Add ability to download on demand snapshots (#20488)

* on demand snapshot utils

* add optional loading state to feature toggle buttons

* add on demand snapshot button to single camera live view

* i18n

web/public/locales/en/views/live.json

@@ -73,6 +73,12 @@
     "enable": "Enable Snapshots",
     "disable": "Disable Snapshots"
   },
+  "snapshot": {
+    "takeSnapshot": "Download instant snapshot",
+    "noVideoSource": "No video source available for snapshot.",
+    "captureFailed": "Failed to capture snapshot.",
+    "downloadStarted": "Snapshot download started."
+  },
   "audioDetect": {
     "enable": "Enable Audio Detect",
     "disable": "Disable Audio Detect"
@@ -90,8 +96,8 @@
     "disable": "Hide Stream Stats"
   },
   "manualRecording": {
-    "title": "On-Demand Recording",
+    "title": "On-Demand",
-    "tips": "Start a manual event based on this camera's recording retention settings.",
+    "tips": "Download an instant snapshot or start a manual event based on this camera's recording retention settings.",
     "playInBackground": {
       "label": "Play in background",
       "desc": "Enable this option to continue streaming when the player is hidden."

web/src/components/dynamic/CameraFeatureToggle.tsx

@@ -6,6 +6,7 @@ import {
 } from "@/components/ui/tooltip";
 import { isDesktop } from "react-device-detect";
 import { cn } from "@/lib/utils";
+import ActivityIndicator from "../indicators/activity-indicator";
 
 const variants = {
   primary: {
@@ -30,7 +31,8 @@ type CameraFeatureToggleProps = {
   Icon: IconType;
   title: string;
   onClick?: () => void;
-  disabled?: boolean; // New prop for disabling
+  disabled?: boolean;
+  loading?: boolean;
 };
 
 export default function CameraFeatureToggle({
@@ -40,7 +42,8 @@ export default function CameraFeatureToggle({
   Icon,
   title,
   onClick,
-  disabled = false, // Default to false
+  disabled = false,
+  loading = false,
 }: CameraFeatureToggleProps) {
   const content = (
     <div
@@ -53,6 +56,9 @@ export default function CameraFeatureToggle({
         className,
       )}
     >
+      {loading ? (
+        <ActivityIndicator className="size-5 md:m-[6px]" />
+      ) : (
         <Icon
           className={cn(
             "size-5 md:m-[6px]",
@@ -63,6 +69,7 @@ export default function CameraFeatureToggle({
                 : "text-secondary-foreground",
           )}
         />
+      )}
     </div>
   );
 

web/src/utils/snapshotUtil.ts

@@ -0,0 +1,163 @@
+import { baseUrl } from "@/api/baseUrl";
+
+type SnapshotResponse = {
+  dataUrl: string;
+  blob: Blob;
+  contentType: string;
+};
+
+export type SnapshotResult =
+  | {
+      success: true;
+      data: SnapshotResponse;
+    }
+  | {
+      success: false;
+      error: string;
+    };
+
+export async function fetchCameraSnapshot(
+  name: string,
+): Promise<SnapshotResult> {
+  try {
+    const url = `${baseUrl}api/${encodeURIComponent(name)}/latest.jpg`;
+
+    const response = await fetch(url, {
+      method: "GET",
+      cache: "no-store",
+      credentials: "same-origin",
+    });
+
+    if (!response.ok) {
+      return {
+        success: false,
+        error: `Snapshot request failed with status ${response.status}`,
+      };
+    }
+
+    const blob = await response.blob();
+
+    if (!blob || blob.size === 0) {
+      return {
+        success: false,
+        error: "Snapshot response was empty",
+      };
+    }
+
+    const dataUrl = await blobToDataUrl(blob);
+    const contentType = response.headers.get("content-type") ?? `image/jpeg`;
+
+    return {
+      success: true,
+      data: {
+        dataUrl,
+        blob,
+        contentType,
+      },
+    };
+  } catch (error) {
+    return {
+      success: false,
+      error: error instanceof Error ? error.message : "Unknown error occurred",
+    };
+  }
+}
+
+function blobToDataUrl(blob: Blob): Promise<string> {
+  return new Promise((resolve, reject) => {
+    const reader = new FileReader();
+
+    reader.onloadend = () => {
+      if (typeof reader.result === "string") {
+        resolve(reader.result);
+      } else {
+        reject(new Error("Failed to convert blob to data URL"));
+      }
+    };
+
+    reader.onerror = () => {
+      reject(reader.error ?? new Error("Failed to read snapshot blob"));
+    };
+
+    reader.readAsDataURL(blob);
+  });
+}
+
+export function downloadSnapshot(dataUrl: string, filename: string): void {
+  try {
+    const link = document.createElement("a");
+    link.href = dataUrl;
+    link.download = filename;
+    document.body.appendChild(link);
+    link.click();
+    document.body.removeChild(link);
+  } catch (error) {
+    // eslint-disable-next-line no-console
+    console.error(`Failed to download snapshot for ${filename}:`, error);
+  }
+}
+
+export function generateSnapshotFilename(cameraName: string): string {
+  const timestamp = new Date().toISOString().replace(/[:.]/g, "-").slice(0, -5);
+  return `${cameraName}_snapshot_${timestamp}.jpg`;
+}
+
+export async function grabVideoSnapshot(): Promise<SnapshotResult> {
+  try {
+    // Find the video element in the player
+    const videoElement = document.querySelector(
+      "#player-container video",
+    ) as HTMLVideoElement;
+
+    if (!videoElement) {
+      return {
+        success: false,
+        error: "Video element not found",
+      };
+    }
+
+    const width = videoElement.videoWidth;
+    const height = videoElement.videoHeight;
+
+    if (width === 0 || height === 0) {
+      return {
+        success: false,
+        error: "Video element has no dimensions",
+      };
+    }
+
+    const canvas = document.createElement("canvas");
+    canvas.width = width;
+    canvas.height = height;
+
+    const context = canvas.getContext("2d");
+
+    if (!context) {
+      return {
+        success: false,
+        error: "Failed to get canvas context",
+      };
+    }
+
+    context.drawImage(videoElement, 0, 0, width, height);
+    const dataUrl = canvas.toDataURL("image/jpeg", 0.9);
+
+    // Convert data URL to blob
+    const response = await fetch(dataUrl);
+    const blob = await response.blob();
+
+    return {
+      success: true,
+      data: {
+        dataUrl,
+        blob,
+        contentType: "image/jpeg",
+      },
+    };
+  } catch (error) {
+    return {
+      success: false,
+      error: error instanceof Error ? error.message : "Unknown error occurred",
+    };
+  }
+}

web/src/views/live/LiveCameraView.tsx

@@ -57,6 +57,7 @@ import {
 } from "react-icons/fa";
 import { GiSpeaker, GiSpeakerOff } from "react-icons/gi";
 import {
+  TbCameraDown,
   TbRecordMail,
   TbRecordMailOff,
   TbViewfinder,
@@ -112,6 +113,14 @@ import { useDocDomain } from "@/hooks/use-doc-domain";
 import PtzControlPanel from "@/components/overlay/PtzControlPanel";
 import ObjectSettingsView from "../settings/ObjectSettingsView";
 import { useSearchEffect } from "@/hooks/use-overlay-state";
+import {
+  downloadSnapshot,
+  fetchCameraSnapshot,
+  generateSnapshotFilename,
+  grabVideoSnapshot,
+  SnapshotResult,
+} from "@/utils/snapshotUtil";
+import ActivityIndicator from "@/components/indicators/activity-indicator";
 
 type LiveCameraViewProps = {
   config?: FrigateConfig;
@@ -882,6 +891,34 @@ function FrigateCameraFeatures({
     }
   }, [createEvent, endEvent, isRecording]);
 
+  const [isSnapshotLoading, setIsSnapshotLoading] = useState(false);
+
+  const handleSnapshotClick = useCallback(async () => {
+    setIsSnapshotLoading(true);
+    try {
+      let result: SnapshotResult;
+
+      if (isRestreamed && preferredLiveMode !== "jsmpeg") {
+        // For restreamed streams with video elements (MSE/WebRTC), grab directly from video element
+        result = await grabVideoSnapshot();
+      } else {
+        // For detect stream or JSMpeg players, use the API endpoint
+        result = await fetchCameraSnapshot(camera.name);
+      }
+
+      if (result.success) {
+        const { dataUrl } = result.data;
+        const filename = generateSnapshotFilename(camera.name);
+        downloadSnapshot(dataUrl, filename);
+        toast.success(t("snapshot.downloadStarted"));
+      } else {
+        toast.error(t("snapshot.captureFailed"));
+      }
+    } finally {
+      setIsSnapshotLoading(false);
+    }
+  }, [camera.name, isRestreamed, preferredLiveMode, t]);
+
   useEffect(() => {
     // ensure manual event is stopped when component unmounts
     return () => {
@@ -1016,6 +1053,16 @@ function FrigateCameraFeatures({
           onClick={handleEventButtonClick}
           disabled={!cameraEnabled || debug}
         />
+        <CameraFeatureToggle
+          className="p-2 md:p-0"
+          variant={fullscreen ? "overlay" : "primary"}
+          Icon={TbCameraDown}
+          isActive={false}
+          title={t("snapshot.takeSnapshot")}
+          onClick={handleSnapshotClick}
+          disabled={!cameraEnabled || debug || isSnapshotLoading}
+          loading={isSnapshotLoading}
+        />
         <DropdownMenu modal={false}>
           <DropdownMenuTrigger>
             <div
@@ -1584,16 +1631,28 @@ function FrigateCameraFeatures({
             <div className="mb-1 text-sm font-medium leading-none">
               {t("manualRecording.title")}
             </div>
+            <div className="flex flex-row items-stretch gap-2">
+              <Button
+                onClick={handleSnapshotClick}
+                disabled={!cameraEnabled || debug || isSnapshotLoading}
+                className="h-auto w-full whitespace-normal"
+              >
+                {isSnapshotLoading && (
+                  <ActivityIndicator className="mr-2 size-4" />
+                )}
+                {t("snapshot.takeSnapshot")}
+              </Button>
               <Button
                 onClick={handleEventButtonClick}
                 className={cn(
-                "w-full",
+                  "h-auto w-full whitespace-normal",
                   isRecording && "animate-pulse bg-red-500 hover:bg-red-600",
                 )}
                 disabled={debug}
               >
                 {t("manualRecording." + (isRecording ? "end" : "start"))}
               </Button>
+            </div>
             <p className="text-sm text-muted-foreground">
               {t("manualRecording.tips")}
             </p>