•type, t
指定类型是in代表淡入，out代表淡出，默认为in

•start_frame, s
指定应用效果的开始时间，默认为0.

•nb_frames, n
应用效果的最后一帧序数。
对于淡入，在此帧后将以本身的视频输出，对于淡出此帧后将以设定的颜色输出，默认25.

•alpha
如果设置为1，则只在透明通道实施效果（如果只存在一个输入），默认为0

•start_time, st
指定按秒的开始时间戳来应用效果。
如果start_frame和start_time都被设置，则效果会在更后的时间开始，默认为0

•duration, d
按秒的效果持续时间。
对于淡入，在此时后将以本身的视频输出，对于淡出此时后将以设定的颜色输出。
如果duration和nb_frames同时被设置，将采用duration值。默认为0（此时采用nb_frames作为默认）

•color, c
设置淡化后（淡入前）的颜色，默认为"black".

•30帧开始淡入
fade=in:0:30

•等效上面
fade=t=in:s=0:n=30

•在200帧视频中从最后45帧淡出
fade=out:155:45 fade=type=out:start_frame=155:nb_frames=45

•对1000帧的视频25帧淡入，最后25帧淡出:
fade=in:0:25, fade=out:975:25

•让前5帧为黄色，然后在5-24淡入:
fade=in:5:20:color=yellow

•仅在透明通道的第25开始淡入
fade=in:0:25:alpha=1

•设置5.5秒的黑场，然后开始0.5秒的淡入:
fade=t=in:st=5.5:d=0.5

ffmpeg -i 1.mp4 -vf fade=in:0:50 out3.mp4

Apply Gaussian blur filter.

The filter accepts the following options:

sigma
Set horizontal sigma, standard deviation of Gaussian blur. Default is 0.5.

steps
Set number of steps for Gaussian approximation. Default is 1.

planes
Set which planes to filter. By default all planes are filtered.

sigmaV
Set vertical sigma, if negative it will be same as sigma. Default is -1.

ffmpeg -i 纸短情长.mp4 -filter_complex [0:v]crop=(ih/16*9):ih,scale=iw/10:-2,gblur=sigma=5,scale=720:1280[vbg];[vbg][0:v]overlay=0:(H-h)/2 -y out.mp4	

[0:v]crop=(ih/16*9):ih,scale=iw/10:-2,gblur=sigma=5,scale=720:1280[vbg];

[vbg][0:v]overlay=0:(H-h)/2

ffmpeg -i ceshi2.png -i mask.png -filter_complex [1:v]alphaextract[mask];[0:v][mask]alphamerge -y out.png

ffmpeg -i mask.png -vf alphaextract -y extract.png

color
The color which will be replaced with transparency.
用于抠图的背景色。这个色值将会被替换成透明色

similarity
Similarity percentage with the key color.
0.01 matches only the exact key color, while 1.0 matches everything.
相似度，范围[0.01-1]，1的话匹配所有色值


blend
Blend percentage.
0.0 makes pixels either fully transparent, or not transparent at all.
Higher values result in semi-transparent pixels, with a higher transparency the more similar the pixels color is to the key color.
透明度[0-1]，默认0，完全透明，例如0.5则是50%的透明度

ffmpeg -i pic1.png -vf colorkey=0xc9c8c8:0.3 -y colorkey_test_1.png

Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
边缘检测，使用canny边缘算法

The filter accepts the following options:
滤镜接收一下参数

low
high
Set low and high threshold values used by the Canny thresholding algorithm.
设置Canny阈值算法使用的低阈值和高阈值。

The high threshold selects the "strong" edge pixels, which are then connected through 8-connectivity with the "weak" edge pixels selected by the low threshold.
高阈值选择“强”边缘像素，然后通过8-连通性与低阈值选择的“弱”边缘像素连接
四连通区域是11011其中0代表中心点，4个1代表上下左右四个方向。
八连通区域是111101111也就是除了上下左右四个方向外，还有左上、右上、左下、右下。

low and high threshold values must be chosen in the range [0,1], and low should be lesser or equal to high.
必须在[0,1]范围内选择低阈值和高阈值，低阈值应小于或等于高阈值。

Default value for low is 20/255, and default value for high is 50/255.
“低”的默认值为20/255，“高”的默认值为50/255

mode
Define the drawing mode.
定义绘图模式

‘wires’
Draw white/gray wires on black background.
如上图，黑白

‘colormix’
Mix the colors to create a paint/cartoon effect.
最后生成图，类似油画效果，卡通效果

‘canny’
Apply Canny edge detector on all selected planes.

Default value is wires.

planes
Select planes for filtering. By default all available planes are filtered.

ffmpeg -i 11.jpg -vf color=c=green:s=720x1280[vbg];[vbg][0:v]overlay=x='if(lte(t,5),-w+(W+w)/2/5*t,(W-w)/2)':y=(H-h)/2 -t 5 -y move.mp4

//输入文件
-i 11.jpg

//创建一个绿色的底板
color=c=green:s=720x1280[vbg]

//两个层叠加
[vbg][0:v]overlay=x='if(lte(t,5),-w+(W+w)/2/5*t,(W-w)/2)':y=(H-h)/2
//x的坐标
x='if(lte(t,5),-w+(W+w)/2/5*t,(W-w)/2)'
//y的坐标
y=(H-h)/2

//总时长5秒
-t 5

//生成并覆盖文件
-y move.mp4

核心是x的坐标计算
x='if(lte(t,5),-w+(W+w)/2/5*t,(W-w)/2)'

lte(t,5)当t小于等于5的时候，执行-w+(W+w)/2/5*t

其中最核心的是-w+(W+w)/2/5*t
1.移动距离(W+w)/2
2.移动速度(W+w)/2/5
3.当前时刻的移动距离(W+w)/2/5*t
4.当前位置-w+(W+w)/2/5*t

ffmpeg –i input –r 25 output # 用 -r 参数设置帧率
ffmpeg -i 1.mp4 -vf fps=fps=25 11.mp4  # 用fps的filter设置帧率

ffmpeg -i input.avi -r 29.97 output.mp4
ffmpeg -i input.avi -r 30000/1001 output.mp4
ffmpeg -i input.avi -r netsc output.mp4

ffmpeg -i 1.mp4 -b 1.5M 2.mp4  # 设置参数-b
ffmpeg -i input.avi -b:v 1500k output.mp4 # 音频：-b:a ,视频： -b:v  设置视频码率为1500kbps

控制输出文件大小
-fs (file size首字母缩写) 
    ffmpeg -i input.avi -fs 1024K output.mp4

计算输出文件大小
    (视频码率+音频码率) * 时长 /8 = 文件大小

crop的参数格式为w:h:x:y，
w、h为输出视频的宽和高，
x、y标记输入视频中的某点，将该点作为基准点，向右下进行裁剪得到输出视频。
    如果x y不写的话，默认居中剪切

ffmpeg -i 3.mp4 -vf crop=400:400 33.mp4 -y
ffmpeg -i 3.mp4 -vf crop=400:400:0:0 333.mp4 -y

ffmpeg -i 1.mp4 -filter_complex "[0:v]pad=h=2*ih[a];[0:v]vflip[b];[a][b]overlay=y=h" duichen3.mp4 -y

ffmpeg -i 1.mp4 -filter_complex "[0:v]pad=w=2*iw[a];[0:v]hflip[b];[a][b]overlay=x=w" duichen2.mp4 -y

ffmpeg -i 4.mp4 -vf "split [main][tmp];[tmp] crop=iw:ih/2:0:0, vflip [flip];[main][flip] overlay=0:H/2" 44.mp4 -y

1.mp4
原视频

2.mp4
将视频宽度放大一倍，高不变，视频被横向拉伸
ffmpeg -i 1.mp4 -vf scale=iw*2:ih 2.mp4

3.mp4
宽高各放大一倍
ffmpeg -i 1.mp4 -vf scale=iw*2:ih*2 3.mp4

4.mp4
将宽度扩展一倍，不是缩放，不是拉伸，而是加长，用黑色填充。
ffmpeg -i 1.mp4 -vf pad=2*iw 4.mp4

5.mp4
视频水平翻转hflip 如果是竖直翻转vflip
ffmpeg -i 1.mp4 -vf hflip 5.mp4

6.mp4
将视频4和5结合，5放在4的空白区域内
ffmpeg -i 4.mp4 -i 5.mp4 -filter_complex overlay=w:0 6.mp4

7.mp4
使用过滤器链，一句命令搞定4，5，6步
ffmpeg -i 1.mp4 -vf split[a][b];[a]pad=2*iw[1];[b]hflip[2];[1][2]overlay=w:0 7.mp4
    F1: split过滤器创建两个输入文件的拷贝并标记为[a],[b]
    F2: [a]作为pad过滤器的输入，pad过滤器产生2倍宽度并输出到[1].
    F3: [b]作为hflip过滤器的输入，vflip过滤器水平翻转视频并输出到[2].
    F4: 用overlay过滤器把 [2]覆盖到[1]的旁边.

1、用-s参数设置视频分辨率，参数值wxh，w宽度单位是像素，h高度单位是像素
ffmpeg -i input_file -s 320x240 output_file

2、预定义的视频尺寸
    下面两条命令有相同效果
    ffmpeg -i input.avi -s 640x480 output.avi
    ffmpeg -i input.avi -s vga output.avi

Scale filter的优点是可以使用一些额外的参数
    Scale=width:height[:interl={1|-1}]
    
下面两条命令有相同效果
    ffmpeg -i input.mpg -s 320x240 output.mp4 
    ffmpeg -i input.mpg -vf scale=320:240 output.mp4

对输入视频成比例缩放
改变为源视频一半大小
    ffmpeg -i input.mpg -vf scale=iw/2:ih/2 output.mp4
改变为原视频的90%大小：
    ffmpeg -i input.mpg -vf scale=iw*0.9:ih*0.9 output.mp4

宽度固定400，高度成比例：
    ffmpeg -i input.avi -vf scale=400:-2

相反地，高度固定300，宽度成比例：
    ffmpeg -i input.avi -vf scale=-2:300

w, out_w
The width of the output video. It defaults to iw. This expression is evaluated only once during the filter configuration, or when the ‘w’ or ‘out_w’ command is sent.

h, out_h
The height of the output video. It defaults to ih. This expression is evaluated only once during the filter configuration, or when the ‘h’ or ‘out_h’ command is sent.

x
The horizontal position, in the input video, of the left edge of the output video. It defaults to (in_w-out_w)/2. This expression is evaluated per-frame.

y
The vertical position, in the input video, of the top edge of the output video. It defaults to (in_h-out_h)/2. This expression is evaluated per-frame.

crop=w=100:h=100:x=12:y=34

width, w
height, h
Set the output video dimension expression. Default value is the input dimension.

If the width or w value is 0, the input width is used for the output. If the height or h value is 0, the input height is used for the output.

If one and only one of the values is -n with n >= 1, the scale filter will use a value that maintains the aspect ratio of the input image, calculated from the other specified dimension. After that it will, however, make sure that the calculated dimension is divisible by n and adjust the value if necessary.

If both values are -n with n >= 1, the behavior will be identical to both values being set to 0 as previously detailed.

See below for the list of accepted constants for use in the dimension expression.

scale=w=200:h=100
scale=w=iw/2:h=ih/2

x
y
Set the expression for the x and y coordinates of the overlaid video on the main video.
Default value is "0" for both expressions. 
In case the expression is invalid, it is set to a huge value 
(meaning that the overlay will not be displayed within the output visible area)

overlay=0:0

ffmpeg -i 10.mp4 -vf scale=1111:1111 101010.mp4

ffmpeg -i 10.mp4 -vf scale=1110:1110 101010.mp4

ffmpeg -i 10.mp4 -vf scale=trunc(1111/2)*2:trunc(1111/2)*2 101010.mp4

ffmpeg -i in.mp4 -vf scale=iw:-2 out.mp4

ffmpeg -i INPUT OUTPUT

ffmpeg -i INPUT -map single_highest_quality_video_stream_from_all_inputs -map single_highest_quality_audio_stream_from_all_inputs OUTPUT

# fmpeg -i input.mkv

ffmpeg version ... Copyright (c) 2000-2012 the FFmpeg developers
...
Input #0, matroska,webm, from 'input.mkv':
  Duration: 01:39:44.02, start: 0.000000, bitrate: 5793 kb/s
    Stream #0:0(eng): Video: h264 (High), yuv420p, 1920x800, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
    Stream #0:1(ger): Audio: dts (DTS), 48000 Hz, 5.1(side), s16, 1536 kb/s (default)
    Stream #0:2(eng): Audio: dts (DTS), 48000 Hz, 5.1(side), s16, 1536 kb/s
    Stream #0:3(ger): Subtitle: text (default)
At least one output file must be specified

ffmpeg -i input.mkv \
    -map 0:0 -map 0:1 -map 0:1 -map 0:3 \
    -c:v copy \
    -c:a:0 libmp3lame -b:a:0 128k \
    -c:a:1 libfaac -b:a:1 96k \
    -c:s copy \
    output.mkv

Output #0, matroska, to 'output.mkv':
    Stream #0:0(eng): Video ...
    Stream #0:1(ger): Audio ...
    Stream #0:2(ger): Audio ...
    Stream #0:3(ger): Subtitle ...

Output #0, matroska, to 'output.mkv':
    Stream #0:0(eng): Video ...
    Stream #0:1(ger): Audio ...
    Stream #0:2(ger): Audio ...
    Stream #0:3(ger): Subtitle ...
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (dca -> libmp3lame)
  Stream #0:2 -> #0:2 (dca -> libfaac)
  Stream #0:3 -> #0:3 (copy)

Stream #0:0(ger): Subtitle: text (default)
Stream #0:1(eng): Audio: dts (DTS), 48000 Hz, 5.1(side), s16, 1536 kb/s
Stream #0:2(ger): Audio: dts (DTS), 48000 Hz, 5.1(side), s16, 1536 kb/s (default)
Stream #0:3(eng): Video: h264 (High), yuv420p, 1920x800, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)

ffmpeg -i input.mkv -map 0:3 -map 0:2 -map 0:1 -map 0:0 -c copy output.mkv

ffmpeg -i input.mkv -map 0:1 -map 0:2 -c copy output.mkv

ffmpeg -i input.mkv -map 0 -c copy -c:v mpeg2video output.mkv

ffmpeg -i input.mkv -map 0:1 -map 0:2 audios_only.mkv -map 0:0 video_only.mkv

ffmpeg -i INPUT -filter_complex "[0] scale=100x100[smaller_sized]"  -map "[smaller_sized]" out.mp4

ffmpeg -i INPUT -filter_complex “[0:0] scale=100x100[smaller_sized]” -map “[smaller_sized]” out.mp4

ffmpeg -i input -map 0:v -map 0:a output.mkv # chooses video and audio from input 0

ffmpeg -i INPUT -map 0:6 OUTPUT # 每次运行产生的结果可能都不一样，请不要这样使用!

$ ffmpeg -probesize 50M -analyzeduration 50M -i INPUT
...
Input #0, mpegts, from 'INPUT':
  Duration: N/A, start: 22159.226833, bitrate: N/A
  Program 1344
    Metadata:
      service_name    : 7 Digital
      service_provider: Seven Network
    Stream #0:0[0x401]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv), 720x576 [SAR 64:45 DAR 16:9], max. 14950 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0:1[0x402](eng): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, s16p, 256 kb/s
  Program 1346
    Metadata:
      service_name    : 7TWO
      service_provider: Seven Network
    Stream #0:3[0x406]: Unknown: none ([5][0][0][0] / 0x0005)
    Stream #0:6[0x421]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv), 720x576 [SAR 64:45 DAR 16:9], max. 14950 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
    Stream #0:7[0x422](eng): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, s16p, 192 kb/s
    Stream #0:8[0x424](eng): Subtitle: dvb_teletext ([6][0][0][0] / 0x0006), 492x250
    Stream #0:4[0x499]: Unknown: none ([11][0][0][0] / 0x000B)

ffmpeg -i INPUT -map 0:p:1344 OUTPUT # 从程序1344中输入两个输入，在本例子中是通道“7 digital”

ffmpeg -i INPUT -map i:0x401 OUTPUT # 从找到的任何地方用PID（MPEG Packet ID [stream identifier]）`0x401拉入单个输入流，在本例中，它是“7 digital”中的视频流

ffmpeg -i input -map 0 output.mp4 # 从一个输入重新编码所有视频和音频通道 
ffmpeg -i input -map 0 -c copy output.mp4 # 将所有视频和音频通道从一个输入复制到输出，而不是仅一个视频

Reverse a video clip.

Warning: This filter requires memory to buffer the entire clip, so trimming is suggested.

Examples
Take the first 5 seconds of a clip, and reverse it.
trim=end=5,reverse

ffmpeg -i G:\1\c6cfb2d13929eb4967417e0bd81c314c.mp4 -vf reverse -y reverse.mp4

ffmpeg -i input.mp4 -an -c:v rawvideo -pixel_format yuv420p out.yuv
-c:v rawvideo 指定将视频转成原始数据
-pixel_format yuv420p 指定转换格式为yuv420p

播放这个
ffplay -s wxh out.yuv

YUV转H264
ffmpeg -f rawvideo -pix_fmt yuv420p -s 320x240 -r 30 -i out.yuv -c:v libx264 -f rawvideo out.h264

提取PCM数据
ffmpeg -i out.mp4 -vn -ar 44100 -ac 2 -f s16le out.pcm

播放PCM
ffplay -ar 44100 -ac 2 -f s16le -i out.pcm

PCM转WAV
ffmpeg -f s16be -ar 8000 -ac 2 -acodec pcm_s16be -i input.raw output.wav

//特效边框+底板视频，生成yuv视频
ffmpeg -i a3.mp4 -stream_loop -1 -i partPlay_color_video_12.mp4 -stream_loop -1 -i partPlay_gray_video_12.mp4 -filter_complex [1:v][2:v]alphamerge[vTheme];[0:v][vTheme]overlay=(W-w)/2:(H-h)/2 -an -c:v rawvideo -pixel_format yuv420p -t 100 -y outTest.yuv

//播放这个视频
ffplay -s 1280x720 outTest.yuv

Duration: 00:11:23.60, start: 0.025057, bitrate: 128 kb/s
Stream #0:0: Audio: mp3, 44100 Hz, stereo, fltp, 128 kb/s

ffmpeg -i C:\Users\Administrator\Desktop\materials\蕊希.mp3 -ac 1 -ar 48000 -y test.mp3

其中：
-ac 1 设置声道数为1
-ar 48000 设置采样率为48000Hz

Duration: 00:11:23.59, start: 0.023021, bitrate: 64 kb/s
Stream #0:0: Audio: mp3, 48000 Hz, mono, fltp, 64 kb/s

//音量翻倍，写在滤镜里，例如
ffmpeg -i 1.wav -af volume=2 -y 2.wav

//音量翻倍，不写在滤镜中，例如
ffmpeg -i 1.wav -vol 2000 -y 2.wav

//每隔10帧设置一个关键帧，如果是30帧的视频，则代表每秒3个关键帧
ffmpeg -i 2.mp4 -c:v libx264 -x264opts keyint=10 -y keyint10.mp4

//每帧都是关键帧
ffmpeg -i 2.mp4 -c:v libx264 -x264opts keyint=1 -y keyint11.mp4

//每秒一个关键帧
ffmpeg -i 2.mp4 -c:v libx264 -x264opts keyint=30 -y keyint12.mp4



-i 2.mp4
输入文件

-c:v libx264
编码器使用libx264

-x264opts keyint=10
视频文件每隔 10帧设置一个关键帧

-y keyint10.mp4
输出文件

Rotate video by an arbitrary angle expressed in radians.

The filter accepts the following options:

A description of the optional parameters follows.

angle, a
Set an expression for the angle by which to rotate the input video clockwise, expressed as a number of radians. A negative value will result in a counter-clockwise rotation. By default it is set to "0".

This expression is evaluated for each frame.

out_w, ow
Set the output width expression, default value is "iw". This expression is evaluated just once during configuration.

out_h, oh
Set the output height expression, default value is "ih". This expression is evaluated just once during configuration.

bilinear
Enable bilinear interpolation if set to 1, a value of 0 disables it. Default value is 1.

fillcolor, c
Set the color used to fill the output area not covered by the rotated image. For the general syntax of this option, check the (ffmpeg-utils)"Color" section in the ffmpeg-utils manual. If the special value "none" is selected then no background is printed (useful for example if the background is never shown).

Default value is "black".

The expressions for the angle and the output size can contain the following constants and functions:

n
sequential number of the input frame, starting from 0. It is always NAN before the first frame is filtered.

t
time in seconds of the input frame, it is set to 0 when the filter is configured. It is always NAN before the first frame is filtered.

hsub
vsub
horizontal and vertical chroma subsample values. For example for the pixel format "yuv422p" hsub is 2 and vsub is 1.

in_w, iw
in_h, ih
the input video width and height

out_w, ow
out_h, oh
the output width and height, that is the size of the padded area as specified by the width and height expressions

rotw(a)
roth(a)
the minimal width/height required for completely containing the input video rotated by a radians.

These are only available when computing the out_w and out_h expressions.

//T为旋转一周的时长，如果为视频的时长，则旋转一圈，正好可以播放完
ffmpeg -i a3.mp4 -vf rotate=PI*2/T*t rotate8.mp4

ffmpeg -i a3.mp4 -vf rotate=PI/2 rotate9.mp4

//水平翻转
ffmpeg -i fan.jpg -vf hflip -y hflip.png

//旋转60°，是带有黑底的。图片的原始宽高并没有改变
ffmpeg -i fan.jpg -vf rotate=PI/3 -y rotate60.png

//逆时针旋转90°
ffmpeg -i fan.jpg -vf transpose=2 -y transpose2.png
//逆时针旋转90°，然后垂直翻转
ffmpeg -i fan.jpg -vf transpose=0 -y transpose0.png

//方案1 （有黑底）

ffmpeg -loop 1 -i 圆形.png -i maskBase.mp4 -i a3.mp4 -filter_complex [0:v]alphaextract[vMaskAlpha];[1:v][vMaskAlpha]alphamerge[vTop];[vTop]rotate=PI*2/10*t[vRotate];[2:v][vRotate]overlay=(W-w)/2:(H-h)/2 -y maskRotateOverlay.mp4

// 方案二：分成两步
// 1.视频加上Mask以后，并且旋转
// mask和底部视频尺寸要一致，时长也要一致，所以加上了-loop 1
ffmpeg -loop 1 -i 圆形.png -i maskBase.mp4  -filter_complex [0:v]alphaextract[vMaskAlpha];[1:v][vMaskAlpha]alphamerge[vTop];[vTop]rotate=PI*2/10*t[vRotate];color=c=black:s=648x648[vBg];[vBg][vRotate]overlay -t 10 -y maskRotate.mp4
// 2.去掉黑底，并且overlay
ffmpeg -i a3.mp4 -i maskRotate.mp4 -filter_complex [1]split[m][a];[a]geq='if(gt(lum(X,Y),50),255,0)',hue=s=0[al];[m][al]alphamerge[ovr];[0][ovr]overlay=(W-w)/2:(H-h)/2 -y maskRotateOverlay2.mp4
// 不够完美，黑色去掉的有点多了，有好的方案在改吧

// 方案三：最终方案
// 在方案一的基础上给rotate加一个参数c=none
ffmpeg -loop 1 -i 圆形.png -i maskBase.mp4 -i a3.mp4 -filter_complex [0:v]alphaextract[vMaskAlpha];[1:v][vMaskAlpha]alphamerge[vTop];[vTop]rotate=PI*2/10*t:c=none[vRotate];[2:v][vRotate]overlay=(W-w)/2:(H-h)/2 -y maskRotateOverlay33.mp4

// 方案四：如果顶部是一个方形的视频
// 可以看到就像扑克牌一样，一帧帧的铺开，所以要用圆形来旋转，即使加上eof_action=pass，也只是最后播放完成后，顶层视频帧一起消失
ffmpeg -i maskBase.mp4 -i a3.mp4 -filter_complex [0:v]format=bgra,rotate='PI*2/10*t:ow=hypot(iw,ih):oh=ow:c=none'[vRotate];[1:v][vRotate]overlay=(W-w)/2:(H-h)/2 -t 3 -y maskRotateOverlay55.mp4


// 最终方案，核心，c=0x00000000 给一个透明色即可
ffmpeg -loop 1 -i 1567495070237.bmp -i a3.mp4 -filter_complex [0:v]format=bgra,rotate='PI*2/10*t:ow=hypot(iw,ih):oh=ow:c=0x00000000'[vRotate];[1:v][vRotate]overlay=(W-w)/2:(H-h)/2 -t 3 -y noBlackPad.mp4

ffmpeg -i a2.mp4 -i a3.mp4 -filter_complex [0:v]format=yuva444p,colorchannelmixer=aa=0.5[valpha];[1:v][valpha]overlay=(W-w)/2:(H-h)/2 -ss 0 -t 5  -y overlay4.mp4

ffmpeg -i in4.png -i a3.mp4 -filter_complex [0:v]geq=a='122':lum='lum(X,Y)':cb='cb(X,Y)':cr='cr(X,Y)'[topV];[1:v][topV]overlay=(W-w)/2:(H-h)/2 -ss 0 -t 5 -y overlay3.mp4

//此处经过测试，同样在ffmpeg 4.13下。Windows，Android，iOS 只有IOS下可以对视频进行geq
ffmpeg -i a2.mp4 -i a3.mp4 -filter_complex [0:v]geq=a='122':lum='lum(X,Y)':cb='cb(X,Y)':cr='cr(X,Y)'[topV];[1:v][topV]overlay=(W-w)/2:(H-h)/2 -ss 0 -t 5 -y overlay2.mp4

ffmpeg -i out3.mp4 -filter_complex color=s=1000x1000:c=black@.3[vc];[0:v][vc]overlay[out] -ss 0 -to 10 -map [out] -y ou4.mp4

ffmpeg -i 123.mov -filter_complex color=s=1000x1000:c=black@.9[vc];[0:v][vc]overlay[out] -ss 0 -to 10 -map [out] -y ou4.mp4

视频转gif
ffmpeg -i out.mp4 -ss 00:00:00 -t 10 out.gif
    t的格式
    -t  1.1
    -t 00:00:01
    -r 帧率每秒的帧数，数值越大越流畅

ffmpeg -i test.asf -y -f  image2  -ss 00:01:00 -vframes 1  test1.jpg
or
ffmpeg -i test.asf -y -f  image2  -ss 60 -vframes 1  test1.jpg
//png格式不会压缩
ffmpeg -i 1.avi -f image2 -ss 2 -vframes 1 test1.png

ffmpeg -i 2.mp4 -r 1 -f image2 image-%d.jpg

ffmpeg -framerate 10 -i img-%d.jpeg out.mkv
ffmpeg -framerate 30 -i image-%d.jpg -y out.mp4

//png图片的合成，如果没有特殊加背景，则背景是黑色的。
ffmpeg -framerate 30 -i image-%d.png -c:v libx264 -pix_fmt yuv420p -y out3.mp4

类似上例，但开始的数字是100，即索引是从100开始计数:
ffmpeg -framerate 10 -start_number 100 -i 'img-%d.jpeg' out.mkv

读取"*.png" 以通配符模式处理，这将包含所有".png"结尾的文件:
ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv

//单张图片合成视频，这里需要用到-loop 1 开启循环，和-t 10 设置为10秒
ffmpeg -r 1 -f image2 -loop 1 -i 1.png  -t 10 out.mp4 -y

ffmpeg -i 1.png -filter_complex color=s=500x500:c=black,trim=0:5[vbg];[0:v]scale=500x500[sv];[vbg][sv]overlay[vout] -map [vout] -y 1.mp4

ffmpeg -i 1.jpg -filter_complex color=s=720x1280:c=black[vbg];[0:v]scale=720x1280[sv];[vbg][sv]overlay[vout] -map [vout] -ss 0 -to 10 -y 1.mp4

ffmpeg 
-i 
1.png 
-filter_complex 
color=s=500x500:c=black,trim=0:5[vbg];
[0:v]scale=500x500[sv];
[vbg][sv]overlay[vout] 
-map 
[vout] 
-y 
1.mp4

ffmpeg -i E:\1\subtitle\out3.mp4 -i E:\1\subtitle\music3D.wav -filter_complex [1:a]aloop=loop=-1:size=2e+09[out];[out][0:a]amix -ss 0 -t 60 -y out.mp4

ffmpeg -i video.mp4 -stream_loop -1 -i audio.wav -filter_complex [0:a][1:a]amix -t 60 -y out.mp4

ffmpeg -an -i video.mp4 -stream_loop -1 -i audio.wav -t 60 -y out2.mp4

-an -i video.mp4 代表消除视频中的音频

ffmpeg -an -i video.mp4 -stream_loop -1 -i audio.wav -c:v copy -t 60 -y out.mp4

ffmpeg -i video_no_audio.mp4 -stream_loop -1 -i 世界这么大.wav -ss 0 -t 30 -y out.mp4

默认字体 Sans
默认颜色 black
默认字体大小 16

ffmpeg -i a3.mp4 -vf drawtext="text=test test" -y out1.mp4

ffmpeg -i a3.mp4 -vf drawtext="text=test test:x=100:y=100:fontsize=100:fontcolor=white:box=1:boxcolor=blue" -y out2.mp4

ffmpeg -i a3.mp4 -vf drawtext="fontsize=100:fontcolor=white:text='hello world':x=(w-text_w)/2:y=(h-text_h)/2" -y out3.mp4

视频加速
ffmpeg -i 1.mp4 -vf "setpts=0.5*PTS" 1jiasu.mp4
视频减速
ffmpeg -i 2.mp4 -vf "setpts=2.0*PTS" 2jiansu.mp4

音频加速
"atempo"滤镜对音频速度调整限制在0.5 到 2.0 之间，（即半速或倍速）
2倍速
ffmpeg -i 1jiasu.mp4 -af "atempo=2.0" 1quanbujiasu.mp4
4倍速
ffmpeg -i 1jiasu.mp4 -af "atempo=2.0,atempo=2.0" 1quanbujiasu.mp4

使用更复杂的滤镜，可以同时加速视频和音频：
ffmpeg -i 1.mp4 -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" 11quanbu.mp4

inputs
The number of inputs. If unspecified, it defaults to 2.//输入的数量，如果没有指明，默认为2.
 
duration
How to determine the end-of-stream.//决定了流的结束
 
            longest
            The duration of the longest input. (default)//最长输入的持续时间
            shortest
            The duration of the shortest input.//最短输入的持续时间
            first
            The duration of the first input.//第一个输入的持续时间
 
dropout_transition
The transition time, in seconds, for volume renormalization when an input stream ends. The default value is 2 seconds.
//指一个输入流结束时音量从正常到无声渐止效果，默认为2秒

ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT

$ ffmpeg -an -skip_frame nokey -i 输入文件 -vf scale=导出分辨率:flags=fast_bilinear,palettegen=max_colors=色彩数量:stats_mode=diff 色板文件
$ ffmpeg -an -i 输入文件 -i 色板文件 -r 输出文件帧率 -lavfi "framestep=原视频帧率/输出文件帧率*变速速率,setpts=PTS/变速速率,scale=导出分辨率:flags=lanczos [x]; [x][1:v] paletteuse=dither=bayer" 输出文件

$ ffmpeg -i input.mp4 -filter:v "minterpolate='fps=60:mi_mode=mci:mc_mode=aobmc:vsbmc=1'" optical_flow.mp4

$ ffmpeg -i input.mp4 -vf vidstabdetect=shakiness=10:result="mytransforms.trf" -f null -
$ ffmpeg -i input.mp4 -vf vidstabtransform=smoothing=30:input="mytransforms.trf",unsharp=5:5:0.8:3:3:0.4  stabilized.mp4

$ ffprobe -v error -show_format -show_streams input.mp4

$ ffprobe -v quiet -select_streams V:0 -show_entries stream=width,height,r_frame_rate,bit_rate -of csv=p=0:sv=fail -i input.mp4

$ ffmpeg -i input.wav -c:a flac -compression_level 12 output.flac

$ ffmpeg -i input.wav -c:a libopus -b:a 128k output.ogg

#!/bin/bash

echo '#EXTM3U'
echo '#EXT-X-VERSION:3'
echo '#EXT-X-MEDIA-SEQUENCE:1'

maxDuration=0

while read f; do
    duration="$(ffprobe -v error -select_streams v:0 -show_entries stream=duration -of default=noprint_wrappers=1:nokey=1 "$f" |  grep -E '^[0-9]+(\.[0-9]+)?$' | head -n1)"
    echo "#EXTINF:$duration,"
    echo $f

    if [ `echo "$duration > $maxDuration" | bc` -eq 1 ]; then
        maxDuration="$duration"
    fi
done

echo '#EXT-X-ENDLIST'
echo "#EXT-X-TARGETDURATION:$maxDuration"

# 在Debian上安装依赖
sudo apt install ffmpeg bc

wget -O gen_ts_m3u8.sh https://vkceyugu.cdn.bspapp.com/VKCEYUGU-cc8cf08f-49f5-4fc5-83c3-ed2a683704d4/4db7c4a8-9131-4771-9d36-71a2b30ca35a.sh
chmod +x gen_ts_m3u8.sh
ls *.ts | ./gen_ts_m3u8.sh | tee main.m3u8

ffmpeg -hwaccels

ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
  libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Hardware acceleration methods:
vdpau
cuda
vaapi
drm
opencl
cuvid

ffmpeg -hwaccel cuvid -c:v h264_cuvid -i 0.mp4 -c:v h264_nvenc -y 00.mp4

ffmpeg -hwaccel cuvid -c:v h264_cuvid -i 0.mp4 -c:v h264_nvenc -r 15 -b 500k -y 00.mp4

ffmpeg -hwaccel cuvid -c:v h264_cuvid -i <input> -c:v h264_nvenc -b:v 2048k -vf scale_npp=1280:-1 -y <output>

ffmpeg -hwaccel cuvid -hwaccel_device 0 -c:v h264_cuvid -i <input> -c:v h264_nvenc -b:v 2048k -vf scale_npp=1280:-1 -y <output>

ffmpeg -hwaccel cuvid -hwaccel_device 1 -c:v h264_cuvid -i <input> -c:v h264_nvenc -b:v 2048k -vf scale_npp=1280:-1 -y <output>

ffmpeg -i .\a.mp4 -c:v h264_amf .\b.mp4

ffprobe -v error -count_frames -select_streams v:0 -show_entries stream=nb_read_frames -of default=nokey=1:noprint_wrappers=1 input.mp4