The A7S III HEVC 4:2:2 files (Sony calls this XAVC HS) might not work with Vegas yet if they haven't support for HEVC 2.0 specification yet that includes HEVC 4:2:2, as it only supports HEVC 1.0 which is max 4:2:0. That is the problem as the codec is more advanced than the codecs supported in Vegas - but they are working on it as per this post.

I'd suggest sticking with the AVC 4:2:2 (Sony calls this XAVC S) or HEVC 4:2:0 codecs until support is added for the HEVC 4:2:2 (XAVC HS) codec.

It turns out that HEVC is no longer a delivery codec anymore, and is starting to get traction for capture as processing power is increasing faster and faster. This is good for most but some peoples' PCs will need upgrading to be able to handle these files adequately - but the A7S III has a proxy feature that records a proxy as well as this intensive file - at the same time - so that might be something to look into to save time, to not have Vegas make you a proxy after you're done shooting.

Just tried a 422 hevc mp4 clip using an 11th gen Intel cpu that has an onboard uhd750 igpu which is part of the Iris family. And it indeed decodes it in hardware and plays back pretty good. In both vp18 and vp19. I did the test by taking a Sony a7III xavc 422 clip and transcoding it to 422 hevc with ffmpeg. I was able to play both versions but the xavc would not play at full rate like the hevc one.

I did the test by taking a Sony a7III xavc 422 clip and transcoding it to 422 hevc with ffmpeg. I was able to play both versions but the xavc would not play at full rate like the hevc one.

So that's a comparison of AVC without hardware decoding and HEVC with hardware decoding, with HEVC winning. I would have thought with your system they should both have full playback framerate

it should work, but if you've gone into internal settings and disabled so4compoundplug.dll, then it will not read those files. I'm pretty sure 15 was the version they added support for those 10 bit formats.

Question, can the A7siii record 4K 10bit 422 but using H264 (XAVCS) instead of HEVC?

can you even mix and match the resolution, color depth, chroma sampling and codecs?

I remember I try GH5s camera I can shoot 1080p at 10bit.

It can.

https://helpguide.sony.net/ilc/2010/v1/en/contents/TP0003212154.html and https://helpguide.sony.net/ilc/2010/v1/en/contents/TP0003212155.html

Yes it can, but again, I would stay away from 422 unless you really need it (chroma key). Best to shoot XAVCS-Intra for best editing speed (and enjoy nvidia acceleration which outperforms igpu intel any time). If you want to edit 10-bit HEVC 420 4K SLOG3 at speed, you might have to look elsewhere to resolve those issuez.

I've been shooting 4k zlog2 420 hevc for the last year which edits so well in Vegas on my systems that I usually don't bother with proxies. But having shot with an xf305 (422 hd) for over a decade, I still lust for an xf705. The Iris-class igpu's capability of decoding hevc 422 brings me a step closer. If Intel ever releases a pcie gpu like that, I'd throw one into all my other machines. Although it would probably benefit Ryzens just as much... which might explain Intel's foot dragging.

in theory, most 'contemporary' nVidia GPUs should already support 444. But not 422. So, if Vegas was codec friendly, in my ideal world (which I don't live in), one should be able to ingest 10bit 422, convert to proxy and edit, and render out using another 444 prerender uprez utilizing full GPU power after that. But there's no Vegas Prepare (broken promise) since VP18 release. No native transcode. No 422.

That convert upon import in Vegas would be so handy for this and also variable framerate files that Vegas doesn't like.

one should be able to ingest 10bit 422

10 bit 4K 4:2:2 files recorded by my S1's work fine in VEGAS. No GPU support, unless using 11th gen QSV, but it does work.