javacv从入门到精通进阶——第七章：高级音频处理_Java

学习如何使用ffmpeg进行高级音频处理

javacv中的ffmpeg库提供了广泛的音频处理功能，可以进行各种高级音频处理，包括但不限于以下内容：

音频裁剪

通过指定音频的起始时间和持续时间来裁剪音频文件，以获得需要的音频片段。

public static void audioclip(string inputpath, string outputpath, double starttime, double duration) throws exception {
    ffmpegframegrabber grabber = new ffmpegframegrabber(inputpath);
    grabber.start();

    ffmpegframerecorder recorder = new ffmpegframerecorder(outputpath, grabber.getaudiochannels());
    recorder.setaudiocodec(grabber.getaudiocodec());
    recorder.setaudiobitrate(grabber.getaudiobitrate());
    recorder.setsamplerate(grabber.getsamplerate());
    recorder.start();

    double endtime = starttime + duration;

    frame frame;
    while ((frame = grabber.grabframe()) != null) {
        if (frame.samples == null) {
            break;
        }

        double timestamp = grabber.gettimestamp() / 1000000.0;
        if (timestamp >= starttime && timestamp <= endtime) {
            recorder.record(frame);
        }
    }

    grabber.stop();
    recorder.stop();
}

音频削弱：

通过调整音频的音量和音频的增益来削弱音频，以减少音频的噪音和失真。

public static void audioreduce(string inputpath, string outputpath, double volume) throws exception {
    ffmpegframegrabber grabber = new ffmpegframegrabber(inputpath);
    grabber.start();

    ffmpegframerecorder recorder = new ffmpegframerecorder(outputpath, grabber.getaudiochannels());
    recorder.setaudiocodec(grabber.getaudiocodec());
    recorder.setaudiobitrate(grabber.getaudiobitrate());
    recorder.setsamplerate(grabber.getsamplerate());
    recorder.start();

    frame frame;
    while ((frame = grabber.grabframe()) != null) {
        if (frame.samples == null) {
            break;
        }

        shortbuffer buffer = (shortbuffer) frame.samples[0];
        for (int i = 0; i < buffer.limit(); i++) {
            buffer.put(i, (short) (buffer.get(i) * volume));
        }

        recorder.record(frame);
    }

    grabber.stop();
    recorder.stop();
}

音频混音：

将两个或多个音频文件混合在一起，以创建一个新的混合音频文件。

public static void audiomix(string inputpath1, string inputpath2, string outputpath) throws exception {
    ffmpegframegrabber grabber1 = new ffmpegframegrabber(inputpath1);
    grabber1.start();

    ffmpegframegrabber grabber2 = new ffmpegframegrabber(inputp