H.264 Decoding Tackled For Reverse-Engineered "Cedrus" Allwinner Video Decode Driver

[chithanh]

If my memory serves me right, 370X -> 370 -> 270X -> 7970 are basically the same GPU

Almost.
R7 370X/370 -> R9 270X/270/R7 265 -> 7870/7850 are based on Pitcairn.
R9 280X/280 -> 7970/7950/7870XT are based on Tahiti.

Both are first-generation GCN with only two(?) async compute queues and no FreeSync support for gaming. Supposedly they have FreeSync support for video playback, but I have never seen this work under any OS.

[pal666]

They can reverse-engineer it with 13 people in the company, but AMD cannot provide it for their own gcn1 devices? Weird.

on what planet those 13 people reverse-engineered h264 decode on allwinner for amdgpu?

[jernej]

This preliminary H.264 video decoding with the Cedrus driver works with multimedia programs in user-space via the libvdpau-sunxi user-space component for offering up the well-supported VDPAU video decode API to media players, etc.

Michael You mixed up libvdpau-sunxi, which is a precursor project, where most reverse engineering happened and current project, implementing V4L2 VPU kernel driver, which is based on knowledge from libvdpau-sunxi. However, there will be optional userspace library (since V4L2 codecs based on request API are not yet supported by any player), which will implement VAAPI interface.

[Brisse]

It is ported to amdgpu unofficially for like two years, I'm even on amdgpu-pro(here it's official) currently, and vdpauinfo shows support for MPEG1, MPEG2_SIMPLE, MPEG2_MAIN.
In the old radeon driver, there are a few h.264 and a bit more, but they don't work. All videos played are mostly pink and cpu usage is as high or higher than without it, I mean playback through Epiphany or Chromium-beta with video decode.

Those apps both use gstreamer, right? I've had a lot of trouble with hardware decoding on my AMD R9 Fury with anything that uses gstreamer, but mpv and ffmpeg works flawlessly.

[Namenlos]

Full decode and encode capabilities are supported on GCN 1.0 devices with the radeon driver.

But with that you lose Vulkan. I am still hoping AMD manages to release the compatible firmware. So GCN 1.0 users like the ones who brought the barely three years old R9 370X can enjoy video acceleration and Vulkan.

[agd5f]

They can reverse-engineer it with 13 people in the company, but AMD cannot provide it for their own gcn1 devices? Weird.

Full decode and encode capabilities are supported on GCN 1.0 devices with the radeon driver.

[Michael]

Is IT possible to Port to Raspberry Pi and openelec?

Raspberry Pi doesn't use Allwinner SoC.... So no, it doesn't have the same video decode hardware. OpenELEC meanwhile is a Linux distribution that when it pulls in the kernel patches or a supported mainline kernel, it would have this driver.

[predator7]

Is IT possible to Port to Raspberry Pi and openelec?

[Namenlos]

It is ported to amdgpu unofficially for like two years[…]

No GCN 1.0 dosn't work because they are missing some 40bit firmware. The enablement is a wip from a year and not two ago that is stalled because of the missing firmware. With RadeonSI the uvd works, but there is no vulkan support. I think Christian König wanted to check with the legal team for the 40bit firmware, but that was one year ago.

[boxie]

They can reverse-engineer it with 13 people in the company, but AMD cannot provide it for their own gcn1 devices? Weird.

you do realise that GCN 1.0 parts were released more than 6 years ago yeah? and were superseded nearly 5 years ago...

I am sure support for it will come in time, but for now I would love to see them wrangle more performance out of the latest stuff!