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Include Huffman codec optimizations borrowed from TurboJPEG

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git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@24 632fc199-4ca6-4c93-a231-07263d6284db
This commit is contained in:
DRC
2009-03-12 17:24:27 +00:00
parent 0747ad2b12
commit 99313388cc
1 changed files with 146 additions and 108 deletions
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254
jchuff.c
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@@ -14,12 +14,34 @@
* permanent JPEG objects only upon successful completion of an MCU. * permanent JPEG objects only upon successful completion of an MCU.
*/ */
/* Modifications:
* Copyright (C)2007 Sun Microsystems, Inc.
* Copyright (C)2009 D. R. Commander
*
* This library is free software and may be redistributed and/or modified under
* the terms of the wxWindows Library License, Version 3.1 or (at your option)
* any later version. The full license is in the LICENSE.txt file included
* with this distribution.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* wxWindows Library License for more details.
*/
#define JPEG_INTERNALS #define JPEG_INTERNALS
#include "jinclude.h" #include "jinclude.h"
#include "jpeglib.h" #include "jpeglib.h"
#include "jchuff.h" /* Declarations shared with jcphuff.c */ #include "jchuff.h" /* Declarations shared with jcphuff.c */
static unsigned char jpeg_first_bit_table[65536];
int jpeg_first_bit_table_init=0;
#define CALC_FIRST_BIT(nbits, t) \
nbits = jpeg_first_bit_table[t&255]; \
if (t > 255) nbits = jpeg_first_bit_table[t>>8] + 8;
/* Expanded entropy encoder object for Huffman encoding. /* Expanded entropy encoder object for Huffman encoding.
* *
* The savable_state subrecord contains fields that change within an MCU, * The savable_state subrecord contains fields that change within an MCU,
@@ -261,6 +283,15 @@ jpeg_make_c_derived_tbl (j_compress_ptr cinfo, boolean isDC, int tblno,
dtbl->ehufco[i] = huffcode[p]; dtbl->ehufco[i] = huffcode[p];
dtbl->ehufsi[i] = huffsize[p]; dtbl->ehufsi[i] = huffsize[p];
} }
if(!jpeg_first_bit_table_init) {
for(i = 0; i < 65536; i++) {
int bit = 0, val = i;
while (val) {val >>= 1; bit++;}
jpeg_first_bit_table[i] = bit;
}
jpeg_first_bit_table_init = 1;
}
} }
@@ -297,147 +328,154 @@ dump_buffer (working_state * state)
* between calls, so 24 bits are sufficient. * between calls, so 24 bits are sufficient.
*/ */
inline /***************************************************************/
LOCAL(boolean)
emit_bits (working_state * state, unsigned int code, int size)
/* Emit some bits; return TRUE if successful, FALSE if must suspend */
{
/* This routine is heavily used, so it's worth coding tightly. */
register INT32 put_buffer = (INT32) code;
register int put_bits = state->cur.put_bits;
/* if size is 0, caller used an invalid Huffman table entry */ #define DUMP_BITS_(code, size) { \
if (size == 0) put_bits += size; \
ERREXIT(state->cinfo, JERR_HUFF_MISSING_CODE); put_buffer = (put_buffer << size) | code; \
if (put_bits > 7) \
while(put_bits > 7) \
if (0xFF == (*buffer++ = put_buffer >> (put_bits -= 8))) \
*buffer++ = 0; \
}
put_buffer &= (((INT32) 1)<<size) - 1; /* mask off any extra bits in code */ /***************************************************************/
put_bits += size; /* new number of bits in buffer */
put_buffer <<= 24 - put_bits; /* align incoming bits */
put_buffer |= state->cur.put_buffer; /* and merge with old buffer contents */ #define DUMP_BITS(code, size) { \
put_bits += size; \
while (put_bits >= 8) { put_buffer = (put_buffer << size) | code; \
int c = (int) ((put_buffer >> 16) & 0xFF); if (put_bits > 15) { \
if (0xFF == (*buffer++ = put_buffer >> (put_bits -= 8))) \
emit_byte(state, c, return FALSE); *buffer++ = 0; \
if (c == 0xFF) { /* need to stuff a zero byte? */ if (0xFF == (*buffer++ = put_buffer >> (put_bits -= 8))) \
emit_byte(state, 0, return FALSE); *buffer++ = 0; \
} } \
put_buffer <<= 8; }
put_bits -= 8;
}
state->cur.put_buffer = put_buffer; /* update state variables */ /***************************************************************/
state->cur.put_bits = put_bits;
return TRUE; #define DUMP_SINGLE_VALUE(ht, codevalue) { \
} size = ht->ehufsi[codevalue]; \
code = ht->ehufco[codevalue]; \
\
DUMP_BITS(code, size) \
}
/***************************************************************/
#define DUMP_VALUE(ht, codevalue, t, nbits) { \
size = ht->ehufsi[codevalue]; \
code = ht->ehufco[codevalue]; \
t &= ~(-1 << nbits); \
DUMP_BITS(code, size) \
DUMP_BITS(t, nbits) \
}
/***************************************************************/
LOCAL(boolean) LOCAL(boolean)
flush_bits (working_state * state) flush_bits (working_state * state)
{ {
if (! emit_bits(state, 0x7F, 7)) /* fill any partial byte with ones */ unsigned char *buffer;
return FALSE; int put_buffer, put_bits;
if ((state)->free_in_buffer < DCTSIZE2 * 2)
if (! dump_buffer(state)) return FALSE;
buffer = state->next_output_byte;
put_buffer = state->cur.put_buffer;
put_bits = state->cur.put_bits;
DUMP_BITS_(0x7F, 7)
state->cur.put_buffer = 0; /* and reset bit-buffer to empty */ state->cur.put_buffer = 0; /* and reset bit-buffer to empty */
state->cur.put_bits = 0; state->cur.put_bits = 0;
state->free_in_buffer -= (buffer - state->next_output_byte);
state->next_output_byte = buffer;
if ((state)->free_in_buffer < DCTSIZE2 * 2)
if (! dump_buffer(state)) return FALSE;
return TRUE; return TRUE;
} }
/* Encode a single block's worth of coefficients */ /* Encode a single block's worth of coefficients */
LOCAL(boolean) LOCAL(boolean)
encode_one_block (working_state * state, JCOEFPTR block, int last_dc_val, encode_one_block (working_state * state, JCOEFPTR block, int last_dc_val,
c_derived_tbl *dctbl, c_derived_tbl *actbl) c_derived_tbl *dctbl, c_derived_tbl *actbl)
{ {
register int temp, temp2; int temp, temp2;
register int nbits; int nbits;
register int k, r, i; int r, sflag, size, code;
unsigned char *buffer;
int put_buffer, put_bits;
int code_0xf0 = actbl->ehufco[0xf0], size_0xf0 = actbl->ehufsi[0xf0];
if ((state)->free_in_buffer < DCTSIZE2 * 2)
if (! dump_buffer(state)) return FALSE;
buffer = state->next_output_byte;
put_buffer = state->cur.put_buffer;
put_bits = state->cur.put_bits;
/* Encode the DC coefficient difference per section F.1.2.1 */ /* Encode the DC coefficient difference per section F.1.2.1 */
temp = temp2 = block[0] - last_dc_val; temp = temp2 = block[0] - last_dc_val;
if (temp < 0) { sflag = temp >> 31;
temp = -temp; /* temp is abs value of input */ temp -= ((temp + temp) & sflag);
/* For a negative input, want temp2 = bitwise complement of abs(input) */ temp2 += sflag;
/* This code assumes we are on a two's complement machine */ CALC_FIRST_BIT(nbits, temp)
temp2--; DUMP_VALUE(dctbl, nbits, temp2, nbits)
}
/* Find the number of bits needed for the magnitude of the coefficient */
nbits = 0;
while (temp) {
nbits++;
temp >>= 1;
}
/* Check for out-of-range coefficient values.
* Since we're encoding a difference, the range limit is twice as much.
*/
if (nbits > MAX_COEF_BITS+1)
ERREXIT(state->cinfo, JERR_BAD_DCT_COEF);
/* Emit the Huffman-coded symbol for the number of bits */
if (! emit_bits(state, dctbl->ehufco[nbits], dctbl->ehufsi[nbits]))
return FALSE;
/* Emit that number of bits of the value, if positive, */
/* or the complement of its magnitude, if negative. */
if (nbits) /* emit_bits rejects calls with size 0 */
if (! emit_bits(state, (unsigned int) temp2, nbits))
return FALSE;
/* Encode the AC coefficients per section F.1.2.2 */ /* Encode the AC coefficients per section F.1.2.2 */
r = 0; /* r = run length of zeros */ r = 0; /* r = run length of zeros */
for (k = 1; k < DCTSIZE2; k++) {
if ((temp = block[jpeg_natural_order[k]]) == 0) {
r++;
} else {
/* if run length > 15, must emit special run-length-16 codes (0xF0) */
while (r > 15) {
if (! emit_bits(state, actbl->ehufco[0xF0], actbl->ehufsi[0xF0]))
return FALSE;
r -= 16;
}
temp2 = temp; #define innerloop(order) { \
if (temp < 0) { temp2 = *(JCOEF*)((unsigned char*)block + order); \
temp = -temp; /* temp is abs value of input */ if(temp2 == 0) r++; \
/* This code assumes we are on a two's complement machine */ else { \
temp2--; temp = (JCOEF)temp2; \
} sflag = temp >> 31; \
temp = (temp ^ sflag) - sflag; \
/* Find the number of bits needed for the magnitude of the coefficient */ temp2 += sflag; \
nbits = 1; /* there must be at least one 1 bit */ nbits = jpeg_first_bit_table[temp]; \
while ((temp >>= 1)) for(; r > 15; r -= 16) DUMP_BITS(code_0xf0, size_0xf0) \
nbits++; sflag = (r << 4) + nbits; \
/* Check for out-of-range coefficient values */ DUMP_VALUE(actbl, sflag, temp2, nbits) \
if (nbits > MAX_COEF_BITS) r = 0; \
ERREXIT(state->cinfo, JERR_BAD_DCT_COEF); }}
/* Emit Huffman symbol for run length / number of bits */
i = (r << 4) + nbits;
if (! emit_bits(state, actbl->ehufco[i], actbl->ehufsi[i]))
return FALSE;
/* Emit that number of bits of the value, if positive, */ innerloop(2*1); innerloop(2*8); innerloop(2*16); innerloop(2*9);
/* or the complement of its magnitude, if negative. */ innerloop(2*2); innerloop(2*3); innerloop(2*10); innerloop(2*17);
if (! emit_bits(state, (unsigned int) temp2, nbits)) innerloop(2*24); innerloop(2*32); innerloop(2*25); innerloop(2*18);
return FALSE; innerloop(2*11); innerloop(2*4); innerloop(2*5); innerloop(2*12);
innerloop(2*19); innerloop(2*26); innerloop(2*33); innerloop(2*40);
r = 0; innerloop(2*48); innerloop(2*41); innerloop(2*34); innerloop(2*27);
} innerloop(2*20); innerloop(2*13); innerloop(2*6); innerloop(2*7);
} innerloop(2*14); innerloop(2*21); innerloop(2*28); innerloop(2*35);
innerloop(2*42); innerloop(2*49); innerloop(2*56); innerloop(2*57);
innerloop(2*50); innerloop(2*43); innerloop(2*36); innerloop(2*29);
innerloop(2*22); innerloop(2*15); innerloop(2*23); innerloop(2*30);
innerloop(2*37); innerloop(2*44); innerloop(2*51); innerloop(2*58);
innerloop(2*59); innerloop(2*52); innerloop(2*45); innerloop(2*38);
innerloop(2*31); innerloop(2*39); innerloop(2*46); innerloop(2*53);
innerloop(2*60); innerloop(2*61); innerloop(2*54); innerloop(2*47);
innerloop(2*55); innerloop(2*62); innerloop(2*63);
/* If the last coef(s) were zero, emit an end-of-block code */ /* If the last coef(s) were zero, emit an end-of-block code */
if (r > 0) if (r > 0) DUMP_SINGLE_VALUE(actbl, 0x0)
if (! emit_bits(state, actbl->ehufco[0], actbl->ehufsi[0]))
return FALSE; state->cur.put_buffer = put_buffer;
state->cur.put_bits = put_bits;
state->free_in_buffer -= (buffer - state->next_output_byte);
state->next_output_byte = buffer;
if ((state)->free_in_buffer < DCTSIZE2 * 2)
if (! dump_buffer(state)) return FALSE;
return TRUE; return TRUE;
} }