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change to sign-folded rice coding, add golomb coder

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This commit is contained in:
Josh Coalson
2001-01-06 01:24:22 +00:00
parent 942fad9618
commit 7efa1051c4
2 changed files with 363 additions and 48 deletions
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402
src/libFLAC/bitbuffer.c
View File

@@ -33,6 +33,15 @@ static const unsigned FLAC__BITBUFFER_DEFAULT_CAPACITY = 65536; /* bytes */
#endif
#define max(x,y) ((x)>(y)?(x):(y))
static unsigned ilog2_(unsigned v)
{
unsigned l = 0;
assert(v > 0);
while(v >>= 1)
l++;
return l;
}
static bool bitbuffer_resize_(FLAC__BitBuffer *bb, unsigned new_capacity)
{
byte *new_buffer;
@@ -391,43 +400,125 @@ bool FLAC__bitbuffer_write_raw_int64(FLAC__BitBuffer *bb, int64 val, unsigned bi
return FLAC__bitbuffer_write_raw_uint64(bb, (uint64)val, bits);
}
bool FLAC__bitbuffer_write_rice_signed(FLAC__BitBuffer *bb, int val, unsigned parameter)
unsigned FLAC__bitbuffer_rice_bits(int val, unsigned parameter)
{
unsigned msbs, uval;
/* convert signed to unsigned */
if(val < 0)
/* equivalent to
* (unsigned)(((--val) << 1) - 1);
* but without the overflow problem at -MAXINT
*/
uval = (unsigned)(((-(++val)) << 1) + 1);
else
uval = (unsigned)(val << 1);
msbs = uval >> parameter;
return 1 + parameter + msbs;
}
unsigned FLAC__bitbuffer_golomb_bits_signed(int val, unsigned parameter)
{
unsigned bits, msbs, uval;
unsigned k;
assert(parameter > 0);
/* convert signed to unsigned */
if(val < 0)
/* equivalent to
* (unsigned)(((--val) << 1) - 1);
* but without the overflow problem at -MAXINT
*/
uval = (unsigned)(((-(++val)) << 1) + 1);
else
uval = (unsigned)(val << 1);
k = ilog2_(parameter);
if(parameter == 1u<<k) {
assert(k <= 30);
msbs = uval >> k;
bits = 1 + k + msbs;
}
else {
unsigned q, r, d;
d = (1 << (k+1)) - parameter;
q = uval / parameter;
r = uval - (q * parameter);
bits = 1 + q + k;
if(r >= d)
bits++;
}
return bits;
}
unsigned FLAC__bitbuffer_golomb_bits_unsigned(unsigned uval, unsigned parameter)
{
unsigned bits, msbs;
unsigned k;
assert(parameter > 0);
k = ilog2_(parameter);
if(parameter == 1u<<k) {
assert(k <= 30);
msbs = uval >> k;
bits = 1 + k + msbs;
}
else {
unsigned q, r, d;
d = (1 << (k+1)) - parameter;
q = uval / parameter;
r = uval - (q * parameter);
bits = 1 + q + k;
if(r >= d)
bits++;
}
return bits;
}
bool FLAC__bitbuffer_write_rice_signed(FLAC__BitBuffer *bb, int val, unsigned parameter)
{
unsigned bits, msbs, uval;
uint32 pattern;
assert(bb != 0);
assert(bb->buffer != 0);
assert(parameter <= 30);
/* init pattern with sign bit */
if(val < 0) {
pattern = 1;
val = -val;
}
/* convert signed to unsigned */
if(val < 0)
/* equivalent to
* (unsigned)(((--val) << 1) - 1);
* but without the overflow problem at -MAXINT
*/
uval = (unsigned)(((-(++val)) << 1) + 1);
else
pattern = 0;
uval = (unsigned)(val << 1);
msbs = val >> parameter;
bits = 2 + parameter + msbs;
msbs = uval >> parameter;
bits = 1 + parameter + msbs;
pattern = 1 << parameter; /* the unary end bit */
pattern |= (uval & ((1<<parameter)-1)); /* the binary LSBs */
if(bits <= 32) {
pattern = (pattern << parameter) | (val & ((1<<parameter)-1));
pattern = (pattern << (msbs+1)) | 1;
if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, bits))
return false;
}
else {
/* write the sign bit */
if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, 1))
return false;
/* write the binary LSBs */
if(!FLAC__bitbuffer_write_raw_uint32(bb, val & ((1<<parameter)-1), parameter))
return false;
/* write the unary MSBs */
if(!FLAC__bitbuffer_write_zeroes(bb, msbs))
return false;
/* write the end bit */
if(!FLAC__bitbuffer_write_raw_uint32(bb, 1, 1))
/* write the unary end bit and binary LSBs */
if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, parameter+1))
return false;
}
return true;
@@ -435,28 +526,31 @@ bool FLAC__bitbuffer_write_rice_signed(FLAC__BitBuffer *bb, int val, unsigned pa
bool FLAC__bitbuffer_write_rice_signed_guarded(FLAC__BitBuffer *bb, int val, unsigned parameter, unsigned max_bits, bool *overflow)
{
unsigned bits, msbs;
unsigned bits, msbs, uval;
uint32 pattern;
assert(bb != 0);
assert(bb->buffer != 0);
assert(parameter <= 30);
*overflow = false;
/* init pattern with sign bit */
if(val < 0) {
pattern = 1;
val = -val;
}
/* convert signed to unsigned */
if(val < 0)
/* equivalent to
* (unsigned)(((--val) << 1) - 1);
* but without the overflow problem at -MAXINT
*/
uval = (unsigned)(((-(++val)) << 1) + 1);
else
pattern = 0;
uval = (unsigned)(val << 1);
msbs = val >> parameter;
bits = 2 + parameter + msbs;
msbs = uval >> parameter;
bits = 1 + parameter + msbs;
pattern = 1 << parameter; /* the unary end bit */
pattern |= (uval & ((1<<parameter)-1)); /* the binary LSBs */
if(bits <= 32) {
pattern = (pattern << parameter) | (val & ((1<<parameter)-1));
pattern = (pattern << (msbs+1)) | 1;
if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, bits))
return false;
}
@@ -465,18 +559,138 @@ bool FLAC__bitbuffer_write_rice_signed_guarded(FLAC__BitBuffer *bb, int val, uns
return true;
}
else {
/* write the sign bit */
if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, 1))
return false;
/* write the binary LSBs */
if(!FLAC__bitbuffer_write_raw_uint32(bb, val & ((1<<parameter)-1), parameter))
return false;
/* write the unary MSBs */
if(!FLAC__bitbuffer_write_zeroes(bb, msbs))
return false;
/* write the end bit */
/* write the unary end bit and binary LSBs */
if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, parameter+1))
return false;
}
return true;
}
bool FLAC__bitbuffer_write_golomb_signed(FLAC__BitBuffer *bb, int val, unsigned parameter)
{
unsigned bits, msbs, uval;
unsigned k;
assert(bb != 0);
assert(bb->buffer != 0);
assert(parameter > 0);
/* convert signed to unsigned */
if(val < 0)
/* equivalent to
* (unsigned)(((--val) << 1) - 1);
* but without the overflow problem at -MAXINT
*/
uval = (unsigned)(((-(++val)) << 1) + 1);
else
uval = (unsigned)(val << 1);
k = ilog2_(parameter);
if(parameter == 1u<<k) {
unsigned pattern;
assert(k <= 30);
msbs = uval >> k;
bits = 1 + k + msbs;
pattern = 1 << k; /* the unary end bit */
pattern |= (uval & ((1u<<k)-1)); /* the binary LSBs */
if(bits <= 32) {
if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, bits))
return false;
}
else {
/* write the unary MSBs */
if(!FLAC__bitbuffer_write_zeroes(bb, msbs))
return false;
/* write the unary end bit and binary LSBs */
if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, k+1))
return false;
}
}
else {
unsigned q, r, d;
d = (1 << (k+1)) - parameter;
q = uval / parameter;
r = uval - (q * parameter);
/* write the unary MSBs */
if(!FLAC__bitbuffer_write_zeroes(bb, q))
return false;
/* write the unary end bit */
if(!FLAC__bitbuffer_write_raw_uint32(bb, 1, 1))
return false;
/* write the binary LSBs */
if(r >= d) {
if(!FLAC__bitbuffer_write_raw_uint32(bb, r+d, k+1))
return false;
}
else {
if(!FLAC__bitbuffer_write_raw_uint32(bb, r, k))
return false;
}
}
return true;
}
bool FLAC__bitbuffer_write_golomb_unsigned(FLAC__BitBuffer *bb, unsigned uval, unsigned parameter)
{
unsigned bits, msbs;
unsigned k;
assert(bb != 0);
assert(bb->buffer != 0);
assert(parameter > 0);
k = ilog2_(parameter);
if(parameter == 1u<<k) {
unsigned pattern;
assert(k <= 30);
msbs = uval >> k;
bits = 1 + k + msbs;
pattern = 1 << k; /* the unary end bit */
pattern |= (uval & ((1u<<k)-1)); /* the binary LSBs */
if(bits <= 32) {
if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, bits))
return false;
}
else {
/* write the unary MSBs */
if(!FLAC__bitbuffer_write_zeroes(bb, msbs))
return false;
/* write the unary end bit and binary LSBs */
if(!FLAC__bitbuffer_write_raw_uint32(bb, pattern, k+1))
return false;
}
}
else {
unsigned q, r, d;
d = (1 << (k+1)) - parameter;
q = uval / parameter;
r = uval - (q * parameter);
/* write the unary MSBs */
if(!FLAC__bitbuffer_write_zeroes(bb, q))
return false;
/* write the unary end bit */
if(!FLAC__bitbuffer_write_raw_uint32(bb, 1, 1))
return false;
/* write the binary LSBs */
if(r >= d) {
if(!FLAC__bitbuffer_write_raw_uint32(bb, r+d, k+1))
return false;
}
else {
if(!FLAC__bitbuffer_write_raw_uint32(bb, r, k))
return false;
}
}
return true;
}
@@ -791,18 +1005,13 @@ bool FLAC__bitbuffer_read_raw_int64(FLAC__BitBuffer *bb, int64 *val, unsigned bi
bool FLAC__bitbuffer_read_rice_signed(FLAC__BitBuffer *bb, int *val, unsigned parameter, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data)
{
uint32 sign = 0, lsbs, msbs = 0;
unsigned bit;
uint32 lsbs, msbs = 0;
unsigned bit, uval;
assert(bb != 0);
assert(bb->buffer != 0);
assert(parameter <= 32);
/* read the sign bit */
if(!FLAC__bitbuffer_read_bit_to_uint32(bb, &sign, read_callback, client_data))
return false;
/* read the binary LSBs */
if(!FLAC__bitbuffer_read_raw_uint32(bb, &lsbs, parameter, read_callback, client_data))
return false;
/* read the unary MSBs and end bit */
while(1) {
if(!FLAC__bitbuffer_read_bit(bb, &bit, read_callback, client_data))
@@ -812,10 +1021,107 @@ bool FLAC__bitbuffer_read_rice_signed(FLAC__BitBuffer *bb, int *val, unsigned pa
else
msbs++;
}
/* read the binary LSBs */
if(!FLAC__bitbuffer_read_raw_uint32(bb, &lsbs, parameter, read_callback, client_data))
return false;
/* compose the value */
*val = (msbs << parameter) | lsbs;
if(sign)
*val = -(*val);
uval = (msbs << parameter) | lsbs;
if(uval & 1)
*val = -((int)(uval >> 1)) - 1;
else
*val = (int)(uval >> 1);
return true;
}
bool FLAC__bitbuffer_read_golomb_signed(FLAC__BitBuffer *bb, int *val, unsigned parameter, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data)
{
uint32 lsbs, msbs = 0;
unsigned bit, uval, k;
assert(bb != 0);
assert(bb->buffer != 0);
k = ilog2_(parameter);
/* read the unary MSBs and end bit */
while(1) {
if(!FLAC__bitbuffer_read_bit(bb, &bit, read_callback, client_data))
return false;
if(bit)
break;
else
msbs++;
}
/* read the binary LSBs */
if(!FLAC__bitbuffer_read_raw_uint32(bb, &lsbs, k, read_callback, client_data))
return false;
if(parameter == 1u<<k) {
/* compose the value */
uval = (msbs << k) | lsbs;
}
else {
unsigned d = (1 << (k+1)) - parameter;
if(lsbs >= d) {
if(!FLAC__bitbuffer_read_bit(bb, &bit, read_callback, client_data))
return false;
lsbs <<= 1;
lsbs |= bit;
lsbs -= d;
}
/* compose the value */
uval = msbs * parameter + lsbs;
}
/* unfold unsigned to signed */
if(uval & 1)
*val = -((int)(uval >> 1)) - 1;
else
*val = (int)(uval >> 1);
return true;
}
bool FLAC__bitbuffer_read_golomb_unsigned(FLAC__BitBuffer *bb, unsigned *val, unsigned parameter, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data)
{
uint32 lsbs, msbs = 0;
unsigned bit, k;
assert(bb != 0);
assert(bb->buffer != 0);
k = ilog2_(parameter);
/* read the unary MSBs and end bit */
while(1) {
if(!FLAC__bitbuffer_read_bit(bb, &bit, read_callback, client_data))
return false;
if(bit)
break;
else
msbs++;
}
/* read the binary LSBs */
if(!FLAC__bitbuffer_read_raw_uint32(bb, &lsbs, k, read_callback, client_data))
return false;
if(parameter == 1u<<k) {
/* compose the value */
*val = (msbs << k) | lsbs;
}
else {
unsigned d = (1 << (k+1)) - parameter;
if(lsbs >= d) {
if(!FLAC__bitbuffer_read_bit(bb, &bit, read_callback, client_data))
return false;
lsbs <<= 1;
lsbs |= bit;
lsbs -= d;
}
/* compose the value */
*val = msbs * parameter + lsbs;
}
return true;
}

9
src/libFLAC/include/private/bitbuffer.h
View File

@@ -43,8 +43,15 @@ bool FLAC__bitbuffer_write_raw_uint32(FLAC__BitBuffer *bb, uint32 val, unsigned
bool FLAC__bitbuffer_write_raw_int32(FLAC__BitBuffer *bb, int32 val, unsigned bits);
bool FLAC__bitbuffer_write_raw_uint64(FLAC__BitBuffer *bb, uint64 val, unsigned bits);
bool FLAC__bitbuffer_write_raw_int64(FLAC__BitBuffer *bb, int64 val, unsigned bits);
unsigned FLAC__bitbuffer_rice_bits(int val, unsigned parameter);
unsigned FLAC__bitbuffer_golomb_bits_signed(int val, unsigned parameter);
unsigned FLAC__bitbuffer_golomb_bits_unsigned(unsigned val, unsigned parameter);
bool FLAC__bitbuffer_write_rice_signed(FLAC__BitBuffer *bb, int val, unsigned parameter);
bool FLAC__bitbuffer_write_rice_signed_guarded(FLAC__BitBuffer *bb, int val, unsigned parameter, unsigned max_bits, bool *overflow);
bool FLAC__bitbuffer_write_golomb_signed(FLAC__BitBuffer *bb, int val, unsigned parameter);
bool FLAC__bitbuffer_write_golomb_signed_guarded(FLAC__BitBuffer *bb, int val, unsigned parameter, unsigned max_bits, bool *overflow);
bool FLAC__bitbuffer_write_golomb_unsigned(FLAC__BitBuffer *bb, unsigned val, unsigned parameter);
bool FLAC__bitbuffer_write_golomb_unsigned_guarded(FLAC__BitBuffer *bb, unsigned val, unsigned parameter, unsigned max_bits, bool *overflow);
bool FLAC__bitbuffer_write_utf8_uint32(FLAC__BitBuffer *bb, uint32 val);
bool FLAC__bitbuffer_write_utf8_uint64(FLAC__BitBuffer *bb, uint64 val);
bool FLAC__bitbuffer_zero_pad_to_byte_boundary(FLAC__BitBuffer *bb);
@@ -57,6 +64,8 @@ bool FLAC__bitbuffer_read_raw_int32(FLAC__BitBuffer *bb, int32 *val, unsigned bi
bool FLAC__bitbuffer_read_raw_uint64(FLAC__BitBuffer *bb, uint64 *val, unsigned bits, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data);
bool FLAC__bitbuffer_read_raw_int64(FLAC__BitBuffer *bb, int64 *val, unsigned bits, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data);
bool FLAC__bitbuffer_read_rice_signed(FLAC__BitBuffer *bb, int *val, unsigned parameter, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data);
bool FLAC__bitbuffer_read_golomb_signed(FLAC__BitBuffer *bb, int *val, unsigned parameter, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data);
bool FLAC__bitbuffer_read_golomb_unsigned(FLAC__BitBuffer *bb, unsigned *val, unsigned parameter, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data);
bool FLAC__bitbuffer_read_utf8_uint32(FLAC__BitBuffer *bb, uint32 *val, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data, byte *raw, unsigned *rawlen);
bool FLAC__bitbuffer_read_utf8_uint64(FLAC__BitBuffer *bb, uint64 *val, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data, byte *raw, unsigned *rawlen);
void FLAC__bitbuffer_dump(const FLAC__BitBuffer *bb, FILE *out);