ffmpeg功能说明：超级好用的音视频编码器
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
See man ffmpeg for detailed description of the options.
ffplay功能说明：简单的多媒体播放器
Simple media player
usage: ffplay [options] input_file
ffprobe功能说明：简单的多媒体流分析工具
Simple multimedia streams analyzer
usage: ffprobe [OPTIONS] [INPUT_FILE]