/*
Same as CalculateBlockSymbolSize, but with the histogram provided by the caller.
*/
static size_t CalculateBlockSymbolSizeGivenCounts(const size_t* ll_counts,
const size_t* d_counts,
const unsigned* ll_lengths,
const unsigned* d_lengths,
const ZopfliLZ77Store* lz77,
size_t lstart, size_t lend) {
size_t result = 0;
size_t i;
if (lstart + ZOPFLI_NUM_LL * 3 > lend) {
return CalculateBlockSymbolSizeSmall(
ll_lengths, d_lengths, lz77, lstart, lend);
} else {
for (i = 0; i < 256; i++) {
result += ll_lengths[i] * ll_counts[i];
}
for (i = 257; i < 286; i++) {
result += ll_lengths[i] * ll_counts[i];
result += ZopfliGetLengthSymbolExtraBits(i) * ll_counts[i];
}
for (i = 0; i < 30; i++) {
result += d_lengths[i] * d_counts[i];
result += ZopfliGetDistSymbolExtraBits(i) * d_counts[i];
}
result += ll_lengths[256]; /*end symbol*/
return result;
}
}
/*
Calculates size of the part after the header and tree of an LZ77 block, in bits.
*/
static size_t CalculateBlockSymbolSize(const unsigned* ll_lengths,
const unsigned* d_lengths,
const ZopfliLZ77Store* lz77,
size_t lstart, size_t lend) {
size_t result = 0;
size_t i;
if (lstart + ZOPFLI_NUM_LL * 3 > lend) {
for (i = lstart; i < lend; i++) {
assert(i < lz77->size);
assert(lz77->litlens[i] < 259);
if (lz77->dists[i] == 0) {
result += ll_lengths[lz77->litlens[i]];
} else {
int ll_symbol = ZopfliGetLengthSymbol(lz77->litlens[i]);
int d_symbol = ZopfliGetDistSymbol(lz77->dists[i]);
result += ll_lengths[ll_symbol];
result += d_lengths[d_symbol];
result += ZopfliGetLengthSymbolExtraBits(ll_symbol);
result += ZopfliGetDistSymbolExtraBits(d_symbol);
}
}
} else {
size_t ll_counts[ZOPFLI_NUM_LL];
size_t d_counts[ZOPFLI_NUM_D];
ZopfliLZ77GetHistogram(lz77, lstart, lend, ll_counts, d_counts);
for (i = 0; i < 256; i++) {
result += ll_lengths[i] * ll_counts[i];
}
for (i = 257; i < 286; i++) {
result += ll_lengths[i] * ll_counts[i];
result += ZopfliGetLengthSymbolExtraBits(i) * ll_counts[i];
}
for (i = 0; i < 30; i++) {
result += d_lengths[i] * d_counts[i];
result += ZopfliGetDistSymbolExtraBits(i) * d_counts[i];
}
}
result += ll_lengths[256]; /*end symbol*/
return result;
}
/*
Same as CalculateBlockSymbolSize, but for block size smaller than histogram
size.
*/
static size_t CalculateBlockSymbolSizeSmall(const unsigned* ll_lengths,
const unsigned* d_lengths,
const ZopfliLZ77Store* lz77,
size_t lstart, size_t lend) {
size_t result = 0;
size_t i;
for (i = lstart; i < lend; i++) {
assert(i < lz77->size);
assert(lz77->litlens[i] < 259);
if (lz77->dists[i] == 0) {
result += ll_lengths[lz77->litlens[i]];
} else {
int ll_symbol = ZopfliGetLengthSymbol(lz77->litlens[i]);
int d_symbol = ZopfliGetDistSymbol(lz77->dists[i]);
result += ll_lengths[ll_symbol];
result += d_lengths[d_symbol];
result += ZopfliGetLengthSymbolExtraBits(ll_symbol);
result += ZopfliGetDistSymbolExtraBits(d_symbol);
}
}
result += ll_lengths[256]; /*end symbol*/
return result;
}
