[libcamera-devel] [PATCH v4 1/1] gstreamer: Provide mulitple colorimetry support

[Rishikesh Donadkar]

Iterate over each GValue in the colorimetry list,
retrieve the colorimetry string, convert to colorspace using the
function colorspace_from_colorimetry() and validate the camera configuration.
Retrieve the colorspace after validation, convert to colorimetry and
check if the it is same as the colorimetry requested.

If none of the colorimetry requested is supported by the camera (i.e. not
the same after validation) then set the stream_cfg to the previous
configuration that was present before trying new colorimetry.

Signed-off-by: Rishikesh Donadkar <rishikeshdonadkar at gmail.com>
Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
---
 src/gstreamer/gstlibcamera-utils.cpp | 75 +++++++++++++++++++++-------
 src/gstreamer/gstlibcamera-utils.h   |  4 +-
 src/gstreamer/gstlibcamerasrc.cpp    |  2 +-
 3 files changed, 62 insertions(+), 19 deletions(-)

diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp
index d895a67d..2a88444c 100644
--- a/src/gstreamer/gstlibcamera-utils.cpp
+++ b/src/gstreamer/gstlibcamera-utils.cpp
@@ -302,13 +302,39 @@ gst_libcamera_stream_configuration_to_caps(const StreamConfiguration &stream_cfg
 	return caps;
 }
 
+static int
+configure_colorspace_from_caps(StreamConfiguration &stream_cfg,
+			       const gchar *colorimetry_str)
+{
+	gint colorimetry_valid = 1, colorimetry_invalid = 0;
+	if (colorimetry_str) {
+		GstVideoColorimetry colorimetry;
+
+		if (!gst_video_colorimetry_from_string(&colorimetry, colorimetry_str)) {
+			g_critical("Invalid colorimetry %s", colorimetry_str);
+			return colorimetry_invalid;
+		}
+
+		stream_cfg.colorSpace = colorspace_from_colorimetry(colorimetry);
+		/* Check if colorimetry had any identifiers which did not map */
+		if (colorimetry.primaries != GST_VIDEO_COLOR_PRIMARIES_UNKNOWN &&
+		    stream_cfg.colorSpace == ColorSpace::Raw) {
+			GST_ERROR("One or more identifiers could not be mapped for %s colorimetry",
+				  colorimetry_str);
+			stream_cfg.colorSpace = std::nullopt;
+		}
+	}
+	return colorimetry_valid;
+}
+
 void
-gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg,
+gst_libcamera_configure_stream_from_caps(std::unique_ptr<CameraConfiguration> &cam_cfg,
+					 StreamConfiguration &stream_cfg,
 					 GstCaps *caps)
 {
 	GstVideoFormat gst_format = pixel_format_to_gst_format(stream_cfg.pixelFormat);
 	guint i;
-	gint best_fixed = -1, best_in_range = -1;
+	gint best_fixed = -1, best_in_range = -1, ret;
 	GstStructure *s;
 
 	/*
@@ -381,23 +407,38 @@ gst_libcamera_configure_stream_from_caps(StreamConfiguration &stream_cfg,
 	stream_cfg.size.width = width;
 	stream_cfg.size.height = height;
 
-	/* Configure colorimetry */
-	if (gst_structure_has_field(s, "colorimetry")) {
-		const gchar *colorimetry_str = gst_structure_get_string(s, "colorimetry");
-		GstVideoColorimetry colorimetry;
-
-		if (!gst_video_colorimetry_from_string(&colorimetry, colorimetry_str))
-			g_critical("Invalid colorimetry %s", colorimetry_str);
-
-		stream_cfg.colorSpace = colorspace_from_colorimetry(colorimetry);
-		/* Check if colorimetry had any identifiers which did not map */
-		if (colorimetry.primaries != GST_VIDEO_COLOR_PRIMARIES_UNKNOWN &&
-		    stream_cfg.colorSpace == ColorSpace::Raw) {
-			GST_ERROR("One or more identifiers could not be mapped for %s colorimetry",
-				  colorimetry_str);
-			stream_cfg.colorSpace = std::nullopt;
+	const GValue *colorimetry = gst_structure_get_value(s, "colorimetry");
+	if (!colorimetry)
+		return;
+
+	/* Configure Colorimetry */
+	if (GST_VALUE_HOLDS_LIST(colorimetry)) {
+		StreamConfiguration pristine_stream_cfg = stream_cfg;
+		for (i = 0; i < gst_value_list_get_size(colorimetry); i++) {
+			const GValue *val = gst_value_list_get_value(colorimetry, i);
+			GstVideoColorimetry colorimetry_old, colorimetry_new;
+
+			ret = configure_colorspace_from_caps(stream_cfg, g_value_get_string(val));
+			if (!ret)
+				continue;
+
+			colorimetry_old = colorimetry_from_colorspace(stream_cfg.colorSpace.value());
+
+			/* Validate the configuration and check if the requested
+			 * colorimetry can be applied to the sensor.
+			 */
+			if (cam_cfg->validate() != CameraConfiguration::Invalid) {
+				colorimetry_new = colorimetry_from_colorspace(stream_cfg.colorSpace.value());
+				if (gst_video_colorimetry_is_equal(&colorimetry_old, &colorimetry_new)) {
+					g_print("Selected colorimetry %s\n", gst_video_colorimetry_to_string(&colorimetry_new));
+					break;
+				} else
+					stream_cfg = pristine_stream_cfg;
+			}
 		}
 	}
+	if (G_VALUE_TYPE(colorimetry) == G_TYPE_STRING)
+		configure_colorspace_from_caps(stream_cfg, g_value_get_string(colorimetry));
 }
 
 #if !GST_CHECK_VERSION(1, 17, 1)
diff --git a/src/gstreamer/gstlibcamera-utils.h b/src/gstreamer/gstlibcamera-utils.h
index 164189a2..7afad576 100644
--- a/src/gstreamer/gstlibcamera-utils.h
+++ b/src/gstreamer/gstlibcamera-utils.h
@@ -8,6 +8,7 @@
 
 #pragma once
 
+#include <libcamera/camera.h>
 #include <libcamera/camera_manager.h>
 #include <libcamera/stream.h>
 
@@ -16,7 +17,8 @@
 
 GstCaps *gst_libcamera_stream_formats_to_caps(const libcamera::StreamFormats &formats);
 GstCaps *gst_libcamera_stream_configuration_to_caps(const libcamera::StreamConfiguration &stream_cfg);
-void gst_libcamera_configure_stream_from_caps(libcamera::StreamConfiguration &stream_cfg,
+void gst_libcamera_configure_stream_from_caps(std::unique_ptr<libcamera::CameraConfiguration> &cam_cfg,
+					      libcamera::StreamConfiguration &stream_cfg,
 					      GstCaps *caps);
 #if !GST_CHECK_VERSION(1, 17, 1)
 gboolean gst_task_resume(GstTask *task);
diff --git a/src/gstreamer/gstlibcamerasrc.cpp b/src/gstreamer/gstlibcamerasrc.cpp
index 16d70fea..25059914 100644
--- a/src/gstreamer/gstlibcamerasrc.cpp
+++ b/src/gstreamer/gstlibcamerasrc.cpp
@@ -503,7 +503,7 @@ gst_libcamera_src_task_enter(GstTask *task, [[maybe_unused]] GThread *thread,
 
 		/* Fixate caps and configure the stream. */
 		caps = gst_caps_make_writable(caps);
-		gst_libcamera_configure_stream_from_caps(stream_cfg, caps);
+		gst_libcamera_configure_stream_from_caps(state->config_, stream_cfg, caps);
 	}
 
 	if (flow_ret != GST_FLOW_OK)
-- 
2.25.1