Hi Guix, Currently VDPAU, through libvdpau, can't find backends as they are not part of where it will search:
<https://vdpau.pages.freedesktop.org/libvdpau/group__api__winsys__x11.html> Namely, it will search where it is configured to at build time via pkg-config, but for us our backends will be somewhere in the store unknown unless we include e.g. mesa as an input. Rather than increasing the closure to include any VDPAU backends (I know of mesa and libvdpau-va-gl), an environment variable can be specified at runtime, VDPAU_DRIVER_PATH. However, I'm not sure how we can use that as a search path unless we require users to install libvdpau and a backend, like mesa, in their profile. This doesn't seem like the cleanest option. Any other options? For testing, here is mpv not finding a VDPAU backend (trying with vaapi or hwdec auto will use vaapi successfully): --8<---------------cut here---------------start------------->8--- ❯ guix shell mpv -- mpv -vo=vdpau ~/test.mkv (+) Video --vid=1 (*) (h264 1920x1080 30.000fps) (+) Audio --aid=1 (*) 'Track1' (aac 2ch 48000Hz) Failed to open VDPAU backend libvdpau_radeonsi.so: cannot open shared object file: No such file or directory [vo/vdpau] Error when calling vdp_device_create_x11: 1 Error opening/initializing the selected video_out (--vo) device. Video: no video Exiting... (Errors when loading file) --8<---------------cut here---------------end--------------->8--- but we can specify mesa explicitly: --8<---------------cut here---------------start------------->8--- ❯ VDPAU_DRIVER_PATH=$(guix build mesa | tail -n1)/lib/vdpau guix shell mpv -- mpv -vo=vdpau ~/test.mkv (+) Video --vid=1 (*) (h264 1920x1080 30.000fps) (+) Audio --aid=1 (*) 'Track1' (aac 2ch 48000Hz) [vo/vdpau] Warning: this compatibility VO is low quality and may have issues with OSD, scaling, screenshots and more. [vo/vdpau] vo=gpu is the preferred choice in any case and includes VDPAU support via hwdec=vdpau or vdpau-copy. AO: [pulse] 48000Hz stereo 2ch float VO: [vdpau] 1920x1080 yuv420p [vo/vdpau] Compositing window manager detected. Assuming timing info is inaccurate. AV: 00:00:00 / 00:20:25 (0%) A-V: 0.005 DS: 2.067/0 Exiting... (Quit) --8<---------------cut here---------------end--------------->8--- Or, of course, using vdpauinfo: --8<---------------cut here---------------start------------->8--- ❯ guix shell vdpauinfo -- vdpauinfo display: :0.0 screen: 0 Failed to open VDPAU backend libvdpau_radeonsi.so: cannot open shared object file: No such file or directory Error creating VDPAU device: 1 ❯ VDPAU_DRIVER_PATH=$(guix build mesa | tail -n1)/lib/vdpau guix shell vdpauinfo -- vdpauinfo display: :0.0 screen: 0 API version: 1 Information string: G3DVL VDPAU Driver Shared Library version 1.0 Video surface: name width height types ------------------------------------------------------------------------ 420 16384 16384 NV12 YV12 422 16384 16384 UYVY YUYV 444 16384 16384 Y8U8V8A8 V8U8Y8A8 420_16 16384 16384 422_16 16384 16384 444_16 16384 16384 [...] --8<---------------cut here---------------end--------------->8--- John PS: I didn't check in detail, but I would guess <https://issues.guix.gnu.org/48868> is related; though there at least mesa is an input for VLC (including libvdpau-va-gl wouldn't be much for a 1.6 gig package already).
