-- Adaptive Predictive PCM

-- L. Stewart, last updated: August 28, 1979 10:27 AM

DIRECTORY

AdpcmDefs: FROM "AdpcmDefs";

AdpcmPrivateDefs: DEFINITIONS =

BEGIN

NModes: CARDINAL = 20; -- enough for now

Ex200: TYPE = [-128..127];

QVal: TYPE = [0..377B];

QValPair: TYPE = RECORD [lo, hi: QVal];

BreakpointTable: TYPE = ARRAY [0..NModes) OF INTEGER;

QuantizerTable: TYPE = ARRAY [0..NModes) OF QValPair;

PredictorTable: TYPE = PACKED ARRAY Ex200 OF Ex200;

QControl: TYPE = RECORD

[

BTabs: POINTER TO BreakpointTable,

QTabs: POINTER TO QuantizerTable,

PTab: POINTER TO PredictorTable,

state: AdpcmDefs.AdpcmState

];

GetqTabs: PROCEDURE RETURNS [POINTER TO QuantizerTable];

GetbTabs: PROCEDURE RETURNS [POINTER TO BreakpointTable];

GetpTab: PROCEDURE RETURNS [POINTER TO PredictorTable];

END.