java调用FFmpeg实现视屏压缩功能的详细步骤

ffmpeg -i 待压缩文件 -b:v 1.5M  压缩后的文件
参考：
ffmpeg -i Desktop/1.mov -b:v 1.5M  Desktop/1.mp4

 
    private static  void toCompressFile(String convertFile,String targetFile){
        try{
            Runtime runtime = Runtime.getRuntime();
            
            String cutCmd="ffmpeg -i " + convertFile + " -r 15 -b:v 600k  -s 1280x720 "+ targetFile;
            System.out.println("cutCmd:"+cutCmd);
            runtime.exec(cutCmd);
            System.out.println("文件："+convertFile+" 正在转换中。。。");
        }catch(Exception e){
            e.printStackTrace();
            System.out.println("压缩文件出现异常："+e.getMessage());
        }
    }
 
    public static void main(String[] ars ){
        long startTime = System.currentTimeMillis();
        final String convertFile="C:\\Users\\issuser\\Desktop\\a\\";
        File f=new File(convertFile);
        File[] fs=f.listFiles();
        for(File ff:fs){
            if(ff.toPath().toString().toLowerCase().endsWith(".mp4")){
                String f1=convertFile+ff.getName();
                String f2=convertFile+"压缩后_"+ff.getName();
                toCompressFile(f1,f2);
            }
        }
        System.out.println("耗时："+(System.currentTimeMillis()-startTime));
    }

import java.io.BufferedReader;
import java.io.File;
import java.io.InputStream;
import java.io.InputStreamReader;
 
public class FFmpegVideo {
 
    
    private static  void toCompressFile(String convertFile,String targetFile){
        try{
            Runtime runtime = Runtime.getRuntime();
            
            String cutCmd="ffmpeg -i " + convertFile + " -r 15 -b:v 600k  -s 1280x720 "+ targetFile;
            System.out.println("cutCmd:"+cutCmd);
            runCmd(cutCmd);
            System.out.println("文件："+convertFile+" 视屏压缩完成");
        }catch(Exception e){
            e.printStackTrace();
            System.out.println("压缩文件出现异常："+e.getMessage());
        }
    }
 
    public static void main(String[] ars ){
        long startTime = System.currentTimeMillis();
        final String convertFile="C:\\Users\\issuser\\Desktop\\a\\";
        File f=new File(convertFile);
        File[] fs=f.listFiles();
        for(File ff:fs){
            if(ff.toPath().toString().toLowerCase().endsWith(".mp4")){
                String f1=convertFile+ff.getName();
                String f2=convertFile+"after_"+ff.getName();
                toCompressFile(f1,f2);
            }
        }
        System.out.println("耗时："+(System.currentTimeMillis()-startTime));
    }
 
    
    public static void runCmd(String command) {
        try {
            Runtime rt = Runtime.getRuntime();
            Process proc = rt.exec(command);
            InputStream stderr = proc.getErrorStream();
            InputStreamReader isr = new InputStreamReader(stderr);
            BufferedReader br = new BufferedReader(isr);
            String line;
            System.out.println("开始执行");
            while ((line = br.readLine()) != null){
                System.out.println(line);
            }
            System.out.println("执行结束");
            int exitVal = proc.waitFor();
            System.out.println("Process exitValue: " + exitVal);
        } catch (Throwable t) {
            System.out.println(t);
            t.printStackTrace();
        }
 
    }
}