Fix Xbox proxy: Filter REQUEST body instead of response

BREAKING FIX: DeviceProfile is sent FROM client TO server in request body,
not returned in response. This was the bug preventing the filter from working.

Changes:
- Filter DeviceProfile in POST request body before sending to Jellyfin
- Add extensive debug logging to track filtering process
- Remove unnecessary response filtering (DeviceProfile not in response)
- Simplify response handling (always stream)

Now logs:
- 'Xbox PlaybackInfo request detected' when Xbox client detected
- 'Filtering Xbox DeviceProfile in REQUEST' when filtering
- 'No DeviceProfile found' if profile missing (debug info)

docker/jellyfin-xbox-proxy/xbox-filter.py

@@ -73,43 +73,41 @@ def proxy(path):
     headers['X-Forwarded-Host'] = request.host
     headers['X-Real-IP'] = request.remote_addr
 
+    # Get request body
+    request_data = request.get_data()
+
+    # Filter REQUEST body for Xbox PlaybackInfo (DeviceProfile is sent TO server)
+    if is_xbox and is_playback_info:
+        logger.info(f"Xbox PlaybackInfo request detected: {path}, User-Agent: {user_agent}")
+        if request_data:
+            try:
+                data = json.loads(request_data)
+                if "DeviceProfile" in data:
+                    logger.info(f"Filtering Xbox DeviceProfile in REQUEST")
+                    original_profile = data["DeviceProfile"]
+                    filtered_profile = filter_codecs(data["DeviceProfile"])
+                    data["DeviceProfile"] = filtered_profile
+                    request_data = json.dumps(data).encode('utf-8')
+                    headers['Content-Length'] = str(len(request_data))
+                    logger.info("DeviceProfile filtered successfully in REQUEST")
+                else:
+                    logger.warning("No DeviceProfile found in REQUEST body")
+            except Exception as e:
+                logger.error(f"Error filtering request: {e}", exc_info=True)
+        else:
+            logger.warning("No request body found for PlaybackInfo")
+
     resp = requests.request(
         method=request.method,
         url=url,
         headers=headers,
-        data=request.get_data(),
+        data=request_data,
         cookies=request.cookies,
         allow_redirects=False,
         stream=True  # Support large file streaming
     )
 
-    # Filter response for Xbox PlaybackInfo requests
-    if is_xbox and is_playback_info and resp.status_code == 200:
-        try:
-            # Read full response for JSON manipulation
-            data = resp.json()
-
-            # Filter DeviceProfile in request body (if sent back)
-            if "DeviceProfile" in data:
-                logger.info(f"Filtering Xbox DeviceProfile for User-Agent: {user_agent}")
-                data["DeviceProfile"] = filter_codecs(data["DeviceProfile"])
-
-            # Filter MediaSources DirectPlayProfiles (generated server-side)
-            if "MediaSources" in data:
-                for source in data["MediaSources"]:
-                    if "TranscodingUrl" in source:
-                        # Already filtered by Jellyfin
-                        pass
-
-            response_data = json.dumps(data)
-            response = Response(response_data, status=resp.status_code)
-            response.headers['Content-Type'] = 'application/json'
-        except Exception as e:
-            logger.error(f"Error filtering response: {e}")
-            # Fallback to streaming response
-            response = Response(resp.iter_content(chunk_size=8192), status=resp.status_code)
-    else:
-        # Stream response for large files (videos, etc.)
+    # Stream all responses (no need to filter response, DeviceProfile only in request)
     response = Response(resp.iter_content(chunk_size=8192), status=resp.status_code)
 
     # Copy headers from Jellyfin response