Fixing an issue with bufferedwriter

src/camera.py

@@ -1,4 +1,5 @@
 import logging
+import io
 import shutil
 import subprocess
 import threading
@@ -23,22 +24,23 @@ SEGMENT_COUNT = 5  # segments to keep in playlist
 BITRATE = 2_000_000  # 2 Mbps — adjust for bandwidth needs
 
 
-class PipeOutput:
+class PipeOutput(io.RawIOBase):
-    """Accepts H.264 bytes from picamera2 and writes to a subprocess stdin pipe."""
+    """Wraps ffmpeg stdin pipe as a BufferedIOBase-compatible stream."""
 
     def __init__(self, proc: subprocess.Popen[bytes]) -> None:
         self._proc = proc
 
-    def write(self, data: bytes) -> None:
+    def write(self, data: bytes) -> int:  # type: ignore[override]
-        if self._proc.stdin:
+        if self._proc.stdin and not self._proc.stdin.closed:
             try:
                 self._proc.stdin.write(data)
+                return len(data)
             except BrokenPipeError:
                 pass
+        return 0
 
-    def close(self) -> None:
+    def writable(self) -> bool:
-        if self._proc.stdin:
+        return True
-            self._proc.stdin.close()
 
 
 class Camera:
@@ -104,7 +106,8 @@ class Camera:
         )
         self._picam.configure(config)
         self._encoder = H264Encoder(bitrate=BITRATE)
-        self._picam.start_recording(self._encoder, FileOutput(self._output))
+        buffered = io.BufferedWriter(self._output)
+        self._picam.start_recording(self._encoder, FileOutput(buffered))
 
         # watch for the playlist to appear — signals first segment is ready
         self._stop_event.clear()
@@ -145,6 +148,9 @@ class Camera:
         if self._output:
             self._output.close()
 
+        if self._ffmpeg and self._ffmpeg.stdin:
+            self._ffmpeg.stdin.close()
+
         if self._ffmpeg:
             try:
                 self._ffmpeg.wait(timeout=5)