/${NAME}-1080.mp4
#ENCODE 720p
ffmpeg -y -i ../buffer/${NAME}-1080.mp4 -c:a aac -b:a 256k -ar 48000 -ac 2 -async 1 -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -s 1280x720 -r $FPSC -b:v 2400k -maxrate 2400k -bufsize 1500k -profile:v main -crf 22 -t $DUR ../buffer/${NAME}-720.mp4
#ENCODE 360p
ffmpeg -y -i ../buffer/${NAME}-720.mp4 -c:a aac -b:a 128k -ar 48000 -ac 2 -async 1 -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -s 640x360 -r $FPSC -b:v 800k -maxrate 800k -bufsize 500k -profile:v main -crf 22 -t $DUR ../buffer/${NAME}-360.mp4
done
#enter in buffer
cd ..
cd buffer
#CONCAT 1080 SET
# with a bash for loop
for f in ./*1080.mp4; do echo "file '$f'" >> 1080list.txt; done
ffmpeg -f concat -safe 0 -i 1080list.txt -t $TOTDUR -c copy ../output/1080set.mp4
#CONCAT 720 SET
# with a bash for loop
for f in ./*720.mp4; do echo "file '$f'" >> 720list.txt; done
ffmpeg -f concat -safe 0 -i 720list.txt -t $TOTDUR -c copy ../output/720set.mp4
#CONCAT 360 SET
# with a bash for loop
for f in ./*360.mp4; do echo "file '$f'" >> 360list.txt; done
ffmpeg -f concat -safe 0 -i 360list.txt -t $TOTDUR -c copy ../output/360set.mp4
#CLEAN BUFFER
rm *.mp4
rm *.txt
echo "CONCAT COMPLETED:"
echo "frame-rate: $fps"
echo "total duration in seconds: $TOTALDURATION"
echo "total duration corrected in seconds: $TOTDUR"
带有相对文件夹的完整文件:
The full file with relative folders:
有人可以帮助我理解为什么我在连音期间无法消除总持续时间的小数位吗? 以及如何检查总体关键帧分配? 同样欢迎任何我忽略的改进！
There is someone who can help me to understand why I can not eliminate the decimals of the total duration during concat? And how to check overall keyframes allignment? Also any impovement that i ignore is welcome!
非常感谢！
马西莫(Massimo)
Massimo
推荐答案
我了解算法中存在一个大错误:总持续时间是在单个视频剪辑过程之前计算出来的，因此总持续时间通常会更长有效修复时间，我会解决，
I understand that there was a big mistake in the algorithm: the total duration is calculated before the single videos cut process, so the total duration is always more long then the effective concatention duration, i fix it,
现在
total duration in seconds: 824.044000
total duration corrected in seconds: 824
ffprobe度量值:824.012000，我无法在没有小数的情况下获取它，并无法检查总体关键帧的对齐方式.
ffprobe measure: 824.012000, im unable to get it without decimals and check the overall keyframes alignment.
#!/bin/bash
#CANCAT 0.2
cd input
fps=()
# GET FPS OF ALL VIDEOS INTO ARRAY
for f in *.mp4; do
_f=$(ffmpeg -i "$f" 2>&1 | sed -n "s/.*, \\(.*\\) fp.*/\\1/p")
fps+=("$_f")
done
#GET NUMBER OF ELEMENTS IN FPS ARRAY
tLen=${#fps[@]}
#CHECK FPS EQUALITY
for tLen in "${fps[@]:1}"; do
if [[ $tLen != ${fps[0]} ]]; then
printf "WARNING: VIDEO’S FRAME-RATE ARE NOT EQUALS, THE PROCESS CAN’T START."
printf "%s\\0" "${fps[@]}" |
sort -zu |
xargs -0 printf " %s"
printf "\\n"
exit 1
fi
done
for f in *.mp4; do
#GET DURATION OF EACH VIDEO
DUR="$(ffprobe -i "$f" -show_entries format=duration -v quiet -of csv="p=0")"
DUR=$(echo "$DUR" | cut -d'.' -f1) # DELETE DECIMAL
#GET FPS OF EACH VIDEO
FPS="$(ffmpeg -i "$f" 2>&1 | sed -n "s/.*, \(.*\) fp.*/\1/p")"
#ROUND FPS OF EACH VIDEO
FPSC=$( echo "($FPS+0.5)/1" | bc )
#REMOVE EXTENSION FROM VIDEO FILE NAME
NAME=$(echo "$f" | cut -d'.' -f1)
#GET GOP
GOP="$((FPSC*2))"
DELTADUR="$((DUR%2))"
DUR="$(($DUR-$DELTADUR))"
#ENCODE 1080p
ffmpeg -y -i "$f" -i ../logo/logo.png -c:a aac -b:a 384k -ar 48000 -ac 2 -async 1 -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -r $FPSC -b:v 4800k -maxrate 4800k -bufsize 3000k -profile:v main -crf 22 -t $DUR -filter_complex "[0:v][1:v]overlay=main_w-overlay_w-10:10,scale=1920:1080,setsar=1" ../buffer/${NAME}-1080.mp4
#ENCODE 720p
ffmpeg -y -i ../buffer/${NAME}-1080.mp4 -c:a aac -b:a 256k -ar 48000 -ac 2 -async 1 -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -s 1280x720 -r $FPSC -b:v 2400k -maxrate 2400k -bufsize 1500k -profile:v main -crf 22 -t $DUR ../buffer/${NAME}-720.mp4
#ENCODE 360p
ffmpeg -y -i ../buffer/${NAME}-720.mp4 -c:a aac -b:a 128k -ar 48000 -ac 2 -async 1 -c:v libx264 -x264opts keyint=$GOP:min-keyint=$GOP:no-scenecut -bf 0 -s 640x360 -r $FPSC -b:v 800k -maxrate 800k -bufsize 500k -profile:v main -crf 22 -t $DUR ../buffer/${NAME}-360.mp4
done
#enter in buffer
cd ..
cd buffer
times=()
for f in *1080.mp4; do
_t=$(ffprobe -i "$f" -show_entries format=duration -v quiet -of csv="p=0")
times+=("$_t")
done
#SUM ALL DURATIONS
TOTALDURATION=$( echo "${times[@]}" | sed 's/ /+/g' | bc )
#DELETE DECIMAL
DURROUND=$(echo "$TOTALDURATION" | cut -d'.' -f1)
#GET REST OF DIVISION BY 2 AS GOP
TOTDELTA="$((DURROUND%2))"
#SUBTRACT DELTA FROM TOTAL DURATION
TOTDUR="$(($DURROUND-$TOTDELTA))"
#CONCAT 1080 SET
# with a bash for loop
for f in ./*1080.mp4; do echo "file '$f'" >> 1080list.txt; done
ffmpeg -f concat -safe 0 -i 1080list.txt -t $TOTDUR -c copy ../output/1080set.mp4
#CONCAT 720 SET
# with a bash for loop
for f in ./*720.mp4; do echo "file '$f'" >> 720list.txt; done
ffmpeg -f concat -safe 0 -i 720list.txt -t $TOTDUR -c copy ../output/720set.mp4
#CONCAT 360 SET
# with a bash for loop
for f in ./*360.mp4; do echo "file '$f'" >> 360list.txt; done
ffmpeg -f concat -safe 0 -i 360list.txt -t $TOTDUR -c copy ../output/360set.mp4
#CLEAN BUFFER
rm *.mp4
rm *.txt
echo "CONCAT COMPLETED:"
echo "frame-rate: $fps"
echo "total duration in seconds: $TOTALDURATION"
echo "total duration corrected in seconds: $TOTDUR"
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