macos - 如何使用ffmpeg在macos上录制音视频？

Question

$ ffmpeg -f avfoundation -list_devices true -i ""
...
[AVFoundation indev @ 0x7fa8c24312c0] AVFoundation video devices:
[AVFoundation indev @ 0x7fa8c24312c0] [0] FaceTime HD Camera
[AVFoundation indev @ 0x7fa8c24312c0] [1] Capture screen 0
[AVFoundation indev @ 0x7fa8c24312c0] AVFoundation audio devices:
[AVFoundation indev @ 0x7fa8c24312c0] [0] MacBook Pro Microphone

这些是我的音频和视频设备。
我正在尝试从屏幕的麦克风和视频捕获中录制音频。
但是，当我尝试运行命令时，出现此错误:

$ ffmpeg -f avfoundation -i "1:0"  \             
  ~/Videos/screencast.mp4
ffmpeg version 4.3.2 Copyright (c) 2000-2021 the FFmpeg developers
  built with Apple clang version 12.0.0 (clang-1200.0.32.29)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.3.2 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  7.100 /  5.  7.100
  libswresample   3.  7.100 /  3.  7.100
  libpostproc    55.  7.100 / 55.  7.100
[AVFoundation indev @ 0x7fced1c315c0] Configuration of video device failed, falling back to default.
[avfoundation @ 0x7fced2009000] Selected pixel format (yuv420p) is not supported by the input device.
[avfoundation @ 0x7fced2009000] Supported pixel formats:
[avfoundation @ 0x7fced2009000]   uyvy422
[avfoundation @ 0x7fced2009000]   yuyv422
[avfoundation @ 0x7fced2009000]   nv12
[avfoundation @ 0x7fced2009000]   0rgb
[avfoundation @ 0x7fced2009000]   bgr0
[avfoundation @ 0x7fced2009000] Overriding selected pixel format to use uyvy422 instead.

另外我想在右下角捕捉相机。这就是我在 Linux 上的做法，但基础知识甚至不适用于 MacOS。

screencap() {
  file=`date +%Y-%m-%d-%H.%M.%S`
  ffmpeg -f alsa -i pulse -f x11grab -thread_queue_size 64 -i :0.0 \
  -video_size 384x216 -i /dev/video0 \
        -filter_complex 'overlay=main_w-overlay_w:main_h-overlay_h' \
  -r 60 -preset ultrafast ~/Videos/screencast-${file}.mp4
}

Answer 1

在使用 FFMPEG 录制我的 MacOs 屏幕后，我总是在 FFMPEG 挂起之前收到相同的错误:

Configuration of video device failed, falling back to default.

最后，我找到了适合我的解决方案。
问题是由 引起的权限不足在 Screen Recording环境。
添加后 iterm (或任何其他终端应用程序)到允许的应用程序，以下 FFMPEG 命令按预期工作:

ffmpeg -f avfoundation -i "2:0" output.mkv

不要忘记编辑屏幕/音频索引