H.264 4:2:2 10-bit support in Resolve 20

The 'Codecs' section of the DaVinci Resolve 20 announcement says:

+ GPU accelerated H.265 4:2:2 encodes on supported Nvidia systems.
+ GPU accelerated H.265 4:2:2 decodes on supported Nvidia systems.

I am specifically interested in knowing if Resolve 20 supports GPU accelerated H.264 10-bit 4:2:2 on Nvidia RTX 50-series. This codec is native to my Panasonic Lumix cameras and others like Sony.

I am specifically interested in knowing if Resolve 20 supports GPU accelerated H.264 10-bit 4:2:2 on Nvidia RTX 50-series. This codec is native to my Panasonic Lumix cameras and others like Sony.

I've requested 50 series owners to try a number of different files, they never do, only ever complain about bugs affects 50 series owners. So they're here, but not helpful.

As for if they do have compatibility, they might, but if it's the same level of compatibility seen with the V19 beta versions 5090 Reviewers were using, they are compatible with some H.264 422 10bit files but not others. This may be why V20 is not officially compatible or alternatively there may be no H.264 422 10bit GPU decoding ability in V20 until Resolve has full compatibility at which point it will be turned on.

What specific file do you want to test with? Links please

The answer is yes!

I was sent a h264 high 4:2:2 L5.1, yuv422p10le, 3840x2160 file and it's decoded in hardware. No cpu increase and the hardware decoder load increased (verified both in Task Manager and GPU-Z).

Gratitude and honor to Mads Johansen for verifying the H.264 hardware decode in the RTX 5070 Ti. You have done us all a great favor!

That's great news for rtx 50-series owners. Unfortunately, Davinci Resolve 20 doesn't seem to utilize Intel ARC hardware encoders for h264 10 bit 422. At least the 140t igpu on my intel 255h cpu isn't crunching it. H265 10 bit 422 is however decoded on it and running smoothly.

Really hoping blackmagic will enable hardware decoding for h264 10 bit 422 (4k) soon, as this is the format I shoot in the vast majority of the time, and right now it's not editing smoothly.

That's great news for rtx 50-series owners. Unfortunately, Davinci Resolve 20 doesn't seem to utilize Intel ARC hardware encoders for h264 10 bit 422. ...
Really hoping blackmagic will enable hardware decoding for h264 10 bit 422 (4k) soon,....

It seems the encode/decode *hardware* for H.264 10-bit 4:2:2 is not present in the Intel iGPU and ARC series of Intel discrete GPU's. As you can see in my signature, I have an ARC A770 16GB, and it will get replaced with an Nvidia RTX 50-series.

That's great news for rtx 50-series owners. Unfortunately, Davinci Resolve 20 doesn't seem to utilize Intel ARC hardware encoders for h264 10 bit 422. ...
Really hoping blackmagic will enable hardware decoding for h264 10 bit 422 (4k) soon,....

It seems the encode/decode *hardware* for H.264 10-bit 4:2:2 is not present in the Intel iGPU and ARC series of Intel discrete GPU's. As you can see in my signature, I have an ARC A770 16GB, and it will get replaced with an Nvidia RTX 50-series.

Hi Gary, you're right... Oh dear... Why, Intel, why? Was hoping to be able to do some smooth but light editing on my new Lenovo Yoga pro 7i gen 10 with the latest 255h cpu... Seems like I might have to return it and start looking for something with a Rtx 5060 instead. Sigh.

The 'Codecs' section of the DaVinci Resolve 20 announcement says:

+ GPU accelerated H.265 4:2:2 encodes on supported Nvidia systems.
+ GPU accelerated H.265 4:2:2 decodes on supported Nvidia systems.

I am specifically interested in knowing if Resolve 20 supports GPU accelerated H.264 10-bit 4:2:2 on Nvidia RTX 50-series. This codec is native to my Panasonic Lumix cameras and others like Sony.

My brand new RTX 5070 Ti does NOT accelerate Sony XAVC S-I 4K from A7S3 camera in Resolve 20.

MediaInfo reports the Codec ID "XAVC (XAVC/mp42/iso2)", Format profile "High 4:2:2 Intra@L5.2"

I checked further, here is info from ffprobe

"Stream #0:0[0x1](und): Video: h264 (High 4:2:2 Intra) (avc1 / 0x31637661), yuv422p10le(pc, progressive), 3840x2160 [SAR 1:1 DAR 16:9], 478495 kb/s, 50 fps, 50 tbr, 50k tbn (default)"

I'm still pleased to have updated my old 2080 Ti though as I can now edit Sony XAVC HS format (HEVC) that my older CPU struggled with.

The 'Codecs' section of the DaVinci Resolve 20 announcement says:

+ GPU accelerated H.265 4:2:2 encodes on supported Nvidia systems.
+ GPU accelerated H.265 4:2:2 decodes on supported Nvidia systems.

I am specifically interested in knowing if Resolve 20 supports GPU accelerated H.264 10-bit 4:2:2 on Nvidia RTX 50-series. This codec is native to my Panasonic Lumix cameras and others like Sony.

My brand new RTX 5070 Ti does NOT accelerate Sony XAVC S-I 4K from A7S3 camera in Resolve 20.

MediaInfo reports the Codec ID "XAVC (XAVC/mp42/iso2)", Format profile "High 4:2:2 Intra@L5.2"

I checked further, here is info from ffprobe

"Stream #0:0[0x1](und): Video: h264 (High 4:2:2 Intra) (avc1 / 0x31637661), yuv422p10le(pc, progressive), 3840x2160 [SAR 1:1 DAR 16:9], 478495 kb/s, 50 fps, 50 tbr, 50k tbn (default)"

I'm still pleased to have updated my old 2080 Ti though as I can now edit Sony XAVC HS format (HEVC) that my older CPU struggled with.

Can you be persuaded to upload a 10 second video somewhere for verification?

This was recorded on my A7S3 in S-Log3 S-Gamut3 for use in an HDR project.

Download link
https://www.transfernow.net/dl/20250619dRC7y2oG

This was recorded on my A7S3 in S-Log3 S-Gamut3 for use in an HDR project.

Download link
https://www.transfernow.net/dl/20250619dRC7y2oG

Thanks. You are indeed right, nothing is used on a 5070 TI with this file

This was recorded on my A7S3 in S-Log3 S-Gamut3 for use in an HDR project.

Download link
https://www.transfernow.net/dl/20250619dRC7y2oG

Thanks. You are indeed right, nothing is used on a 5070 TI with this file

That is odd as I was under impression any Blackwell card should be able to do it. Are you experiencing same lack of 5070 Ti hardware acceleration with any H.264 10-bit 4:2:2 file or just with this particular one? If you try playing this particular one with some other software does it end up using hardware acceleration?

Hi Gary, you're right... Oh dear... Why, Intel, why?

264 isn't that demanding anymore. CPUs are fast enough for the most part. Partly what was the last new camera to use 264 4.2.2?

264 was for 4k and lower with so many cameras supporting 6k and above it doesn't make sense for the camera makers to use.

If your camera offers other options it might be simpler to switch recording formats.

This was recorded on my A7S3 in S-Log3 S-Gamut3 for use in an HDR project.

Download link
https://www.transfernow.net/dl/20250619dRC7y2oG

Thanks. You are indeed right, nothing is used on a 5070 TI with this file

That is odd as I was under impression any Blackwell card should be able to do it. Are you experiencing same lack of 5070 Ti hardware acceleration with any H.264 10-bit 4:2:2 file or just with this particular one? If you try playing this particular one with some other software does it end up using hardware acceleration?

I haven't had the time yet to do my entire test suite of what flavors of H264 and H265 the 5070 TI supports ( https://en.wikipedia.org/wiki/Advanced_ ... g#Profiles ), the pixel formats yuv420, yuv422, yuv444, yuv420p10le, yuv422p10le, yuv444p10le and how the nvdec is accessed (d3d11va, d3d12va, vulkan, cuda).
We know the h264 high 4:2:2 L5.1 yuv422p10le is supported while h264 high 4:2:2 intra L5.2 yuv422p10le is not.

With that background of the way:
I'm sceptical of the need for hardware decoding of h.264 intra, as I can decode the file from Claire at 200 fps.
And no, with the files I normally deal with (eg h264 high), they are all hardware decoded.

Hi Gary, you're right... Oh dear... Why, Intel, why?

264 isn't that demanding anymore. CPUs are fast enough for the most part. Partly what was the last new camera to use 264 4.2.2?

264 was for 4k and lower with so many cameras supporting 6k and above it doesn't make sense for the camera makers to use.

If your camera offers other options it might be simpler to switch recording formats.

Hi Nick, I shoot on the Sony A6700, and the reason I am locked into using 264 still, is because Sony cameras for some odd reason doesn't have 25p in h265 when shooting in pal (only 50p and 100p). I would be fine using h265 if it wasn't for that limitation, but I still need 25p.

My new Lenovo yoga pro 7i gen 10 with the Intel 255h Cpu can edit h.264, but the fans ramp up like crazy as the CPU is utilized 100% and it is not as smooth at all as when editing h.264. The noise from the fans and the lack of smooth scrubbing on the time line kind of takes the fun out of editing fast.

I haven't had the time yet to do my entire test suite of what flavors of H264 and H265 the 5070 TI supports ... We know the h264 high 4:2:2 L5.1 yuv422p10le is supported while h264 high 4:2:2 intra L5.2 yuv422p10le is not.

With that background of the way:
I'm sceptical of the need for hardware decoding of h.264 intra, as I can decode the file from Claire at 200 fps.

Thank you! How exactly do you test decoding speed, please? I would like to test my system.

I haven't had the time yet to do my entire test suite of what flavors of H264 and H265 the 5070 TI supports ... We know the h264 high 4:2:2 L5.1 yuv422p10le is supported while h264 high 4:2:2 intra L5.2 yuv422p10le is not.

With that background of the way:
I'm sceptical of the need for hardware decoding of h.264 intra, as I can decode the file from Claire at 200 fps.

Thank you! How exactly do you test decoding speed, please? I would like to test my system.

ffmpeg.exe -i example.h264 -f null NUL

I'm not aware of any "read a file and do nothing with it" functionality in Davinci, sadly.

I haven't had the time yet to do my entire test suite of what flavors of H264 and H265 the 5070 TI supports ... We know the h264 high 4:2:2 L5.1 yuv422p10le is supported while h264 high 4:2:2 intra L5.2 yuv422p10le is not.

With that background of the way:
I'm sceptical of the need for hardware decoding of h.264 intra, as I can decode the file from Claire at 200 fps.

Thank you! How exactly do you test decoding speed, please? I would like to test my system.

ffmpeg.exe -i example.h264 -f null NUL

I'm not aware of any "read a file and do nothing with it" functionality in Davinci, sadly.

Thank you! My 10920X was able to decode Claire's file with ffmpeg at 260fps which wasn't giving me enough time to judge what was going on with CPU. In Resolve her file played at full speed 50fps without any dropped frames, 30+% overall CPU usage across several cores and at least 2 cores being maxed out when in color page (25+% and one core maxed out when in edit page). So maybe the question isn't can ffmpeg easily decode it without sweating the CPU but how much of CPU usage when in Resolve is due to decoding and how much is due to rest / how much of benefit H.264 GPU acceleration would give.

P.S. Do you know of way to tell ffmpeg to keep doing test decoding in the loop, please, so I can get better idea how much CPU load it causes vs. Resolve?

Thank you! My 10920X was able to decode Claire's file with ffmpeg at 260fps which wasn't giving me enough time to judge what was going on with CPU. In Resolve her file played at full speed 50fps without any dropped frames, 30+% overall CPU usage across several cores and at least 2 cores being maxed out when in color page (25+% and one core maxed out when in edit page). So maybe the question isn't can ffmpeg easily decode it without sweating the CPU but how much of CPU usage when in Resolve is due to decoding and how much is due to rest / how much of benefit H.264 GPU acceleration would give.

P.S. Do you know of way to tell ffmpeg to keep doing test decoding in the loop, please, so I can get better idea how much CPU load it causes vs. Resolve?

The only thing I can think of is to create a bat file with

Code: Select all

ffmpeg.exe -i example.h264 -f null NUL
ffmpeg.exe -i example.h264 -f null NUL
ffmpeg.exe -i example.h264 -f null NUL
....
ffmpeg.exe -i example.h264 -f null NUL
ffmpeg.exe -i example.h264 -f null NUL


(the same command multiple times)

You're talking about CPU usage over 1-ish second, right? I haven't verified this but it looks exactly like what we need.
I like https://systeminformer.sourceforge.io/ for it's detailed information.

I haven't tested if we can subtract Davinci from itself: Create a new timeline, add a generator, convert to Compound Clip, then play back. Then take the cpu usage from that as a Davinci basal use and subtract from other measurements.

The other thing I've been thinking of is to indirectly measure how long it takes to go one frame back in a long GOP file: Record via OBS and go to the end of a known GOP file, then go one frame back. Count the frames between button press and resolve responds = GOP length/response time = decode fps.
But it's tangential to the cpu usage

The only thing I can think of is to create a bat file with ...

I ended up creating batch file that kept calling ffmpeg.exe in the loop. Load on CPU was 45-75% very evenly spread across all 24 cores. In other words, ffmpeg efficiently used every single resource at its disposal and can't be used to judge whether Resolve will benefit from GPU H264 acceleration, pattern of CPU usage between the two is obviously very different.

I haven't tested if we can subtract Davinci from itself ...

You have 5070 Ti, correct? IIRC one can tell Resolve whether to use GPU or CPU for decoding, which could give an idea how much H264 GPU decoding helps in Resolve, how big is an impact on CPU. If yes what kind of file you would need to test that, please? Would 4K SI file from FX30 work?

The other thing I've been thinking of is to indirectly measure how long it takes to go one frame back in a long GOP file: Record via OBS and go to the end of a known GOP file, then go one frame back. Count the frames between button press and resolve responds = GOP length/response time = decode fps. But it's tangential to the cpu usage

That's a very good idea. Using 2 machine setup with recording card would eliminate any concerns over vampire system load. Unfortunately I don't have a setup I could test that with.