如何优雅的用java实现视频转码

1. 开源项目 JAVE (Java Audio Video Encoder)
2. 引入依赖

<dependency>
    <groupId>ws.schild</groupId>
    <artifactId>jave-all-deps</artifactId>
    <version>2.7.2</version>
</dependency>

3. 编码测试

package test;

import java.io.File;
import ws.schild.jave.AudioAttributes;
import ws.schild.jave.AudioInfo;
import ws.schild.jave.Encoder;
import ws.schild.jave.EncodingAttributes;
import ws.schild.jave.MultimediaInfo;
import ws.schild.jave.MultimediaObject;
import ws.schild.jave.VideoAttributes;
import ws.schild.jave.VideoInfo;
import ws.schild.jave.VideoSize;

public class Test {
    
    public static void main(String[] args) throws Exception {
        
        File source = new File("d:/source.mp4");
        File target = new File("d:/target.mp4");
        
        System.out.println("源视频信息");
        MultimediaObject object = new MultimediaObject(source);
        MultimediaInfo info = object.getInfo();
        System.out.println("格式format：" + info.getFormat());
        System.out.println("时长duration：" + info.getDuration());
        VideoInfo videoInfo = info.getVideo();
        System.out.println("编码decoder：" + videoInfo.getDecoder());
        System.out.println("码率bitRate：" + videoInfo.getBitRate());
        System.out.println("帧率frameRate：" + videoInfo.getFrameRate());
        VideoSize videoSize = videoInfo.getSize();
        System.out.println("分辨率：" + videoSize.getWidth() + " x " + videoSize.getHeight());
        AudioInfo audioInfo = info.getAudio();
        System.out.println("编码decoder：" + audioInfo.getDecoder());
        System.out.println("码率bitRate：" + audioInfo.getBitRate());
        System.out.println("声道channels：" + audioInfo.getChannels());
        System.out.println("采样率samplingRate：" + audioInfo.getSamplingRate());
        
        // 视频属性
        VideoAttributes video = new VideoAttributes();
        video.setCodec("libx264");
        video.setBitRate(256000); // 码率：256kbps
        video.setFrameRate(25); // 帧率：25fps
        int width = 640; // 固定宽度
        int height = width * videoSize.getHeight() / videoSize.getWidth();
        height = height%2==0 ? height : height+1; // 视频宽高必须是偶数
        video.setSize(new VideoSize(width, height));
        // 音频属性
        AudioAttributes audio = new AudioAttributes();
        audio.setCodec("aac");
        audio.setBitRate(64000); // 码率：64kbps
        audio.setSamplingRate(24000); // 采样率：24kHz
        // 转码属性
        EncodingAttributes attributes = new EncodingAttributes();
        attributes.setVideoAttributes(video);
        attributes.setAudioAttributes(audio);
        attributes.setFormat("mp4");

        Encoder encoder = new Encoder();
        encoder.encode(object, target, attributes);
        
        System.out.println("转码完成：新分辨率：" + width + " x " + height);
    }
    
}

3. 测试结果

源视频信息
格式format：mov
时长duration：268280
编码decoder：h264 (Main) (avc1 / 0x31637661)
码率bitRate：500000
帧率frameRate：25.0
分辨率：768 x 432
编码decoder：aac (LC) (mp4a / 0x6134706D)
码率bitRate：96000
声道channels：2
采样率samplingRate：44100

转码完成：新分辨率：640 x 360