https://bugs.kde.org/show_bug.cgi?id=515044
Ryan <[email protected]> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|general |panels: information Product|dragonplayer |dolphin Assignee|[email protected] |[email protected] |g | CC| |[email protected], | |[email protected] --- Comment #5 from Ryan <[email protected]> --- I'm encountering the same issue with both Dolphin (in information panel preview) and Dragon running a Fedora 44 KDE VM in QEMU with no HW decode support. Note that software fallback for h.265 works, while AV1 does not. The QT_FFMPEG_DECODING_HW_DEVICE_TYPES workaround Harald mentioned does work for me. Summary --- I encountered this same bug viewing AV1 .webm files running Fedora 44 KDE under UTM/QEMU on an M2 Macbook both with Dragon and Dolphin's video preview. Attempting to view them would result in audio playback from the container, but blank video, and the noted errors below in console. Setting the env variable below to disable HW decode allowed for successful playback of both video and audio from the same files in both Dragon and Dolphin. export QT_FFMPEG_DECODING_HW_DEVICE_TYPES=, This isn't ideal since it disables *all* HW decoding support (although not a problem in my VM use case). It's possible that customizing specific HW_DEVICE_TYPES listed might provide a workaround that supports some but not all HW decode. Note that h.265 decoding successfully falls back to software decoding without the workaround, unlike AV1. System Info --- CPU: QEMU Virtual ARM64 GPU: QEMU Virtual virgl / virtio_gpu (running via UTM 4.7.5, QEMU 10.0) Packages: dragon.aarch64 26.08.0-1.fc44 updates ffmpeg-free.aarch64 8.1.2-4.fc44 updates ffmpegthumbs.aarch64 26.08.0-1.fc44 updates gstreamer1.aarch64 1.28.6-1.fc44 updates gstreamer1-plugins-bad-free-libs.aarch64 1.28.6-1.fc44 updates gstreamer1-plugins-base.aarch64 1.28.6-1.fc44 updates libdav1d.aarch64 1.5.3-1.fc44 e8f4790dbb0b44ac9eb86ca3c7e5cd26 qt6-qtmultimedia.aarch64 6.11.1-1.fc44 updates Additional Information --- When attempting to play a .webm AV1: Stream #0:0: Video: av1 (libdav1d) (Main), yuv420p10le(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 30 fps, 30 tbr, 1k tbn Metadata: ENCODER : Lavc63.1.101 libsvtav1 DURATION : 00:06:16.366000000 Without the workaround, the following error messages repeat, and no video is displayed (audio from the same container is output successfully): [av1 @ 0xaaaad6bb25f0] No support for codec av1 profile 0. [av1 @ 0xaaaad6bb25f0] Failed setup for format vaapi: hwaccel initialisation returned error. [av1 @ 0xaaaad6bb25f0] Your platform doesn't support hardware accelerated AV1 decoding. [av1 @ 0xaaaad6bb25f0] Failed to get pixel format. [av1 @ 0xaaaad6bb25f0] Get current frame error With the workaround, the following warning message is displayed once, and both video and audio play as expected: qt.multimedia.playbackengine.codec: "No HW decoder found" By comparison, playing an h.265 stream from an MP4 container works regardless of the env setting: Stream #0:0[0x1](und): Video: hevc (Main) (hvc1 / 0x31637668), yuv420p(tv, bt709, progressive), 1920x1080, 913 kb/s, 30 fps, 30 tbr, 30k tbn (default) Metadata: handler_name : VideoHandler encoder : Lavc63.8.100 libx265 Displays the following warning and successfully plays video+audio: [hevc @ 0xaaaae5fb3870] No support for codec hevc profile 1. [hevc @ 0xaaaae5fb3870] Failed setup for format vaapi: hwaccel initialisation returned error. So, this seems to be specific to AV1 (or perhaps .webm) since HW decode for hevc is also missing, but falls back successfully. In all cases the notification/warning is displayed when initializing video playback: qt.multimedia.ffmpeg: Using Qt multimedia with FFmpeg version 8.1.2 GPL version 3 or later Failed to open VDPAU backend libvdpau_nvidia.so: cannot open shared object file: No such file or directory -- You are receiving this mail because: You are watching all bug changes.
