refactor: add FFmpegRTSPReader for enhanced RTSP stream handling with CUDA acceleration

core/streaming/readers.py

@@ -9,6 +9,7 @@ import threading
 import requests
 import numpy as np
 import os
+import subprocess
 from typing import Optional, Callable
 
 # Suppress FFMPEG/H.264 error messages if needed
@@ -19,6 +20,143 @@ os.environ["OPENCV_FFMPEG_LOGLEVEL"] = "-8"  # Suppress FFMPEG warnings
 logger = logging.getLogger(__name__)
 
 
+class FFmpegRTSPReader:
+    """RTSP stream reader using subprocess FFmpeg with CUDA hardware acceleration."""
+
+    def __init__(self, camera_id: str, rtsp_url: str, max_retries: int = 3):
+        self.camera_id = camera_id
+        self.rtsp_url = rtsp_url
+        self.max_retries = max_retries
+        self.process = None
+        self.stop_event = threading.Event()
+        self.thread = None
+        self.frame_callback: Optional[Callable] = None
+
+        # Stream specs
+        self.width = 1280
+        self.height = 720
+
+    def set_frame_callback(self, callback: Callable[[str, np.ndarray], None]):
+        """Set callback function to handle captured frames."""
+        self.frame_callback = callback
+
+    def start(self):
+        """Start the FFmpeg subprocess reader."""
+        if self.thread and self.thread.is_alive():
+            logger.warning(f"FFmpeg reader for {self.camera_id} already running")
+            return
+
+        self.stop_event.clear()
+        self.thread = threading.Thread(target=self._read_frames, daemon=True)
+        self.thread.start()
+        logger.info(f"Started FFmpeg reader for camera {self.camera_id}")
+
+    def stop(self):
+        """Stop the FFmpeg subprocess reader."""
+        self.stop_event.set()
+        if self.process:
+            self.process.terminate()
+            try:
+                self.process.wait(timeout=5)
+            except subprocess.TimeoutExpired:
+                self.process.kill()
+        if self.thread:
+            self.thread.join(timeout=5.0)
+        logger.info(f"Stopped FFmpeg reader for camera {self.camera_id}")
+
+    def _start_ffmpeg_process(self):
+        """Start FFmpeg subprocess with CUDA hardware acceleration."""
+        cmd = [
+            'ffmpeg',
+            '-hwaccel', 'cuda',
+            '-hwaccel_device', '0',
+            '-rtsp_transport', 'tcp',
+            '-i', self.rtsp_url,
+            '-f', 'rawvideo',
+            '-pix_fmt', 'bgr24',
+            '-an',  # No audio
+            '-'  # Output to stdout
+        ]
+
+        try:
+            self.process = subprocess.Popen(
+                cmd,
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE,
+                bufsize=0
+            )
+            logger.info(f"Started FFmpeg process for camera {self.camera_id}")
+            return True
+        except Exception as e:
+            logger.error(f"Failed to start FFmpeg for camera {self.camera_id}: {e}")
+            return False
+
+    def _read_frames(self):
+        """Read frames from FFmpeg stdout pipe."""
+        consecutive_errors = 0
+        frame_count = 0
+        last_log_time = time.time()
+        bytes_per_frame = self.width * self.height * 3  # BGR = 3 bytes per pixel
+
+        while not self.stop_event.is_set():
+            try:
+                # Start/restart FFmpeg process if needed
+                if not self.process or self.process.poll() is not None:
+                    if not self._start_ffmpeg_process():
+                        time.sleep(5.0)
+                        continue
+
+                # Read one frame worth of data
+                frame_data = self.process.stdout.read(bytes_per_frame)
+
+                if len(frame_data) != bytes_per_frame:
+                    consecutive_errors += 1
+                    if consecutive_errors >= 30:
+                        logger.error(f"Camera {self.camera_id}: Too many read errors, restarting FFmpeg")
+                        if self.process:
+                            self.process.terminate()
+                        consecutive_errors = 0
+                    continue
+
+                # Convert raw bytes to numpy array
+                frame = np.frombuffer(frame_data, dtype=np.uint8)
+                frame = frame.reshape((self.height, self.width, 3))
+
+                # Frame is valid
+                consecutive_errors = 0
+                frame_count += 1
+
+                # Call frame callback
+                if self.frame_callback:
+                    try:
+                        self.frame_callback(self.camera_id, frame)
+                    except Exception as e:
+                        logger.error(f"Camera {self.camera_id}: Frame callback error: {e}")
+
+                # Log progress
+                current_time = time.time()
+                if current_time - last_log_time >= 30:
+                    logger.info(f"Camera {self.camera_id}: {frame_count} frames processed via FFmpeg")
+                    last_log_time = current_time
+
+            except Exception as e:
+                logger.error(f"Camera {self.camera_id}: FFmpeg read error: {e}")
+                consecutive_errors += 1
+                if consecutive_errors >= 30:
+                    if self.process:
+                        self.process.terminate()
+                    consecutive_errors = 0
+                time.sleep(1.0)
+
+        # Cleanup
+        if self.process:
+            self.process.terminate()
+        logger.info(f"FFmpeg reader thread ended for camera {self.camera_id}")
+
+
+logger = logging.getLogger(__name__)
+
+
 class RTSPReader:
     """RTSP stream frame reader optimized for 1280x720 @ 6fps streams."""
 
@@ -90,14 +228,12 @@ class RTSPReader:
 
                 # Read frame immediately without rate limiting for minimum latency
                 try:
-                    # Force grab then retrieve for better error handling
-                    ret = self.cap.grab()
-                    if ret:
-                        ret, frame = self.cap.retrieve()
-                    else:
-                        frame = None
+                    ret, frame = self.cap.read()
+                    if ret and frame is None:
+                        # Grab succeeded but retrieve failed - decoder issue
+                        logger.error(f"Camera {self.camera_id}: Frame grab OK but decode failed")
                 except Exception as read_error:
-                    logger.error(f"Camera {self.camera_id}: cap.grab/retrieve threw exception: {type(read_error).__name__}: {read_error}")
+                    logger.error(f"Camera {self.camera_id}: cap.read() threw exception: {type(read_error).__name__}: {read_error}")
                     ret, frame = False, None
 
                 if not ret or frame is None: