System Details:

OS: Fedora 41 Version: <= DAILY BUILD OpenShot-v3.4.0-release-candidate-14702-9a262882-0b018e34-x86_64

Describe the bug:

When nvidia dec or va-api is selected, 3.40 is crashing when loading a mp4 file. (any mp4 file). versions < 3.4 do not crash, they load the video, but the decoding is mostly greenish with some artefacts. when hw decoding is disabled, openshot works fine.

The attached logs contain all combinations of hw decoding options.

it starts with enabled nvdec decoding.

Log Files:

openshot.tar.gz

Exception / Stacktrace:

none are created

Oct 07 '25 22:10 Cyborgscode

I can tell, that the breakage happend between 22.08.2025 and 3.10.2025 .

$ vainfo Trying display: wayland Trying display: x11 libva info: VA-API version 1.22.0 libva info: Trying to open /usr/lib64/dri-nonfree/nvidia_drv_video.so libva info: Trying to open /usr/lib64/dri-freeworld/nvidia_drv_video.so libva info: Trying to open /usr/lib64/dri/nvidia_drv_video.so libva info: Found init function __vaDriverInit_1_0 libva info: va_openDriver() returns 0 vainfo: VA-API version: 1.22 (libva 2.22.0) vainfo: Driver version: VA-API NVDEC driver [direct backend] vainfo: Supported profile and entrypoints VAProfileMPEG2Simple : VAEntrypointVLD VAProfileMPEG2Main : VAEntrypointVLD VAProfileVC1Simple : VAEntrypointVLD VAProfileVC1Main : VAEntrypointVLD VAProfileVC1Advanced : VAEntrypointVLD VAProfileH264Main : VAEntrypointVLD VAProfileH264High : VAEntrypointVLD VAProfileH264ConstrainedBaseline: VAEntrypointVLD VAProfileHEVCMain : VAEntrypointVLD VAProfileVP8Version0_3 : VAEntrypointVLD VAProfileVP9Profile0 : VAEntrypointVLD VAProfileAV1Profile0 : VAEntrypointVLD VAProfileHEVCMain10 : VAEntrypointVLD VAProfileHEVCMain12 : VAEntrypointVLD VAProfileVP9Profile2 : VAEntrypointVLD VAProfileHEVCMain444 : VAEntrypointVLD VAProfileHEVCMain444_10 : VAEntrypointVLD VAProfileHEVCMain444_12 : VAEntrypointVLD

nvidia-smi

rpm -qi akmod_nvidia

Name : akmod-nvidia Epoch : 3 Version : 580.82.09 Release : 1.fc41 Architecture: x86_64 Install Date: Fr 19 Sep 2025 10:01:49 CEST Group : Unspecified Size : 98833 License : Redistributable, no modification permitted Signature : RSA/SHA256, Do 11 Sep 2025 10:20:54 CEST, Key ID 6a2af96194843c65 Source RPM : nvidia-kmod-580.82.09-1.fc41.src.rpm Build Date : Do 11 Sep 2025 01:29:13 CEST Build Host : buildvm-07.virt.rpmfusion.net Packager : RPM Fusion Vendor : RPM Fusion URL : https://www.nvidia.com/ Bug URL : https://bugz.rpmfusion.org/nvidia-kmod Summary : Akmod package for nvidia kernel module(s) Description :

Oct 07 '25 22:10 Cyborgscode

BTW: nvidia hw decoding mp4 files with the os-version of ffmpeg works :

fmpeg -hwaccel cuvid -threads 11 -c:v h264_cuvid -hwaccel_output_format cuda -i "$filename" -map 0:1 -map 0:0 -c:v:0 h264_nvenc -b:v:0 $BITS -c:a:0 copy -f mp4 new.mp4

Oct 07 '25 22:10 Cyborgscode

Hardware acceleration in OpenSHot is currently broken and has been for some time. Not sure when the lead developer will get to it.

Oct 07 '25 23:10 Colorjet3

hmm.. strange, because it worked at least until the 22th of August, and version 3.3 was in use for months before this.

In mid september, nvidia drivers got updated. I can't downgrade the old driver version atm, so can't check it. But I'm certain, that it's a minor issue to fix, something like the wrong decoder matrix type i.e. RGBA <-> ARGB, something like that kind of mistake.

Oct 08 '25 08:10 Cyborgscode

I don't run Linux so I don't have experience with that. In Windows environment it hasn't worked since v2.6.x.

By the way, are you running the AppImage? If not, see if the AppImage works. You will need to install libfuse2 for the AppImage to start.

Oct 08 '25 16:10 Colorjet3

I wonder if this could be related to issue #5800? The time-frame when the breakage happened matches up. Do you run the AppImage? If so, then I'm surprised it's working at all. The AppImage on Fedora42 has been broken since early July. Ever since Fedora updated those MESA drivers. It's still broken now with latest daily build (14712), MESA drivers at 25.1.9.

Oct 12 '25 22:10 Bert-H

Fedora 41 runs currently mesa 25.0.7 I upgraded to mesa 25.1.9 from fedora 42

Result: runs fine with mesa 25.1.9 and rest of fedora 41. If there is a bug with fedora libs, it's not mesa.

and the reason for it is ofcourse: MESA is NOT LOADED at all, if hwdecoding is disabled.

while testing, if hwdec works now ( stettings window ), it loaded these files:

[pid 10123] openat(AT_FDCWD, "/usr/share/glvnd/egl_vendor.d/50_mesa.json", O_RDONLY) = 182 [pid 10123] openat(AT_FDCWD, "/lib64/libEGL_mesa.so.0", O_RDONLY|O_CLOEXEC) = 182

$ rpm -qf /lib64/libEGL_mesa.so.0 mesa-libEGL-25.1.9-1.fc42.x86_64

hw tests are still failing.

I noticed this unrelated error message in the stderr output:

INFO main_window: updateStatusChanged [8088:8161:1013/090841.507395:ERROR:simple_version_upgrade.cc(165)] Disk cache backend fake index file has wrong magic number. [8088:8161:1013/090841.507494:ERROR:simple_backend_impl.cc(757)] Simple Cache Backend: wrong file structure on disk: 3 path: /home/xxx/.cache/openshot/QtWebEngine/Default/Cache INFO timeline: Dropping item on timeline - item_id: OSE0030S3Q, item_type: clip INFO main_window: updateStatusChanged

maybe a hint for another bug?

Oct 13 '25 07:10 Cyborgscode

Update:

After starting "OpenShot-v3.4.0-release-candidate-14775-55963445-0b018e34-x86_64.AppImage" 7th Nov build on Fedora 42, the three hw decoding api fail all together. The Testbuttons is red for all three, but.. NVDEC still delivers the greenish result, while VA-API and VDPAU both do not even give defective frames out.

Version 3.3.0 | 0.4.0 Testresult: it starts. it loads projects. That's it. No function, no preview, no nothing.

I will inform the fedora maintainer about this devasting result myself.

Nov 12 '25 08:11 Cyborgscode

btw.. NVENC works.. why is NVDEC not working proper?

Nov 12 '25 08:11 Cyborgscode

nvidia hw decoding broken - decoded video is mostly greenish

nvidia-smi

rpm -qi akmod_nvidia