HP SVA V2.1 Parallel Compositing Reference Guide

2 Overview of Functions and Properties
This chapter summarizes the Library functions and any properties related to the functions.
Parameter Types
The following parameter types are used by functions in the Library:
Table 2-1 Properties of Library Parameter Types
Properties of the TypePC Type
A structure that describes a result. See Section for more
information.
PCchannel
An opaque value representing an instance of a Library
context. A PCcontext is needed on Library calls where
it is necessary to identify the context to be manipulated
by the Library.
PCcontext
Fixed set of integer values that typically have predefined
meanings. The list of properties for a context is an example
of a PCenum.
PCenum
Unsigned integer representing the status of a library call.
Call pcGetErrorString for a text string describing a
status.
PCerr
Unsigned integer representing an instance of a Library
object, such as a frame.
PCid
Signed integer.
PCint
Null-terminated sequence of characters.
PCstring
Unsigned integer.
PCuint
An unspecified memory area.
PCvoidp
PCchannel Type
The Library uses arrays to describe pixels that are to be composited by the Library and then
returned to a program through a result. Because these arrays are managed by the Library, the
program needs various pieces of information to read information in the array. This information
is distilled into a PCchannel structure whose fields are described in Table 2-2.
Table 2-2 PCchannel Fields
DescriptionResult Property
The address of the origin of the array.
address
The memory alignment of the first array element in a row:
1 byte aligned
2 even byte aligned (least significant bit of address is 0)
4 quad byte aligned (2 least significant bits are 0)
8 octa byte aligned (3 least significant bits are 0)
alignment
The type of channel described by the channel structure.
channelType
The frame id associated with the result.
frameId
The height of the result in pixels.
height
Format of the pixels in the result.
pixelFormat
Parameter Types 25