fix: browser compatibility

demo.html

@@ -166,11 +166,18 @@ async function executeMission() {
         videoForm.append("prompt", mission);
         videoForm.append("detector", detector);
 
+        console.log("[process_video] submitting request", { detector, missionLength: mission.length, fileSize: videoFile.size });
         const response = await fetch(PROCESS_VIDEO_URL, {
             method: "POST",
             body: videoForm
         });
 
+        console.log(
+            "[process_video] response meta",
+            response.status,
+            response.statusText,
+            { contentLength: response.headers.get("content-length"), contentType: response.headers.get("content-type") }
+        );
         if (!response.ok) {
             let errorDetail = `Request failed (${response.status})`;
             try {
@@ -183,10 +190,21 @@ async function executeMission() {
         }
 
         const videoBlob = await response.blob();
+        console.log("[process_video] blob size", videoBlob.size, videoBlob.type);
         const videoUrl = URL.createObjectURL(videoBlob);
         const videoEl = document.getElementById("processedVideo");
+        videoEl.addEventListener("loadeddata", () => {
+            console.log("[process_video] video loadeddata event", videoEl.readyState);
+        }, { once: true });
+        videoEl.addEventListener("error", (event) => {
+            console.error("[process_video] video error", videoEl.error, event);
+        }, { once: true });
         videoEl.src = videoUrl;
         videoEl.load();
+        console.log("[process_video] video element readyState after load()", videoEl.readyState);
+        if (videoEl.error) {
+            console.error("[process_video] immediate video error", videoEl.error);
+        }
 
         statusEl.textContent = "Generating summary...";
 
@@ -195,6 +213,7 @@ async function executeMission() {
         summaryForm.append("prompt", mission);
         summaryForm.append("detector", detector);
 
+        console.log("[mission_summary] submitting request", { detector, missionLength: mission.length, fileSize: videoFile.size });
         const summaryResponse = await fetch(SUMMARY_URL, {
             method: "POST",
             body: summaryForm
@@ -208,6 +227,12 @@ async function executeMission() {
             throw new Error(errorDetail);
         }
 
+        console.log(
+            "[mission_summary] response meta",
+            summaryResponse.status,
+            summaryResponse.statusText,
+            { contentLength: summaryResponse.headers.get("content-length"), contentType: summaryResponse.headers.get("content-type") }
+        );
         const summaryJson = await summaryResponse.json();
         const summaryText = summaryJson.mission_summary || "No summary returned.";
         summaryEl.textContent = summaryText;

utils/video.py

@@ -1,3 +1,4 @@
+import logging
 from typing import List, Tuple
 
 import cv2
@@ -30,10 +31,19 @@ def extract_frames(video_path: str) -> Tuple[List[np.ndarray], float, int, int]:
 def write_video(frames: List[np.ndarray], output_path: str, fps: float, width: int, height: int) -> None:
     if not frames:
         raise ValueError("No frames available for writing.")
-    fourcc = cv2.VideoWriter_fourcc(*"mp4v")
-    writer = cv2.VideoWriter(output_path, fourcc, fps or 1.0, (width, height))
-    if not writer.isOpened():
-        raise ValueError("Failed to open VideoWriter.")
+    candidates = ("avc1", "mp4v")
+    writer = None
+    for codec in candidates:
+        fourcc = cv2.VideoWriter_fourcc(*codec)
+        writer = cv2.VideoWriter(output_path, fourcc, fps or 1.0, (width, height))
+        if writer.isOpened():
+            if codec != candidates[0]:
+                logging.warning("Falling back to %s codec for VideoWriter.", codec)
+            break
+        writer.release()
+        writer = None
+    if writer is None or not writer.isOpened():
+        raise ValueError("Failed to open VideoWriter with a supported codec.")
 
     for frame in frames:
         writer.write(frame)