Blackmagic Forum

Hi,
I was wondering if you had the opportunity to add some hardware accelerating for XAVC-H (all flavours for BURANO 8K?).

Thank you for your response.

Fred Savoir
Amazing Digital Studios

What GPU do you have? I had simlair decoding issue with XAVC I from FX6. Where it should have been Hardware accelerated, because it just a H.264 codec, and XAVC-H is H.265, both supported by my Nvidia RTX5080. I noticed that mxf files are not being hardware accelerated, but mp4 file with the same codec are accelerated by the GPU, which is a bit strange.

qiyuxuan wrote:I had simlair decoding issue with XAVC I from FX6. Where it should have been Hardware accelerated, because it just a H.264 codec...I noticed that mxf files are not being hardware accelerated, but mp4 file with the same codec are accelerated by the GPU, which is a bit strange.

XAVC-I is an all-intra codec using AVC (H.264) on single frames, not Long GOP. By definition, it is always 10-bit 4:2:2. It is generally fast and smooth to edit, with or without hardware acceleration. In fact, you can test that by turning on/off H.264/H.265 acceleration in Resolve Preferences>Decode Options (assuming your platform supports hardware decode acceleration for 10-bit 4:2:2 H.264).

That said, there can be advantages to using hardware decode acceleration on XAVC-I. Even ProRes 422 (on Apple Silicon) can be hardware accelerated, but you usually don't need it as much.

The closest Sony MP4 format to MXF XAVC-I would be 10-bit 4:2:2 XAVC SI (not XAVC-S nor XAVC HS, which are Long GOP). On Windows, there is no hardware decode acceleration for H.264 10-bit 4:2:2 before the RTX 50-series, and that requires Resolve Studio 20 beta. It has been available on Mac for several years.

I didn't think hardware decode acceleration worked on Windows Resolve Studio 19.x for 10-bit 4:2:2 H.264, regardless of whether the container is MP4 or MXF, and regardless of whether it's All-Intra or Long GOP.

The options are shown on the Puget Systems tables: https://www.pugetsystems.com/labs/artic ... tudio-2122

Re the OP question, XAVC-H is 10-bit 4:2:2 H.265. There are three variants; XAVC H-I HQ (All-Intra), XAVC H-I SQ (All-Intra) and XAVC H-L (Long GOP). There is no 10-bit 4:2:0 or 8-bit 4:2:0 version. Therefore, your hardware would have to be Intel Quick Sync 11th gen or later, NVIDIA RTX 50 series or Intel ARC. NVDEC on NVIDIA RTX 50 is only supported starting with Resolve Studio 20 beta, not on Resolve Studio 19 or before.

joema4 wrote: On Windows, there is no hardware decode acceleration for H.264 10-bit 4:2:2 before the RTX 50-series, and that requires Resolve Studio 20 beta. It has been available on Mac for several years.

The options are shown on the Puget Systems tables: https://www.pugetsystems.com/labs/artic ... tudio-2122

Could someone with a 50 series GPU fact check Puget Systems, does Resolve V20b4 actually have 422 10bit decode of H.264 (in an mp4 wrapper) BMD have never made that claim.

But there is H.265 4:2:2 decode of mp4 on V20 with the user questioning why no hardware decode of XAVC-H (H.265 codec in MXF_OP1a wrapper)