Save detect dimensions to config on add camera wizard save (#22349)

* add util for optimal detect resolution

* add detect to type

* save optimal detect resolution to config on wizard save

* use const

web/src/components/settings/CameraWizardDialog.tsx

@@ -20,7 +20,10 @@ import type {
   CameraConfigData,
   ConfigSetBody,
 } from "@/types/cameraWizard";
-import { processCameraName } from "@/utils/cameraUtil";
+import {
+  processCameraName,
+  calculateDetectDimensions,
+} from "@/utils/cameraUtil";
 import { cn } from "@/lib/utils";
 
 type WizardState = {
@@ -203,6 +206,25 @@ export default function CameraWizardDialog({
         },
       };
 
+      // Calculate detect dimensions from the detect stream's probed resolution
+      const detectStream = wizardData.streams.find((stream) =>
+        stream.roles.includes("detect"),
+      );
+      if (detectStream?.testResult?.resolution) {
+        const [streamWidth, streamHeight] = detectStream.testResult.resolution
+          .split("x")
+          .map(Number);
+        if (streamWidth > 0 && streamHeight > 0) {
+          const detectDimensions = calculateDetectDimensions(
+            streamWidth,
+            streamHeight,
+          );
+          if (detectDimensions) {
+            configData.cameras[finalCameraName].detect = detectDimensions;
+          }
+        }
+      }
+
       // Add live.streams configuration for go2rtc streams
       if (wizardData.streams && wizardData.streams.length > 0) {
         configData.cameras[finalCameraName].live = {

web/src/types/cameraWizard.ts

@@ -162,6 +162,10 @@ export type CameraConfigData = {
           input_args?: string;
         }[];
       };
+      detect?: {
+        width: number;
+        height: number;
+      };
       live?: {
         streams: Record<string, string>;
       };

web/src/utils/cameraUtil.ts

@@ -115,6 +115,51 @@ export type CameraAudioFeatures = {
  * @param requireSecureContext - If true, two-way audio requires secure context (default: true)
  * @returns CameraAudioFeatures object with detected capabilities
  */
+/**
+ * Calculates optimal detect dimensions from stream resolution.
+ *
+ * Scales dimensions to an efficient size for object detection while
+ * preserving the stream's aspect ratio. Does not upscale.
+ *
+ * @param streamWidth - Native stream width in pixels
+ * @param streamHeight - Native stream height in pixels
+ * @returns Detect dimensions with even values, or null if inputs are invalid
+ */
+
+// Target size for the smaller dimension (width or height) for detect streams
+export const DETECT_TARGET_PX = 720;
+
+export function calculateDetectDimensions(
+  streamWidth: number,
+  streamHeight: number,
+): { width: number; height: number } | null {
+  if (
+    !Number.isFinite(streamWidth) ||
+    !Number.isFinite(streamHeight) ||
+    streamWidth <= 0 ||
+    streamHeight <= 0
+  ) {
+    return null;
+  }
+
+  const smallerDim = Math.min(streamWidth, streamHeight);
+  const target = Math.min(DETECT_TARGET_PX, smallerDim);
+  const scale = target / smallerDim;
+
+  let width = Math.round(streamWidth * scale);
+  let height = Math.round(streamHeight * scale);
+
+  // Round down to even numbers (required for video processing)
+  width = width - (width % 2);
+  height = height - (height % 2);
+
+  if (width < 2 || height < 2) {
+    return null;
+  }
+
+  return { width, height };
+}
+
 export function detectCameraAudioFeatures(
   metadata: LiveStreamMetadata | null | undefined,
   requireSecureContext: boolean = true,