利用"spring boot 2.5.2,minio 8.5.2,ffmpeg"技术，需求是：1.通过minio获取视频链接地址，将视频缓存到linux系统本地；2.将该视频按分辨率："480p,720p,1080p,2k,4k"切片；3.切片m3u8文件放在对应分辨率目录下，并建立index.m3u8文件；4.将切片后的视频批量打包上传到minio；5.minio存储桶目录按bucket/日期/视频文件名称/分级存放，请提供完整代码。

以下是大致的代码实现思路：

1. 通过MinIO SDK获取视频链接地址，并将视频缓存到本地：

MinioClient minioClient = new MinioClient("https://play.min.io", "YOUR_ACCESS_KEY", "YOUR_SECRET_KEY");
InputStream stream = minioClient.getObject("mybucket", "myvideo.mp4");
File videoFile = new File("/path/to/video/myvideo.mp4");
FileUtils.copyInputStreamToFile(stream, videoFile);

2. 利用FFmpeg将视频按分辨率切片：

String videoPath = "/path/to/video/myvideo.mp4";
String outputPath = "/path/to/output/directory/";
String[] resolutions = {"480p", "720p", "1080p", "2k", "4k"};
for (String resolution : resolutions) {
    String outputFileName = "myvideo_" + resolution + ".m3u8";
    String cmd = "ffmpeg -i " + videoPath + " -c:v libx264 -c:a aac -preset ultrafast -crf 18 -maxrate 4000k -bufsize 8000k -hls_time 10 -hls_list_size 0 -hls_segment_filename " + outputPath + resolution + "/%06d.ts " + outputPath + resolution + "/" + outputFileName;
    Process p = Runtime.getRuntime().exec(cmd);
    p.waitFor();
}

3. 将切片后的视频文件上传到MinIO：

String bucketName = "mybucket";
String date = LocalDate.now().toString();
String videoName = "myvideo";
for (String resolution : resolutions) {
    String directoryPath = bucketName + "/" + date + "/" + videoName + "/" + resolution + "/";
    File directory = new File(outputPath + resolution);
    for (File file : directory.listFiles()) {
        String objectName = file.getName();
        InputStream inputStream = new FileInputStream(file);
        minioClient.putObject(bucketName, directoryPath + objectName, inputStream, inputStream.available(), null, null, null);
        inputStream.close();
    }
}

4. 建立index.m3u8文件：

for (String resolution : resolutions) {
    String outputFileName = "myvideo_" + resolution + ".m3u8";
    File outputFile = new File(outputPath + resolution + "/" + outputFileName);
    List<String> lines = Files.readAllLines(outputFile.toPath());
    // Change the paths in the m3u8 file to relative paths
    List<String> updatedLines = new ArrayList<>();
    for (String line : lines) {
        if (line.endsWith(".ts")) {
            updatedLines.add(line.substring(line.lastIndexOf("/") + 1));
        } else {
            updatedLines.add(line);
        }
    }
    // Write the updated m3u8 file
    Files.write(outputFile.toPath(), updatedLines);
    // Create the index.m3u8 file
    File indexFile = new File(outputPath + resolution + "/index.m3u8");
    Files.write(indexFile.toPath(), Collections.singletonList("#EXTM3U\n#EXT-X-STREAM-INF:BANDWIDTH=8000000,"), StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
    Files.write(indexFile.toPath(), Collections.singletonList(outputFileName), StandardOpenOption.APPEND);
}

完整代码如下：