claunia/flac
1
0
Fork 0
mirror of https://github.com/claunia/flac.git synced 2025-12-16 18:54:26 +00:00
Code Issues Packages Projects Releases Wiki Activity

minor optimizations to FLAC__bitwriter_write_rice_signed_block()

Browse Source
This commit is contained in:
Josh Coalson
2007-04-04 00:55:44 +00:00
parent 0a0a10f358
commit 4cc675bf19
1 changed files with 11 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
src/libFLAC/bitwriter.c
View File

@@ -540,7 +540,7 @@ FLAC__bool FLAC__bitwriter_write_rice_signed_block(FLAC__BitWriter *bw, const FL
const FLAC__uint32 mask1 = FLAC__WORD_ALL_ONES << parameter; /* we val|=mask1 to set the stop bit above it... */
const FLAC__uint32 mask2 = FLAC__WORD_ALL_ONES >> (31-parameter); /* ...then mask off the bits above the stop bit with val&=mask2*/
FLAC__uint32 uval;
register unsigned left;
unsigned left;
const unsigned lsbits = 1 + parameter;
unsigned msbits;
@@ -558,22 +558,24 @@ FLAC__bool FLAC__bitwriter_write_rice_signed_block(FLAC__BitWriter *bw, const FL
/* slightly pessimistic size check but faster than "<= bw->words + (bw->bits+msbits+lsbits+FLAC__BITS_PER_WORD-1)/FLAC__BITS_PER_WORD" */
/* OPT: pessimism may cause flurry of false calls to grow_ which eat up all savings before it */
if(bw->capacity <= bw->words + bw->bits + msbits + lsbits && !bitwriter_grow_(bw, msbits+lsbits))
if(bw->capacity <= bw->words + bw->bits + msbits + 1/*lsbits always fit in 1 bwword*/ && !bitwriter_grow_(bw, msbits+lsbits))
return false;
if(msbits) {
/* first part gets to word alignment */
if(bw->bits) {
left = min(FLAC__BITS_PER_WORD - bw->bits, msbits);
bw->accum <<= left;
msbits -= left;
bw->bits += left;
if(bw->bits == FLAC__BITS_PER_WORD) {
left = FLAC__BITS_PER_WORD - bw->bits;
if(msbits < left) {
bw->accum <<= msbits;
bw->bits += msbits;
goto break1;
}
else {
bw->accum <<= left;
msbits -= left;
bw->buffer[bw->words++] = SWAP_BE_WORD_TO_HOST(bw->accum);
bw->bits = 0;
}
else
goto break1;
}
/* do whole words */
while(msbits >= FLAC__BITS_PER_WORD) {