modprobe 및 gphoto2를 사용하여 640x426보다 큰 형식을 얻는 방법

Nikon을 웹캠으로 사용하려면 다음 명령을 사용합니다.

sudo modprobe v4l2loopback && gphoto2 --stdout --capture-movie | ffmpeg -i - -vcodec rawvideo -pix_fmt yuv420p -threads 0 -f v4l2 /dev/video2

이것은 매력처럼 작동합니다.

ffmpeg version N-49161-g50e194e6e1-static https://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
  configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-6 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gmp --enable-gray --enable-libaom --enable-libfribidi --enable-libass --enable-libvmaf --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librubberband --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libvorbis --enable-libopus --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libdav1d --enable-libxvid --enable-libzvbi --enable-libzimg
  libavutil      56. 30.100 / 56. 30.100
  libavcodec     58. 53.101 / 58. 53.101
  libavformat    58. 28.101 / 58. 28.101
  libavdevice    58.  7.100 / 58.  7.100
  libavfilter     7. 55.100 /  7. 55.100
  libswscale      5.  4.101 /  5.  4.101
  libswresample   3.  4.100 /  3.  4.100
  libpostproc    55.  4.100 / 55.  4.100
Capturing preview frames as movie to 'stdout'. Press Ctrl-C to abort.
[mjpeg @ 0x6d15940] Format mjpeg detected only with low score of 25, misdetection possible!
Input #0, mjpeg, from 'pipe:':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: mjpeg (Baseline), yuvj422p(pc, bt470bg/unknown/unknown), 640x426, 25 tbr, 1200k tbn, 25 tbc

그러나 최대 해상도는 얼마이며 640x426가능하다면 더 큰 형식을 사용하고 싶습니까?