Use target frame rate for op to handle downsampling

Author: mattdawkins

client/src/components/annotators/NativeVideoAnnotator.vue

@@ -128,8 +128,9 @@ export default defineComponent({
      * Get the URL for a specific frame
      */
     function getFrameUrl(frameNumber: number): string {
-      const fps = videoInfo.value?.fps || props.originalFps || props.frameRate;
-      return `${baseApiUrl}/frame?path=${encodeURIComponent(props.nativeVideoPath)}&frame=${frameNumber}&fps=${fps}`;
+      // Use annotation frame rate since frameNumber is an annotation frame number.
+      // timestamp = frameNumber / annotationFps gives the correct time in the video.
+      return `${baseApiUrl}/frame?path=${encodeURIComponent(props.nativeVideoPath)}&frame=${frameNumber}&fps=${props.frameRate}`;
     }
 
     /**