/*
sectioning Stage 2:greedy merge algorithm, merge connected sections with
maximum bit gain until no more gain is possible
*/
static void
gmStage2(SECTION_INFO *sectionInfo,
Word16 mergeGainLookUp[MAX_SFB_LONG],
Word16 bitLookUp[MAX_SFB_LONG][CODE_BOOK_ESC_NDX + 1],
const Word16 maxSfb,
const Word16 *sideInfoTab)
{
Word16 i;
for (i=0; i+sectionInfo[i].sfbCnt<maxSfb; i+=sectionInfo[i].sfbCnt) {
mergeGainLookUp[i] = CalcMergeGain(sectionInfo,
bitLookUp,
sideInfoTab,
i,
(i + sectionInfo[i].sfbCnt));
}
while (TRUE) {
Word16 maxMergeGain, maxNdx, maxNdxNext, maxNdxLast;
maxMergeGain = findMaxMerge(mergeGainLookUp, sectionInfo, maxSfb, &maxNdx);
if (maxMergeGain <= 0)
break;
maxNdxNext = maxNdx + sectionInfo[maxNdx].sfbCnt;
sectionInfo[maxNdx].sfbCnt = sectionInfo[maxNdx].sfbCnt + sectionInfo[maxNdxNext].sfbCnt;
sectionInfo[maxNdx].sectionBits = sectionInfo[maxNdx].sectionBits +
(sectionInfo[maxNdxNext].sectionBits - maxMergeGain);
mergeBitLookUp(bitLookUp[maxNdx], bitLookUp[maxNdxNext]);
if (maxNdx != 0) {
maxNdxLast = sectionInfo[maxNdx - 1].sfbStart;
mergeGainLookUp[maxNdxLast] = CalcMergeGain(sectionInfo,
bitLookUp,
sideInfoTab,
maxNdxLast,
maxNdx);
}
maxNdxNext = maxNdx + sectionInfo[maxNdx].sfbCnt;
sectionInfo[maxNdxNext - 1].sfbStart = sectionInfo[maxNdx].sfbStart;
if (maxNdxNext - maxSfb < 0) {
mergeGainLookUp[maxNdx] = CalcMergeGain(sectionInfo,
bitLookUp,
sideInfoTab,
maxNdx,
maxNdxNext);
}
}
}
static void
gmStage2(SECTION_INFO * section,
int mergeGainLookUp[MAX_SFB_LONG],
int bitLookUp[MAX_SFB_LONG][CODE_BOOK_ESC_NDX + 1],
const int maxSfb,
const int *sideInfoTab)
{
int i;
COUNT_sub_start("gmStage2");
PTR_INIT(2); /* pointers for section[],
mergeGainLookUp[]
*/
LOOP(1);
for (i = 0; i + section[i].sfbCnt < maxSfb; i += section[i].sfbCnt)
{
ADD(1); FUNC(5); STORE(1);
mergeGainLookUp[i] = CalcMergeGain(section,
bitLookUp,
sideInfoTab,
i,
i + section[i].sfbCnt);
}
LOOP(1);
while (TRUE)
{
int maxMergeGain, maxNdx = 0, maxNdxNext, maxNdxLast;
PTR_INIT(1); FUNC(4);
maxMergeGain = findMaxMerge(mergeGainLookUp, section, maxSfb, &maxNdx);
/*
exit while loop if no more gain is possible
*/
BRANCH(1);
if (maxMergeGain <= 0)
break;
PTR_INIT(3); /* pointers for section[maxNdx],
bitLookUp[maxNdx],
mergeGainLookUp[maxNdx]
*/
ADD(1);
maxNdxNext = maxNdx + section[maxNdx].sfbCnt;
PTR_INIT(2); /* pointers for section[maxNdxNext],
bitLookUp[maxNdxNext]
*/
ADD(1);
section[maxNdx].sfbCnt += section[maxNdxNext].sfbCnt;
ADD(2);
section[maxNdx].sectionBits += section[maxNdxNext].sectionBits - maxMergeGain;
FUNC(2);
mergeBitLookUp(bitLookUp[maxNdx], bitLookUp[maxNdxNext]);
BRANCH(1);
if (maxNdx != 0)
{
MOVE(1);
maxNdxLast = section[maxNdx - 1].sfbStart;
FUNC(5); INDIRECT(1); STORE(1);
mergeGainLookUp[maxNdxLast] = CalcMergeGain(section,
bitLookUp,
sideInfoTab,
maxNdxLast,
maxNdx);
}
ADD(1);
maxNdxNext = maxNdx + section[maxNdx].sfbCnt;
PTR_INIT(1); /* pointers for section[maxNdxNext] */
MOVE(1);
section[maxNdxNext - 1].sfbStart = section[maxNdx].sfbStart;
ADD(1); BRANCH(1);
if (maxNdxNext < maxSfb)
{
FUNC(5); STORE(1);
mergeGainLookUp[maxNdx] = CalcMergeGain(section,
bitLookUp,
sideInfoTab,
maxNdx,
maxNdxNext);
}
}
COUNT_sub_end();
}