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The Independent JPEG Group's JPEG software v2

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This commit is contained in:
Thomas G. Lane
1991-12-13 00:00:00 +00:00
committed by Kornel Lesiński
parent 7a9a82bf06
commit 98f16a9b4d
59 changed files with 4585 additions and 1143 deletions
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63
jchuff.c
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@@ -39,8 +39,8 @@ fix_huff_tbl (HUFF_TBL * htbl)
p = 0;
for (l = 1; l <= 16; l++) {
for (i = 1; i <= htbl->bits[l]; i++)
huffsize[p++] = l;
for (i = 1; i <= (int) htbl->bits[l]; i++)
huffsize[p++] = (char) l;
}
huffsize[p] = 0;
lastp = p;
@@ -52,7 +52,7 @@ fix_huff_tbl (HUFF_TBL * htbl)
si = huffsize[0];
p = 0;
while (huffsize[p]) {
while (huffsize[p] == si) {
while (((int) huffsize[p]) == si) {
huffcode[p++] = code;
code++;
}
@@ -95,10 +95,10 @@ flush_bytes (void)
}
#define emit_byte(val) ((bytes_in_buffer >= JPEG_BUF_SIZE ? \
(flush_bytes(), 0) : 0), \
output_buffer[bytes_in_buffer] = (val), \
bytes_in_buffer++)
#define emit_byte(val) \
MAKESTMT( if (bytes_in_buffer >= JPEG_BUF_SIZE) \
flush_bytes(); \
output_buffer[bytes_in_buffer++] = (char) (val); )
@@ -157,16 +157,22 @@ flush_bits (void)
LOCAL void
encode_one_block (JBLOCK block, HUFF_TBL *dctbl, HUFF_TBL *actbl)
{
register INT32 temp;
register int temp, temp2;
register int nbits;
register int k, r, i;
/* Encode the DC coefficient difference per section 7.3.5.1 */
/* Find the number of bits needed for the magnitude of the coefficient */
temp = block[0];
if (temp < 0) temp = -temp;
temp = temp2 = block[0];
if (temp < 0) {
temp = -temp; /* temp is abs value of input */
/* For a negative input, want temp2 = bitwise complement of abs(input) */
/* This code assumes we are on a two's complement machine */
temp2--;
}
/* Find the number of bits needed for the magnitude of the coefficient */
nbits = 0;
while (temp) {
nbits++;
@@ -175,13 +181,10 @@ encode_one_block (JBLOCK block, HUFF_TBL *dctbl, HUFF_TBL *actbl)
/* Emit the Huffman-coded symbol for the number of bits */
emit_bits(dctbl->ehufco[nbits], dctbl->ehufsi[nbits]);
/* If positive, emit nbits low order bits; */
/* if negative, emit nbits low order bits of value-1 */
if ((temp = block[0]) < 0)
temp--;
emit_bits((UINT16) temp, nbits);
/* Emit that number of bits of the value, if positive, */
/* or the complement of its magnitude, if negative. */
emit_bits((UINT16) temp2, nbits);
/* Encode the AC coefficients per section 7.3.5.2 */
@@ -196,10 +199,15 @@ encode_one_block (JBLOCK block, HUFF_TBL *dctbl, HUFF_TBL *actbl)
emit_bits(actbl->ehufco[0xF0], actbl->ehufsi[0xF0]);
r -= 16;
}
temp2 = temp;
if (temp < 0) {
temp = -temp; /* temp is abs value of input */
/* This code assumes we are on a two's complement machine */
temp2--;
}
/* Find the number of bits needed for the magnitude of the coefficient */
if (temp < 0) temp = -temp;
nbits = 1; /* there must be at least one 1 bit */
while (temp >>= 1)
nbits++;
@@ -208,12 +216,9 @@ encode_one_block (JBLOCK block, HUFF_TBL *dctbl, HUFF_TBL *actbl)
i = (r << 4) + nbits;
emit_bits(actbl->ehufco[i], actbl->ehufsi[i]);
/* If positive, emit nbits low order bits; */
/* if negative, emit nbits low order bits of value-1 */
if ((temp = block[k]) < 0)
temp--;
emit_bits((UINT16) temp, nbits);
/* Emit that number of bits of the value, if positive, */
/* or the complement of its magnitude, if negative. */
emit_bits((UINT16) temp2, nbits);
r = 0;
}
@@ -488,7 +493,7 @@ gen_huff_coding (compress_info_ptr cinfo, HUFF_TBL *htbl, long freq[])
for (i = 1; i <= MAX_CLEN; i++) {
for (j = 0; j <= 255; j++) {
if (codesize[j] == i) {
htbl->huffval[p] = j;
htbl->huffval[p] = (UINT8) j;
p++;
}
}
@@ -645,7 +650,7 @@ huff_optimize (compress_info_ptr cinfo, MCU_output_caller_ptr source_method)
if (dc_count_ptrs[tbl] != NULL) {
htblptr = & cinfo->dc_huff_tbl_ptrs[tbl];
if (*htblptr == NULL)
*htblptr = (*cinfo->emethods->alloc_small) (SIZEOF(HUFF_TBL));
*htblptr = (HUFF_TBL *) (*cinfo->emethods->alloc_small) (SIZEOF(HUFF_TBL));
/* Set sent_table FALSE so updated table will be written to JPEG file. */
(*htblptr)->sent_table = FALSE;
/* Compute the optimal Huffman encoding */
@@ -656,7 +661,7 @@ huff_optimize (compress_info_ptr cinfo, MCU_output_caller_ptr source_method)
if (ac_count_ptrs[tbl] != NULL) {
htblptr = & cinfo->ac_huff_tbl_ptrs[tbl];
if (*htblptr == NULL)
*htblptr = (*cinfo->emethods->alloc_small) (SIZEOF(HUFF_TBL));
*htblptr = (HUFF_TBL *) (*cinfo->emethods->alloc_small) (SIZEOF(HUFF_TBL));
/* Set sent_table FALSE so updated table will be written to JPEG file. */
(*htblptr)->sent_table = FALSE;
/* Compute the optimal Huffman encoding */