import subprocess
import os

import re


def cut_video_by_frames(video_path, frame_segments, total_frames, output_dir):
    """
    将视频按照指定的帧切片进行切割。

    参数：
    - video_path: 输入视频的路径
    - frame_segments: 切片的帧序号数组，例如：[0, M1, M2, ..., Mlast]
    - output_dir: 输出视频文件的目录
    """
    fps = 30   # default fps

    # 获取视频的帧率 (fps)
    command = [
        "ffmpeg", "-i", video_path, "-vf", "fps=1", "-f", "null", "-"
    ]
    result = subprocess.run(command, stdout=subprocess.PIPE,
                            stderr=subprocess.PIPE, text=True)
    output = result.stderr
    # 解析 fps，查找信息
    fps_line = next(line for line in output.splitlines() if 'fps' in line)
    # 使用正则表达式提取帧率值（假设fps值总是出现在"fps"前面）
    match = re.search(r'(\d+(\.\d+)?)\s*fps', fps_line)
    if match:
        fps = float(match.group(1))  # 提取并转换为 float
        print(f"FPS: {fps}")

    print(f"视频的总帧数: {total_frames}, 帧率: {fps}")

    # 遍历切片区间
    for i in range(len(frame_segments) - 1):
        start_frame = frame_segments[i]
        end_frame = frame_segments[i + 1]

        
        start_time = float(start_frame) / fps
        end_time = float(end_frame) / fps

        output_file = os.path.join(output_dir, f"segment_{i + 1}.mp4")

        
        # 使用 FFmpeg 命令来切割视频
        command = [
            "ffmpeg", "-i", video_path, "-ss", f"{start_time:.10f}", "-to", f"{end_time:.10f}",
            "-c:v", "libx264", "-c:a", "copy","-crf", "18","-preset", "veryslow", output_file
        ]
        print(" ".join(command))
       
        subprocess.run(command)

    # 最后一段处理（从最后一个切片到视频结束）
    last_start_frame = frame_segments[-1]
    last_start_time = last_start_frame / fps
    output_file = os.path.join(
        output_dir, f"segment_{len(frame_segments)}.mp4")

    #print(f"正在切割最后一段：从 {last_start_time:.10f}s 到视频结束，保存为 {output_file}")
    command = [
        "ffmpeg", "-i", video_path, "-ss", f"{last_start_time:.10f}",
        "-c:v", "libx264", "-c:a", "copy","-crf", "18","-preset", "veryslow", output_file
    ]
    print(" ".join(command))
    subprocess.run(command)


target_file = "E:/抖音-AI风景/新建文件夹\_demoold.mp4"
selected_labels = [0, 60, 79, 98, 116, 135,
                   153, 172, 190, 209, 228, 246, 264, 283]
frame_count = 305
output_dir = "E:/抖音-AI风景/新建文件夹\ProcessResults"

cut_video_by_frames(target_file, selected_labels, frame_count, output_dir)