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add FLAC__bitbuffer_read_rice_signed_block()

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This commit is contained in:
Josh Coalson
2002-04-25 05:21:09 +00:00
parent 8e46a5e53e
commit b28559ab6b
3 changed files with 217 additions and 5 deletions
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209
src/libFLAC/bitbuffer.c
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@@ -1941,6 +1941,214 @@ FLAC__bool FLAC__bitbuffer_read_rice_signed(FLAC__BitBuffer *bb, int *val, unsig
return true;
}
FLAC__bool FLAC__bitbuffer_read_rice_signed_block(FLAC__BitBuffer *bb, int vals[], unsigned nvals, unsigned parameter, FLAC__bool (*read_callback)(FLAC__byte buffer[], unsigned *bytes, void *client_data), void *client_data)
{
const FLAC__blurb *buffer = bb->buffer;
unsigned i, j, uval, val_i = 0;
unsigned msbs = 0, lsbs_left;
FLAC__blurb blurb, save_blurb, cbits;
unsigned state = 0; /* 0 = getting unary MSBs, 1 = getting binary LSBs */
FLAC__ASSERT(bb != 0);
FLAC__ASSERT(bb->buffer != 0);
FLAC__ASSERT(parameter <= 31);
if(nvals == 0)
return true;
i = bb->consumed_blurbs;
/*
* We unroll the main loop to take care of partially consumed blurbs here.
*/
if(bb->consumed_bits > 0) {
save_blurb = blurb = buffer[i];
cbits = bb->consumed_bits;
blurb <<= cbits;
while(1) {
if(state == 0) {
if(blurb) {
for(j = 0; !(blurb & FLAC__BLURB_TOP_BIT_ONE); j++)
blurb <<= 1;
msbs += j;
/* dispose of the unary end bit */
blurb <<= 1;
j++;
cbits += j;
uval = 0;
lsbs_left = parameter;
state++;
if(cbits == FLAC__BITS_PER_BLURB) {
cbits = 0;
CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16);
break;
}
}
else {
msbs += FLAC__BITS_PER_BLURB - cbits;
cbits = 0;
CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16);
break;
}
}
else {
const unsigned available_bits = FLAC__BITS_PER_BLURB - cbits;
if(lsbs_left >= available_bits) {
uval <<= available_bits;
uval |= (blurb >> cbits);
cbits = 0;
CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16);
if(lsbs_left == available_bits) {
/* compose the value */
uval |= (msbs << parameter);
if(uval & 1)
vals[val_i++] = -((int)(uval >> 1)) - 1;
else
vals[val_i++] = (int)(uval >> 1);
if(val_i == nvals)
break;
msbs = 0;
state = 0;
}
lsbs_left -= available_bits;
break;
}
else {
uval <<= lsbs_left;
uval |= (blurb >> (FLAC__BITS_PER_BLURB - lsbs_left));
blurb <<= lsbs_left;
cbits += lsbs_left;
/* compose the value */
uval |= (msbs << parameter);
if(uval & 1)
vals[val_i++] = -((int)(uval >> 1)) - 1;
else
vals[val_i++] = (int)(uval >> 1);
if(val_i == nvals) {
/* back up one if we exited the for loop because we read all nvals but the end came in the middle of a blurb */
i--;
break;
}
msbs = 0;
state = 0;
}
}
}
i++;
bb->consumed_blurbs = i;
bb->consumed_bits = cbits;
bb->total_consumed_bits = (i << FLAC__BITS_PER_BLURB_LOG2) | cbits;
}
/*
* Now that we are blurb-aligned the logic is slightly simpler
*/
while(val_i < nvals) {
for( ; i < bb->blurbs && val_i < nvals; i++) {
save_blurb = blurb = buffer[i];
cbits = 0;
while(1) {
if(state == 0) {
if(blurb) {
for(j = 0; !(blurb & FLAC__BLURB_TOP_BIT_ONE); j++)
blurb <<= 1;
msbs += j;
/* dispose of the unary end bit */
blurb <<= 1;
j++;
cbits += j;
uval = 0;
lsbs_left = parameter;
state++;
if(cbits == FLAC__BITS_PER_BLURB) {
cbits = 0;
CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16);
break;
}
}
else {
msbs += FLAC__BITS_PER_BLURB - cbits;
cbits = 0;
CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16);
break;
}
}
else {
const unsigned available_bits = FLAC__BITS_PER_BLURB - cbits;
if(lsbs_left >= available_bits) {
uval <<= available_bits;
uval |= (blurb >> cbits);
cbits = 0;
CRC16_UPDATE_BLURB(bb, save_blurb, bb->read_crc16);
if(lsbs_left == available_bits) {
/* compose the value */
uval |= (msbs << parameter);
if(uval & 1)
vals[val_i++] = -((int)(uval >> 1)) - 1;
else
vals[val_i++] = (int)(uval >> 1);
if(val_i == nvals)
break;
msbs = 0;
state = 0;
}
lsbs_left -= available_bits;
break;
}
else {
uval <<= lsbs_left;
uval |= (blurb >> (FLAC__BITS_PER_BLURB - lsbs_left));
blurb <<= lsbs_left;
cbits += lsbs_left;
/* compose the value */
uval |= (msbs << parameter);
if(uval & 1)
vals[val_i++] = -((int)(uval >> 1)) - 1;
else
vals[val_i++] = (int)(uval >> 1);
if(val_i == nvals) {
/* back up one if we exited the for loop because we read all nvals but the end came in the middle of a blurb */
i--;
break;
}
msbs = 0;
state = 0;
}
}
}
}
bb->consumed_blurbs = i;
bb->consumed_bits = cbits;
bb->total_consumed_bits = (i << FLAC__BITS_PER_BLURB_LOG2) | cbits;
if(val_i < nvals) {
if(!bitbuffer_read_from_client_(bb, read_callback, client_data))
return false;
/* these must be zero because we can only get here if we got to the end of the buffer */
FLAC__ASSERT(bb->consumed_blurbs == 0);
FLAC__ASSERT(bb->consumed_bits == 0);
i = 0;
}
}
return true;
}
#if 0 /* UNUSED */
FLAC__bool FLAC__bitbuffer_read_golomb_signed(FLAC__BitBuffer *bb, int *val, unsigned parameter, FLAC__bool (*read_callback)(FLAC__byte buffer[], unsigned *bytes, void *client_data), void *client_data)
{
@@ -2147,6 +2355,7 @@ void FLAC__bitbuffer_dump(const FLAC__BitBuffer *bb, FILE *out)
}
else {
fprintf(out, "bitbuffer: capacity=%u blurbs=%u bits=%u total_bits=%u consumed: blurbs=%u, bits=%u, total_bits=%u\n", bb->capacity, bb->blurbs, bb->bits, bb->total_bits, bb->consumed_blurbs, bb->consumed_bits, bb->total_consumed_bits);
return;//@@@
for(i = 0; i < bb->blurbs; i++) {
fprintf(out, "%08X: ", i);
for(j = 0; j < FLAC__BITS_PER_BLURB; j++)