ffmpeg
ffmpeg 是用于记录，转换和流式传输音频和视频的跨平台解决方案，
ffmpeg 下载和安装
选择对应的版本进行安装：download。
window: 在命令行中添加 ffmpeg 命令
右键【此电脑】>【属性】>【高级】>【环境变量】。选择 'Path'，添加 D:\ffmpeg\bin
ffmpeg -version
ffmpeg 参数中文详细解释
window 执行 ./bin/ffmpeg -h
-L show license
-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
-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 errors (0.0: no errors, 1.0: 100% errors) above which ffmpeg returns an error instead of success.
-bits_per_raw_sample number set the number of bits per raw sample
-vol volume change audio volume (256=normal)
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)
-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)
-timecode hh:mm:ss[:;.]ff set initial TimeCode value.
-pass n select the pass number (1 to 3)
-vf filter_graph set video filters
-ab bitrate audio bitrate (please use -b:a)
-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)
-vol volume change audio volume (256=normal)
-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
中文参考可参考 ffmpeg 参数中文详细解释
ffmpeg 常用命令总结
# 视频格式转换
ffmpeg -i input.mp4 output.ts
# 视频剪切
ffmpeg -ss 00:00:15 -t 00:00:05 -i input.mp4 -vcodec copy -acodec copy output.mp4
# 视频切片
ffmpeg -re -i ./videos/tennis.mp4 -c copy -f segment -segment_format mp4 segment_%d.mp4
# 抓取视频的一些帧，存为图片。'-r' 表示每一秒几帧 '-q:v' 表示存储 jpeg 的图像质量，一般 2 是高质量。
ffmpeg -i input.mp4 -ss 00:00:20 -t 10 -r 1 -q:v 2 -f image2 pic-%03d.jpeg
# 提取音频
# '-vn':不处理视频
ffmpeg -i input.mp4 -vn -acodec copy output.mp3
# '-ss':从第15秒开始 '-t':截取10秒的音频
ffmpeg -ss 00:00:15 -t 00:00:10 -i input.mp4 -vn output.mp3
# '-acodec copy': 不对音频重新编码
ffmpeg -ss 00:00:15 -t 00:00:10 -i ./videos/tennis.mp4 -vn -acodec copy output.aac
# '-f mp3': 强制转换成 mp3 格式
ffmpeg -ss 00:00:15 -t 00:00:10 -i ./videos/tennis.mp4 -vn -f mp3 output.mp3
ffmpeg filter 过滤器
# show available filters
ffmpeg -filters
将输入的 1920x1080 缩小到 960x540 输出
ffmpeg -i input.mp4 -vf scale=960:540 output.mp4
为视频添加 logo
# 左上角
ffmpeg -i input.mp4 -i logo.png -filter_complex overlay output.mp4
# 右上角
ffmpeg -i input.mp4 -i logo.png -filter_complex overlay=W-w output.mp4
# 左下角
ffmpeg -i input.mp4 -i logo.png -filter_complex overlay=0:H-h output.mp4
# 右下角
ffmpeg -i input.mp4 -i logo.png -filter_complex overlay=W-w:H-h output.mp4
去掉视频的 logo
用 ffmpeg 的 delogo 过滤器。
语法：-vf delogo=x:y:w:h[:t[:show]]
- x:y 离左上角的坐标。
- w:h logo 的宽和高。
- t: 矩形边缘的厚度，默认值 4。
- show：若设置为 1 有一个绿色的矩形，默认值 0。
ffmpeg -i input.mp4 -vf delogo=0:0:220:90:100:1 output.mp4
旋转视频
ffmpeg -i input.mp4 -vf transpose=1 output.mp4
添加字幕
ffmpeg -i input.mp4 -vf subtitles=en.vtt vvt.mp4
ffmpeg -i input.mp4 -vf subtitles=en.srt srt.mp4