ffmpeg命令详解

原文网址：ffmpeg命令详解_IT利刃出鞘的博客-CSDN博客

简介

本文介绍ffmpeg命令的用法。

命令示例

1.mp4和avi的基本互转

ffmpeg -i D:\input.mp4 E:\output.avi
ffmpeg -i D:\input.avi E:\output.mp4

-i 表示input，即输入。后面填一个输入地址和一个输出地址，这种方式没有指定任何参数和解码器，都用默认，会发现转换得到的文件压缩严重，avi文件只有200kbps的码率。

2.mp4和avi的无损互转

mp4转换avi

ffmpeg -i D:\input.mp4 -qscale 0 E:\output.avi
或者
ffmpeg -i D:\input.mp4 -c copy E:\output.avi

这里更推荐第一种方式，-qscale表示质量控制，0表示0损失，现在的ffmpeg已经采用qsacle取代了原来的sameq方式。

第二种方式 -c copy表明会把原视频的所有流一模一样的复制，即不进行解码和重新编码，这种情况下得到的avi文件需要额外的解码器如potplayer才能打开，win10自带的是不行的。

注：-c copy包含了-c:v copy(视频流），-c:a copy（音频流）等所有流。另外其他写法如-vcodec -codec:v与-c:v copy是同义的，其余以此类推。

avi转mp4

ffmpeg -i D:\input.mp4 -c:v copy -c:a copy E:\output.avi -y

-y表示不用确认覆盖文件，如果有重名的文件一般会在命令行向用户确认。

mp4转avi就直接copy就可以了，win10自带也能播。

3.截取视频片段

ffmpeg -i input.avi -c:v copy -c:a copy -ss 00:00:00 -to 00:00:30 cutout.avi -y

这是截取30s的，和前面一样，如果只是截取视频片段就不要重新编码了，一个-c copy搞定。
-ss后面跟的是时间位置，开始时间 -to 结束时间。

4.批量截取视频图片

for /R %v IN (*.avi) do ( ffmpeg -i %v -r 1 -f image2 %v%d.jpeg)

假设一个视频文件夹里有很多avi文件，我想每一个avi文件都间隔一帧截图，就是这条语句了。for…IN…do是命令行的循环格式。%v是文件名，%d是自动递增的数字名。-r定义的是间隔多少帧截图一次。

5.把大量图片组合成视频

ffmpeg -f image2 -framerate 30 -i %d.jpg xxx.avi

-framerate设定帧数，这里设成了30，也就是一秒30张图片，%d表示从1开始的图片，这里推荐大家一个软件renamer，免费版的就足够使用了，可以快速批量重命名文件，不用每次写重命名代码了。

命令详解

用法

ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

1. options 全局参数
2. infile options 输入文件参数
3. infile 输入文件
4. outfile options 输出文件参数
5. outfile 输出文件

全局选项

输入输出选项

视频选项

音频选项

副标题选项

查看帮助文档

简单文档

可以用此命令查看详解：

ffmpeg --help

结果： 

Hyper fast Audio and Video encoder
usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

Getting help:
    -h      -- print basic options
    -h long -- print more options
    -h full -- print all options (including all format and codec specific options, very long)
    -h type=name -- print all options for the named decoder/encoder/demuxer/muxer/filter/bsf/protocol
    See man ffmpeg for detailed description of the options.

Print help / information / capabilities:
-L                  show license
-h topic            show help
-? topic            show help
-help topic         show help
--help topic        show help
-version            show version
-buildconf          show build configuration
-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
-layouts            show standard channel layouts
-sample_fmts        show available audio sample formats
-dispositions       show available stream dispositions
-colors             show available color names
-sources device     list sources of the input device
-sinks device       list sinks of the output device
-hwaccels           show available HW acceleration methods

Global options (affect whole program instead of just one file):
-loglevel loglevel  set logging level
-v loglevel         set logging level
-report             generate a report
-max_alloc bytes    set maximum size of a single allocated block
-y                  overwrite output files
-n                  never overwrite output files
-ignore_unknown     Ignore unknown stream types
-filter_threads     number of non-complex filter threads
-filter_complex_threads  number of threads for -filter_complex
-stats              print progress report during encoding
-max_error_rate maximum error rate  ratio of decoding errors (0.0: no errors, 1.0: 100% errors) above which ffmpeg returns an error instead of success.

Per-file main options:
-f fmt              force format
-c codec            codec name
-codec codec        codec name
-pre preset         preset name
-map_metadata outfile[,metadata]:infile[,metadata]  set metadata information of outfile from infile
-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
-seek_timestamp     enable/disable seeking by timestamp with -ss
-timestamp time     set the recording timestamp ('now' to set the current time)
-metadata string=string  add metadata
-program title=string:st=number...  add program with specified streams
-target type        specify target file type ("vcd", "svcd", "dvd", "dv" or "dv50" with optional prefixes "pal-", "ntsc-" or "film-")
-apad               audio pad
-frames number      set the number of frames to output
-filter filter_graph  set stream filtergraph
-filter_script filename  read stream filtergraph description from a file
-reinit_filter      reinit filtergraph on input parameter changes
-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)
-fpsmax rate        set max 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)
-display_rotation angle  set pure counter-clockwise rotation in degrees for stream(s)
-display_hflip      set display horizontal flip for stream(s) (overrides any display rotation if it is not set)
-display_vflip      set display vertical flip for stream(s) (overrides any display rotation if it is not set)
-vn                 disable video
-vcodec codec       force video codec ('copy' to copy stream)
-timecode hh:mm:ss[:;.]ff  set initial TimeCode value.
-pass n             select the pass number (1 to 3)
-vf filter_graph    set video filters
-b bitrate          video bitrate (please use -b:v)
-dn                 disable data

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)
-ab bitrate         audio bitrate (please use -b:a)
-af filter_graph    set audio filters

Subtitle options:
-s size             set frame size (WxH or abbreviation)
-sn                 disable subtitle
-scodec codec       force subtitle codec ('copy' to copy stream)
-stag fourcc/tag    force subtitle tag/fourcc
-fix_sub_duration   fix subtitles duration
-canvas_size size   set canvas size (WxH or abbreviation)
-spre preset        set the subtitle options to the indicated preset

细节文档