Av Card Receiver Software -

recording = False out_video = None out_audio = None audio_frames = [] recording_lock = threading.Lock()

def signal_handler(sig, frame): print("\nExiting...") cleanup() sys.exit(0)

signal.signal(signal.SIGINT, signal_handler)

def cleanup(): global out_video, out_audio if recording: stop_recording() cv2.destroyAllWindows()

def start_recording(cap, filename=None): global out_video, recording, audio_frames with recording_lock: if not filename: timestamp = datetime.now().strftime("%Y%m%d_%H%M%S") filename = f"OUTPUT_DIRav_record_timestamp.mp4"

    # Video writer (codec: H.264)
    fourcc = cv2.VideoWriter_fourcc(*'mp4v')
    width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
    height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
    fps = cap.get(cv2.CAP_PROP_FPS)
    if fps <= 0:
        fps = FPS_TARGET
out_video = cv2.VideoWriter(filename, fourcc, fps, (width, height))
    if not out_video.isOpened():
        print("Error: Could not open video writer.")
        return False
recording = True
    audio_frames = []
    print(f"Recording started: filename")
    return True

def stop_recording(): global out_video, recording, out_audio with recording_lock: recording = False if out_video: out_video.release() out_video = None print("Recording stopped.") av card receiver software

def audio_capture_loop(): """Example audio capture thread (runs if PyAudio is available).""" if not AUDIO_SUPPORT: return # This is a placeholder — actual implementation requires opening a specific audio device. # For a real capture card, you'd match the video device's audio input. pass

def main(): # Ensure output directory exists import os os.makedirs(OUTPUT_DIR, exist_ok=True)

# Open capture device
cap = cv2.VideoCapture(DEVICE_ID)
if not cap.isOpened():
    print(f"Error: Cannot open AV device DEVICE_ID.")
    print("Available devices:")
    for i in range(5):
        test = cv2.VideoCapture(i)
        if test.isOpened():
            print(f"  Device i available")
            test.release()
    sys.exit(1)
# Set resolution (if supported)
cap.set(cv2.CAP_PROP_FRAME_WIDTH, FRAME_WIDTH)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, FRAME_HEIGHT)
cap.set(cv2.CAP_PROP_FPS, FPS_TARGET)
print("AV Card Receiver Running")
print("Controls:")
print("  'r' - Start/Stop recording")
print("  'q' - Quit")
# Show first frame to confirm
ret, frame = cap.read()
if not ret:
    print("Failed to grab frame from AV card.")
    cap.release()
    sys.exit(1)
while True:
    ret, frame = cap.read()
    if not ret:
        print("Lost signal from AV card.")
        break
# Display recording status
    if recording:
        cv2.putText(frame, "RECORDING", (10, 40), cv2.FONT_HERSHEY_SIMPLEX,
                    1, (0, 0, 255), 2, cv2.LINE_AA)
cv2.imshow("AV Card Receiver", frame)
# Write frame if recording
    with recording_lock:
        if recording and out_video:
            out_video.write(frame)
key = cv2.waitKey(1) & 0xFF
    if key == ord('q'):
        break
    elif key == ord('r'):
        if not recording:
            start_recording(cap)
        else:
            stop_recording()
cleanup()
cap.release()
cv2.destroyAllWindows()

if name == "main": main()

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Best for: VHS digitization, old gaming consoles (PS2, N64), and CCTV. Price: Free.

Modern software often fails with interlaced composite video. VirtualDub (with the capture module) allows you to tweak vertical blank interval timing and codec settings that modern apps ignore. recording = False out_video = None out_audio =

Title
Design and Implementation of AV Card Receiver Software for Real-Time Audio-Visual Signal Processing

Abstract
Brief summary of purpose, methods (software-defined receiver architecture), key results (latency, accuracy, hardware compatibility), and conclusion.

1. Introduction

2. Background & Related Work

3. System Architecture

4. Software Design & Implementation

5. Experimental Evaluation

Comparative results vs. hardware receiver or VLC

6. Discussion

7. Conclusion & Future Work

References
(e.g., IEEE Xplore, FFmpeg documentation, SDR papers) if name == " main ": main()

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