rollback ffnvcodec to 12.1.14.1

[ulmus-scott]

This reduces the minimum Nvidia driver level to 530 from 550. Nvidia lists versions 535 and 550 for download for Linux.

Debian currently only packages 535 for Debian 12 and above.

Fixes #1039. This should also be applied to fixes/35

Checklist

• contribution does not duplicate one of our existing pull requests
• contribution is in a branch rebased against master
• code compiles successfully without errors
• commits are logically organised and have good commit messages

[bennettpeter]

I cannot recreate the error that the user had, see #1039. Playback is fine with nvidia 550. Do we really want to revert to older software?

[ulmus-scott]

https://www.mythtv.org/wiki/Coding_Standards lists Debian stable, which is currently 12, as supported, and Debian 12 only has a package for the Nvidia 535 driver.

When I updated ffnvcodec for FFmpeg 7.1, I didn't have a specific reason to use 12.2.72.1, just that it was the newest and I thought the 550 driver had been out for long enough that it would have been widely available, which apparently was incorrect. I only needed a different version since FFmpeg no longer accepted the 9.1.23.2 version and would disable NVDEC/NVENC completely otherwise.

12.2.72.1 lists 550 as the minimum driver version, so I would expect it to work. 12.1.14.1 lists 530 as the minimum driver version.

I don't think there is any significant difference for NVDEC between those versions, but, if 12.1.14.1 works with 535 and 12.2.72.1 doesn't, I think we should roll ffnvcodec back to 12.1.14.1.

ffnvcodec is just a copy of the Nvidia headers that FFmpeg needs to dynamically load the CUDA library for NVDEC and NVENC, so, since the newer drivers still accept the older interface, I don't think it is really "older software", just that it is allowing FFmpeg to work with older drivers.

[bennettpeter]

OK I will test with 535 without and with the patch.

[ulmus-scott]

I am closing this since #1039 has been resolved and this only effects NVENC, which is disabled by configure but enabled by cmake, pending discussion on the mailing list.