#11574: FFmpeg fails to handle symlinks to video devide -----------------------------------+---------------------------------- Reporter: Martmists | Type: defect Status: new | Priority: normal Component: ffplay | Version: 7.1 Keywords: | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | -----------------------------------+---------------------------------- Summary of the bug: On Linux, FFmpeg gives an Invalid argument error trying to playback symlinks to video devices. How to reproduce: I have the following udev rule: {{{ SUBSYSTEM=="video4linux", KERNEL=="video*", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="0893", ATTRS{serial}=="287A4655", SYMLINK+="webcam" }}} This creates a symlink /dev/webcam to, in this case, /dev/video0. {{{ $ readlink /dev/webcam video0 }}} However, FFmpeg fails to play it back: {{{ $ ffplay -v 9 -loglevel 99 /dev/webcam ffplay version n7.1.1 ... Initialized opengl renderer. [AVFormatContext @ 0x728098000c80] Opening '/dev/webcam' for reading [file @ 0x728098001340] Setting default whitelist 'file,crypto,data' [AVIOContext @ 0x728098011540] Statistics: 0 bytes read, 0 seeks /dev/webcam: Invalid argument }}} Using the device it points to works fine, however: {{{ $ ffplay /dev/video0 ... [video playback starts] }}} FFmpeg version: {{{ ffplay version n7.1.1 Copyright (c) 2003-2025 the FFmpeg developers built with gcc 14.2.1 (GCC) 20250207 configuration: --prefix=/usr --disable-debug --disable-static --disable- stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-frei0r --enable-gmp --enable-gnutls --enable- gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libdav1d --enable-libdrm --enable-libdvdnav --enable-libdvdread --enable-libfreetype --enable-libfribidi --enable- libglslang --enable-libgsm --enable-libharfbuzz --enable-libiec61883 --enable-libjack --enable-libjxl --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libplacebo --enable-libpulse --enable-librav1e --enable-librsvg --enable-librubberband --enable- libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable- libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable- libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpl --enable- libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-nvdec --enable-nvenc --enable-opencl --enable-opengl --enable- shared --enable-vapoursynth --enable-version3 --enable-vulkan libavutil 59. 39.100 / 59. 39.100 libavcodec 61. 19.101 / 61. 19.101 libavformat 61. 7.100 / 61. 7.100 libavdevice 61. 3.100 / 61. 3.100 libavfilter 10. 4.100 / 10. 4.100 libswscale 8. 3.100 / 8. 3.100 libswresample 5. 3.100 / 5. 3.100 libpostproc 58. 3.100 / 58. 3.100 }}} -- Ticket URL: <https://trac.ffmpeg.org/ticket/11574> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker