Use cases

HaiyueDecember 19, 2023About 4 min

How to get help

Parameters 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

Basic Options

Global options

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

Usuage

Split media into multi-parts

# segment_time 
ffmpeg -i somefile.mp3 -f segment -segment_time 3 -c copy out%03d.mp3

# From time 4.5 seconds to output 1 frame named output.png
ffmpeg -i input.mp4 -ss 4.500 -vframes 1 output.png

# From time 4.5 seconds to output 10 frame continously named output%d.png (%d if format string for integer)
ffmpeg -i input.mp4 -ss 4.500 -vframes 10 output%d.png

# set frame per senond is 1, output 1 frame per second.
ffmpeg -i input.mp4 -vf fps=1 output%d.png

# set frame per senond is 0.1, output 0.1 frame per second, so the result is output 1 frame every 10 seconds.
ffmpeg -i input.mp4 -vf fps=0.1 output%d.png

# set frame per senond is 10, output 10 frame per second
ffmpeg -i input.mp4 -vf fps=10 output%d.png

Other Resources

然后从视频中提取图片的命令如下：
ffmpeg -i [视频路径] -r 1 -q:v 2 -f image2 image-%d.jpeg
 视频路径：如 "myvideo.mp4"(这时这个视频也在bin文件目录下才可以直接这么写)，或者完整路径的

  -r   ：每秒提取的帧数，如上面为每秒1帧，即一张图像
  -q:v ：图片质量
  -f   ：图片格式，上述为image2
image-%d.jpeg：生成图像的文件名，可以加上完整路径，%d会使文件名按整数编号，如上述生成图像为image-1.jpeg, image-2.jpeg, ...

还有其他参数：
  -t      ：持续时间，如-t 4表示持续4s
  -ss     ：起始时间，如-ss 01:30:14，从01:30:14开始
  -vframes：指定抽取的帧数，如-vframes 120，指定抽取120张
  -s      ：格式大小，如-s 640x360
  -y      ：覆盖，直接使用

Clip mp3

# clip input.mp3 from 10 seconds to 16 seconds
ffmpeg -ss 10 -to 16 -i input.mp3 output.mp3

# clip input.mp3 from 10 seconds to keep 16 seconds length
ffmpeg -ss 10 -t 16 -i input.mp3 output.mp3

ffmpeg使用：
https://blog.csdn.net/qq_43057180/article/details/105676230

youtube downloader online: https://yt1s.com/en17

How to join ts files into a single file

ffmpeg -f concat -i filelist.txt -c copy output.mp4

filelist.txt

file 'seg-1-v1-a1.ts'
file 'seg-2-v1-a1.ts'
file 'seg-3-v1-a1.ts'
file 'seg-4-v1-a1.ts'
file 'seg-5-v1-a1.ts'

Change Resolution

ffmpeg -i video1.mp4 -vf "scale=1920:1080" -c:a copy resized_video1.mp4

Merge Audio and Video

reencode audio

ffmpeg -i video.mp4 -i audio.wav -c:v copy -c:a aac output.mp4

copy audio

ffmpeg -i video.mp4 -i audio.wav -c copy output.mkv

ffmpeg -i video.mp4 -i audio.wav -c:v copy -c:a aac -map 0:v:0 -map 1:a:0 output.mp4
The -map option makes ffmpeg only use the first video stream from the first input and the first audio stream from the second input for the output file.

Pictures to Video

One image per second

ffmpeg -framerate 1 -pattern_type glob -i '*.png' \
  -c:v libx264 -r 30 -pix_fmt yuv420p out.mp4

With Duration

ffmpeg -loop 1 -i image.png -c:v libx264 -t 15 -pix_fmt yuv420p -vf scale=320:240 out.mp4

With Transition

ffmpeg \
-loop 1 -t 3 -i p1-s1.jpg \
-loop 1 -t 3 -i p2-s1.jpg \
-loop 1 -t 3 -i p3-s1.jpg \
-loop 1 -t 3 -i p4-s1.jpg \
-loop 1 -t 3 -i p5-s1.jpg \
-filter_complex \
"[1]fade=d=1:t=in:alpha=1,setpts=PTS-STARTPTS+2/TB[f0]; \
 [2]fade=d=1:t=in:alpha=1,setpts=PTS-STARTPTS+4/TB[f1]; \
 [3]fade=d=1:t=in:alpha=1,setpts=PTS-STARTPTS+6/TB[f2]; \
 [4]fade=d=1:t=in:alpha=1,setpts=PTS-STARTPTS+8/TB[f3]; \
 [0][f0]overlay[bg1];[bg1][f1]overlay[bg2];[bg2][f2]overlay[bg3]; \
 [bg3][f3]overlay,format=yuv420p[v]" -map "[v]" -r 25 -c:v libx264  -pix_fmt yuv420p output-crossfade.mp4

References

Add some audio

ffmpeg -framerate 1 -pattern_type glob -i '*.png' -i audio.ogg \
  -c:a copy -shortest -c:v libx264 -r 30 -pix_fmt yuv420p out.mp4

Add overlay Logo

ffmpeg.exe -i video.mp4 -i logo.png -filter_complex “overlay=X:Y” output.mp4
Resource