javacv使用笔记

程序员 Java, 程序员 评论

使用过程中遇到的异常

异常：Could not initialize class org.bytedeco.javacpp.avutil

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Exception in thread "main" java.lang.NoClassDefFoundError: Could not initialize class org.bytedeco.javacpp.avutil
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:274)
at org.bytedeco.javacpp.Loader.load(Loader.java:385)
at org.bytedeco.javacpp.Loader.load(Loader.java:353)
at org.bytedeco.javacpp.avformat$AVFormatContext.<clinit>(avformat.java:2249)
at org.bytedeco.javacv.FFmpegFrameGrabber.startUnsafe(FFmpegFrameGrabber.java:346)
at org.bytedeco.javacv.FFmpegFrameGrabber.start(FFmpegFrameGrabber.java:340)

解决办法：

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mvn package exec:java -Dplatform.dependencies -Dexec.mainClass=Demo

警告：Warning: data is not aligned! This can lead to a speedloss

出现这个警告是因为ffmpeg要求视频的宽度必须是32的倍数，高度必须是2的倍数，按要求修改下宽高就好了。

使用示例

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import com.google.common.collect.Lists;
import org.apache.commons.io.FileUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.math.NumberUtils;
import org.bytedeco.javacpp.avcodec;
import org.bytedeco.javacpp.opencv_core;
import org.bytedeco.javacpp.opencv_imgcodecs;
import org.bytedeco.javacv.*;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.Collections;
import java.util.List;

/**
 * @author Gao Youbo
 * @since 2018-08-15 16:43
 */
public class OpenCVUtils {
    public static void main(String[] args) throws Exception {
        List<BufferedImage> images = grab(new File("/data/opencv/test.mp4"));
        int i = 1;
        for (BufferedImage image : images) {
            ImageIO.write(image, "jpg", new File("/data/opencv/frame/" + i + ".jpg"));
            i++;
        }

        // grabAudioFromVideo(new File("/data/opencv/test.mp4"), new File("/data/opencv/test.aac"));

        List<File> files = Lists.newArrayList(FileUtils.listFiles(new File("/data/opencv/frame/"), new String[]{"jpg"}, false));
        Collections.sort(files, (o1, o2) -> {
            int i1 = NumberUtils.toInt(StringUtils.substringBefore(o1.getName(), "."));
            int i2 = NumberUtils.toInt(StringUtils.substringBefore(o2.getName(), "."));
            return Integer.compare(i1, i2);
        });
        record("/data/opencv/out.mp4", files, new File("/data/opencv/test.aac"), 544, 960);
    }

    /**
     * 将多个图片文件合成视频
     *
     * @param output    输出文件
     * @param images    序列帧图片
     * @param audioFile 音频
     * @param width     宽
     * @param height    高
     * @throws Exception
     */
    public static void record(String output, List<File> images, File audioFile, int width, int height) throws Exception {
        try (FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(output, width, height);
             FFmpegFrameGrabber grabber = FFmpegFrameGrabber.createDefault(audioFile)) {
            recorder.setVideoCodec(avcodec.AV_CODEC_ID_H264);
            recorder.setFormat("mp4");
            recorder.setFrameRate(30);
            recorder.setAudioBitrate(192000);
            recorder.setAudioQuality(0);
            recorder.setSampleRate(44100);
            recorder.setAudioChannels(2);
            recorder.start();

            OpenCVFrameConverter.ToIplImage converter = new OpenCVFrameConverter.ToIplImage();
            for (File file : images) {
                opencv_core.IplImage image = opencv_imgcodecs.cvLoadImage(file.getPath());
                recorder.record(converter.convert(image));
                opencv_core.cvReleaseImage(image);
            }

            grabber.start();
            Frame frame;
            while ((frame = grabber.grabSamples()) != null) {
                recorder.setTimestamp(frame.timestamp);
                recorder.recordSamples(frame.sampleRate, frame.audioChannels, frame.samples);
            }
        }
    }

    /**
     * 从视频中将每一帧的图片提取出来
     *
     * @param video
     * @return
     * @throws FrameGrabber.Exception
     */
    public static List<BufferedImage> grab(File video) throws Exception {
        try (FFmpegFrameGrabber grabber = FFmpegFrameGrabber.createDefault(video.getPath())) {
            grabber.start();

            List<BufferedImage> images = Lists.newArrayList();
            Frame frame;
            while ((frame = grabber.grabImage()) != null) {
                images.add(Java2DFrameUtils.toBufferedImage(frame));
            }
            return images;
        }
    }

    /**
     * 从视频中提取出音频
     *
     * @param video
     * @param outputAudio
     */
    public static void grabAudioFromVideo(File video, File outputAudio) throws Exception {
        try (FFmpegFrameGrabber grabber = FFmpegFrameGrabber.createDefault(video);
             FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(outputAudio, 1)) {
            grabber.start();
            recorder.setAudioCodec(avcodec.AV_CODEC_ID_AAC);
            recorder.start();

            Frame frame;
            while ((frame = grabber.grab()) != null) {
                if (frame.audioChannels == 1) {
                    recorder.recordSamples(frame.sampleRate, frame.audioChannels, frame.samples);
                }
            }
        }
    }

}

图片合成视频简单的封装

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private static class VideoRecorder implements Closeable {
        private FFmpegFrameRecorder recorder;

        public VideoRecorder(String output, int width, int height) throws FrameRecorder.Exception {
            recorder = new FFmpegFrameRecorder(output, width, height);
            recorder.setVideoCodec(avcodec.AV_CODEC_ID_H264);
            recorder.setFormat("mp4");
            recorder.setFrameRate(FPS);
            recorder.setAudioBitrate(192000);
            recorder.setAudioQuality(0);
            recorder.setSampleRate(44100);
            recorder.setAudioChannels(2);
            recorder.start();
        }

        public void addFrame(BufferedImage image) throws FrameRecorder.Exception {
            Frame frame = Java2DFrameUtils.toFrame(image);
            recorder.record(frame, avutil.AV_PIX_FMT_ARGB);
        }

        public void addAudio(File audioFile) throws FrameGrabber.Exception, FrameRecorder.Exception {
            if (audioFile == null || !audioFile.exists()) {
                return;
            }
            try (FFmpegFrameGrabber grabber = FFmpegFrameGrabber.createDefault(audioFile)) {
                grabber.start();
                Frame frame;
                while ((frame = grabber.grabSamples()) != null) {
                    recorder.recordSamples(frame.sampleRate, frame.audioChannels, frame.samples);
                }
            }
        }

        @Override
        public void close() throws IOException {
            recorder.close();
        }
    }

解决maven打包时将不必要的包引入进来的问题

我在实际使用中只用到了ffmpeg，但是打包的时候却将flycapture、libdc1394、libfreenect、artoolkitplus、tesseract…等包都打进来了，这些都是我不需要的，下面贴出我的maven配置示例。

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<properties>
    <javacpp.version>1.4.2</javacpp.version>
    <!-- 这里要根据自己的平台选择不同的依赖 -->
    <!--<javacpp.platform.dependencies>linux-x86_64</javacpp.platform.dependencies>-->
    <javacpp.platform.dependencies>macosx-x86_64</javacpp.platform.dependencies>
</properties>
<dependencies>
        <dependency>
            <groupId>org.bytedeco</groupId>
            <artifactId>javacv</artifactId>
            <version>${javacpp.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>org.bytedeco.javacpp-presets</groupId>
                    <artifactId>*</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.bytedeco.javacpp-presets</groupId>
            <artifactId>opencv</artifactId>
            <version>3.4.2-${javacpp.version}</version>
        </dependency>
        <dependency>
            <groupId>org.bytedeco.javacpp-presets</groupId>
            <artifactId>ffmpeg</artifactId>
            <version>4.0.1-${javacpp.version}</version>
        </dependency>
        <dependency>
            <groupId>org.bytedeco.javacpp-presets</groupId>
            <artifactId>ffmpeg</artifactId>
            <version>4.0.1-${javacpp.version}</version>
            <classifier>${javacpp.platform.dependencies}</classifier>
        </dependency>
    </dependencies>

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