No hardware encoders found, but only for decoding on ARC

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1

Hello. I’ve recently updated to Kdenlive 25.12.0B, on Windows 11 24H2. I’m using MLT 7.35.0.

Firstly, I have a laptop (W11 25H2) that has an AMD 6000 series mobile APU and an Nvidia dGPU, both of whose encoders are found in KDENlive’s config wizard, and I can confirm the new hardware decoding feature works on it.

Sadly, this doesn’t seem to work on my PC, where the program refuses to detect the Intel ARC B580 card. I can manually select QSV hardware acceleration, but it automatically deselects QSV hardware encoding and ignores the “suggeted” hardware decoding (D3D11va).

I have confirmed there is 0 difference between using the “hardware decoder” and not using it.

It seems KDENlive just doesn’t want to detect my ARC card, and I don’t know why. It’s especially weird considering that I’ve been using its hardware AV1 encoding for months now, I can confirm it STILL works great, and yet the decoding bit refuses to even acknowledge the card’s existence.

Is there some setting I need to select? Maybe I have the wrong version of some internal file (ffprobe, ffplay, something that should recognize the tool but doesn’t)? I don’t know. Please help.

Thanks for reading.

2

This is the source code bit that does the QSV test:

https://github.com/KDE/kdenlive/blob/c58d228b67e3da9a3b663a4a3108b333cd5dbb23/src/dialogs/wizard.cpp#L779

As you can see, it uses hevc_qsv. I have tested hevc_qsv for video encoding, and it works fine, so it’s not like that encoder doesn’t work with KDENlive. Something else seems to not work. It seems like the way the script is formatted to check for QSV doesn’t actually check for it properly.