Add missing multi_res_output.py and update gpu_output.py

- multi_res_output.py was not tracked, causing import errors
- Update gpu_output.py with recent changes

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

streaming/gpu_output.py

@@ -325,6 +325,20 @@ class GPUHLSOutput:
             stderr=subprocess.PIPE,  # Capture stderr for debugging
         )
 
+        # Start thread to drain stderr (prevents pipe buffer from filling and blocking FFmpeg)
+        self._stderr_thread = threading.Thread(target=self._drain_stderr, daemon=True)
+        self._stderr_thread.start()
+
+    def _drain_stderr(self):
+        """Drain FFmpeg stderr to prevent blocking."""
+        try:
+            for line in self._muxer.stderr:
+                line_str = line.decode('utf-8', errors='replace').strip()
+                if line_str:
+                    print(f"[FFmpeg] {line_str}", file=sys.stderr)
+        except Exception as e:
+            print(f"[FFmpeg stderr] Error reading: {e}", file=sys.stderr)
+
     def write(self, frame: Union[np.ndarray, 'cp.ndarray'], t: float = 0):
         """Write a frame using GPU encoding."""
         if not self._is_open:
@@ -342,7 +356,15 @@ class GPUHLSOutput:
         if encoded:
             try:
                 self._muxer.stdin.write(encoded)
-            except BrokenPipeError:
+            except BrokenPipeError as e:
+                print(f"[GPUHLSOutput] FFmpeg pipe broken after {self._frames_in_segment} frames in segment, total segments: {self._current_segment}", file=sys.stderr)
+                # Check if muxer is still running
+                if self._muxer.poll() is not None:
+                    print(f"[GPUHLSOutput] FFmpeg exited with code {self._muxer.returncode}", file=sys.stderr)
+                self._is_open = False
+                return
+            except Exception as e:
+                print(f"[GPUHLSOutput] Error writing to FFmpeg: {e}", file=sys.stderr)
                 self._is_open = False
                 return