【目标检测】视频输出体积太大？分析视频的编码与码率问题

vid_writer[i] = cv2.VideoWriter(save_path, cv2.VideoWriter_fourcc(*'mp4v'), fps, (w, h))

import subprocess

# 输入和输出视频文件路径
input_video = 'input.mp4'
output_video = 'output.mp4'

# 设置比特率（这里设置为1000k）
bitrate = '1000k'

# 构建 FFmpeg 命令
ffmpeg_command = f'ffmpeg -i {input_video} -b:v {bitrate} {output_video}'

# 运行 FFmpeg 命令
try:
    subprocess.run(ffmpeg_command, shell=True, check=True)
    print("视频重新编码成功！")
except subprocess.CalledProcessError as e:
    print(f"视频重新编码失败: {e}")

import os
from moviepy.editor import VideoFileClip

# 指定视频文件所在文件夹路径
videos_directory = "cs1/"
videos_save = "cs2"

# 设置目标比特率（kbps）
target_bitrate = "20208k"  # 例如，设置为 20208 kbps

# 遍历指定文件夹中的所有视频文件
for file in os.listdir(videos_directory):
    if file.endswith(".mp4") or file.endswith(".avi") or file.endswith(".mov"):
        # 构建视频文件的完整路径
        file_path = os.path.join(videos_directory, file)
        # 读取视频文件
        clip = VideoFileClip(file_path)
        # 写入视频文件并设置比特率
        output_file = os.path.join(videos_save, file)
        clip.write_videofile(output_file, codec='libx264', bitrate=target_bitrate)
        print(f"视频 {file} 处理完成并写入 {output_file}")

print("批量处理完成")

import cv2
from moviepy.editor import VideoFileClip


def get_original_bitrate(input_video):
    cap = cv2.VideoCapture(input_video)
    if not cap.isOpened():
        print("无法打开视频文件")
        return None
    # 获取视频的原始比特率
    original_bitrate = cap.get(cv2.CAP_PROP_BITRATE)
    # 释放资源
    cap.release()
    return original_bitrate

def crop_video(input_video, output_video, target_bitrate):
    # 对视频进行空间上的裁剪（使用 OpenCV）
    cap = cv2.VideoCapture(input_video)
    if not cap.isOpened():
        print("无法打开视频文件")
        return

    # 获取视频的基本信息
    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))

    # 设置输出视频的编解码器和写入对象
    fourcc = cv2.VideoWriter_fourcc(*'mp4v')
    out = cv2.VideoWriter(output_video, fourcc, fps, (894, 710))

    while True:
        ret, frame = cap.read()
        if not ret:
            break

        # 对每一帧进行裁剪
        cropped_frame = frame[161:871, 493:1387]  # 这里是你想要的空间裁剪区域的坐标

        # 写入裁剪后的帧到输出视频文件
        out.write(cropped_frame)

    # 释放资源
    cap.release()
    out.release()
    cv2.destroyAllWindows()

    # 读取视频文件
    clip = VideoFileClip(output_video)
    output_video2 = output_video.replace('.mp4', '_Update.mp4')
    # 保存裁剪和修改比特率后的视频
    clip.write_videofile(output_video2, codec='libx264', bitrate=target_bitrate)


if __name__ == '__main__':
    # 输入视频文件路径
    input_video_path = 'Video.mp4'
    # 输出视频文件路径
    output_video_path = input_video_path.replace('.mp4', '_Crop.mp4')
    # 获取视频的原始比特率
    original_bitrate = get_original_bitrate(input_video_path)
    # 设置目标比特率
    original_bitrate = str(int(original_bitrate)) + 'k'
    # 调用函数进行视频裁剪和修改比特率
    crop_video(input_video_path, output_video_path, original_bitrate)