Archive:Hardware Accelerated Video Decoding Development and Default control tags: Difference between pages

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This article will cover potential methods of and the '''development''' around Hardware Accelerated Video Decoding.
Here are the tags and attributes available for all controls. '''Note that they're all lowercase, as XML is case sensitive'''.


'''Note!''' XBMC does not yet support any methods of hardware accelereated video decoding. Developers wanted!
=== Tags available to all controls ===
{| class="wikitable"
! description
| Only used to make things clear for the skinner. Not read by XBMC at all.
|-
! type
| The type of control.
|-
! id
| Specifies the control's id. The value this takes depends on the control type, and the window that you are using the control on. There are special control id's that must be present in each window. Any other controls that the skinner adds can be any id they like. Any controls that the skinner specifies content needs not have an id unless it's needed for animation purposes.  For instance, most image and label controls don't need an id if the skinner specifies they're content.
|-
! posx
| Specifies where the left edge of the control should be drawn, relative to it's parent's left edge. If an "r" is included (eg 180r) then the measurement is taken from the parent's right edge (in the left direction).
|-
! posy
| Specifies where the top edge of the control should be drawn, relative to it's parent's top edge. If an "r" is included (eg 180r) then the measurement is taken from the parent's bottom edge (in the up direction).
|-
! width
| Specifies the width that should be used to draw the control.
|-
! height
| Specifies the height that should be used to draw the control.
|-
! visible
| Specifies a condition as to when this control will be visible. Can be true, false, or a condition. See [[Conditional Visibility]] for more information.  Defaults to true.
|-
! animation
| Specifies the animation to be run when the control enters a particular state. See [[Animating your skin]] for more information.
|-
! camera
| Specifies the location (relative to the parent's coordinates) of the camera. Useful for the 3D animations such as rotatey.  Format is <code><camera x="20" y="30" /></code>
|-
! colordiffuse
| This specifies the color to be used for the texture basis. It's in hex AARRGGBB format. If you define <code><colordiffuse>FFFF00FF</colordiffuse></code> (magenta), the image will be given a magenta tint when rendered. Defaults to FFFFFFFF (no tint).  You can also specify this as a name from the [[Colour Themes|colour theme]].
|}


=Hardware Accelerated Video Decoding=
=== Tags available to focusable controls ===
"Hardware Accelerated Video Decoding" is the when a video-playback software-application offload portions of the [http://en.wikipedia.org/wiki/Video_decoding video decoding process] to the [http://en.wikipedia.org/wiki/Graphics_processing_unit GPU (Graphic) hardware], it does this by executing specific code algorithms on the GPU. In theory this process should also reduce bus bandwidth requirements.


[http://ffmpeg.mplayerhq.hu FFmpeg] (and [http://www.mplayerhq.hu MPlayer]) should probably be the reference and test platform for all hardware accelerated video decoding development. The reason for this is that XBMC used FFmpeg as the base for its [[DVDPlayer|DVDPlayer-playback-core]] core, and FFmpeg is used as the codec-suit inside XBMC [[MPlayer|MPlayer-playback-core]]. Also, since both [http://ffmpeg.mplayerhq.hu FFmpeg] and [http://www.mplayerhq.hu MPlayer] are cross-platform code we can get help from non-XBMC developers.
In addition, any control that is focusable (e.g. a buttoncontrol) will have the following tags available.


==Hardware Accelerated Video Decoding under Linux==
{| class="wikitable"
Developers wanted!, for more information on XBMC and Linux please see the [[Linux port project]] article in this WIKI.
! onup
===Video decoding processes which could be accelerated===
| Specifies the <code><id></code> of the control that should be moved to when the user moves up off this control.  Can point to a control group (which remembers previous focused items).
XvMC for Linux could possible be extended in the future to support the same processes:
|-
* Motion compensation (mo comp)
! ondown
* Inverse Discrete Cosine Transform (iDCT)
| Specifies the <code><id></code> of the control that should be moved to when the user moves down off this control.  Can point to a control group (which remembers previous focused items).
* Inverse Telecine 3:2 and 2:2 pull-down correction
|-
* Bitstream processing (CAVLC/CABAC)
! onleft
* in-loop deblocking
| Specifies the <code><id></code> of the control that should be moved to when the user moves left off this control.  Can point to a control group (which remembers previous focused items).
* inverse quantization (IQ)
|-
* Variable-Length Decoding (VLD), more commonly known as slice level acceleration
! onright
* Spatial-Temporal De-Interlacing, (plus automatic interlace/progressive source detection)
| Specifies the <code><id></code> of the control that should be moved to when the user moves right off this control.  Can point to a control group (which remembers previous focused items).
|-
! hitrect
| Specifies the location and size of the "focus area" of this control (relative to the parent's coordinates) used by the mouse cursor. Format is <code><hitrect x="20" y="30" w="50" h="10" /></code>
|-
! enable
| Specifies a condition as to when this control will be enabled. Can be true, false, or a condition. See [[Conditional Visibility]] for more information.  Defaults to true.
|-
! pulseonselect
| This specifies whether or not a button type will "pulse" when it has focus.  This is done by varying the alpha channel of the button.  Defaults to true.
|}


===XvMC===
==Similar page names==
[http://en.wikipedia.org/wiki/X-Video_Motion_Compensation X-Video Motion Compensation (XvMC)], is an extension of the [http://en.wikipedia.org/wiki/X_video_extension X video extension (Xv)] for the [http://en.wikipedia.org/wiki/X_Window_System X Window System]. The XvMC [http://en.wikipedia.org/wiki/API API] allows a simple way to add hardware accelerated video decoding to video-playback software-application
{{#lst:Tags|similar pages}}


====NVIDIA====
==See also==
Even though NVIDIA closed source binary device driver for Linux currently only support XvMC hardware acceleration of motion compensation (mo comp), and inverse discrete cosine transform (iDCT) for MPEG-2, the closed source binary device driver for Microsoft Windows from NVIDIA features many more additional video decoding processes which can be passed on to modern GPU (such as NVIDIA's GeForce 6-series, from 6150 and on) which on Microsoft Windows can accelerate many more video decoding processes via [http://en.wikipedia.org/wiki/DirectX_Video_Acceleration Microsoft's DxVA (DirectX Video Acceleration) API], (the Microsoft Windows equivalent to XvMC).
'''Development:'''
* [[Add-on development]]
* [[Skinning]]


=====NVIDIA PureVideo Technology=====
[[Category:Skin Development]]
NVIDIA's GeForce 6-series (from GeForce 6150 and on) features a video acceleration engine called "PureVideo", NVIDIA's GeForce 8-series (with the exception of GeForce 8800) features an updated version of the PureVideo technology which NVIDIA calls "PureVideo HD". NVIDIA PureVideo Technology is a true discrete programmable processing core inside the NVIDIA GPU. The NVIDIA PureVideo technology is a combination of a hardware video processor and video decode software, meaning it only offloads parts of the video decoding to the GPU (but since those are the 'heavy' and processor intensive parts it results in a [http://www.bit-tech.net/news/2006/01/07/nvidia_decode_h264/ huge diffrence on CPU usage when using PureVideo vs. not using PureVideo]).
 
NVIDIA closed source binary device driver for Microsoft Windows has since ForceWare version 85 featured PureVideo Technology support for accelerated hardware video decoding of MPEG-2, MPEG-4 AVC (H.264), VC-1, and WMV9, (plus it also Spatial-Temporal De-Interlacing), via [http://en.wikipedia.org/wiki/DirectX_Video_Acceleration DXVA] (which is Microsoft's equivalent of the XvMC API).
 
====Intel (GMA)====
Intel's open source device drivers for Linux supports motion compensation (mo comp), and inverse discrete cosine transform (iDCT), and de-interlacing for MPEG-2.
 
=====Intel Clear Video Technology=====
[http://www.intel.com/products/chipsets/clear_video/index.htm Intel® Clear Video Technology] is a combination of video processing hardware and software technologies for a wide range of digital displays. This technology is available on all Intel® G965 Express Chipset-based hardware platforms. According to Intel, Clear Video Technology enables; ''Enhanced high-definition video playback, Sharper images, Precise color control, and Advanced display capability''.
 
'''Intel Clear Video Technology Features and benefits;'''
*MPEG-2 decode iDCT + motion compensation. Up to 2 stream support (1 HD and 1 SD)
*De-interlacing Advanced pixel adaptive (SD/HD-1080i)
*Color control ProcAmp: brightness, hue, saturation, contrast.
*Video scaling 4x4 scaling
*Digital Display Support (through SDVO) Digital Video Interface (DVI), High-Definition Multimedia Interface (HDMI)
*Display support RGB (QXGA), HDMI, UDI, DVI, HDTV (1080i/p, 720p), Composite, Component, S-Video (via Intel Serial Digital Video Out), TV-out, CRT
*Aspect ratio 16:9, 4:3, letterbox
*Maximum resolution support 2048 x 1536 at 75 Hz, RGB (QXGA)
 
===Alternative methods of hardware accelerated video decoding===
Video decoding processes could possible also be accelerated under Linux/UNIX (and Microsoft Windows) by using other methods than the previously mentioned PureVideo Technology from NVIDIA (alternative methods could also be used in combination with PureVideo to run video decoding processes that PureVideo do not support). Programming [http://en.wikipedia.org/wiki/Shader shaders (Pixel Shader or Vertex Shader)], with one shader for each video decoding process that one would wish to accelerate is one such method. GPGPU (General-Purpose Computing on Graphics Processing Units) is another possible method. All these alternative methods requires [http://en.wikipedia.org/wiki/Shader Shader Model 3.0] support by the GPU, (which is one of the reasons why we made [http://en.wikipedia.org/wiki/Shader Shader Model 3.0] a minimum end-user requirement for the [[Linux port project|XBMC Linux port]]).
 
=== GLSL (OpenGL Shading Language) ===
[http://en.wikipedia.org/wiki/OpenGL_Shading_Language OpenGL Shading Language (GLSL, a.k.a. GLslang)] is a high-level shader programming-language (based on the C programming-language) which offers such possibilities, (GLSL was originally introduced as an extension to OpenGL 1.5 but the OpenGL ARB only formally included GLSL into the OpenGL 2.0 core).
http://en.wikipedia.org/wiki/OpenGL_Shading_Language
=== Cg (C for Graphics) ===
[http://en.wikipedia.org/wiki/Cg_programming_language Cg (or "C for Graphics")] is a another high-level shading programming-language, created by NVIDIA for programming vertex and pixel shaders it is compatible with other GPU hardware manufactures as well. Like GLSL, Cg is also based on the C programming language, and although they share the same syntax, some features of C were modified and new data types were added to make Cg more suitable for programming graphics processing units. The Cg programming-language seems to have survived the introduction of the newer shading languages very well, mainly (???) of its established momentum in the digital content creation area, although the language is seldom used in final products.
 
=== GPGPU (General-Purpose Computing on Graphics Processing Units) ===
[http://en.wikipedia.org/wiki/GPGPU General-Purpose Computing on Graphics Processing Units (GPGPU, also referred to as GPGP and to a lesser extent GP²)] is a recent trend in computer science that uses the Graphics Processing Unit to perform the computations rather than the CPU. The addition of programmable stages and higher precision arithmetic to the GPU rendering pipeline have allowed software developers to use the GPU for non graphics related applications. Because of the extremely parallel nature of the graphics pipeline the GPU is especially useful for programs that can be cast as stream processing and real-time computing problems. Simplest way to enable GPGPU support is by using a library such as [http://en.wikipedia.org/wiki/Lib_Sh Lib Sh (GPGPU library for C++)], or [http://en.wikipedia.org/wiki/BrookGPU BrookGPU] (the latter, BrookGPU is probably the better of the two for XBMC video decoding purposes).
 
=== CUDA (Compute Unified Device Architecture) ===
[http://en.wikipedia.org/wiki/CUDA CUDA (Compute Unified Device Architecture)] is an [http://en.wikipedia.org/wiki/GPGPU GPGPU technology] and API that NVIDIA introduced in the GeForce 8-series (G8X based) GPUs. CUDA allows a programmer to use the C programming-language to code algorithms for execution on the GPU. A video decoding process could be a such code algorithms that is executed on the GPU via CUDA.
 
==Possible development tools and resources==
Tools and resources that could possible help in the development. Note that GLSL shaders will need to be created and tested in a development tool prior to the injection in the video-playback software-application that will use them, (to do so, GLSL developer tools exists, see "Development Tools" below).
===Development Tools===
* [http://sourceforge.net/projects/lumina/ Lumina] -  GLSL development tool (IDE). It is platform independent and the interface uses the [http://en.wikipedia.org/wiki/Qt_%28toolkit%29 Qt (toolkit)].
*NVIDIA [http://developer.nvidia.com/object/nvshaderperf_1_8_home.html ShaderPerf1.8] and [http://developer.nvidia.com/object/nvshaderperf_home.html ShaderPerf 2.0 Alpha] - handy utility that reports detailed shader performance metrics for a wide range of inputs. It is available both as a command line utility and with a user interface in [http://developer.nvidia.com/object/fx_composer_home.html FX Composer]. Please note that ShaderPerf 2.0 Alpha only supports DirectX shaders written in HLSL or assembly, (so either use version 1.8 or use [http://en.wikipedia.org/wiki/HLSL2GLSL HLSL2GLSL] which can be used to convert a HLSL shader into a GLSL shader).
* [http://developer.nvidia.com/object/fx_composer_home.html FX Composer] - provides an IDE interface to create, compile and debug GLSL (as well as DirectX) shaders.
* [http://www.ati.com/developer/rendermonkey/ RenderMonkey] - provides an IDE interface to create, compile and debug GLSL (as well as DirectX) shaders.
* [http://www.blender.org/ Blender] - This popular opensource 3D modeling and animation package can now use GLSL materials, thus allowing any shader developer to use it as a developement tool.
* [http://en.wikipedia.org/wiki/OpenSceneGraph OpenSceneGraph] - open source multiplatform graphics and shader IDE (also see [http://developer.3dlabs.com/documents/presentations/osg_glsl_july2005.zip GLSL Shading with OSG — 1.20MB zipped PDF])
* [http://en.wikipedia.org/wiki/HLSL2GLSL HLSL2GLSL] - library and tool that converts HLSL (High Level Shader Language) shaders to GLSL (OpenGL Shading Language)
* [http://sourceforge.net/projects/dxglwrap/ DirectX OpenGL Wrapper] - emulates API calls thru OpenGL commands and other platform specific commands in order to run DirectX 8 application running on other platform than Windows.
 
===Open Source Device Drivers===
* [http://intellinuxgraphics.org intellinuxgraphics.org] open source Linux Graphics Device Drivers from Intel (with XvMC for MPEG-2 acceleration support)
* [http://www.openchrome.org openChrome Project] - open source device drivers for VIA (has updated XvMC with MPEG-2/MPEG-4 acceleration support)
* [http://nouveau.freedesktop.org/wiki/XvMC Nouveau] - open source device driver for NVIDIA-based graphic controllers (does not yet feature any XvMC support)
 
===Source Code and Libraries===
* [http://en.wikipedia.org/wiki/BrookGPU BrookGPU] - GPGPU library in ANSI C for general purpose computations on GPU (OpenGL and DirectX compatible)
* [http://en.wikipedia.org/wiki/Lib_Sh Lib Sh] - GPGPU library in metaprogramming language and C++ for general purpose computations on GPU
* [http://www.shadertech.com/shaders/stsummer04/JianqingWang-src.zip Discrete Wavelet Transform (DWT) of JPEG 2000 (JasPer) on GPU written in Cg shader]
* [http://sourceforge.net/projects/opencvlibrary OpenCV (Open Computer Vision Library)] - a collection of algorithms and sample code for various computer vision problems. The library is compatible with [http://www.intel.com/cd/software/products/asmo-na/eng/perflib/ipp/302910.htm Intel Image Processing Library (IPL) and utilizes Intel Integrated Performance Primitives] for better performance. Features a bi-linear interpolation and color space conversion functions in IPL, (I also read that motion estimation with block matching and Hough transform is on the roadmap so you might want to check out their CVS).
* [http://www.antigrain.com Anti-Grain Geometry] - A High Quality Rendering Engine (High Fidelity 2D Graphics Renderer) for C++ (GPL licensced)
*[http://www.crusaderky.altervista.org//?s=downloads SDL_buffer] - a SDL extension library that is useful when you have to resize an image multiple times.
* [http://members.cox.net/dolsen6/resize.zip SDL_Resize] - basic image resizing library, high quality output suited for prerendering images.
*[http://sdl-cfg.sourceforge.net SDL_Config] - Library designed for reading and writing configuration (.ini) files in an easy, cross-platform way.
* [http://www.ferzkopp.net/~aschiffler/Software/SDL_bgrab/index.html SDL_bgrab] - SDL convertion of libbgrab (a framegrabber lib from the same author).
* [http://developer.download.nvidia.com/shaderlibrary/webpages/shader_library.html NVIDIA Shader Library] (color space conversions, blurring, interpolation, anti-aliasing, etc.)
 
===Other developer resources===
====Online Documentation and Tutorials====
* [http://www.lighthouse3d.com/opengl/glsl/ GLSL (OpenGL Shader Language) Tutorial @ Lighthouse 3D]
*[http://developer.3dlabs.com/documents/index.htm OpenGL specification and OpenGL Shading Language reference documents (3DLabs)]
 
====Books (hard-copy)====
*[http://developer.nvidia.com/object/gpu_gems_2_home.html GPU Gems 2 (published by NVIDIA)] for and by developers
**there is also [http://developer.nvidia.com/object/gpu_gems_home.html GPU Gems 1] but it does not cover GPCPU
 
== External links ==
====XvMC====
* [http://en.wikipedia.org/wiki/X-Video_Motion_Compensation Wikipedia.org article on XvMC (X-Video_Motion_Compensation)]
* [http://www.mythtv.org/wiki/index.php/XvMC MythTV WIKI article on XvMC under Linux]
* [http://www.bit-tech.net/news/2006/01/07/nvidia_decode_h264/ bit-tech.net article on NVIDIA PureVideo Technology]
====GLSL====
* [http://en.wikipedia.org/wiki/GLSL Wikipedia.org article on GLSL (OpenGL Shading Language)]
* [http://www.shadertech.com shadertech.com] -  Shader development news, forums, tools, code, and links.
 
[[category:Inner Workings]]
[[category:Development]]
[[category:Linux]]
[[category:To-Do]]

Revision as of 22:44, 26 January 2013

Here are the tags and attributes available for all controls. Note that they're all lowercase, as XML is case sensitive.

Tags available to all controls

description Only used to make things clear for the skinner. Not read by XBMC at all.
type The type of control.
id Specifies the control's id. The value this takes depends on the control type, and the window that you are using the control on. There are special control id's that must be present in each window. Any other controls that the skinner adds can be any id they like. Any controls that the skinner specifies content needs not have an id unless it's needed for animation purposes. For instance, most image and label controls don't need an id if the skinner specifies they're content.
posx Specifies where the left edge of the control should be drawn, relative to it's parent's left edge. If an "r" is included (eg 180r) then the measurement is taken from the parent's right edge (in the left direction).
posy Specifies where the top edge of the control should be drawn, relative to it's parent's top edge. If an "r" is included (eg 180r) then the measurement is taken from the parent's bottom edge (in the up direction).
width Specifies the width that should be used to draw the control.
height Specifies the height that should be used to draw the control.
visible Specifies a condition as to when this control will be visible. Can be true, false, or a condition. See Conditional Visibility for more information. Defaults to true.
animation Specifies the animation to be run when the control enters a particular state. See Animating your skin for more information.
camera Specifies the location (relative to the parent's coordinates) of the camera. Useful for the 3D animations such as rotatey. Format is <camera x="20" y="30" />
colordiffuse This specifies the color to be used for the texture basis. It's in hex AARRGGBB format. If you define <colordiffuse>FFFF00FF</colordiffuse> (magenta), the image will be given a magenta tint when rendered. Defaults to FFFFFFFF (no tint). You can also specify this as a name from the colour theme.

Tags available to focusable controls

In addition, any control that is focusable (e.g. a buttoncontrol) will have the following tags available.

onup Specifies the <id> of the control that should be moved to when the user moves up off this control. Can point to a control group (which remembers previous focused items).
ondown Specifies the <id> of the control that should be moved to when the user moves down off this control. Can point to a control group (which remembers previous focused items).
onleft Specifies the <id> of the control that should be moved to when the user moves left off this control. Can point to a control group (which remembers previous focused items).
onright Specifies the <id> of the control that should be moved to when the user moves right off this control. Can point to a control group (which remembers previous focused items).
hitrect Specifies the location and size of the "focus area" of this control (relative to the parent's coordinates) used by the mouse cursor. Format is <hitrect x="20" y="30" w="50" h="10" />
enable Specifies a condition as to when this control will be enabled. Can be true, false, or a condition. See Conditional Visibility for more information. Defaults to true.
pulseonselect This specifies whether or not a button type will "pulse" when it has focus. This is done by varying the alpha channel of the button. Defaults to true.

Similar page names

See also

Development: