From 64f4fbcaf7743659a2e70d6f6c64c2fc880e44ce Mon Sep 17 00:00:00 2001 From: Josh Coalson Date: Tue, 24 Apr 2001 02:36:08 +0000 Subject: [PATCH] start some read optimizations --- src/libFLAC/bitbuffer.c | 71 ++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 58 insertions(+), 13 deletions(-) diff --git a/src/libFLAC/bitbuffer.c b/src/libFLAC/bitbuffer.c index bc94d20..42a729e 100644 --- a/src/libFLAC/bitbuffer.c +++ b/src/libFLAC/bitbuffer.c @@ -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) { -- 2.7.4