Compaq ECQD2KCTE manual Multimedia Graphics and Video Support, Mnemonic Operation

Models: ECQD2KCTE

1 371
Download 371 pages 20.35 Kb
Page 207
Image 207

4.13 Multimedia (Graphics and Video) Support

Alpha provides the following instructions that enhance support for graphics and video algorithms:

Mnemonic

Operation

 

 

MINUB8

Vector Unsigned Byte Minimum

MINSB8

Vector Signed Byte Minimum

MINUW4

Vector Unsigned Word Minimum

MINSW4

Vector Signed Word Minimum

MAXUB8

Vector Unsigned Byte Maximum

MAXSB8

Vector Signed Byte Maximum

MAXUW4

Vector Unsigned Word Maximum

MAXSW4

Vector Signed Word Maximum

PERR

Pixel Error

PKLB

Pack Longwords to Bytes

PKWB

Pack Words to Bytes

UNPKBL

Unpack Bytes to Longwords

UNPKBW

Unpack Bytes to Words

 

 

The MIN and MAX instructions allow the clamping of pixel values to maximium values that are allowed in different standards and stages of the CODECs.

The PERR instruction accelerates the macroblock search in motion estimation.

The pack and unpack (PKxB and UNPKBx) instructions accelerate the blocking of interleaved YUV coordinates for processing by the CODEC.

Implementation Note:

Alpha processors for which the AMASK instruction returns bit 8 set implement these instructions. Those processors for which AMASK does not return bit 8 set can take an Illegal Instruction trap, and software can emulate their function, if required.

Instruction Descriptions 4–151

Page 207
Image 207
Compaq ECQD2KCTE manual Multimedia Graphics and Video Support, Mnemonic Operation