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

[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.

[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?

[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.