Read out analog balance and write to TIFF

Currently has an issue in the kernel driver where it doesn't return
the values after disabling autobalance.

src/io_pipeline.c

@@ -34,7 +34,9 @@ struct camera_info {
 
 	bool has_auto_focus_continuous;
 	bool has_auto_focus_start;
-
+	
+	bool has_whitebalance;
+	bool has_redbluebalance;
 	// unsigned int entity_id;
 	// enum v4l2_buf_type type;
 
@@ -85,6 +87,10 @@ struct control_state {
 
 	bool exposure_is_manual;
 	int exposure;
+
+	bool wb_is_manual;
+	int red_balance;
+	int blue_balance;
 };
 
 static struct control_state desired_controls = {};
@@ -216,6 +222,13 @@ setup_camera(MPDeviceList **device_list, const struct mp_camera_config *config)
 			info->gain_ctrl = V4L2_CID_ANALOGUE_GAIN;
 			info->gain_max = control.max;
 		}
+
+		if (mp_camera_query_control(info->camera, V4L2_CID_AUTO_WHITE_BALANCE, NULL)) {
+			info->has_whitebalance = true;
+		}
+		if (mp_camera_query_control(info->camera, V4L2_CID_RED_BALANCE, NULL)) {
+			info->has_redbluebalance = true;
+		}
 	}
 }
 
@@ -272,6 +285,12 @@ update_process_pipeline()
 		current_controls.exposure =
 			mp_camera_control_get_int32(info->camera, V4L2_CID_EXPOSURE);
 	}
+	if (!current_controls.wb_is_manual) {
+		current_controls.red_balance = 
+			mp_camera_control_get_int32(info->camera, V4L2_CID_RED_BALANCE);
+		current_controls.blue_balance = 
+			mp_camera_control_get_int32(info->camera, V4L2_CID_BLUE_BALANCE);
+	}
 
 	struct mp_process_pipeline_state pipeline_state = {
 		.camera = camera,
@@ -286,6 +305,9 @@ update_process_pipeline()
 		.gain_max = info->gain_max,
 		.exposure_is_manual = current_controls.exposure_is_manual,
 		.exposure = current_controls.exposure,
+		.wb_is_manual = current_controls.wb_is_manual,
+		.red_balance = current_controls.red_balance,
+		.blue_balance = current_controls.blue_balance,
 		.has_auto_focus_continuous = info->has_auto_focus_continuous,
 		.has_auto_focus_start = info->has_auto_focus_start,
 	};
@@ -311,10 +333,13 @@ capture(MPPipeline *pipeline, const void *data)
 
 	captures_remaining = burst_length;
 
-	// Disable the autogain/exposure while taking the burst
+	// Disable the autogain/exposure/wb while taking the burst
 	mp_camera_control_set_int32(info->camera, V4L2_CID_AUTOGAIN, 0);
 	mp_camera_control_set_int32(info->camera, V4L2_CID_EXPOSURE_AUTO,
 				    V4L2_EXPOSURE_MANUAL);
+	if (info->has_whitebalance) {
+		mp_camera_control_set_int32(info->camera, V4L2_CID_AUTO_WHITE_BALANCE, 0);
+	}
 
 	// Change camera mode for capturing
 	mp_process_pipeline_sync();
@@ -454,6 +479,11 @@ on_frame(MPBuffer buffer, void * _data)
 							   V4L2_CID_AUTOGAIN, true);
 			}
 
+			if (!current_controls.wb_is_manual) {
+				mp_camera_control_set_bool(info->camera,
+							   V4L2_CID_AUTO_WHITE_BALANCE, true);
+			}
+
 			// Go back to preview mode
 			mp_process_pipeline_sync();
 			mp_camera_stop_capture(info->camera);
@@ -522,6 +552,9 @@ update_state(MPPipeline *pipeline, const struct mp_io_pipeline_state *state)
 				V4L2_EXPOSURE_MANUAL;
 			current_controls.exposure = mp_camera_control_get_int32(
 				info->camera, V4L2_CID_EXPOSURE);
+			current_controls.wb_is_manual =
+				mp_camera_control_get_bool(info->camera,
+							   V4L2_CID_AUTO_WHITE_BALANCE) == 0;
 		}
 	}
 
@@ -543,6 +576,7 @@ update_state(MPPipeline *pipeline, const struct mp_io_pipeline_state *state)
 		desired_controls.gain = state->gain;
 		desired_controls.exposure_is_manual = state->exposure_is_manual;
 		desired_controls.exposure = state->exposure;
+		desired_controls.wb_is_manual = state->wb_is_manual;
 
 		has_changed =
 			has_changed || memcmp(&previous_desired, &desired_controls,

src/io_pipeline.h

@@ -18,6 +18,8 @@ struct mp_io_pipeline_state {
 	bool exposure_is_manual;
 	int exposure;
 
+	bool wb_is_manual;
+
 	bool save_dng;
 };
 

src/main.c

@@ -46,6 +46,8 @@ static bool gain_is_manual = false;
 static int gain;
 static int gain_max;
 
+static bool wb_is_manual = false;
+
 static bool exposure_is_manual = false;
 static int exposure;
 
@@ -105,6 +107,7 @@ update_io_pipeline()
 		.gain = gain,
 		.exposure_is_manual = exposure_is_manual,
 		.exposure = exposure,
+		.wb_is_manual = wb_is_manual,
 		.save_dng = gtk_check_button_get_active(GTK_CHECK_BUTTON(setting_dng)),
 	};
 	mp_io_pipeline_update_state(&io_state);

src/process_pipeline.c

@@ -51,6 +51,10 @@ static int gain_max;
 static bool exposure_is_manual;
 static int exposure;
 
+static bool wb_is_manual;
+static int red_balance;
+static int blue_balance;
+
 static bool save_dng;
 
 static char capture_fname[255];
@@ -397,9 +401,13 @@ process_image_for_capture(const uint8_t *image, int count)
 	if (camera->forwardmatrix[0]) {
 		TIFFSetField(tif, TIFFTAG_FORWARDMATRIX1, 9, camera->forwardmatrix);
 	}
-	static const float neutral[] = { 1.0, 1.0, 1.0 };
-	TIFFSetField(tif, TIFFTAG_ASSHOTNEUTRAL, 3, neutral);
+	//static const float neutral[] = { 1.0, 1.0, 1.0 };
+	//TIFFSetField(tif, TIFFTAG_ASSHOTNEUTRAL, 3, neutral);
 	TIFFSetField(tif, TIFFTAG_CALIBRATIONILLUMINANT1, 21);
+
+	static const float ab[] = {red_balance/4096, 1.0, blue_balance/4096};
+	TIFFSetField(tif, TIFFTAG_ANALOGBALANCE, 3, ab);
+
 	// Write black thumbnail, only windows uses this
 	{
 		unsigned char *buf =
@@ -723,6 +731,10 @@ update_state(MPPipeline *pipeline, const struct mp_process_pipeline_state *state
 	exposure_is_manual = state->exposure_is_manual;
 	exposure = state->exposure;
 
+	wb_is_manual = state->wb_is_manual;
+	red_balance = state->red_balance;
+	blue_balance = state->blue_balance;
+
 	if (output_changed) {
 		camera_rotation = mod(camera->rotate - device_rotation, 360);
 

src/process_pipeline.h

@@ -25,6 +25,10 @@ struct mp_process_pipeline_state {
 	bool has_auto_focus_continuous;
 	bool has_auto_focus_start;
 
+	bool wb_is_manual;
+	int red_balance;
+	int blue_balance;
+
 	bool save_dng;
 };