Unified Video Decoder

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Unified Video Decoder (UVD), previously called Universal Video Decoder, is the name given to AMD's dedicated video decoding ASIC. There are multiple versions implementing a multitude of video codecs, such as H.264 and VC-1.

UVD was introduced with the Radeon HD 2000 Series and is integrated into some of the AMD GPUs and APUs. UVD occupies a considerable amount of the die surface[1] and is not to be confused with AMD's Video Codec Engine (VCE).

Overview[edit]

The UVD is based on an ATI Xilleon video processor, which is incorporated onto the same die as the GPU and is part of the ATI Avivo HD for hardware video decoding, along with the Advanced Video Processor (AVP). UVD, as stated by AMD, handles decoding of H.264/AVC, and VC-1 video codecs entirely in hardware.

The UVD technology is based on the Cadence Tensilica Xtensa[2] processor,[3][4][5] which was originally licensed by ATI Technologies Inc. in 2004.[6]

UVD/UVD+[edit]

In early versions of UVD, video post-processing is passed to the pixel shaders and OpenCL kernels. MPEG-2 decoding is not performed within UVD, but in the shader processors. The decoder meets the performance and profile requirements of Blu-ray and HD DVD, decoding H.264 bitstreams up to a bitrate of 40 Mbit/s. It has context-adaptive binary arithmetic coding (CABAC) support for H.264/AVC.

Unlike video acceleration blocks in previous generation GPUs, which demanded considerable host-CPU involvement, UVD offloads the entire video-decoder process for VC-1 and H.264 except for video post-processing, which is offloaded to the shaders. MPEG-2 decode is also supported, but the bitstream/entropy decode is not performed for MPEG-2 video in hardware. Previously, neither ATI Radeon R520 series' ATI Avivo nor NVidia Geforce 7 series' PureVideo assisted front-end bitstream/entropy decompression in VC-1 and H.264 - the host CPU performed this work.[7] UVD handles VLC/CAVLC/CABAC, frequency transform, pixel prediction and inloop deblocking, but passes the post processing to the shaders.[8] Post-processing includes denoising, de-interlacing, and scaling/resizing. AMD has also stated that the UVD component being incorporated into the GPU core only occupies 4.7 mm² in area on 65 nm fabrication process node.

A variation on UVD, called UVD+, was introduced with the Radeon HD 3000 series. UVD+ support HDCP for higher resolution video streams.[9] But UVD+ was also being marketed as simply UVD.

UVD 2[edit]

The UVD saw a refresh with the release of the Radeon HD 4000 series products. The UVD 2 features full bitstream decoding of H.264/MPEG-4 AVC, VC-1, as well as iDCT level acceleration of MPEG2 video streams. Performance improvements allow dual video stream decoding and Picture-in-Picture mode. This makes UVD2 full BD-Live compliant.

The UVD 2.2 features a re-designed local memory interface and enhances the compatibility with MPEG2/H.264/VC-1 videos. However, it was marketed under the same alias as "UVD 2 Enhanced" as the "special core-logic, available in RV770 and RV730 series of GPUs, for hardware decoding of MPEG2, H.264 and VC-1 video with dual-stream decoding". The nature of UVD 2.2 being an incremental update to the UVD 2 can be accounted for this move.

UVD 3[edit]

UVD 3 adds support for additional hardware MPEG2 decoding (entropy decode), DivX and Xvid via MPEG-4 Part 2 decoding (entropy decode, inverse transform, motion compensation) and Blu-ray 3D via MVC (entropy decode, inverse transform, motion compensation, in-loop deblocking).[10][11] along with 120 Hz stereo 3D support,[12] and is optimized to utilize less CPU processing power.

UVD 3 also adds support for Blu-ray 3D stereoscopic displays.[citation needed]

UVD 4[edit]

UVD 4 includes improved frame interpolation with H.264 decoder.[13] UVD 4.2 was introduced with the AMD Radeon Rx 200 series and Kaveri APU.[citation needed]

UVD 5[edit]

UVD 5 was introduced with the AMD Radeon R9 285.[citation needed]

Availability[edit]

Most of the Radeon HD 2000 series video cards implement the UVD for hardware decoding of 1080p high definition contents.[14] However, the Radeon HD 2900 series video cards do not include the UVD (though it is able to provide partial functionality through the use of its shaders), which was incorrectly stated to be present on the product pages and package boxes of the add-in partners' products before the launch of the Radeon HD 2900 XT,[citation needed] either stating the card as featuring ATI Avivo HD or explicitly UVD,[citation needed] which only the former statement of ATI Avivo HD is correct. The exclusion of UVD was also confirmed by AMD officials.[15]

UVD2 is implemented in the Radeon RV7x0 and R7x0 series GPUs. This also includes the RS7x0 series used for the AMD 700 chipset series IGP motherboards.

Feature overview[edit]

The entire AMD Accelerated Processing Unit lines and some of their features
Brand Brazos
(low power)		 Llano Trinity Richland Kabini & Temash
(low power)		 Kaveri Beema & Mullins
(low power)		 Carrizo Carrizo-L
(low power)
Released Jan 2011 Aug 2011 Oct 2012 2013 May 2013 Jan 2014 Q2 2014 2015 2015
Fab (nm) TSMC 40 nm GlobalFoundries 32 nm SOI 28 28 28 28 28
APU Socket FT1 FM1
FS1		 FM2
FS1+
FP2		 AM1
FT3		 FM2+
FP3		 FT3b TBA TBA
CPU cores Bobcat AMD 10h Piledriver Jaguar Steamroller Puma Excavator Puma+[16]
3D engine1 80:8:4 400:20:8 384:24:6 384:24:6 128:8:4 512:32:8 128:8:4 TBA TBA
TeraScale 2 (VLIW5) TeraScale 3 (VLIW4) Graphics Core Next (Mantle, HSA)
IOMMUv1 IOMMUv2 IOMMUv1[17] TBA TBA
Unified Video Decoder UVD 3 UVD 4 UVD 4.2 TBA TBA
Video Codec Engine N/A VCE 1.0 VCE 2.0 TBA TBA
TrueAudio N/A Yes[18] N/A[17] TBA TBA
Max. № of displays2 2 2–3 2–4 2 2–4 2 TBA TBA
Direct Rendering Manager/
Mesa 3D driver[19][20]		 Yes[20] WiP[21] WiP[22]


UVD-enabled GPUs[edit]

Operating system support[edit]

The UVD SIP core needs to be supported by the device driver, which provides one or more interfaces such as VDPAU, VAAPI or DXVA. One of these interfaces is then used by end-user software, for example VLC media player or GStreamer, to access the UVD hardware and make use of it.

AMD Catalyst, AMD's proprietary graphics device driver that supports UVD, is available for Microsoft Windows and some Linux distributions. Additionally, a free device driver is available, which also supports the UVD hardware.

Linux[edit]

Linux support for the UVD ASIC is provided by the Linux kernel device driver amdgpu.[26]

Support for UVD has been available in AMD's proprietary driver Catalyst version 8.10 since October 2008 through X-Video Motion Compensation (XvMC) or X-Video Bitstream Acceleration (XvBA).[27][28] Since April 2013,[29] UVD is supported by the free and open-source "radeon" device driver through Video Decode and Presentation API for Unix (VDPAU). An implementation of VDPAU is available as Gallium3D state tracker in Mesa 3D.

On 28 June 2014, Phoronix published some benchmarks on using Unified Video Decoder through the VDPAU interface running MPlayer on Ubuntu 14.04 with version 10.3-testing of Mesa 3D.[30]

Windows[edit]

Windows supported UVD since it was launched. UVD currently only supports DXVA (DirectX Video Acceleration) API specification for the Microsoft Windows and Xbox 360 platforms to allow video decoding to be hardware accelerated, thus the media player software also has to support DXVA to be able to utilize UVD hardware acceleration.

Others[edit]

Support for running custom FreeRTOS-based firmware on the Radeon HD 2400's UVD core (based on an Xtensa CPU), interfaced with a STM32 ARM-based board via I2C, was attempted as of January 2012.[31]

See also[edit]

Predecessors[edit]

Notes[edit]

  1. ^ Dual-GPU variants with two of the latter GPUs.
  2. ^ Driver version 8.371 or later must be used if the GPU is "Mobility Radeon HD 2300" for enabling UVD functions for H.264 videos, or system may crash.

References[edit]

  1. ^ "AMD A-Series APU block diagram". 2011-06-30. Retrieved 2015-01-22. 
  2. ^ "Linux operating system on Xtensa processors". 
  3. ^ Cheung, Ken (2009-01-08). "Consumer Electronics Show Features Tensilica-enabled Products". EDA Geek. Retrieved 2014-05-15. 
  4. ^ "Customer Profiles | Cadence IP". Ip.cadence.com. 2014-04-13. Retrieved 2014-05-15. 
  5. ^ "Tensilica News: Excellent AMD ATI Video with Xtensa". tensilica.com. 2009-10-05. Retrieved 2014-05-15. 
  6. ^ "ATI Licenses Tensilica's Xtensa Configurable Processor". Business Wire. 2004-10-18. Retrieved 2014-05-15. 
  7. ^ "HardSpell review" (in Chinese). [dead link]
  8. ^ Smith, Ryan (February 24, 2010). "AMD’s Radeon HD 5450: The Next Step In HTPC Video Cards". AnandTech. AnandTech, Inc. p. 4. Retrieved April 7, 2010. Since deinterlacing and other AVIVO post-processing actions are done by the shader hardware, the limited shading capabilities of these cards meant that AMD couldn’t offer the full suite of AVIVO abilities at once. 
  9. ^ (Chinese) PC-DVD discussion thread, retrieved August 23, 2008
  10. ^ White Paper | AMD Unified Video Decoder (UVD)
  11. ^ http://www.dailytech.com/Radeon+6800+Series+Launches+Targets+GeForce+GTX+460/article19928.htm by Jansen Ng, 10/21/2010 DailyTech
  12. ^ "AMD A6-3650 Llano APU Review - Page 5". Hardwarecanucks.com. Retrieved 2014-04-17. 
  13. ^ AMD A10-7850K 'Kaveri' review: AMD's new APU
  14. ^ HKEPC report
  15. ^ DailyTech report
  16. ^ "AMD Mobile “Carrizo” Family of APUs Designed to Deliver Significant Leap in Performance, Energy Efficiency in 2015" (Press release). 2014-11-20. Retrieved 2015-02-16. 
  17. ^ a b Thomas De Maesschalck (2013-11-14). "AMD teases Mullins and Beema tablet/convertibles APU". Retrieved 2015-02-24. 
  18. ^ "A technical look at AMD’s Kaveri architecture". Semi Accurate. Retrieved 6 July 2014. 
  19. ^ Airlie, David (2009-11-26). "DisplayPort supported by KMS driver mainlined into Linux kernel 2.6.33". Retrieved 2014-07-02. 
  20. ^ a b "Radeon feature matrix". freedesktop.org. Retrieved 2015-02-13. 
  21. ^ "AMDKFD Driver Does More Prepping For Carrizo / VI APUs". 2015-01-13. Retrieved 2015-01-13. 
  22. ^ "AMDKFD Driver Does More Prepping For Carrizo / VI APUs". 2015-01-13. Retrieved 2015-01-13. 
  23. ^ "How do I connect three or More Monitors to an AMD Radeon™ HD 5000, HD 6000, and HD 7000 Series Graphics Card?". AMD. Retrieved 2014-12-08. 
  24. ^ a b [1][dead link]
  25. ^ a b c d "Phoronix.com Forum". phoronix.com. Retrieved 2014-08-26. 
  26. ^ Michael Larabel (October 8, 2014). "The Slides Announcing The New "AMDGPU" Kernel Driver". Phoronix. Retrieved January 22, 2015. 
  27. ^ "UVD Is Enabled For Linux In Catalyst 8.10". Phoronix. 2008-10-15. Retrieved 2015-01-22. 
  28. ^ "AMD's X-Video Bitstream Acceleration". Phoronix. 2008-10-28. Retrieved 2015-01-22. 
  29. ^ "AMD Releases Open-Source UVD Video Support". Phoronix. 2013-04-02. Retrieved 2015-01-22. 
  30. ^ "AMD Radeon VDPAU Video Performance With Gallium3D". Phoronix. 2014-06-28. Retrieved 2015-01-22. 
  31. ^ "Interfacing a PC graphics card (Radeon HD 2400) with a STM32 microcontroller". Edaboard.com. 2012-01-09. Retrieved 2014-04-27. 

External links[edit]
 
Fixed pipeline
Unified shaders
TeraScale
Unified shaders & memory
GCN
 
Current technologies and software
Audio/Video acceleration
GPU technologies
Software
 
Other brands and products
Workstations & Supercomputers
Consoles
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