gstreamer: Fix width and height range handling

This changes is fixing critical error message
"gst_value_set_int_range_step: assertion 'start < end' failed" observed
when building GStreamer caps from a stream configuration whose size
range holds a single size.

GStreamer range step definition requires distinct min and max values
definitions, otherwise above error message is output.

libcamera SizeRange instance may return a single size leading to
identical min and max values. Add a conditional check where the min and
max of the range are distinct during iterating the supported sizes for
each pixelformat.

To prevent appending structures that are already expressed with this
update, gst_caps_merge_structure() is used in place of
gst_caps_append_structure().

Signed-off-by: Hou Qi <qi.hou@nxp.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Acked-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 13 insertions, 5 deletions

diff --git a/src/gstreamer/gstlibcamera-utils.cpp b/src/gstreamer/gstlibcamera-utils.cpp
index ec4da435..79f71246 100644
--- a/src/gstreamer/gstlibcamera-utils.cpp
+++ b/src/gstreamer/gstlibcamera-utils.cpp
@@ -359,13 +359,21 @@ gst_libcamera_stream_formats_to_caps(const StreamFormats &formats)
 			GValue val = G_VALUE_INIT;
 
 			g_value_init(&val, GST_TYPE_INT_RANGE);
-			gst_value_set_int_range_step(&val, range.min.width, range.max.width, range.hStep);
-			gst_structure_set_value(s, "width", &val);
-			gst_value_set_int_range_step(&val, range.min.height, range.max.height, range.vStep);
-			gst_structure_set_value(s, "height", &val);
+			if (range.min.width == range.max.width) {
+				gst_structure_set(s, "width", G_TYPE_INT, range.min.width, nullptr);
+			} else {
+				gst_value_set_int_range_step(&val, range.min.width, range.max.width, range.hStep);
+				gst_structure_set_value(s, "width", &val);
+			}
+			if (range.min.height == range.max.height) {
+				gst_structure_set(s, "height", G_TYPE_INT, range.min.height, nullptr);
+			} else {
+				gst_value_set_int_range_step(&val, range.min.height, range.max.height, range.vStep);
+				gst_structure_set_value(s, "height", &val);
+			}
 			g_value_unset(&val);
 
-			gst_caps_append_structure(caps, s);
+			caps = gst_caps_merge_structure(caps, s);
 		}
 	}