update learning group

doc/FFmpeg_command_line.md

@@ -7,70 +7,70 @@ ffprobe用于检测多媒体流格式；ffplay用于播放视频,包括本地与
 # 一、ffmpeg命令行
 ## 1、命令行参数介绍
 Print help / information / capabilities:<br>
---help topic        |show help<br>
--version            |show version<br>
--formats            |show available formats<br>
--muxers             |show available muxers<br>
--demuxers           |show available demuxers<br>
--devices            |show available devices<br>
--codecs             |show available codecs<br>
--decoders           |show available decoders<br>
--encoders           |show available encoders<br>
--bsfs               |show available bit stream filters<br>
--protocols          |show available protocols<br>
--filters            |show available filters<br>
--pix_fmts           |show available pixel formats<br>
--sample_fmts        |show available audio sample formats<br>
--hwaccels           |show available HW acceleration methods<br>
+--help topic$~~~~~~~~$show help<br>
+-version$~~~~~~~~~~~~$show version<br>
+-formats$~~~~~~~~~~~~$show available formats<br>
+-muxers$~~~~~~~~~~~~~$show available muxers<br>
+-demuxers$~~~~~~~~~~~$show available demuxers<br>
+-devices$~~~~~~~~~~~~$show available devices<br>
+-codecs$~~~~~~~~~~~~~$show available codecs<br>
+-decoders$~~~~~~~~~~~$show available decoders<br>
+-encoders$~~~~~~~~~~~$show available encoders<br>
+-bsfs$~~~~~~~~~~~~~~~$show available bit stream filters<br>
+-protocols$~~~~~~~~~~$show available protocols<br>
+-filters$~~~~~~~~~~~~$show available filters<br>
+-pix_fmts$~~~~~~~~~~~$show available pixel formats<br>
+-sample_fmts$~~~~~~~~$show available audio sample formats<br>
+-hwaccels$~~~~~~~~~~~$show available HW acceleration methods<br>
 
 Global options (affect whole program instead of just one file:<br>
--v loglevel         |set logging level<br>
--y                  |overwrite output files<br>
--n                  |never overwrite output files<br>
--filter_threads     |number of non-complex filter threads<br>
--stats              |print progress report during encoding<br>
--vol volume         |change audio volume (256=normal)<br>
+-v loglevel$~~~~~~~~~$set logging level<br>
+-y$~~~~~~~~~~~~~~~~~~$overwrite output files<br>
+-n$~~~~~~~~~~~~~~~~~~$never overwrite output files<br>
+-filter_threads$~~~~~$number of non-complex filter threads<br>
+-stats$~~~~~~~~~~~~~~$print progress report during encoding<br>
+-vol volume$~~~~~~~~~$change audio volume (256=normal)<br>
 
 Per-file main options:<br>
--f fmt              |force format<br>
--c codec            |codec name<br>
--codec codec        |codec name<br>
--t duration         |record or transcode "duration" seconds of audio/video<br>
--to time_stop       |record or transcode stop time<br>
--fs limit_size      |set the limit file size in bytes<br>
--ss time_off        |set the start time offset<br>
--sseof time_off     |set the start time offset relative to EOF<br>
--frames number      |set the number of frames to output<br>
--filter filter_graph  set stream filtergraph<br>
--discard            |discard<br>
--disposition        |disposition<br>
+-f fmt$~~~~~~~~~~~~~~$force format<br>
+-c codec$~~~~~~~~~~~~$codec name<br>
+-codec codec$~~~~~~~~$codec name<br>
+-t duration$~~~~~~~~~$record or transcode "duration" seconds of audio/video<br>
+-to time_stop$~~~~~~~$record or transcode stop time<br>
+-fs limit_size$~~~~~~$set the limit file size in bytes<br>
+-ss time_off$~~~~~~~~$set the start time offset<br>
+-sseof time_off$~~~~~$set the start time offset relative to EOF<br>
+-frames number$~~~~~~$set the number of frames to output<br>
+-filter filter_graph set stream filtergraph<br>
+-discard$~~~~~~~~~~~~$discard<br>
+-disposition$~~~~~~~~$disposition<br>
 
 Video options:<br>
--vframes number     |set the number of video frames to output<br>
--r rate             |set frame rate (Hz value, fraction or abbreviation)<br>
--s size             |set frame size (WxH or abbreviation)<br>
--aspect aspect      |set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)<br>
--vn                 |disable video<br>
--vcodec codec       |force video codec ('copy' to copy stream)<br>
--timecode hh:mm:ss  |set initial TimeCode value.<br>
--vf filter_graph    |set video filters<br>
--ab bitrate         |audio bitrate (please use -b:a)<br>
--b bitrate          |video bitrate (please use -b:v)<br>
+-vframes number$~~~~~$set the number of video frames to output<br>
+-r rate$~~~~~~~~~~~~~$set frame rate (Hz value, fraction or abbreviation)<br>
+-s size$~~~~~~~~~~~~~$set frame size (WxH or abbreviation)<br>
+-aspect aspect$~~~~~~$set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)<br>
+-bits_per_raw_sample number  set the number of bits per raw sample<br>
+-vn$~~~~~~~~~~~~~~~~~$disable video<br>
+-vcodec codec$~~~~~~~$force video codec ('copy' to copy stream)<br>
+-vf filter_graph$~~~~$set video filters<br>
+-ab bitrate$~~~~~~~~~$audio bitrate (please use -b:a)<br>
+-b bitrate$~~~~~~~~~~$video bitrate (please use -b:v)<br>
 
 Audio options:<br>
--aframes number     |set the number of audio frames to output<br>
--aq quality         |set audio quality (codec-specific)<br>
--ar rate            |set audio sampling rate (in Hz)<br>
--ac channels        |set number of audio channels<br>
--an                 |disable audio<br>
--acodec codec       |force audio codec ('copy' to copy stream)<br>
--vol volume         |change audio volume (256=normal)<br>
--af filter_graph    |set audio filters<br>
+-aframes number$~~~~~$set the number of audio frames to output<br>
+-aq quality$~~~~~~~~~$set audio quality (codec-specific)<br>
+-ar rate$~~~~~~~~~~~~$set audio sampling rate (in Hz)<br>
+-ac channels$~~~~~~~~$set number of audio channels<br>
+-an$~~~~~~~~~~~~~~~~~$disable audio<br>
+-acodec codec$~~~~~~~$force audio codec ('copy' to copy stream)<br>
+-vol volume$~~~~~~~~~$change audio volume (256=normal)<br>
+-af filter_graph$~~~~$set audio filters<br>
 
 Subtitle options:<br>
--s size             |set frame size<br>
--sn                 |disable subtitle<br>
--scodec codec       |force subtitle codec ('copy' to copy stream)<br>
+-s size$~~~~~~~~~~~~~$set frame size<br>
+-sn$~~~~~~~~~~~~~~~~~$disable subtitle<br>
+-scodec codec$~~~~~~~$force subtitle codec ('copy' to copy stream)<br>
 
 命令行整体格式：以ffmpeg开头，参数之间用空格隔开，每个参数key以"-"开头，后面跟着参数value，输出文件放在命令行最后。<br>
 
@@ -189,7 +189,7 @@ ffmpeg -ss 20 -accurate_seek -t 10 -i input.mp4 -an -r 5 %3d.jpg<br>
 ffmpeg -i in.mp4 -filter_complex [0:v]setpts=%.2f*PTS[v];[0:a]atempo=%.2f[a] -map [v] -map [a] out.mp4<br>
 
 ### 3.12 旋转视频
-ffmpeg -i in.mp4 -c copy -metadata:s:\v:0 rotate=90 out.mp4<br>
+ffmpeg -i in.mp4 -c copy -metadata:s\:v:0 rotate=90 out.mp4<br>
 
 # 二、ffplay命令行
 ffplay主要用于播放视频，也可以播放网络流，示例如下：<br>