diff --git a/doc/FFmpeg_command_line.md b/doc/FFmpeg_command_line.md
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--- a/doc/FFmpeg_command_line.md
+++ b/doc/FFmpeg_command_line.md
@@ -7,76 +7,66 @@ 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 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
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)
+-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。