diff --git a/doc/FFmpeg_command_line.md b/doc/FFmpeg_command_line.md
index b1604fb..72dccf3 100644
--- a/doc/FFmpeg_command_line.md
+++ b/doc/FFmpeg_command_line.md
@@ -7,70 +7,76 @@ 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:
---help topic$~~~~~~~~$show help
--version$~~~~~~~~~~~~$show version
--formats$~~~~~~~~~~~~$show available formats
--muxers$~~~~~~~~~~~~~$show available muxers
--demuxers$~~~~~~~~~~~$show available demuxers
--devices$~~~~~~~~~~~~$show available devices
--codecs$~~~~~~~~~~~~~$show available codecs
--decoders$~~~~~~~~~~~$show available decoders
--encoders$~~~~~~~~~~~$show available encoders
--bsfs$~~~~~~~~~~~~~~~$show available bit stream filters
--protocols$~~~~~~~~~~$show available protocols
--filters$~~~~~~~~~~~~$show available filters
--pix_fmts$~~~~~~~~~~~$show available pixel formats
--sample_fmts$~~~~~~~~$show available audio sample formats
--hwaccels$~~~~~~~~~~~$show available HW acceleration methods
+|:--------|:--------|
+|--help topic |show help
+|-version |show version
+|-formats |show available formats
+|-muxers |show available muxers
+|-demuxers |show available demuxers
+|-devices |show available devices
+|-codecs |show available codecs
+|-decoders |show available decoders
+|-encoders |show available encoders
+|-bsfs |show available bit stream filters
+|-protocols |show available protocols
+|-filters |show available filters
+|-pix_fmts |show available pixel formats
+|-sample_fmts |show available audio sample formats
+|-hwaccels |show available HW acceleration methods
Global options (affect whole program instead of just one file:
--v loglevel$~~~~~~~~~$set logging level
--y$~~~~~~~~~~~~~~~~~~$overwrite output files
--n$~~~~~~~~~~~~~~~~~~$never overwrite output files
--filter_threads$~~~~~$number of non-complex filter threads
--stats$~~~~~~~~~~~~~~$print progress report during encoding
--vol volume$~~~~~~~~~$change audio volume (256=normal)
+|:--------|:--------|
+|-v loglevel |set logging level
+|-y |overwrite output files
+|-n |never overwrite output files
+|-filter_threads |number of non-complex filter threads
+|-stats |print progress report during encoding
+|-vol volume |change audio volume (256=normal)
Per-file main options:
--f fmt$~~~~~~~~~~~~~~$force format
--c codec$~~~~~~~~~~~~$codec name
--codec codec$~~~~~~~~$codec name
--t duration$~~~~~~~~~$record or transcode "duration" seconds of audio/video
--to time_stop$~~~~~~~$record or transcode stop time
--fs limit_size$~~~~~~$set the limit file size in bytes
--ss time_off$~~~~~~~~$set the start time offset
--sseof time_off$~~~~~$set the start time offset relative to EOF
--frames number$~~~~~~$set the number of frames to output
--filter filter_graph set stream filtergraph
--discard$~~~~~~~~~~~~$discard
--disposition$~~~~~~~~$disposition
+|:--------|:--------|
+|-f fmt |force format
+|-c codec |codec name
+|-codec codec |codec name
+|-t duration |record or transcode "duration" seconds of audio/video
+|-to time_stop |record or transcode stop time
+|-fs limit_size |set the limit file size in bytes
+|-ss time_off |set the start time offset
+|-sseof time_off |set the start time offset relative to EOF
+|-frames number |set the number of frames to output
+|-filter filter_graph |set stream filtergraph
+|-discard |discard
+|-disposition |disposition
Video options:
--vframes number$~~~~~$set the number of video frames to output
--r rate$~~~~~~~~~~~~~$set frame rate (Hz value, fraction or abbreviation)
--s size$~~~~~~~~~~~~~$set frame size (WxH or abbreviation)
--aspect aspect$~~~~~~$set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
--bits_per_raw_sample number set the number of bits per raw sample
--vn$~~~~~~~~~~~~~~~~~$disable video
--vcodec codec$~~~~~~~$force video codec ('copy' to copy stream)
--vf filter_graph$~~~~$set video filters
--ab bitrate$~~~~~~~~~$audio bitrate (please use -b:a)
--b bitrate$~~~~~~~~~~$video bitrate (please use -b:v)
+|:--------|:--------|
+|-vframes number |set the number of video frames to output
+|-r rate |set frame rate (Hz value, fraction or abbreviation)
+|-s size |set frame size (WxH or abbreviation)
+|-aspect aspect |set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
+|-bits_per_raw_sample |number set the number of bits per raw sample
+|-vn |disable video
+|-vcodec codec |force video codec ('copy' to copy stream)
+|-vf filter_graph |set video filters
+|-ab bitrate |audio bitrate (please use -b:a)
+|-b bitrate |video bitrate (please use -b:v)
Audio options:
--aframes number$~~~~~$set the number of audio frames to output
--aq quality$~~~~~~~~~$set audio quality (codec-specific)
--ar rate$~~~~~~~~~~~~$set audio sampling rate (in Hz)
--ac channels$~~~~~~~~$set number of audio channels
--an$~~~~~~~~~~~~~~~~~$disable audio
--acodec codec$~~~~~~~$force audio codec ('copy' to copy stream)
--vol volume$~~~~~~~~~$change audio volume (256=normal)
--af filter_graph$~~~~$set audio filters
+|:--------|:--------|
+|-aframes number |set the number of audio frames to output
+|-aq quality |set audio quality (codec-specific)
+|-ar rate |set audio sampling rate (in Hz)
+|-ac channels |set number of audio channels
+|-an |disable audio
+|-acodec codec |force audio codec ('copy' to copy stream)
+|-vol volume |change audio volume (256=normal)
+|-af filter_graph |set audio filters
Subtitle options:
--s size$~~~~~~~~~~~~~$set frame size
--sn$~~~~~~~~~~~~~~~~~$disable subtitle
--scodec codec$~~~~~~~$force subtitle codec ('copy' to copy stream)
+|:--------|:--------|
+|-s size |set frame size
+|-sn |disable subtitle
+|-scodec codec |force subtitle codec ('copy' to copy stream)
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。