Add support for decompressing to RGB565 (16-bit) pixels
git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1295 632fc199-4ca6-4c93-a231-07263d6284db
diff --git a/jdmerge.c b/jdmerge.c
index c669b17..b82fe47 100644
--- a/jdmerge.c
+++ b/jdmerge.c
@@ -6,6 +6,7 @@
* Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
* libjpeg-turbo Modifications:
* Copyright (C) 2009, 2011, D. R. Commander.
+ * Copyright (C) 2013, Linaro Limited.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains code for merged upsampling/color conversion.
@@ -44,6 +45,38 @@
#ifdef UPSAMPLE_MERGING_SUPPORTED
+#define PACK_SHORT_565(r, g, b) ((((r) << 8) & 0xf800) | \
+ (((g) << 3) & 0x7E0) | ((b) >> 3))
+#define PACK_TWO_PIXELS(l, r) ((r << 16) | l)
+#define PACK_NEED_ALIGNMENT(ptr) (((size_t)(ptr)) & 3)
+
+#define WRITE_TWO_PIXELS(addr, pixels) { \
+ ((INT16*)(addr))[0] = (pixels); \
+ ((INT16*)(addr))[1] = (pixels) >> 16; \
+}
+#define WRITE_TWO_ALIGNED_PIXELS(addr, pixels) ((*(INT32 *)(addr)) = pixels)
+
+#define DITHER_565_R(r, dither) ((r) + ((dither) & 0xFF))
+#define DITHER_565_G(g, dither) ((g) + (((dither) & 0xFF) >> 1))
+#define DITHER_565_B(b, dither) ((b) + ((dither) & 0xFF))
+
+
+/* Declarations for ordered dithering
+ *
+ * We use a 4x4 ordered dither array packed into 32 bits. This array is
+ * sufficent for dithering RGB888 to RGB565.
+ */
+
+#define DITHER_MASK 0x3
+#define DITHER_ROTATE(x) (((x) << 24) | (((x) >> 8) & 0x00FFFFFF))
+static const INT32 dither_matrix[4] = {
+ 0x0008020A,
+ 0x0C040E06,
+ 0x030B0109,
+ 0x0F070D05
+};
+
+
/* Private subobject */
typedef struct {
@@ -260,8 +293,11 @@
if (upsample->spare_full) {
/* If we have a spare row saved from a previous cycle, just return it. */
+ JDIMENSION size = upsample->out_row_width;
+ if (cinfo->out_color_space == JCS_RGB565)
+ size = cinfo->output_width * 2;
jcopy_sample_rows(& upsample->spare_row, 0, output_buf + *out_row_ctr, 0,
- 1, upsample->out_row_width);
+ 1, size);
num_rows = 1;
upsample->spare_full = FALSE;
} else {
@@ -416,6 +452,341 @@
}
+METHODDEF(void)
+h2v1_merged_upsample_565 (j_decompress_ptr cinfo,
+ 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;
+ int cb, cr;
+ register JSAMPROW outptr;
+ JSAMPROW inptr0, inptr1, inptr2;
+ JDIMENSION col;
+ /* copy these pointers into registers if possible */
+ register JSAMPLE * range_limit = cinfo->sample_range_limit;
+ int * Crrtab = upsample->Cr_r_tab;
+ int * Cbbtab = upsample->Cb_b_tab;
+ INT32 * Crgtab = upsample->Cr_g_tab;
+ INT32 * Cbgtab = upsample->Cb_g_tab;
+ unsigned int r, g, b;
+ INT32 rgb;
+ SHIFT_TEMPS
+
+ inptr0 = input_buf[0][in_row_group_ctr];
+ inptr1 = input_buf[1][in_row_group_ctr];
+ inptr2 = input_buf[2][in_row_group_ctr];
+ outptr = output_buf[0];
+
+ /* Loop for each pair of output pixels */
+ for (col = cinfo->output_width >> 1; col > 0; col--) {
+ /* Do the chroma part of the calculation */
+ cb = GETJSAMPLE(*inptr1++);
+ cr = GETJSAMPLE(*inptr2++);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+
+ /* Fetch 2 Y values and emit 2 pixels */
+ y = GETJSAMPLE(*inptr0++);
+ r = range_limit[y + cred];
+ g = range_limit[y + cgreen];
+ b = range_limit[y + cblue];
+ rgb = PACK_SHORT_565(r, g, b);
+
+ y = GETJSAMPLE(*inptr0++);
+ r = range_limit[y + cred];
+ g = range_limit[y + cgreen];
+ b = range_limit[y + cblue];
+ rgb = PACK_TWO_PIXELS(rgb, PACK_SHORT_565(r, g, b));
+
+ WRITE_TWO_PIXELS(outptr, rgb);
+ outptr += 4;
+ }
+
+ /* If image width is odd, do the last output column separately */
+ if (cinfo->output_width & 1) {
+ cb = GETJSAMPLE(*inptr1);
+ cr = GETJSAMPLE(*inptr2);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+ y = GETJSAMPLE(*inptr0);
+ r = range_limit[y + cred];
+ g = range_limit[y + cgreen];
+ b = range_limit[y + cblue];
+ rgb = PACK_SHORT_565(r, g, b);
+ *(INT16*)outptr = rgb;
+ }
+ }
+
+
+METHODDEF(void)
+h2v1_merged_upsample_565D (j_decompress_ptr cinfo,
+ 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;
+ int cb, cr;
+ register JSAMPROW outptr;
+ JSAMPROW inptr0, inptr1, inptr2;
+ JDIMENSION col;
+ /* copy these pointers into registers if possible */
+ register JSAMPLE * range_limit = cinfo->sample_range_limit;
+ int * Crrtab = upsample->Cr_r_tab;
+ int * Cbbtab = upsample->Cb_b_tab;
+ INT32 * Crgtab = upsample->Cr_g_tab;
+ INT32 * Cbgtab = upsample->Cb_g_tab;
+ INT32 d0 = dither_matrix[cinfo->output_scanline & DITHER_MASK];
+ unsigned int r, g, b;
+ INT32 rgb;
+ SHIFT_TEMPS
+
+ inptr0 = input_buf[0][in_row_group_ctr];
+ inptr1 = input_buf[1][in_row_group_ctr];
+ inptr2 = input_buf[2][in_row_group_ctr];
+ outptr = output_buf[0];
+
+ /* Loop for each pair of output pixels */
+ for (col = cinfo->output_width >> 1; col > 0; col--) {
+ /* Do the chroma part of the calculation */
+ cb = GETJSAMPLE(*inptr1++);
+ cr = GETJSAMPLE(*inptr2++);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+
+ /* Fetch 2 Y values and emit 2 pixels */
+ y = GETJSAMPLE(*inptr0++);
+ r = range_limit[DITHER_565_R(y + cred, d0)];
+ g = range_limit[DITHER_565_G(y + cgreen, d0)];
+ b = range_limit[DITHER_565_B(y + cblue, d0)];
+ d0 = DITHER_ROTATE(d0);
+ rgb = PACK_SHORT_565(r, g, b);
+
+ y = GETJSAMPLE(*inptr0++);
+ r = range_limit[DITHER_565_R(y + cred, d0)];
+ g = range_limit[DITHER_565_G(y + cgreen, d0)];
+ b = range_limit[DITHER_565_B(y + cblue, d0)];
+ d0 = DITHER_ROTATE(d0);
+ rgb = PACK_TWO_PIXELS(rgb, PACK_SHORT_565(r, g, b));
+
+ WRITE_TWO_PIXELS(outptr, rgb);
+ outptr += 4;
+ }
+
+ /* If image width is odd, do the last output column separately */
+ if (cinfo->output_width & 1) {
+ cb = GETJSAMPLE(*inptr1);
+ cr = GETJSAMPLE(*inptr2);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+ y = GETJSAMPLE(*inptr0);
+ r = range_limit[DITHER_565_R(y + cred, d0)];
+ g = range_limit[DITHER_565_G(y + cgreen, d0)];
+ b = range_limit[DITHER_565_B(y + cblue, d0)];
+ rgb = PACK_SHORT_565(r, g, b);
+ *(INT16*)outptr = rgb;
+ }
+}
+
+
+METHODDEF(void)
+h2v2_merged_upsample_565 (j_decompress_ptr cinfo,
+ 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;
+ int cb, cr;
+ register JSAMPROW outptr0, outptr1;
+ JSAMPROW inptr00, inptr01, inptr1, inptr2;
+ JDIMENSION col;
+ /* copy these pointers into registers if possible */
+ register JSAMPLE * range_limit = cinfo->sample_range_limit;
+ int * Crrtab = upsample->Cr_r_tab;
+ int * Cbbtab = upsample->Cb_b_tab;
+ INT32 * Crgtab = upsample->Cr_g_tab;
+ INT32 * Cbgtab = upsample->Cb_g_tab;
+ unsigned int r, g, b;
+ INT32 rgb;
+ SHIFT_TEMPS
+
+ inptr00 = input_buf[0][in_row_group_ctr * 2];
+ inptr01 = input_buf[0][in_row_group_ctr * 2 + 1];
+ inptr1 = input_buf[1][in_row_group_ctr];
+ inptr2 = input_buf[2][in_row_group_ctr];
+ outptr0 = output_buf[0];
+ outptr1 = output_buf[1];
+
+ /* Loop for each group of output pixels */
+ for (col = cinfo->output_width >> 1; col > 0; col--) {
+ /* Do the chroma part of the calculation */
+ cb = GETJSAMPLE(*inptr1++);
+ cr = GETJSAMPLE(*inptr2++);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+
+ /* Fetch 4 Y values and emit 4 pixels */
+ y = GETJSAMPLE(*inptr00++);
+ r = range_limit[y + cred];
+ g = range_limit[y + cgreen];
+ b = range_limit[y + cblue];
+ rgb = PACK_SHORT_565(r, g, b);
+
+ y = GETJSAMPLE(*inptr00++);
+ r = range_limit[y + cred];
+ g = range_limit[y + cgreen];
+ b = range_limit[y + cblue];
+ rgb = PACK_TWO_PIXELS(rgb, PACK_SHORT_565(r, g, b));
+
+ WRITE_TWO_PIXELS(outptr0, rgb);
+ outptr0 += 4;
+
+ y = GETJSAMPLE(*inptr01++);
+ r = range_limit[y + cred];
+ g = range_limit[y + cgreen];
+ b = range_limit[y + cblue];
+ rgb = PACK_SHORT_565(r, g, b);
+
+ y = GETJSAMPLE(*inptr01++);
+ r = range_limit[y + cred];
+ g = range_limit[y + cgreen];
+ b = range_limit[y + cblue];
+ rgb = PACK_TWO_PIXELS(rgb, PACK_SHORT_565(r, g, b));
+
+ WRITE_TWO_PIXELS(outptr1, rgb);
+ outptr1 += 4;
+ }
+
+ /* If image width is odd, do the last output column separately */
+ if (cinfo->output_width & 1) {
+ cb = GETJSAMPLE(*inptr1);
+ cr = GETJSAMPLE(*inptr2);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+
+ y = GETJSAMPLE(*inptr00);
+ r = range_limit[y + cred];
+ g = range_limit[y + cgreen];
+ b = range_limit[y + cblue];
+ rgb = PACK_SHORT_565(r, g, b);
+ *(INT16*)outptr0 = rgb;
+
+ y = GETJSAMPLE(*inptr01);
+ r = range_limit[y + cred];
+ g = range_limit[y + cgreen];
+ b = range_limit[y + cblue];
+ rgb = PACK_SHORT_565(r, g, b);
+ *(INT16*)outptr1 = rgb;
+ }
+}
+
+
+METHODDEF(void)
+h2v2_merged_upsample_565D (j_decompress_ptr cinfo,
+ 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;
+ int cb, cr;
+ register JSAMPROW outptr0, outptr1;
+ JSAMPROW inptr00, inptr01, inptr1, inptr2;
+ JDIMENSION col;
+ /* copy these pointers into registers if possible */
+ register JSAMPLE * range_limit = cinfo->sample_range_limit;
+ int * Crrtab = upsample->Cr_r_tab;
+ int * Cbbtab = upsample->Cb_b_tab;
+ INT32 * Crgtab = upsample->Cr_g_tab;
+ INT32 * Cbgtab = upsample->Cb_g_tab;
+ INT32 d0 = dither_matrix[cinfo->output_scanline & DITHER_MASK];
+ INT32 d1 = dither_matrix[(cinfo->output_scanline+1) & DITHER_MASK];
+ unsigned int r, g, b;
+ INT32 rgb;
+ SHIFT_TEMPS
+
+ inptr00 = input_buf[0][in_row_group_ctr*2];
+ inptr01 = input_buf[0][in_row_group_ctr*2 + 1];
+ inptr1 = input_buf[1][in_row_group_ctr];
+ inptr2 = input_buf[2][in_row_group_ctr];
+ outptr0 = output_buf[0];
+ outptr1 = output_buf[1];
+
+ /* Loop for each group of output pixels */
+ for (col = cinfo->output_width >> 1; col > 0; col--) {
+ /* Do the chroma part of the calculation */
+ cb = GETJSAMPLE(*inptr1++);
+ cr = GETJSAMPLE(*inptr2++);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+
+ /* Fetch 4 Y values and emit 4 pixels */
+ y = GETJSAMPLE(*inptr00++);
+ r = range_limit[DITHER_565_R(y + cred, d0)];
+ g = range_limit[DITHER_565_G(y + cgreen, d0)];
+ b = range_limit[DITHER_565_B(y + cblue, d0)];
+ d0 = DITHER_ROTATE(d0);
+ rgb = PACK_SHORT_565(r, g, b);
+
+ y = GETJSAMPLE(*inptr00++);
+ r = range_limit[DITHER_565_R(y + cred, d1)];
+ g = range_limit[DITHER_565_G(y + cgreen, d1)];
+ b = range_limit[DITHER_565_B(y + cblue, d1)];
+ d1 = DITHER_ROTATE(d1);
+ rgb = PACK_TWO_PIXELS(rgb, PACK_SHORT_565(r, g, b));
+
+ WRITE_TWO_PIXELS(outptr0, rgb);
+ outptr0 += 4;
+
+ y = GETJSAMPLE(*inptr01++);
+ r = range_limit[DITHER_565_R(y + cred, d0)];
+ g = range_limit[DITHER_565_G(y + cgreen, d0)];
+ b = range_limit[DITHER_565_B(y + cblue, d0)];
+ d0 = DITHER_ROTATE(d0);
+ rgb = PACK_SHORT_565(r, g, b);
+
+ y = GETJSAMPLE(*inptr01++);
+ r = range_limit[DITHER_565_R(y + cred, d1)];
+ g = range_limit[DITHER_565_G(y + cgreen, d1)];
+ b = range_limit[DITHER_565_B(y + cblue, d1)];
+ d1 = DITHER_ROTATE(d1);
+ rgb = PACK_TWO_PIXELS(rgb, PACK_SHORT_565(r, g, b));
+
+ WRITE_TWO_PIXELS(outptr1, rgb);
+ outptr1 += 4;
+ }
+
+ /* If image width is odd, do the last output column separately */
+ if (cinfo->output_width & 1) {
+ cb = GETJSAMPLE(*inptr1);
+ cr = GETJSAMPLE(*inptr2);
+ cred = Crrtab[cr];
+ cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);
+ cblue = Cbbtab[cb];
+
+ y = GETJSAMPLE(*inptr00);
+ r = range_limit[DITHER_565_R(y + cred, d0)];
+ g = range_limit[DITHER_565_G(y + cgreen, d0)];
+ b = range_limit[DITHER_565_B(y + cblue, d0)];
+ rgb = PACK_SHORT_565(r, g, b);
+ *(INT16*)outptr0 = rgb;
+
+ y = GETJSAMPLE(*inptr01);
+ r = range_limit[DITHER_565_R(y + cred, d1)];
+ g = range_limit[DITHER_565_G(y + cgreen, d1)];
+ b = range_limit[DITHER_565_B(y + cblue, d1)];
+ rgb = PACK_SHORT_565(r, g, b);
+ *(INT16*)outptr1 = rgb;
+ }
+}
+
+
/*
* Module initialization routine for merged upsampling/color conversion.
*
@@ -444,6 +815,13 @@
upsample->upmethod = jsimd_h2v2_merged_upsample;
else
upsample->upmethod = h2v2_merged_upsample;
+ if (cinfo->out_color_space == JCS_RGB565) {
+ if (cinfo->dither_mode != JDITHER_NONE) {
+ upsample->upmethod = h2v2_merged_upsample_565D;
+ } else {
+ upsample->upmethod = h2v2_merged_upsample_565;
+ }
+ }
/* Allocate a spare row buffer */
upsample->spare_row = (JSAMPROW)
(*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
@@ -454,6 +832,13 @@
upsample->upmethod = jsimd_h2v1_merged_upsample;
else
upsample->upmethod = h2v1_merged_upsample;
+ if (cinfo->out_color_space == JCS_RGB565) {
+ if (cinfo->dither_mode != JDITHER_NONE) {
+ upsample->upmethod = h2v1_merged_upsample_565D;
+ } else {
+ upsample->upmethod = h2v1_merged_upsample_565;
+ }
+ }
/* No spare row needed */
upsample->spare_row = NULL;
}