java实现h265视频转h264视频

要将H.265视频转换为H.264视频，可以使用FFmpeg库。以下是使用Java调用FFmpeg库实现H.265到H.264转换的示例代码：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class H265ToH264Converter {

    public static void main(String[] args) {
        String inputFilePath = "input.hevc";
        String outputFilePath = "output.mp4";
        convert(inputFilePath, outputFilePath);
    }

    public static void convert(String inputFilePath, String outputFilePath) {
        List<String> command = new ArrayList<>();
        command.add("ffmpeg");
        command.add("-i");
        command.add(inputFilePath);
        command.add("-c:v");
        command.add("libx264");
        command.add(outputFilePath);

        try {
            ProcessBuilder builder = new ProcessBuilder(command);
            Process process = builder.start();

            BufferedReader reader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }

            int exitCode = process.waitFor();
            if (exitCode == 0) {
                System.out.println("Conversion completed successfully");
            } else {
                System.out.println("Conversion failed");
            }
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }
}

这个示例代码使用Java的ProcessBuilder类启动一个FFmpeg进程，并将H.265视频转换为H.264视频。输入文件路径和输出文件路径作为参数传递给convert()方法。在调用Process.waitFor()方法时，程序会等待FFmpeg进程完成转换操作。转换完成后，程序会输出一条相关消息。