ffmpeg command line
A command line tool to convert multimedia files between formats.
| name | Order | explain |
|---|---|---|
| View current device input information | ffmpeg -f avfoundation -list_devices true -i “” | |
| Mac device recording | ffmpeg -f avfoundation -i “:” output.mkv | |
| capture screen | ffmpeg -f avfoundation -i 1 -r 15 out.yuv | -i (0 camera, 1 built-in screen, 2 external screen-1, 3 external screen-2) |
| yuv sampling video resolution and color space conversion | ffmpeg -video_size 2560x1440 -pix_fmt uyvy422 -i out.yuv -s 1920x1080 -pix_fmt yuv420p out.yuv | |
| Encoding Video Frame Rate Control | ffmpeg -r 80 -i input output ffmpeg -i input -r 20 output | The location of -r is different, which determines whether its parameters work on the input video or the output video. Put it before the input, reduce the fps, and increase the video duration: make the duration of the output file be half and twice the original, that is, the playback speed is twice and half of the original. After putting it into the input, reduce the fps, the video duration will remain the same, the frame will be lost, and the quality will deteriorate: the code stream of the output file is theoretically about half of the input file. |
| Mac video hardcoded | ffmpeg -r 5 -s 1920x1080 -i ppt.yuv -b 1000000 -profile high -coder cabac -vcodec h264_videotoolbox -y out.h264 | |
| Generate video with motion vectors | ffmpeg -flags2 +export_mvs -i input.mp4 -vf codecview=mv=pf+bf+bb output.mp4 | |
| Calculate the psnr of two YUV | ffmpeg -s 720x1280 -i input.yuv -s 720x1280 -i input2.yuv -lavfi psnr=“psnr.log” -f null - | |
| Capture a part of the original video | ffmpeg -s 720x1280 -i input.yuv -ss 00:00:00 -to 00:00:40 output.yuv | Cut the file from 50 seconds to 20 seconds and input it to a new file, -ss is the specified time, -t is the specified duration |
| Remove watermark from video | ffmpeg -i test.mp4 -vf delogo=x=?:y=?:w=?:h=?:show=? out.mp4 | x, y position of the logo; w, h width and height of the logo; show When set to 1, a green rectangle will be drawn on the screen to simplify finding the correct x, y, w and h parameters. The default value is 0. |
| Convert each frame of the video into an image | ffmpeg -i input.mp4 ‘out.bmp’ | |
| video to gif | ffmpeg -i small.mp4 small.gif | |
| video cut | ffmpeg -i input.mp4 -vf crop=410:720 -y out.mp4 | The parameter format of crop is w: h: x : y; w and h are the width and height of the output video; x and y are a certain point in the video, use this point as a reference point, and crop it to the bottom right to get the output video. If x and y are not written, it will be centered by default. |
| rotate transpose | ffmpeg -i input.jpg -vf transpose=2 -y out.jpg | There is no black background after rotation; transpose=0 rotates 90° counterclockwise, then flips vertically; transpose=1 rotates 90° clockwise; transpose=2 rotates 90° counterclockwise; transpose=3 rotates 90° clockwise and then flips vertically. |
| rotate rotate | ffmpeg -i input.jpg -vf rotate=PI/3 -y out.jpg | With a black background after rotation, the original width and height of the video/picture have not changed. |
ffprobe command line
A simple multimedia stream analyzer.
| name | Order | explain |
|---|---|---|
| View video frame frame information | ffprobe -show_frames input.h264 | |
| View video stream information | ffprobe -show_streams input.h264 |
ffplay command line
A simple media player based on SDL and the FFmpeg libraries.
| name | Order | explain |
|---|---|---|
| Show license | ffplay -L | |
| help | ffplay -h | |
| View motion vector mv information | ffplay -flags2 +export_mvs output.h264 -vf codecview=mv=pf | |
| Macroblock MB information is printed to local txt | ffplay -debug mb_type thinkvision-2560x1440.mp4 2>mv.txt | |
| play yuv | ffplay -f rawvideo -video_size 2560x1440 -pixel_format uyvy422 out.yuv | |
| ffplay play aac | ffplay -f f32le -ac 1 -ar 44100 test.aac | -ac specifies the number of channels, -ar specifies the sampling rate |
| ffplay play rgb | ffplay -f rawvideo -pixel_format rgb24 -video_size 480x480 texture.rgb | |
| Specify the window size to play | ffplay -x 400 output.mp4 | Specify the size of the playback window to be 500 pixels |
Batch transcoding/transcapsulation scripts (and delete original files)
#!/bin/bash
for i in *.mkv;
do echo"${i%.*}.mp4";
ffmpeg -i "$i" -codec copy "${i%.*}.mp4";
rm -rf "${i%.*}.mkv";
done