util: add SMPTE pattern support for C2 format

Add support for drawing the SMPTE pattern in a buffer using the C2
indexed format.

As only four colors are available, resolution is halved, and the pattern
is drawn in a PenTile RG-GB matrix, using Floyd-Steinberg dithering.
The magnitude of the green subpixels is reduced, as there are twice as
many green subpixels as red or blue subpixels.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
Dithering example at https://drive.google.com/file/d/1g5O8XeacrjrC8rgaVENvR65YeI6QvmtO/view

v5:
  - Add Reviewed-by,

v4:
  - Replace FILL_COLOR() use by pentile_color_lut[],

v3:
  - Add Acked-by,

v2:
  - New.
main
Geert Uytterhoeven 2022-06-30 18:19:27 +02:00
parent 6b9b462729
commit c895650f5d
1 changed files with 99 additions and 1 deletions

View File

@ -659,6 +659,14 @@ static const struct drm_color_lut bw_color_lut[] = {
EXPAND_COLOR(255, 255, 255), /* white */
};
static const struct drm_color_lut pentile_color_lut[] = {
/* PenTile RG-GB */
EXPAND_COLOR( 0, 0, 0), /* black */
EXPAND_COLOR(255, 0, 0), /* red */
EXPAND_COLOR( 0, 207, 0), /* green */
EXPAND_COLOR( 0, 0, 255), /* blue */
};
static const struct drm_color_lut smpte_color_lut[] = {
[SMPTE_COLOR_GREY] = EXPAND_COLOR(192, 192, 192),
[SMPTE_COLOR_YELLOW] = EXPAND_COLOR(192, 192, 0),
@ -835,6 +843,92 @@ static void fill_smpte_c1(void *mem, unsigned int width, unsigned int height,
free(fsd);
}
static void write_pixel_2(uint8_t *mem, unsigned int x, unsigned int pixel)
{
unsigned int shift = 6 - 2 * (x & 3);
unsigned int mask = 3U << shift;
mem[x / 4] = (mem[x / 4] & ~mask) | ((pixel << shift) & mask);
}
static void write_color_2(struct fsd *fsd, uint8_t *mem, unsigned int stride,
unsigned int x, unsigned int index)
{
struct drm_color_lut color = smpte_color_lut[index];
unsigned int r, g, b;
fsd_dither(fsd, &color);
if (color.red >= 32768) {
r = 1;
color.red = 65535;
} else {
r = 0;
color.red = 0;
}
if (color.green >= 32768) {
g = 2;
color.green = 65535;
} else {
g = 0;
color.green = 0;
}
if (color.blue >= 32768) {
b = 3;
color.blue = 65535;
} else {
b = 0;
color.blue = 0;
}
fsd_update(fsd, &color);
/* Use PenTile RG-GB */
write_pixel_2(mem, 2 * x, r);
write_pixel_2(mem, 2 * x + 1, g);
write_pixel_2(mem + stride, 2 * x, g);
write_pixel_2(mem + stride, 2 * x + 1, b);
}
static void fill_smpte_c2(void *mem, unsigned int width, unsigned int height,
unsigned int stride)
{
struct fsd *fsd = fsd_alloc(width);
unsigned int x;
unsigned int y;
/* Half resolution for PenTile RG-GB */
width /= 2;
height /= 2;
for (y = 0; y < height * 6 / 9; ++y) {
for (x = 0; x < width; ++x)
write_color_2(fsd, mem, stride, x, smpte_top[x * 7 / width]);
mem += 2 * stride;
}
for (; y < height * 7 / 9; ++y) {
for (x = 0; x < width; ++x)
write_color_2(fsd, mem, stride, x, smpte_middle[x * 7 / width]);
mem += 2 * stride;
}
for (; y < height; ++y) {
for (x = 0; x < width * 5 / 7; ++x)
write_color_2(fsd, mem, stride, x,
smpte_bottom[x * 4 / (width * 5 / 7)]);
for (; x < width * 6 / 7; ++x)
write_color_2(fsd, mem, stride, x,
smpte_bottom[(x - width * 5 / 7) * 3 /
(width / 7) + 4]);
for (; x < width; ++x)
write_color_2(fsd, mem, stride, x, smpte_bottom[7]);
mem += 2 * stride;
}
free(fsd);
}
static void write_pixel_4(uint8_t *mem, unsigned int x, unsigned int pixel)
{
if (x & 1)
@ -916,8 +1010,10 @@ void util_smpte_fill_lut(unsigned int ncolors, struct drm_color_lut *lut)
}
memset(lut, 0, ncolors * sizeof(struct drm_color_lut));
if (ncolors < ARRAY_SIZE(smpte_color_lut))
if (ncolors < ARRAY_SIZE(pentile_color_lut))
memcpy(lut, bw_color_lut, sizeof(bw_color_lut));
else if (ncolors < ARRAY_SIZE(smpte_color_lut))
memcpy(lut, pentile_color_lut, sizeof(pentile_color_lut));
else
memcpy(lut, smpte_color_lut, sizeof(smpte_color_lut));
}
@ -931,6 +1027,8 @@ static void fill_smpte(const struct util_format_info *info, void *planes[3],
switch (info->format) {
case DRM_FORMAT_C1:
return fill_smpte_c1(planes[0], width, height, stride);
case DRM_FORMAT_C2:
return fill_smpte_c2(planes[0], width, height, stride);
case DRM_FORMAT_C4:
return fill_smpte_c4(planes[0], width, height, stride);
case DRM_FORMAT_C8: