Hi, Your video4linux loopback device might not be set up on /dev/video0, so this might be your regular webcam.
So try /dev/video1 or /dev/video2 or higher until you get the v4l2 loopback device. CIao, Marcus On Thu, Dec 09, 2021 at 06:52:29PM +0100, Ulrich Salaschek wrote: > Hi to all, > > first, the obligatory Thank You for gphoto!! > > using a command from the wiki, I encountered an error message though, aiming > to use my Nikon D7100 as a webcam. > > When running > $ gphoto2 --stdout --capture-movie | ffmpeg -i - -vcodec rawvideo -pix_fmt > yuv420p -threads 0 -f v4l2 /dev/video0 > the camera's mirror opens but then gphoto aborts with the following error > message from ffmpeg/v4l2 > > > [error message] > gphoto2 --stdout --capture-movie | ffmpeg -i - -vcodec rawvideo -pix_fmt > yuv420p -threads 0 -f v4l2 /dev/video0 > ffmpeg version 4.4-6ubuntu5 Copyright (c) 2000-2021 the FFmpeg developers > built with gcc 11 (Ubuntu 11.2.0-7ubuntu1) > configuration: --prefix=/usr --extra-version=6ubuntu5 --toolchain=hardened > --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu > --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls > --enable-ladspa --enable-libaom --enable-libass --enable-libbluray > --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 > --enable-libdav1d --enable-libflite --enable-libfontconfig > --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm > --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg > --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq > --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr > --enable-libspeex --enable-libsrt --enable-libssh --enable-libtheora > --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx > --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid > --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx > --enable-openal --enable-opencl --enable-opengl --enable-sdl2 > --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 > --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint > --enable-frei0r --enable-libx264 --enable-shared > libavutil 56. 70.100 / 56. 70.100 > libavcodec 58.134.100 / 58.134.100 > libavformat 58. 76.100 / 58. 76.100 > libavdevice 58. 13.100 / 58. 13.100 > libavfilter 7.110.100 / 7.110.100 > libswscale 5. 9.100 / 5. 9.100 > libswresample 3. 9.100 / 3. 9.100 > libpostproc 55. 9.100 / 55. 9.100 > Nehme Vorschaubilder als Film in 'stdout' auf. Drücke Ctrl-C zum abbrechen. > [mjpeg @ 0x5633a608f440] 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), 640x360, 25 tbr, 1200k tbn, 25 tbc > Stream mapping: > Stream #0:0 -> #0:0 (mjpeg (native) -> rawvideo (native)) > [swscaler @ 0x5633a60f7b80] deprecated pixel format used, make sure you did > set range correctly > [video4linux2,v4l2 @ 0x5633a6092f40] ioctl(VIDIOC_G_FMT): Invalid argument > Could not write header for output file #0 (incorrect codec parameters ?): > Invalid argument > Error initializing output stream 0:0 -- > Conversion failed! > [/error message] > > > Help is appreciated. > Kind regards > Ulrich > > > > Running Ubuntu 21.10 with Kernel 5.13.0-22 > v4l2loopback kernel module is installed and loaded alongside videodev > $ gphoto2 --summary displays the camera infos correctly > $ gphoto2 --capture-image-and-download and other commands work as expected > > Versions: > This version of gphoto2 is using the following software versions and > options: > gphoto2 2.5.27 gcc, popt(m), exif, cdk, aa, jpeg, readline > libgphoto2 2.5.27 standard camlibs, gcc, ltdl, EXIF > libgphoto2_port 0.12.0 iolibs: disk ptpip serial usb1 usbdiskdirect > usbscsi, gcc, ltdl, EXIF, USB, serial without locking > > > > _______________________________________________ > Gphoto-devel mailing list > Gphoto-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/gphoto-devel _______________________________________________ Gphoto-devel mailing list Gphoto-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gphoto-devel
