HP SVA V2.0 Parallel Compositing Reference Guide

1 Main Areas of the Parallel Compositing Library
This chapter introduces you to the HP implementation of the Parallel Compositing Library
(Library). It explains differences between the standard implementation compared to the HP
Library. It summarizes Library terminology. It also describes the sample applications that are
available on the Library Kit to get you started.
1.1 HP Library Versus Standard Library
There is a standard implementation of the Library that conforms to the same API specification
as the HP version of the Library. However, the HP version has a number of enhancements:
• Features
Complete API support in the HP implementation as opposed to the standard implementation.
Table 1-1 compares important features between the standard implementation and the HP
implementation.
Table 1-1 Feature Comparison of HP versus Standard Implementation
HP ImplementationStandard Implementation
Framelets can overlap in any fashion (or not at all).Only fully overlapped framelets where the dimensions
of each framelet is the same as the frame.
Depth compositing and alpha blending.Depth compositing and alpha blending.
Up to nine framelets per host.1 or 0 framelets per host.
Result can be obtained on any host. Different parts of
the result can be obtained on different hosts.
Result can be obtained on any host.
Both memory and graphics framelets
(EXT_cur_gfx_ctx).
Memory framelets.
Native IB-based pixel transfer, in addition to TCP
sockets.
TCP sockets based data transfer.
Boundary box framelets to reduce network overhead
to a greater extent than in standard implementation.
Sample code illustrates this. See “Section 1.6.”
Run length compression support to reduce network
overhead.
Extension HP_frame_output provides improved
performance for frame processing.
PC_RETAIN_OUTPUT_LIMIT = = 2 is supported for
double buffering.
Depth compositing without color pixels.
• Robustness
The HP implementation is more robust than the standard implementation. Notably, error
handling is significantly more extensive. In particular, inconsistent context properties are
detected and flagged as errors.
• Performance
The HP implementation is significantly faster than the standard implementation.
1.2 Introduction
The Library is a set of related functions that make it possible for multiple graphics cards to
collectively produce images.
1.1 HP Library Versus Standard Library 11