AuroraMiddleware/flac
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start some read optimizations

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This commit is contained in:
Josh Coalson 2001-04-24 02:36:08 +00:00
parent 9661108c68
commit 64f4fbcaf7
1 changed files with 58 additions and 13 deletions
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71
src/libFLAC/bitbuffer.c
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@ -24,8 +24,11 @@
#include "private/bitmath.h"
#include "private/crc.h"
/* This should be at least twice as large as the largest number of bytes required to represent any 'number' (in any encoding) you are going to read. */
static const unsigned FLAC__BITBUFFER_DEFAULT_CAPACITY = 65536; /* bytes */
static const byte byte_bit_to_mask_[] = { 128, 64, 32, 16, 8, 4, 2, 1 };
#ifdef min
#undef min
#endif
@ -106,7 +109,7 @@ static bool bitbuffer_read_from_client_(FLAC__BitBuffer *bb, bool (*read_callbac
if(!bitbuffer_resize_(bb, 16))
return false;
}
/* finally, read in some data; if OK, go back to read_bit_, else fail */
/* finally, read in some data */
bytes = bb->capacity - bb->bytes;
if(!read_callback(bb->buffer+bb->bytes, &bytes, client_data))
return false;
@ -941,8 +944,6 @@ bool FLAC__bitbuffer_zero_pad_to_byte_boundary(FLAC__BitBuffer *bb)
bool FLAC__bitbuffer_peek_bit(FLAC__BitBuffer *bb, unsigned *val, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data)
{
static const byte mask[] = { 128, 64, 32, 16, 8, 4, 2, 1 };
/* to avoid a drastic speed penalty we don't:
assert(bb != 0);
assert(bb->buffer != 0);
@ -951,7 +952,7 @@ bool FLAC__bitbuffer_peek_bit(FLAC__BitBuffer *bb, unsigned *val, bool (*read_ca
while(1) {
if(bb->total_consumed_bits < bb->total_bits) {
*val = (bb->buffer[bb->consumed_bytes] & mask[bb->consumed_bits])? 1 : 0;
*val = (bb->buffer[bb->consumed_bytes] & byte_bit_to_mask_[bb->consumed_bits])? 1 : 0;
return true;
}
else {
@ -963,8 +964,6 @@ bool FLAC__bitbuffer_peek_bit(FLAC__BitBuffer *bb, unsigned *val, bool (*read_ca
bool FLAC__bitbuffer_read_bit(FLAC__BitBuffer *bb, unsigned *val, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data)
{
static const byte mask[] = { 128, 64, 32, 16, 8, 4, 2, 1 };
/* to avoid a drastic speed penalty we don't:
assert(bb != 0);
assert(bb->buffer != 0);
@ -973,7 +972,7 @@ bool FLAC__bitbuffer_read_bit(FLAC__BitBuffer *bb, unsigned *val, bool (*read_ca
while(1) {
if(bb->total_consumed_bits < bb->total_bits) {
*val = (bb->buffer[bb->consumed_bytes] & mask[bb->consumed_bits])? 1 : 0;
*val = (bb->buffer[bb->consumed_bytes] & byte_bit_to_mask_[bb->consumed_bits])? 1 : 0;
bb->consumed_bits++;
if(bb->consumed_bits == 8) {
FLAC__CRC16_UPDATE(bb->buffer[bb->consumed_bytes], bb->read_crc16);
@ -992,8 +991,6 @@ bool FLAC__bitbuffer_read_bit(FLAC__BitBuffer *bb, unsigned *val, bool (*read_ca
bool FLAC__bitbuffer_read_bit_to_uint32(FLAC__BitBuffer *bb, uint32 *val, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data)
{
static const byte mask[] = { 128, 64, 32, 16, 8, 4, 2, 1 };
/* to avoid a drastic speed penalty we don't:
assert(bb != 0);
assert(bb->buffer != 0);
@ -1003,7 +1000,7 @@ bool FLAC__bitbuffer_read_bit_to_uint32(FLAC__BitBuffer *bb, uint32 *val, bool (
while(1) {
if(bb->total_consumed_bits < bb->total_bits) {
*val <<= 1;
*val |= (bb->buffer[bb->consumed_bytes] & mask[bb->consumed_bits])? 1 : 0;
*val |= (bb->buffer[bb->consumed_bytes] & byte_bit_to_mask_[bb->consumed_bits])? 1 : 0;
bb->consumed_bits++;
if(bb->consumed_bits == 8) {
FLAC__CRC16_UPDATE(bb->buffer[bb->consumed_bytes], bb->read_crc16);
@ -1022,8 +1019,6 @@ bool FLAC__bitbuffer_read_bit_to_uint32(FLAC__BitBuffer *bb, uint32 *val, bool (
bool FLAC__bitbuffer_read_bit_to_uint64(FLAC__BitBuffer *bb, uint64 *val, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data)
{
static const byte mask[] = { 128, 64, 32, 16, 8, 4, 2, 1 };
/* to avoid a drastic speed penalty we don't:
assert(bb != 0);
assert(bb->buffer != 0);
@ -1033,7 +1028,7 @@ bool FLAC__bitbuffer_read_bit_to_uint64(FLAC__BitBuffer *bb, uint64 *val, bool (
while(1) {
if(bb->total_consumed_bits < bb->total_bits) {
*val <<= 1;
*val |= (bb->buffer[bb->consumed_bytes] & mask[bb->consumed_bits])? 1 : 0;
*val |= (bb->buffer[bb->consumed_bytes] & byte_bit_to_mask_[bb->consumed_bits])? 1 : 0;
bb->consumed_bits++;
if(bb->consumed_bits == 8) {
FLAC__CRC16_UPDATE(bb->buffer[bb->consumed_bytes], bb->read_crc16);
@ -1051,6 +1046,7 @@ bool FLAC__bitbuffer_read_bit_to_uint64(FLAC__BitBuffer *bb, uint64 *val, bool (
}
bool FLAC__bitbuffer_read_raw_uint32(FLAC__BitBuffer *bb, uint32 *val, unsigned bits, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data)
#ifdef FLAC__NO_MANUAL_INLINING
{
unsigned i;
@ -1066,6 +1062,55 @@ bool FLAC__bitbuffer_read_raw_uint32(FLAC__BitBuffer *bb, uint32 *val, unsigned
}
return true;
}
#else
{
unsigned i, bits_ = bits;
uint32 v = 0;
assert(bb != 0);
assert(bb->buffer != 0);
assert(bits <= 32);
assert((bb->capacity*8) * 2 >= bits);
while(bb->total_consumed_bits + bits > bb->total_bits) {
if(!bitbuffer_read_from_client_(bb, read_callback, client_data))
return false;
}
if(bb->consumed_bits) {
i = 8 - bb->consumed_bits;
if(i <= bits_) {
v = bb->buffer[bb->consumed_bytes] & (0xff >> bb->consumed_bits);
bits_ -= i;
FLAC__CRC16_UPDATE(bb->buffer[bb->consumed_bytes], bb->read_crc16);
bb->consumed_bytes++;
bb->consumed_bits = 0;
}
else {
*val = (bb->buffer[bb->consumed_bytes] & (0xff >> bb->consumed_bits)) >> (i-bits_);
bb->consumed_bits += bits_;
bb->total_consumed_bits += bits_;
return true;
}
}
while(bits_ >= 8) {
v <<= 8;
v |= bb->buffer[bb->consumed_bytes];
bits_ -= 8;
FLAC__CRC16_UPDATE(bb->buffer[bb->consumed_bytes], bb->read_crc16);
bb->consumed_bytes++;
/* bb->consumed_bits is already 0 */
}
if(bits_ > 0) {
v <<= bits_;
v |= (bb->buffer[bb->consumed_bytes] >> (8-bits_));
bb->consumed_bits = bits_;
}
bb->total_consumed_bits += bits;
*val = v;
return true;
}
#endif
bool FLAC__bitbuffer_read_raw_int32(FLAC__BitBuffer *bb, int32 *val, unsigned bits, bool (*read_callback)(byte buffer[], unsigned *bytes, void *client_data), void *client_data)
{