pythonとc++で動画の各フレームをdxt1圧縮をする

import imageio.v3 as iio
from PIL import Image
import os
import subprocess

frames_temp_dir = "frames_temp"
os.makedirs(frames_temp_dir, exist_ok=True)

source_videos_dir = "source_videos"
anime_titles = os.listdir(source_videos_dir)

output_dir = "all_frames_bin"

for title in anime_titles:
    title_path = os.path.join(source_videos_dir, title)
    if os.path.isdir(title_path):
        video_files = [f for f in os.listdir(title_path) if f.endswith(".mp4")]

        for video_file in video_files:
            base_name = os.path.splitext(video_file)[0]
            video_path = os.path.join(title_path, video_file)
            reader = iio.imiter(video_path, plugin="pyav")
            frame_count = 0

            # 動画の1フレームずつ読み込み
            for i, frame in enumerate(reader):
                img = Image.fromarray(frame).resize((240, 136)).convert("RGB")
                bmp_path = os.path.join(frames_temp_dir, f"{title}_{base_name}_frame{i:04d}.bmp")
                dxt1_path = os.path.join(frames_temp_dir, f"{title}_{base_name}_frame{i:04d}.dxt1")

                # iフレーム目をビットマップ形式で保存
                img.save(bmp_path)
                # ビットマップをDXT1形式に変換
                subprocess.run(["./dxt1_encoder.exe", bmp_path, dxt1_path], check=True)
                frame_count += 1

            # 動画別にbinファイルを作成
            output_bin_path = os.path.join(output_dir, f"{title}_{base_name}_allframes_dxt1.bin")

            # 1つのbinファイルに全フレームのDXT1データを書き足していく
            with open(output_bin_path, "wb") as out:
                for i in range(frame_count):
                    dxt1_path = os.path.join(frames_temp_dir, f"{title}_{base_name}_frame{i:04d}.dxt1")
                    with open(dxt1_path, "rb") as f:
                        out.write(f.read())

            # フレームファイルの削除
            for i in range(frame_count):
                os.remove(os.path.join(frames_temp_dir, f"{title}_{base_name}_frame{i:04d}.bmp"))
                os.remove(os.path.join(frames_temp_dir, f"{title}_{base_name}_frame{i:04d}.dxt1"))

// main.cpp
// 使用： ./dxt1_encoder input.bmp output.dxt1
#define STB_IMAGE_IMPLEMENTATION
#define STB_DXT_IMPLEMENTATION

#include "stb_image.h"
#include "stb_dxt.h"
#include <fstream>
#include <cstdint> 
#include <iostream>

int main(int argc, char** argv) {
    std::cout << "Arguments: " << argv[1] << " " << argv[2] << std::endl; // デバッグ用
    int w, h, c;
    if (argc < 3) {
        std::cerr << "Usage: " << argv[0] << " input.bmp output.dxt1\n";
        return 1;
    }

    // 3チャンネルでRGBとして読み込み（BGRが来ることに注意）
    unsigned char* img = stbi_load(argv[1], &w, &h, &c, 3);
    if (!img) {
        std::cerr << "Failed to load image: " << argv[1] << std::endl;
        return 1;
    }

    std::ofstream out(argv[2], std::ios::binary);
    for (int y = 0; y < h; y += 4) {
        for (int x = 0; x < w; x += 4) {
            unsigned char block[64];
            for (int dy = 0; dy < 4; dy++) {
                for (int dx = 0; dx < 4; dx++) {
                    int px = (x + dx < w) ? x + dx : w - 1;
                    int py = (y + dy < h) ? y + dy : h - 1;

                    block[(dy * 4 + dx) * 4 + 0] = img[(py * w + px) * 3 + 0]; // B
                    block[(dy * 4 + dx) * 4 + 1] = img[(py * w + px) * 3 + 1]; // G
                    block[(dy * 4 + dx) * 4 + 2] = img[(py * w + px) * 3 + 2]; // R
                    block[(dy * 4 + dx) * 4 + 3] = 255; // A
                }
            }

            uint8_t dxt1[8];
            stb_compress_dxt_block(dxt1, block, 0, STB_DXT_HIGHQUAL);
            out.write((char*)dxt1, 8);
        }
    }

    out.close();
    stbi_image_free(img);
    return 0;
}