如何在 yolo v8 中获取视频时间戳

Question

大家好，我尝试获取视频中每次检测的时间戳，我尝试了此操作，但得到了一个空列表

from ultralytics import YOLO
from datetime import timedelta
import cv2


model = YOLO('path/yolov8n-cls.pt')
video_path='your video path'
cap=cv2.VideoCapture(video_path)




results = model.predict(video_path)  # results list for each frame


for i, frame_result in enumerate(results.xyxy[0]):  # xyxy format contains bounding box coordinates and class probabilities
    timestamp = timedelta(seconds=i /cap.get(cv2.CAP_PROP_FPS))  # calculate timestamp
    print(f"Timestamp: {timestamp}, Probs: {frame_result['probs']}")

我尝试设置 Save=true 但什么也没发生

Answer 1

使用边界框的结果使我能够了解何时做出预测。此代码只是将帧和时间戳（以秒为单位）存储到名为“Detected_timestamps”的列表中。时间戳以毫秒为单位。

注意：这会对视频的每一帧运行检测。

import cv2
import time
from datetime import timedelta
from ultralytics import YOLO

# Load the YOLOv8 model
model = YOLO(r'best.pt')

# Open the video file
video_path = r"vid-short.mp4"
cap = cv2.VideoCapture(video_path)

detected_timestamps = []
frame_no = 0

# Loop through the video frames
while cap.isOpened():
    # Read a frame from the video
    success, frame = cap.read()

    if success:
        
        # Run YOLOv8 inference on the frame
        results = model.predict(frame)

        # Visualize the results on the frame
        annotated_frame = results[0].plot()
        
        # Get the box detection tensor
        if len(results[0].boxes.cls) > 0:
            # Get current timestamp
            message = "for frame : " + str(frame_no) + "   timestamp is: ", str(cap.get(cv2.CAP_PROP_POS_MSEC))
            print(message)
            detected_timestamps.append(message)
            
        frame_no += 1

        # Display the annotated frame
        cv2.imshow("YOLOv8 Inference", annotated_frame)

        # Break the loop if 'q' is pressed
        if cv2.waitKey(1) & 0xFF == ord("q"):
            break
    else:
        # Break the loop if the end of the video is reached
        break

# Release the video capture object and close the display window
cap.release()
cv2.destroyAllWindows()

print(detected_timestamps)