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Unified Diff: jquant1.c

Issue 1934113002: Update libjpeg_turbo to 1.4.90 from https://github.com/libjpeg-turbo/ (Closed) Base URL: https://chromium.googlesource.com/chromium/deps/libjpeg_turbo.git@master
Patch Set: Created 4 years, 8 months ago
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Index: jquant1.c
diff --git a/jquant1.c b/jquant1.c
index aa2c59a4be82fe181f7737c0baacc13ab9632b8d..e7814815efe89733de962bde2be87ef573d1acea 100644
--- a/jquant1.c
+++ b/jquant1.c
@@ -4,8 +4,9 @@
* This file was part of the Independent JPEG Group's software:
* Copyright (C) 1991-1996, Thomas G. Lane.
* libjpeg-turbo Modifications:
- * Copyright (C) 2009, D. R. Commander
- * For conditions of distribution and use, see the accompanying README file.
+ * Copyright (C) 2009, 2015, D. R. Commander.
+ * For conditions of distribution and use, see the accompanying README.ijg
+ * file.
*
* This file contains 1-pass color quantization (color mapping) routines.
* These routines provide mapping to a fixed color map using equally spaced
@@ -70,9 +71,9 @@
* table in both directions.
*/
-#define ODITHER_SIZE 16 /* dimension of dither matrix */
+#define ODITHER_SIZE 16 /* dimension of dither matrix */
/* NB: if ODITHER_SIZE is not a power of 2, ODITHER_MASK uses will break */
-#define ODITHER_CELLS (ODITHER_SIZE*ODITHER_SIZE) /* # cells in matrix */
+#define ODITHER_CELLS (ODITHER_SIZE*ODITHER_SIZE) /* # cells in matrix */
#define ODITHER_MASK (ODITHER_SIZE-1) /* mask for wrapping around counters */
typedef int ODITHER_MATRIX[ODITHER_SIZE][ODITHER_SIZE];
@@ -107,8 +108,8 @@ static const UINT8 base_dither_matrix[ODITHER_SIZE][ODITHER_SIZE] = {
* Errors are accumulated into the array fserrors[], at a resolution of
* 1/16th of a pixel count. The error at a given pixel is propagated
* to its not-yet-processed neighbors using the standard F-S fractions,
- * ... (here) 7/16
- * 3/16 5/16 1/16
+ * ... (here) 7/16
+ * 3/16 5/16 1/16
* We work left-to-right on even rows, right-to-left on odd rows.
*
* We can get away with a single array (holding one row's worth of errors)
@@ -121,52 +122,49 @@ static const UINT8 base_dither_matrix[ODITHER_SIZE][ODITHER_SIZE] = {
* The fserrors[] array is indexed [component#][position].
* We provide (#columns + 2) entries per component; the extra entry at each
* end saves us from special-casing the first and last pixels.
- *
- * Note: on a wide image, we might not have enough room in a PC's near data
- * segment to hold the error array; so it is allocated with alloc_large.
*/
#if BITS_IN_JSAMPLE == 8
-typedef INT16 FSERROR; /* 16 bits should be enough */
-typedef int LOCFSERROR; /* use 'int' for calculation temps */
+typedef INT16 FSERROR; /* 16 bits should be enough */
+typedef int LOCFSERROR; /* use 'int' for calculation temps */
#else
-typedef INT32 FSERROR; /* may need more than 16 bits */
-typedef INT32 LOCFSERROR; /* be sure calculation temps are big enough */
+typedef JLONG FSERROR; /* may need more than 16 bits */
+typedef JLONG LOCFSERROR; /* be sure calculation temps are big enough */
#endif
-typedef FSERROR FAR *FSERRPTR; /* pointer to error array (in FAR storage!) */
+typedef FSERROR *FSERRPTR; /* pointer to error array */
/* Private subobject */
-#define MAX_Q_COMPS 4 /* max components I can handle */
+#define MAX_Q_COMPS 4 /* max components I can handle */
typedef struct {
struct jpeg_color_quantizer pub; /* public fields */
/* Initially allocated colormap is saved here */
- JSAMPARRAY sv_colormap; /* The color map as a 2-D pixel array */
- int sv_actual; /* number of entries in use */
+ JSAMPARRAY sv_colormap; /* The color map as a 2-D pixel array */
+ int sv_actual; /* number of entries in use */
- JSAMPARRAY colorindex; /* Precomputed mapping for speed */
+ JSAMPARRAY colorindex; /* Precomputed mapping for speed */
/* colorindex[i][j] = index of color closest to pixel value j in component i,
* premultiplied as described above. Since colormap indexes must fit into
* JSAMPLEs, the entries of this array will too.
*/
- boolean is_padded; /* is the colorindex padded for odither? */
+ boolean is_padded; /* is the colorindex padded for odither? */
- int Ncolors[MAX_Q_COMPS]; /* # of values alloced to each component */
+ int Ncolors[MAX_Q_COMPS]; /* # of values alloced to each component */
/* Variables for ordered dithering */
- int row_index; /* cur row's vertical index in dither matrix */
+ int row_index; /* cur row's vertical index in dither matrix */
ODITHER_MATRIX_PTR odither[MAX_Q_COMPS]; /* one dither array per component */
/* Variables for Floyd-Steinberg dithering */
FSERRPTR fserrors[MAX_Q_COMPS]; /* accumulated errors */
- boolean on_odd_row; /* flag to remember which row we are on */
+ boolean on_odd_row; /* flag to remember which row we are on */
} my_cquantizer;
-typedef my_cquantizer * my_cquantize_ptr;
+typedef my_cquantizer *my_cquantize_ptr;
/*
@@ -205,11 +203,11 @@ select_ncolors (j_decompress_ptr cinfo, int Ncolors[])
iroot = 1;
do {
iroot++;
- temp = iroot; /* set temp = iroot ** nc */
+ temp = iroot; /* set temp = iroot ** nc */
for (i = 1; i < nc; i++)
temp *= iroot;
} while (temp <= (long) max_colors); /* repeat till iroot exceeds root */
- iroot--; /* now iroot = floor(root) */
+ iroot--; /* now iroot = floor(root) */
/* Must have at least 2 color values per component */
if (iroot < 2)
@@ -233,10 +231,10 @@ select_ncolors (j_decompress_ptr cinfo, int Ncolors[])
j = (cinfo->out_color_space == JCS_RGB ? RGB_order[i] : i);
/* calculate new total_colors if Ncolors[j] is incremented */
temp = total_colors / Ncolors[j];
- temp *= Ncolors[j]+1; /* done in long arith to avoid oflo */
+ temp *= Ncolors[j]+1; /* done in long arith to avoid oflo */
if (temp > (long) max_colors)
- break; /* won't fit, done with this pass */
- Ncolors[j]++; /* OK, apply the increment */
+ break; /* won't fit, done with this pass */
+ Ncolors[j]++; /* OK, apply the increment */
total_colors = (int) temp;
changed = TRUE;
}
@@ -256,7 +254,7 @@ output_value (j_decompress_ptr cinfo, int ci, int j, int maxj)
* (Forcing the upper and lower values to the limits ensures that
* dithering can't produce a color outside the selected gamut.)
*/
- return (int) (((INT32) j * MAXJSAMPLE + maxj/2) / maxj);
+ return (int) (((JLONG) j * MAXJSAMPLE + maxj/2) / maxj);
}
@@ -266,7 +264,7 @@ largest_input_value (j_decompress_ptr cinfo, int ci, int j, int maxj)
/* Must have largest(j=0) >= 0, and largest(j=maxj) >= MAXJSAMPLE */
{
/* Breakpoints are halfway between values returned by output_value */
- return (int) (((INT32) (2*j + 1) * MAXJSAMPLE + maxj) / (2*maxj));
+ return (int) (((JLONG) (2*j + 1) * MAXJSAMPLE + maxj) / (2*maxj));
}
@@ -278,8 +276,8 @@ LOCAL(void)
create_colormap (j_decompress_ptr cinfo)
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
- JSAMPARRAY colormap; /* Created colormap */
- int total_colors; /* Number of distinct output colors */
+ JSAMPARRAY colormap; /* Created colormap */
+ int total_colors; /* Number of distinct output colors */
int i,j,k, nci, blksize, blkdist, ptr, val;
/* Select number of colors for each component */
@@ -288,8 +286,8 @@ create_colormap (j_decompress_ptr cinfo)
/* Report selected color counts */
if (cinfo->out_color_components == 3)
TRACEMS4(cinfo, 1, JTRC_QUANT_3_NCOLORS,
- total_colors, cquantize->Ncolors[0],
- cquantize->Ncolors[1], cquantize->Ncolors[2]);
+ total_colors, cquantize->Ncolors[0],
+ cquantize->Ncolors[1], cquantize->Ncolors[2]);
else
TRACEMS1(cinfo, 1, JTRC_QUANT_NCOLORS, total_colors);
@@ -314,12 +312,12 @@ create_colormap (j_decompress_ptr cinfo)
val = output_value(cinfo, i, j, nci-1);
/* Fill in all colormap entries that have this value of this component */
for (ptr = j * blksize; ptr < total_colors; ptr += blkdist) {
- /* fill in blksize entries beginning at ptr */
- for (k = 0; k < blksize; k++)
- colormap[i][ptr+k] = (JSAMPLE) val;
+ /* fill in blksize entries beginning at ptr */
+ for (k = 0; k < blksize; k++)
+ colormap[i][ptr+k] = (JSAMPLE) val;
}
}
- blkdist = blksize; /* blksize of this color is blkdist of next */
+ blkdist = blksize; /* blksize of this color is blkdist of next */
}
/* Save the colormap in private storage,
@@ -377,16 +375,16 @@ create_colorindex (j_decompress_ptr cinfo)
val = 0;
k = largest_input_value(cinfo, i, 0, nci-1);
for (j = 0; j <= MAXJSAMPLE; j++) {
- while (j > k) /* advance val if past boundary */
- k = largest_input_value(cinfo, i, ++val, nci-1);
+ while (j > k) /* advance val if past boundary */
+ k = largest_input_value(cinfo, i, ++val, nci-1);
/* premultiply so that no multiplication needed in main processing */
indexptr[j] = (JSAMPLE) (val * blksize);
}
/* Pad at both ends if necessary */
if (pad)
for (j = 1; j <= MAXJSAMPLE; j++) {
- indexptr[-j] = indexptr[0];
- indexptr[MAXJSAMPLE+j] = indexptr[MAXJSAMPLE];
+ indexptr[-j] = indexptr[0];
+ indexptr[MAXJSAMPLE+j] = indexptr[MAXJSAMPLE];
}
}
}
@@ -402,21 +400,21 @@ make_odither_array (j_decompress_ptr cinfo, int ncolors)
{
ODITHER_MATRIX_PTR odither;
int j,k;
- INT32 num,den;
+ JLONG num,den;
odither = (ODITHER_MATRIX_PTR)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- SIZEOF(ODITHER_MATRIX));
+ sizeof(ODITHER_MATRIX));
/* The inter-value distance for this color is MAXJSAMPLE/(ncolors-1).
* Hence the dither value for the matrix cell with fill order f
* (f=0..N-1) should be (N-1-2*f)/(2*N) * MAXJSAMPLE/(ncolors-1).
* On 16-bit-int machine, be careful to avoid overflow.
*/
- den = 2 * ODITHER_CELLS * ((INT32) (ncolors - 1));
+ den = 2 * ODITHER_CELLS * ((JLONG) (ncolors - 1));
for (j = 0; j < ODITHER_SIZE; j++) {
for (k = 0; k < ODITHER_SIZE; k++) {
- num = ((INT32) (ODITHER_CELLS-1 - 2*((int)base_dither_matrix[j][k])))
- * MAXJSAMPLE;
+ num = ((JLONG) (ODITHER_CELLS-1 - 2*((int)base_dither_matrix[j][k])))
+ * MAXJSAMPLE;
/* Ensure round towards zero despite C's lack of consistency
* about rounding negative values in integer division...
*/
@@ -429,7 +427,7 @@ make_odither_array (j_decompress_ptr cinfo, int ncolors)
/*
* Create the ordered-dither tables.
- * Components having the same number of representative colors may
+ * Components having the same number of representative colors may
* share a dither table.
*/
@@ -442,14 +440,14 @@ create_odither_tables (j_decompress_ptr cinfo)
for (i = 0; i < cinfo->out_color_components; i++) {
nci = cquantize->Ncolors[i]; /* # of distinct values for this color */
- odither = NULL; /* search for matching prior component */
+ odither = NULL; /* search for matching prior component */
for (j = 0; j < i; j++) {
if (nci == cquantize->Ncolors[j]) {
- odither = cquantize->odither[j];
- break;
+ odither = cquantize->odither[j];
+ break;
}
}
- if (odither == NULL) /* need a new table? */
+ if (odither == NULL) /* need a new table? */
odither = make_odither_array(cinfo, nci);
cquantize->odither[i] = odither;
}
@@ -462,7 +460,7 @@ create_odither_tables (j_decompress_ptr cinfo)
METHODDEF(void)
color_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
- JSAMPARRAY output_buf, int num_rows)
+ JSAMPARRAY output_buf, int num_rows)
/* General case, no dithering */
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
@@ -480,7 +478,7 @@ color_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
for (col = width; col > 0; col--) {
pixcode = 0;
for (ci = 0; ci < nc; ci++) {
- pixcode += GETJSAMPLE(colorindex[ci][GETJSAMPLE(*ptrin++)]);
+ pixcode += GETJSAMPLE(colorindex[ci][GETJSAMPLE(*ptrin++)]);
}
*ptrout++ = (JSAMPLE) pixcode;
}
@@ -490,7 +488,7 @@ color_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
METHODDEF(void)
color_quantize3 (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
- JSAMPARRAY output_buf, int num_rows)
+ JSAMPARRAY output_buf, int num_rows)
/* Fast path for out_color_components==3, no dithering */
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
@@ -518,15 +516,15 @@ color_quantize3 (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
METHODDEF(void)
quantize_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
- JSAMPARRAY output_buf, int num_rows)
+ JSAMPARRAY output_buf, int num_rows)
/* General case, with ordered dithering */
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
register JSAMPROW input_ptr;
register JSAMPROW output_ptr;
JSAMPROW colorindex_ci;
- int * dither; /* points to active row of dither matrix */
- int row_index, col_index; /* current indexes into dither matrix */
+ int *dither; /* points to active row of dither matrix */
+ int row_index, col_index; /* current indexes into dither matrix */
int nc = cinfo->out_color_components;
int ci;
int row;
@@ -535,8 +533,7 @@ quantize_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
for (row = 0; row < num_rows; row++) {
/* Initialize output values to 0 so can process components separately */
- jzero_far((void FAR *) output_buf[row],
- (size_t) (width * SIZEOF(JSAMPLE)));
+ jzero_far((void *) output_buf[row], (size_t) (width * sizeof(JSAMPLE)));
row_index = cquantize->row_index;
for (ci = 0; ci < nc; ci++) {
input_ptr = input_buf[row] + ci;
@@ -546,17 +543,17 @@ quantize_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
col_index = 0;
for (col = width; col > 0; col--) {
- /* Form pixel value + dither, range-limit to 0..MAXJSAMPLE,
- * select output value, accumulate into output code for this pixel.
- * Range-limiting need not be done explicitly, as we have extended
- * the colorindex table to produce the right answers for out-of-range
- * inputs. The maximum dither is +- MAXJSAMPLE; this sets the
- * required amount of padding.
- */
- *output_ptr += colorindex_ci[GETJSAMPLE(*input_ptr)+dither[col_index]];
- input_ptr += nc;
- output_ptr++;
- col_index = (col_index + 1) & ODITHER_MASK;
+ /* Form pixel value + dither, range-limit to 0..MAXJSAMPLE,
+ * select output value, accumulate into output code for this pixel.
+ * Range-limiting need not be done explicitly, as we have extended
+ * the colorindex table to produce the right answers for out-of-range
+ * inputs. The maximum dither is +- MAXJSAMPLE; this sets the
+ * required amount of padding.
+ */
+ *output_ptr += colorindex_ci[GETJSAMPLE(*input_ptr)+dither[col_index]];
+ input_ptr += nc;
+ output_ptr++;
+ col_index = (col_index + 1) & ODITHER_MASK;
}
}
/* Advance row index for next row */
@@ -568,7 +565,7 @@ quantize_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
METHODDEF(void)
quantize3_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
- JSAMPARRAY output_buf, int num_rows)
+ JSAMPARRAY output_buf, int num_rows)
/* Fast path for out_color_components==3, with ordered dithering */
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
@@ -578,10 +575,10 @@ quantize3_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
JSAMPROW colorindex0 = cquantize->colorindex[0];
JSAMPROW colorindex1 = cquantize->colorindex[1];
JSAMPROW colorindex2 = cquantize->colorindex[2];
- int * dither0; /* points to active row of dither matrix */
- int * dither1;
- int * dither2;
- int row_index, col_index; /* current indexes into dither matrix */
+ int *dither0; /* points to active row of dither matrix */
+ int *dither1;
+ int *dither2;
+ int row_index, col_index; /* current indexes into dither matrix */
int row;
JDIMENSION col;
JDIMENSION width = cinfo->output_width;
@@ -597,11 +594,11 @@ quantize3_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
for (col = width; col > 0; col--) {
pixcode = GETJSAMPLE(colorindex0[GETJSAMPLE(*input_ptr++) +
- dither0[col_index]]);
+ dither0[col_index]]);
pixcode += GETJSAMPLE(colorindex1[GETJSAMPLE(*input_ptr++) +
- dither1[col_index]]);
+ dither1[col_index]]);
pixcode += GETJSAMPLE(colorindex2[GETJSAMPLE(*input_ptr++) +
- dither2[col_index]]);
+ dither2[col_index]]);
*output_ptr++ = (JSAMPLE) pixcode;
col_index = (col_index + 1) & ODITHER_MASK;
}
@@ -613,24 +610,24 @@ quantize3_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
METHODDEF(void)
quantize_fs_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
- JSAMPARRAY output_buf, int num_rows)
+ JSAMPARRAY output_buf, int num_rows)
/* General case, with Floyd-Steinberg dithering */
{
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize;
- register LOCFSERROR cur; /* current error or pixel value */
- LOCFSERROR belowerr; /* error for pixel below cur */
- LOCFSERROR bpreverr; /* error for below/prev col */
- LOCFSERROR bnexterr; /* error for below/next col */
+ register LOCFSERROR cur; /* current error or pixel value */
+ LOCFSERROR belowerr; /* error for pixel below cur */
+ LOCFSERROR bpreverr; /* error for below/prev col */
+ LOCFSERROR bnexterr; /* error for below/next col */
LOCFSERROR delta;
- register FSERRPTR errorptr; /* => fserrors[] at column before current */
+ register FSERRPTR errorptr; /* => fserrors[] at column before current */
register JSAMPROW input_ptr;
register JSAMPROW output_ptr;
JSAMPROW colorindex_ci;
JSAMPROW colormap_ci;
int pixcode;
int nc = cinfo->out_color_components;
- int dir; /* 1 for left-to-right, -1 for right-to-left */
- int dirnc; /* dir * nc */
+ int dir; /* 1 for left-to-right, -1 for right-to-left */
+ int dirnc; /* dir * nc */
int ci;
int row;
JDIMENSION col;
@@ -640,23 +637,22 @@ quantize_fs_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
for (row = 0; row < num_rows; row++) {
/* Initialize output values to 0 so can process components separately */
- jzero_far((void FAR *) output_buf[row],
- (size_t) (width * SIZEOF(JSAMPLE)));
+ jzero_far((void *) output_buf[row], (size_t) (width * sizeof(JSAMPLE)));
for (ci = 0; ci < nc; ci++) {
input_ptr = input_buf[row] + ci;
output_ptr = output_buf[row];
if (cquantize->on_odd_row) {
- /* work right to left in this row */
- input_ptr += (width-1) * nc; /* so point to rightmost pixel */
- output_ptr += width-1;
- dir = -1;
- dirnc = -nc;
- errorptr = cquantize->fserrors[ci] + (width+1); /* => entry after last column */
+ /* work right to left in this row */
+ input_ptr += (width-1) * nc; /* so point to rightmost pixel */
+ output_ptr += width-1;
+ dir = -1;
+ dirnc = -nc;
+ errorptr = cquantize->fserrors[ci] + (width+1); /* => entry after last column */
} else {
- /* work left to right in this row */
- dir = 1;
- dirnc = nc;
- errorptr = cquantize->fserrors[ci]; /* => entry before first column */
+ /* work left to right in this row */
+ dir = 1;
+ dirnc = nc;
+ errorptr = cquantize->fserrors[ci]; /* => entry before first column */
}
colorindex_ci = cquantize->colorindex[ci];
colormap_ci = cquantize->sv_colormap[ci];
@@ -666,47 +662,47 @@ quantize_fs_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf,
belowerr = bpreverr = 0;
for (col = width; col > 0; col--) {
- /* cur holds the error propagated from the previous pixel on the
- * current line. Add the error propagated from the previous line
- * to form the complete error correction term for this pixel, and
- * round the error term (which is expressed * 16) to an integer.
- * RIGHT_SHIFT rounds towards minus infinity, so adding 8 is correct
- * for either sign of the error value.
- * Note: errorptr points to *previous* column's array entry.
- */
- cur = RIGHT_SHIFT(cur + errorptr[dir] + 8, 4);
- /* Form pixel value + error, and range-limit to 0..MAXJSAMPLE.
- * The maximum error is +- MAXJSAMPLE; this sets the required size
- * of the range_limit array.
- */
- cur += GETJSAMPLE(*input_ptr);
- cur = GETJSAMPLE(range_limit[cur]);
- /* Select output value, accumulate into output code for this pixel */
- pixcode = GETJSAMPLE(colorindex_ci[cur]);
- *output_ptr += (JSAMPLE) pixcode;
- /* Compute actual representation error at this pixel */
- /* Note: we can do this even though we don't have the final */
- /* pixel code, because the colormap is orthogonal. */
- cur -= GETJSAMPLE(colormap_ci[pixcode]);
- /* Compute error fractions to be propagated to adjacent pixels.
- * Add these into the running sums, and simultaneously shift the
- * next-line error sums left by 1 column.
- */
- bnexterr = cur;
- delta = cur * 2;
- cur += delta; /* form error * 3 */
- errorptr[0] = (FSERROR) (bpreverr + cur);
- cur += delta; /* form error * 5 */
- bpreverr = belowerr + cur;
- belowerr = bnexterr;
- cur += delta; /* form error * 7 */
- /* At this point cur contains the 7/16 error value to be propagated
- * to the next pixel on the current line, and all the errors for the
- * next line have been shifted over. We are therefore ready to move on.
- */
- input_ptr += dirnc; /* advance input ptr to next column */
- output_ptr += dir; /* advance output ptr to next column */
- errorptr += dir; /* advance errorptr to current column */
+ /* cur holds the error propagated from the previous pixel on the
+ * current line. Add the error propagated from the previous line
+ * to form the complete error correction term for this pixel, and
+ * round the error term (which is expressed * 16) to an integer.
+ * RIGHT_SHIFT rounds towards minus infinity, so adding 8 is correct
+ * for either sign of the error value.
+ * Note: errorptr points to *previous* column's array entry.
+ */
+ cur = RIGHT_SHIFT(cur + errorptr[dir] + 8, 4);
+ /* Form pixel value + error, and range-limit to 0..MAXJSAMPLE.
+ * The maximum error is +- MAXJSAMPLE; this sets the required size
+ * of the range_limit array.
+ */
+ cur += GETJSAMPLE(*input_ptr);
+ cur = GETJSAMPLE(range_limit[cur]);
+ /* Select output value, accumulate into output code for this pixel */
+ pixcode = GETJSAMPLE(colorindex_ci[cur]);
+ *output_ptr += (JSAMPLE) pixcode;
+ /* Compute actual representation error at this pixel */
+ /* Note: we can do this even though we don't have the final */
+ /* pixel code, because the colormap is orthogonal. */
+ cur -= GETJSAMPLE(colormap_ci[pixcode]);
+ /* Compute error fractions to be propagated to adjacent pixels.
+ * Add these into the running sums, and simultaneously shift the
+ * next-line error sums left by 1 column.
+ */
+ bnexterr = cur;
+ delta = cur * 2;
+ cur += delta; /* form error * 3 */
+ errorptr[0] = (FSERROR) (bpreverr + cur);
+ cur += delta; /* form error * 5 */
+ bpreverr = belowerr + cur;
+ belowerr = bnexterr;
+ cur += delta; /* form error * 7 */
+ /* At this point cur contains the 7/16 error value to be propagated
+ * to the next pixel on the current line, and all the errors for the
+ * next line have been shifted over. We are therefore ready to move on.
+ */
+ input_ptr += dirnc; /* advance input ptr to next column */
+ output_ptr += dir; /* advance output ptr to next column */
+ errorptr += dir; /* advance errorptr to current column */
}
/* Post-loop cleanup: we must unload the final error value into the
* final fserrors[] entry. Note we need not unload belowerr because
@@ -730,7 +726,7 @@ alloc_fs_workspace (j_decompress_ptr cinfo)
size_t arraysize;
int i;
- arraysize = (size_t) ((cinfo->output_width + 2) * SIZEOF(FSERROR));
+ arraysize = (size_t) ((cinfo->output_width + 2) * sizeof(FSERROR));
for (i = 0; i < cinfo->out_color_components; i++) {
cquantize->fserrors[i] = (FSERRPTR)
(*cinfo->mem->alloc_large)((j_common_ptr) cinfo, JPOOL_IMAGE, arraysize);
@@ -766,7 +762,7 @@ start_pass_1_quant (j_decompress_ptr cinfo, boolean is_pre_scan)
cquantize->pub.color_quantize = quantize3_ord_dither;
else
cquantize->pub.color_quantize = quantize_ord_dither;
- cquantize->row_index = 0; /* initialize state for ordered dither */
+ cquantize->row_index = 0; /* initialize state for ordered dither */
/* If user changed to ordered dither from another mode,
* we must recreate the color index table with padding.
* This will cost extra space, but probably isn't very likely.
@@ -784,9 +780,9 @@ start_pass_1_quant (j_decompress_ptr cinfo, boolean is_pre_scan)
if (cquantize->fserrors[0] == NULL)
alloc_fs_workspace(cinfo);
/* Initialize the propagated errors to zero. */
- arraysize = (size_t) ((cinfo->output_width + 2) * SIZEOF(FSERROR));
+ arraysize = (size_t) ((cinfo->output_width + 2) * sizeof(FSERROR));
for (i = 0; i < cinfo->out_color_components; i++)
- jzero_far((void FAR *) cquantize->fserrors[i], arraysize);
+ jzero_far((void *) cquantize->fserrors[i], arraysize);
break;
default:
ERREXIT(cinfo, JERR_NOT_COMPILED);
@@ -829,13 +825,13 @@ jinit_1pass_quantizer (j_decompress_ptr cinfo)
cquantize = (my_cquantize_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- SIZEOF(my_cquantizer));
+ sizeof(my_cquantizer));
cinfo->cquantize = (struct jpeg_color_quantizer *) cquantize;
cquantize->pub.start_pass = start_pass_1_quant;
cquantize->pub.finish_pass = finish_pass_1_quant;
cquantize->pub.new_color_map = new_color_map_1_quant;
cquantize->fserrors[0] = NULL; /* Flag FS workspace not allocated */
- cquantize->odither[0] = NULL; /* Also flag odither arrays not allocated */
+ cquantize->odither[0] = NULL; /* Also flag odither arrays not allocated */
/* Make sure my internal arrays won't overflow */
if (cinfo->out_color_components > MAX_Q_COMPS)
@@ -849,10 +845,10 @@ jinit_1pass_quantizer (j_decompress_ptr cinfo)
create_colorindex(cinfo);
/* Allocate Floyd-Steinberg workspace now if requested.
- * We do this now since it is FAR storage and may affect the memory
- * manager's space calculations. If the user changes to FS dither
- * mode in a later pass, we will allocate the space then, and will
- * possibly overrun the max_memory_to_use setting.
+ * We do this now since it may affect the memory manager's space
+ * calculations. If the user changes to FS dither mode in a later pass, we
+ * will allocate the space then, and will possibly overrun the
+ * max_memory_to_use setting.
*/
if (cinfo->dither_mode == JDITHER_FS)
alloc_fs_workspace(cinfo);

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