FFmpeg

ffmpeg is a complete, cross-platform solution to record, convert and stream audio and video. It is the reference multimedia library for the FFmpeg project.

查看 FFmpeg 支持的容器

~$ ffmpeg -formats

编码

• H.264
• H.265

上面的编码格式都是有版权的，但是可以免费使用。此外，还有几种无版权的视频编码格式

• VP8
• VP9
• AV1

常用的音频编码格式

• MP3
• AAC

~$ ffmpeg -codecs

~$ ffmpeg -encoders

FFmpeg 命令格式

FFmpeg 的命令行参数非常多，可以分成五个部分

~$ ffmpeg {1} {2} -i {3} {4} {5}

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

Clip Video

ffmpeg -i input.mp4 -ss 30 -c copy output.mp4

Merge Audio and Video

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

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

List Devices

~$ ffmpeg -f avfoundation -list_devices true -i ""
[...]
[AVFoundation indev @ 0x14d9042f0] AVFoundation video devices:
[AVFoundation indev @ 0x14d9042f0] [0] FaceTime HD Camera
[AVFoundation indev @ 0x14d9042f0] [1] Lsong’s iPhone 13 Pro Camera
[AVFoundation indev @ 0x14d9042f0] [2] Capture screen 0
[AVFoundation indev @ 0x14d9042f0] AVFoundation audio devices:
[AVFoundation indev @ 0x14d9042f0] [0] LarkAudioDevice
[AVFoundation indev @ 0x14d9042f0] [1] Lsong’s iPhone 13 Pro Microphone
[AVFoundation indev @ 0x14d9042f0] [2] MacBook Pro Microphone
: Input/output error

https://ffmpeg.org/ffmpeg-devices.html

Record Screen Capture

# ffmpeg -f avfoundation -i "<screen device index>:<audio device index>" output.mkv
# [2] Capture screen 0
# [2] MacBook Pro Microphone
ffmpeg -f avfoundation -i "2:2" output.mkv

https://trac.ffmpeg.org/wiki/Capture/Desktop

Record FaceTime Camera

# [0] FaceTime HD Camera
~$ ffmpeg -f avfoundation -r 30 -pix_fmt uyvy422 -i "0" -y out.mov

Record Screen with Camera

~$ ffmpeg -y \
	-f avfoundation -r 30 -video_size 1920x1080 -capture_cursor true -capture_mouse_clicks true -i "2:2" \
	-f avfoundation -r 30 -video_size 1280x720 -i "0" \
	-filter_complex "[1]scale=iw/2:ih/2 [pip]; [0][pip] overlay=W-w-50:H-h-50" \
	output.mkv

YouTube Live

Record Screen with Camera and Push to YouTube

#!/usr/bin/env sh

RTMP_STREAM_URL="rtmp://a.rtmp.youtube.com/live2/<token>"

ffmpeg -y \
	-f avfoundation -r 30 -video_size 1920x1080 -capture_cursor true -capture_mouse_clicks true -i "2:2" \
	-f avfoundation -r 30 -video_size 1280x720 -i "0" \
	-filter_complex "[1]scale=iw/2:ih/2 [pip]; [0][pip] overlay=W-w-50:H-h-50" \
	-f flv "$RTMP_STREAM_URL"

---