* (ie, box filtering), we can save some work in color conversion by
* calculating all the output pixels corresponding to a pair of chroma
* samples at one time. In the conversion equations
- * R = Y + K1 * Cr
- * G = Y + K2 * Cb + K3 * Cr
- * B = Y + K4 * Cb
+ * R = Y + K1 * Cr
+ * G = Y + K2 * Cb + K3 * Cr
+ * B = Y + K4 * Cb
* only the Y term varies among the group of pixels corresponding to a pair
* of chroma samples, so the rest of the terms can be calculated just once.
* At typical sampling ratios, this eliminates half or three-quarters of the
* multiplications needed for color conversion.
*
* This file currently provides implementations for the following cases:
- * YCbCr => RGB color conversion only.
- * Sampling ratios of 2h1v or 2h2v.
- * No scaling needed at upsample time.
- * Corner-aligned (non-CCIR601) sampling alignment.
+ * YCbCr => RGB color conversion only.
+ * Sampling ratios of 2h1v or 2h2v.
+ * No scaling needed at upsample time.
+ * Corner-aligned (non-CCIR601) sampling alignment.
* Other special cases could be added, but in most applications these are
* the only common cases. (For uncommon cases we fall back on the more
* general code in jdsample.c and jdcolor.c.)
/* Private subobject */
typedef struct {
- struct jpeg_upsampler pub; /* public fields */
+ struct jpeg_upsampler pub; /* public fields */
/* Pointer to routine to do actual upsampling/conversion of one row group */
JMETHOD(void, upmethod, (j_decompress_ptr cinfo,
- JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
- JSAMPARRAY output_buf));
+ JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
+ JSAMPARRAY output_buf));
/* Private state for YCC->RGB conversion */
- int * Cr_r_tab; /* => table for Cr to R conversion */
- int * Cb_b_tab; /* => table for Cb to B conversion */
- INT32 * Cr_g_tab; /* => table for Cr to G conversion */
- INT32 * Cb_g_tab; /* => table for Cb to G conversion */
+ int * Cr_r_tab; /* => table for Cr to R conversion */
+ int * Cb_b_tab; /* => table for Cb to B conversion */
+ INT32 * Cr_g_tab; /* => table for Cr to G conversion */
+ INT32 * Cb_g_tab; /* => table for Cb to G conversion */
/* For 2:1 vertical sampling, we produce two output rows at a time.
* We need a "spare" row buffer to hold the second output row if the
* to discard the dummy last row if the image height is odd.
*/
JSAMPROW spare_row;
- boolean spare_full; /* T if spare buffer is occupied */
+ boolean spare_full; /* T if spare buffer is occupied */
- JDIMENSION out_row_width; /* samples per output row */
- JDIMENSION rows_to_go; /* counts rows remaining in image */
+ JDIMENSION out_row_width; /* samples per output row */
+ JDIMENSION rows_to_go; /* counts rows remaining in image */
} my_upsampler;
typedef my_upsampler * my_upsample_ptr;
-#define SCALEBITS 16 /* speediest right-shift on some machines */
-#define ONE_HALF ((INT32) 1 << (SCALEBITS-1))
-#define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
+#define SCALEBITS 16 /* speediest right-shift on some machines */
+#define ONE_HALF ((INT32) 1 << (SCALEBITS-1))
+#define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
/*
upsample->Cr_r_tab = (int *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- (MAXJSAMPLE+1) * SIZEOF(int));
+ (MAXJSAMPLE+1) * SIZEOF(int));
upsample->Cb_b_tab = (int *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- (MAXJSAMPLE+1) * SIZEOF(int));
+ (MAXJSAMPLE+1) * SIZEOF(int));
upsample->Cr_g_tab = (INT32 *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- (MAXJSAMPLE+1) * SIZEOF(INT32));
+ (MAXJSAMPLE+1) * SIZEOF(INT32));
upsample->Cb_g_tab = (INT32 *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- (MAXJSAMPLE+1) * SIZEOF(INT32));
+ (MAXJSAMPLE+1) * SIZEOF(INT32));
for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {
/* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
/* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
/* Cr=>R value is nearest int to 1.40200 * x */
upsample->Cr_r_tab[i] = (int)
- RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);
+ RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);
/* Cb=>B value is nearest int to 1.77200 * x */
upsample->Cb_b_tab[i] = (int)
- RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);
+ RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);
/* Cr=>G value is scaled-up -0.71414 * x */
upsample->Cr_g_tab[i] = (- FIX(0.71414)) * x;
/* Cb=>G value is scaled-up -0.34414 * x */
METHODDEF(void)
merged_2v_upsample (j_decompress_ptr cinfo,
- JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
- JDIMENSION in_row_groups_avail,
- JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
- JDIMENSION out_rows_avail)
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
/* 2:1 vertical sampling case: may need a spare row. */
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
JSAMPROW work_ptrs[2];
- JDIMENSION num_rows; /* number of rows returned to caller */
+ JDIMENSION num_rows; /* number of rows returned to caller */
+
+ in_row_groups_avail = 0;
if (upsample->spare_full) {
/* If we have a spare row saved from a previous cycle, just return it. */
jcopy_sample_rows(& upsample->spare_row, 0, output_buf + *out_row_ctr, 0,
- 1, upsample->out_row_width);
+ 1, upsample->out_row_width);
num_rows = 1;
upsample->spare_full = FALSE;
} else {
METHODDEF(void)
merged_1v_upsample (j_decompress_ptr cinfo,
- JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
- JDIMENSION in_row_groups_avail,
- JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
- JDIMENSION out_rows_avail)
+ JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
+ JDIMENSION in_row_groups_avail,
+ JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
+ JDIMENSION out_rows_avail)
/* 1:1 vertical sampling case: much easier, never need a spare row. */
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
+ in_row_groups_avail = 0;
+ out_rows_avail = 0;
+
/* Just do the upsampling. */
(*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr,
- output_buf + *out_row_ctr);
+ output_buf + *out_row_ctr);
/* Adjust counts */
(*out_row_ctr)++;
(*in_row_group_ctr)++;
METHODDEF(void)
h2v1_merged_upsample (j_decompress_ptr cinfo,
- JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
- JSAMPARRAY output_buf)
+ JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
+ JSAMPARRAY output_buf)
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
register int y, cred, cgreen, cblue;
METHODDEF(void)
h2v2_merged_upsample (j_decompress_ptr cinfo,
- JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
- JSAMPARRAY output_buf)
+ JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
+ JSAMPARRAY output_buf)
{
my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
register int y, cred, cgreen, cblue;
upsample = (my_upsample_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- SIZEOF(my_upsampler));
+ SIZEOF(my_upsampler));
cinfo->upsample = (struct jpeg_upsampler *) upsample;
upsample->pub.start_pass = start_pass_merged_upsample;
upsample->pub.need_context_rows = FALSE;
/* Allocate a spare row buffer */
upsample->spare_row = (JSAMPROW)
(*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- (size_t) (upsample->out_row_width * SIZEOF(JSAMPLE)));
+ (size_t) (upsample->out_row_width * SIZEOF(JSAMPLE)));
} else {
upsample->pub.upsample = merged_1v_upsample;
upsample->upmethod = h2v1_merged_upsample;
git://git.creatis.insa-lyon.fr / gdcm.git / blobdiff