1. 安装 opencv-python

pip install opencv-python

2. 代码逻辑

1. 使用 opencv 读取视频文件

import cv2
import sys

# 使用 cv 打开视频文件
cap = cv2.VideoCapture("./test.mp4")

# 检查视频文件是否呈贡打开
if not cap.isOpened():
	print("failed to open the video file", file=sys.stderr)
	sys.exit(1)

# 持续读取视频每一帧
while True:
	# ret 是读取结果, frame 是视频的每一帧
	ret, frame = cap.read()
	# 如果读取失败
	if not ret:
		print("read video file to end", file=sys.stderr)
		break
	# 显示视频
	# 第一个参数是窗口名称, 第二个参数是视频帧
	cv2.imshow("test.mp4", frame)
	if cv2.waitKey(1) & 0xFF == ord('q'):
		break
cap.release()
cv2.destroyAllWindows()

2. 获取视频属性

# 获取视频 FPS
fps = cap.get(cv2.CAP_PROP_FPS)
# 获取视频尺寸
frame_width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
frame_height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
# 获取视频总帧数
total_frame_count = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))

# 获取当前帧的时间, 毫秒
current_frame_time = (cap.get(cv2.CAP_PROP_POS_MSEC))

3. 获取视频总时长

def get_total_video_time(frame_count, fps):
	(frame_count / fps) * 1000

4. 转换帧时间为字符串

def milliseconds_to_time_str(milliseconds)
	# 将毫秒转换为秒
    seconds = milliseconds / 1000
    # 计算小时数
    hours = int(seconds // 3600)
    seconds %= 3600
    # 计算分钟数
    minutes = int(seconds // 60)
    seconds %= 60
    # 返回格式化的时间字符串
    return f"{hours:02}:{minutes:02}:{seconds:06.3f}"

5. 绘制水印

# 总视频时长
total_video_time = get_total_video_time(total_frame_count, fps)
# 总视频时长字符串
total_video_time_str = milliseconds_to_time_str(total_video_time)

# 当前视频时间字符串
current_frame_time_str = milliseconds_to_time_str(current_frame_time)

# 绘制一个背景
rect_pos_1 = (0, frame_height)
rect_pos_2 = (460, frame_height - 70)
cv2.rectangle(frame, rect_pos_1, rect_pos_2, (25, 25, 25), cv2.FILLED)

# 绘制帧进度
text_pos_1 = (5, frame_height - 40)
text = f"{frame_count:05}/{total_frame_count}"
cv2.putText(frame, text, text_pos_1, cv2.FONT_HERSHEY_DUPLEX ,1, (255, 255, 255), 1)

# 绘制时间进度
text_pos_2 = (5, frame_height - 5)
text = f"{time_str}/{total_time_str}"
cv2.putText(frame, text, text_pos_2, cv2.FONT_HERSHEY_DUPLEX ,1, (255, 255, 255), 1)

6. 保存视频

# 打开视频写
writer = cv2.VideoWriter("./output.mp4")
# 写出帧到视频文件
writer.write(frame)
# 释放写
writer.release()

3. 完整代码

import cv2
import sys

def get_total_video_time(frame_count, fps):
    return (frame_count / fps) * 1000

def milliseconds_to_time_str(milliseconds):
    # 将毫秒转换为秒
    seconds = milliseconds / 1000
    # 计算小时数
    hours = int(seconds // 3600)
    seconds %= 3600
    # 计算分钟数
    minutes = int(seconds // 60)
    seconds %= 60
    # 返回格式化的时间字符串
    return f"{hours:02}:{minutes:02}:{seconds:06.3f}"

def main(input_video, output_video):
    cap = cv2.VideoCapture(input_video)
    if not cap.isOpened():
        print(f"failed to open the video file, video_file={input_video}", file=sys.stderr)
        sys.exit(1)

    fps = cap.get(cv2.CAP_PROP_FPS)
    frame_width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
    frame_height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
    total_frame_count = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
    total_video_time = get_total_video_time(total_frame_count, fps)
    total_video_time_str = milliseconds_to_time_str(total_video_time)
    frame_index = 0

    text_pos_1 = (5, frame_height - 40)
    text_pos_2 = (5, frame_height - 5)

    rect_pos_1 = (0, frame_height)
    rect_pos_2 = (460, frame_height - 70)

    fourcc = cv2.VideoWriter_fourcc(*"mp4v")
    writer = cv2.VideoWriter(output_video, fourcc, fps, (frame_width, frame_height))

    while True:
        ret, frame = cap.read()
        if not ret:
            print("read to end of video", file=sys.stderr)
            sys.exit(1)

        frame_index += 1
        current_time = cap.get(cv2.CAP_PROP_POS_MSEC)
        current_time_str = milliseconds_to_time_str(current_time)

        cv2.rectangle(frame, rect_pos_1, rect_pos_2, (25, 25, 25), cv2.FILLED)

        text = f"{frame_index:05}/{total_frame_count}"
        cv2.putText(frame, text, text_pos_1, cv2.FONT_HERSHEY_DUPLEX, 1, (255, 255, 255), 1)

        text = f"{current_time_str}/{total_video_time_str}"
        cv2.putText(frame, text, text_pos_2, cv2.FONT_HERSHEY_DUPLEX, 1, (255, 255, 255), 1)

        writer.write(frame)
    writer.release()
    cap.release()
    cv2.destroyAllWindows()