OsmoTV: Generate correct amplitude of color signal (hopefully)

src/tv/bas.c

@@ -49,7 +49,7 @@
 #define H_CBURST_STOP	0.0000094
 #define COLOR_CARRIER	4433618.75
 #define COLOR_OFFSET	0.0000004
-#define BURST_AMPLITUDE	0.15
+#define BURST_AMPLITUDE	0.3
 #define COLOR_FILTER_ITER 1
 
 void bas_init(bas_t *bas, double samplerate, enum bas_type type, int fbas, double circle_radius, int color_bar, int grid_only, const char *station_id, int grid_width, unsigned short *img, int width, int height)
@@ -88,7 +88,7 @@ int bas_generate(bas_t *bas, sample_t *sample)
 	int have_image;
 	sample_t color_u[(int)(bas->samplerate / 15625.0) + 10];
 	sample_t color_v[(int)(bas->samplerate / 15625.0) + 10];
-	double _sin, _cos;
+	double _sin, _cos, chroma;
 	double color_step = COLOR_CARRIER / bas->samplerate * 2 * M_PI;
 	/* the offset is specified by delaying Y signal by 0.4 uS. */
 // additianlly we compensate the delay caused by the color filter, that is 2 samples per iteration */
@@ -275,9 +275,9 @@ int bas_generate(bas_t *bas, sample_t *sample)
 					bas->color_phase -= 2.0 * M_PI;
 				_sin = sin(bas->color_phase);
 				_cos = cos(bas->color_phase);
-				sample[c-color_offset] += color_u[c] * _cos - color_v[c] * _sin;
-				sample[c-color_offset] += color_u[c] * _sin + color_v[c] * _cos;
-	//			puts(debug_amplitude(sample[c-color_offset]));
+				chroma = color_u[c] * _cos - color_v[c] * _sin;
+				/* scale level of chroma to range of BAS signal */
+				sample[c-color_offset] += chroma * (WHITE_LEVEL - BLACK_LEVEL);
 			}
 
 			/* filter bas signal */

src/tv/color.c

@@ -60,8 +60,8 @@ int color_gen_line(sample_t *sample, double x, double samplerate, sample_t *colo
 		colorphase = (360.0 - color_bar[b].phase) / 180.0 * M_PI;
 	else
 		colorphase = color_bar[b].phase / 180.0 * M_PI;
-	U = cos(colorphase) * amplitude / 2.0;
-	V = sin(colorphase) * amplitude / 2.0;
+	U = cos(colorphase) * amplitude;
+	V = sin(colorphase) * amplitude;
 	while (x < line_end) {
 		color_u[i] = U;
 		color_v[i] = V;

src/tv/ebu.c

@@ -61,8 +61,8 @@ int ebu_gen_line(sample_t *sample, double x, double samplerate, sample_t *color_
 			colorphase = (360.0 - color_bar[b].phase) / 180.0 * M_PI;
 		else
 			colorphase = color_bar[b].phase / 180.0 * M_PI;
-		U = cos(colorphase) * amplitude / 2.0;
-		V = sin(colorphase) * amplitude / 2.0;
+		U = cos(colorphase) * amplitude;
+		V = sin(colorphase) * amplitude;
 		render_end = (line_end - line_start) / 8 * (b + 1) + line_start;
 		while (x < render_end) {
 			color_u[i] = U;

src/tv/fubk.c

@@ -101,8 +101,8 @@ static double mittelfeld(sample_t *sample, double samplerate, int *_i, double *_
 				colorphase = (360.0 - color_bar[b].phase) / 180.0 * M_PI;
 			else
 				colorphase = color_bar[b].phase / 180.0 * M_PI;
-			U = cos(colorphase) * amplitude / 2.0;
-			V = sin(colorphase) * amplitude / 2.0;
+			U = cos(colorphase) * amplitude;
+			V = sin(colorphase) * amplitude;
 			render_end = render_start + GRID_WIDTH * 1.5;
 			while (x < render_end) {
 				color_u[i] = U;
@@ -223,8 +223,8 @@ static double mittelfeld(sample_t *sample, double samplerate, int *_i, double *_
 					colorphase = (360.0 - 145.9) / 180.0 * M_PI;
 				else
 					colorphase = 145.9 / 180.0 * M_PI;
-				color_u[i] = cos(colorphase) * V / 2.0;
-				color_v[i] = sin(colorphase) * V / 2.0;
+				color_u[i] = cos(colorphase) * V;
+				color_v[i] = sin(colorphase) * V;
 				sample[i++] = Y + sin(phase) / 2.0;
 				phase += phase_step;
 				x += step;