samples: video: capture: add crop/compose support

Demonstrate the crop/compose API by introducing 4 new
CONFIG options in order to define the crop area.
Moreover, if the selection API is available and if
the targetted size is different from the current crop
size, then try to apply a compose in order to reach
the targetted format size.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>

Author: Alain Volmat

samples/drivers/video/capture/Kconfig

@@ -5,6 +5,32 @@ mainmenu "Video capture sample application"
 
 menu "Video capture configuration"
 
+config VIDEO_SOURCE_CROP_LEFT
+	int "Crop area left value"
+	default 0
+	help
+	   Left value of the crop area within the video source.
+
+config VIDEO_SOURCE_CROP_TOP
+	int "Crop area top value"
+	default 0
+	help
+	   Top value of the crop area within the video source.
+
+config VIDEO_SOURCE_CROP_WIDTH
+	int "Crop area width value"
+	default 0
+	help
+	   Width value of the crop area within the video source.
+	   If set to 0, the crop is not applied.
+
+config VIDEO_SOURCE_CROP_HEIGHT
+	int "Crop area height value"
+	default 0
+	help
+	   Height value of the crop area within the video source.
+	   If set to 0, the crop is not applied.
+
 config VIDEO_FRAME_HEIGHT
 	int "Height of the video frame"
 	default 0

samples/drivers/video/capture/src/main.c

@@ -95,7 +95,11 @@ int main(void)
 	struct video_frmival frmival;
 	struct video_frmival_enum fie;
 	enum video_buf_type type = VIDEO_BUF_TYPE_OUTPUT;
+	struct video_selection sel = {
+		.type = VIDEO_BUF_TYPE_OUTPUT,
+	};
 	unsigned int frame = 0;
+	uint32_t frame_width, frame_height;
 	size_t bsize;
 	int i = 0;
 	int err;
@@ -139,6 +143,26 @@ int main(void)
 		return 0;
 	}
 
+	/* Set the crop setting if necessary */
+#if CONFIG_VIDEO_SOURCE_CROP_WIDTH && CONFIG_VIDEO_SOURCE_CROP_HEIGHT
+	sel.target = VIDEO_SEL_TGT_CROP;
+	sel.rect.left = CONFIG_VIDEO_SOURCE_CROP_LEFT;
+	sel.rect.top = CONFIG_VIDEO_SOURCE_CROP_TOP;
+	sel.rect.width = CONFIG_VIDEO_SOURCE_CROP_WIDTH;
+	sel.rect.height = CONFIG_VIDEO_SOURCE_CROP_HEIGHT;
+	if (video_set_selection(video_dev, &sel)) {
+		LOG_ERR("Unable to set selection crop");
+		return 0;
+	}
+	LOG_INF("Selection crop set to (%u,%u)/%ux%u",
+		sel.rect.left, sel.rect.top,
+		sel.rect.width, sel.rect.height);
+#endif
+
+	frame_height = fmt.height;
+	frame_width = fmt.width;
+
+#if CONFIG_VIDEO_FRAME_HEIGHT || CONFIG_VIDEO_FRAME_WIDTH
 #if CONFIG_VIDEO_FRAME_HEIGHT
 	fmt.height = CONFIG_VIDEO_FRAME_HEIGHT;
 #endif
@@ -147,6 +171,31 @@ int main(void)
 	fmt.width = CONFIG_VIDEO_FRAME_WIDTH;
 #endif
 
+	/*
+	 * Check (if possible) if targeted size if same as crop
+	 * and if compose is necessary
+	 */
+	sel.target = VIDEO_SEL_TGT_CROP;
+	err = video_get_selection(video_dev, &sel);
+	if (err == 0) {
+		if (sel.rect.width != fmt.width || sel.rect.height != fmt.height) {
+			sel.target = VIDEO_SEL_TGT_COMPOSE;
+			sel.rect.left = 0;
+			sel.rect.top = 0;
+			sel.rect.width = fmt.width;
+			sel.rect.height = fmt.height;
+			err = video_set_selection(video_dev, &sel);
+			if (err != -ENOSYS && err < 0) {
+				LOG_ERR("Unable to set selection compose");
+				return 0;
+			}
+		}
+	} else if (err != -ENOSYS && err < 0) {
+		LOG_ERR("Unable to get selection crop");
+		return 0;
+	}
+#endif
+
 	if (strcmp(CONFIG_VIDEO_PIXEL_FORMAT, "")) {
 		fmt.pixelformat = VIDEO_FOURCC_FROM_STR(CONFIG_VIDEO_PIXEL_FORMAT);
 	}