scale[0], scale[1], scale[2]);
frag_shader += buf;
- float chroma_offset_x = compute_chroma_offset(
- ycbcr_format.chroma_x_position, ycbcr_format.chroma_subsampling_x, widths[1]);
- float chroma_offset_y = compute_chroma_offset(
- ycbcr_format.chroma_y_position, ycbcr_format.chroma_subsampling_y, heights[1]);
- sprintf(buf, "const vec2 PREFIX(chroma_offset) = vec2(%.8f, %.8f);\n",
- chroma_offset_x, chroma_offset_y);
+ float cb_offset_x = compute_chroma_offset(
+ ycbcr_format.cb_x_position, ycbcr_format.chroma_subsampling_x, widths[1]);
+ float cb_offset_y = compute_chroma_offset(
+ ycbcr_format.cb_y_position, ycbcr_format.chroma_subsampling_y, heights[1]);
+ sprintf(buf, "const vec2 PREFIX(cb_offset) = vec2(%.8f, %.8f);\n",
+ cb_offset_x, cb_offset_y);
+ frag_shader += buf;
+
+ float cr_offset_x = compute_chroma_offset(
+ ycbcr_format.cr_x_position, ycbcr_format.chroma_subsampling_x, widths[2]);
+ float cr_offset_y = compute_chroma_offset(
+ ycbcr_format.cr_y_position, ycbcr_format.chroma_subsampling_y, heights[2]);
+ sprintf(buf, "const vec2 PREFIX(cr_offset) = vec2(%.8f, %.8f);\n",
+ cr_offset_x, cr_offset_y);
frag_shader += buf;
frag_shader += read_file("ycbcr_input.frag");
ycbcr_format.full_range = false;
ycbcr_format.chroma_subsampling_x = 1;
ycbcr_format.chroma_subsampling_y = 1;
- ycbcr_format.chroma_x_position = 0.5f;
- ycbcr_format.chroma_y_position = 0.5f;
+ ycbcr_format.cb_x_position = 0.5f;
+ ycbcr_format.cb_y_position = 0.5f;
+ ycbcr_format.cr_x_position = 0.5f;
+ ycbcr_format.cr_y_position = 0.5f;
YCbCrInput *input = new YCbCrInput(format, ycbcr_format, width, height);
input->set_pixel_data(0, y);
ycbcr_format.full_range = true;
ycbcr_format.chroma_subsampling_x = 1;
ycbcr_format.chroma_subsampling_y = 1;
- ycbcr_format.chroma_x_position = 0.5f;
- ycbcr_format.chroma_y_position = 0.5f;
+ ycbcr_format.cb_x_position = 0.5f;
+ ycbcr_format.cb_y_position = 0.5f;
+ ycbcr_format.cr_x_position = 0.5f;
+ ycbcr_format.cr_y_position = 0.5f;
YCbCrInput *input = new YCbCrInput(format, ycbcr_format, width, height);
input->set_pixel_data(0, y);
ycbcr_format.full_range = false;
ycbcr_format.chroma_subsampling_x = 1;
ycbcr_format.chroma_subsampling_y = 1;
- ycbcr_format.chroma_x_position = 0.5f;
- ycbcr_format.chroma_y_position = 0.5f;
+ ycbcr_format.cb_x_position = 0.5f;
+ ycbcr_format.cb_y_position = 0.5f;
+ ycbcr_format.cr_x_position = 0.5f;
+ ycbcr_format.cr_y_position = 0.5f;
YCbCrInput *input = new YCbCrInput(format, ycbcr_format, width, height);
input->set_pixel_data(0, y);
ycbcr_format.full_range = false;
ycbcr_format.chroma_subsampling_x = 2;
ycbcr_format.chroma_subsampling_y = 2;
- ycbcr_format.chroma_x_position = 0.5f;
- ycbcr_format.chroma_y_position = 0.5f;
+ ycbcr_format.cb_x_position = 0.5f;
+ ycbcr_format.cb_y_position = 0.5f;
+ ycbcr_format.cr_x_position = 0.5f;
+ ycbcr_format.cr_y_position = 0.5f;
YCbCrInput *input = new YCbCrInput(format, ycbcr_format, width, height);
input->set_pixel_data(0, y);
ycbcr_format.full_range = false;
ycbcr_format.chroma_subsampling_x = 2;
ycbcr_format.chroma_subsampling_y = 2;
- ycbcr_format.chroma_x_position = 0.0f;
- ycbcr_format.chroma_y_position = 0.5f;
+ ycbcr_format.cb_x_position = 0.0f;
+ ycbcr_format.cb_y_position = 0.5f;
+ ycbcr_format.cr_x_position = 0.0f;
+ ycbcr_format.cr_y_position = 0.5f;
YCbCrInput *input = new YCbCrInput(format, ycbcr_format, width, height);
input->set_pixel_data(0, y);
// so we need some leeway.
expect_equal(expected_data, out_data, width, height, 0.01, 0.001);
}
+
+// Yes, some 4:2:2 formats actually have this craziness.
+TEST(YCbCrInput, DifferentCbAndCrPositioning) {
+ const int width = 4;
+ const int height = 4;
+
+ unsigned char y[width * height] = {
+ 126, 126, 126, 126,
+ 126, 126, 126, 126,
+ 126, 126, 126, 126,
+ 126, 126, 126, 126,
+ };
+ unsigned char cb[(width/2) * height] = {
+ 64, 128,
+ 128, 192,
+ 128, 128,
+ 128, 128,
+ };
+ unsigned char cr[(width/2) * height] = {
+ 48, 128,
+ 128, 208,
+ 128, 128,
+ 128, 128,
+ };
+
+ // Chroma samples in this csae are always co-sited with a luma sample;
+ // their associated color values and position are marked off in comments.
+ float expected_data_blue[width * height] = {
+ 0.000 /* 0.0 */, 0.250, 0.500 /* 0.5 */, 0.500,
+ 0.500 /* 0.5 */, 0.750, 1.000 /* 1.0 */, 1.000,
+ 0.500 /* 0.5 */, 0.500, 0.500 /* 0.5 */, 0.500,
+ 0.500 /* 0.5 */, 0.500, 0.500 /* 0.5 */, 0.500,
+ };
+ float expected_data_red[width * height] = {
+ 0.000, 0.000 /* 0.0 */, 0.250, 0.500 /* 0.5 */,
+ 0.500, 0.500 /* 0.5 */, 0.750, 1.000 /* 1.0 */,
+ 0.500, 0.500 /* 0.5 */, 0.500, 0.500 /* 0.5 */,
+ 0.500, 0.500 /* 0.5 */, 0.500, 0.500 /* 0.5 */,
+ };
+ float out_data[width * height];
+
+ EffectChainTester tester(NULL, width, height);
+
+ ImageFormat format;
+ format.color_space = COLORSPACE_sRGB;
+ format.gamma_curve = GAMMA_sRGB;
+
+ YCbCrFormat ycbcr_format;
+ ycbcr_format.luma_coefficients = YCBCR_REC_601;
+ ycbcr_format.full_range = false;
+ ycbcr_format.chroma_subsampling_x = 2;
+ ycbcr_format.chroma_subsampling_y = 1;
+ ycbcr_format.cb_x_position = 0.0f;
+ ycbcr_format.cb_y_position = 0.5f;
+ ycbcr_format.cr_x_position = 1.0f;
+ ycbcr_format.cr_y_position = 0.5f;
+
+ YCbCrInput *input = new YCbCrInput(format, ycbcr_format, width, height);
+ input->set_pixel_data(0, y);
+ input->set_pixel_data(1, cb);
+ input->set_pixel_data(2, cr);
+ tester.get_chain()->add_input(input);
+
+ // Y'CbCr isn't 100% accurate (the input values are rounded),
+ // so we need some leeway.
+ tester.run(out_data, GL_RED, COLORSPACE_sRGB, GAMMA_sRGB);
+ expect_equal(expected_data_red, out_data, width, height, 0.02, 0.002);
+
+ tester.run(out_data, GL_BLUE, COLORSPACE_sRGB, GAMMA_sRGB);
+ expect_equal(expected_data_blue, out_data, width, height, 0.01, 0.001);
+}