打从生成缓冲区声音Windows 8应用

本文介绍了打从生成缓冲区声音Windows 8应用的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我移植一些C＃的Windows Phone 7应用到Windows 8中。

的手机应用程序使用的XNA的从缓冲区玩任意声音。在最简单的情况下，我只希望创建所需的持续时间和频率的正弦波。无论是持续时间和频率可以相差很大，所以我宁愿不依赖于MediaElements（除非有好歹基本文件的频率漂移，但是这只会帮助我的单频代）。

什么是XNA SoundEffectInstance在WinRT中的相同呢？

我想我需要要使用DirectX这一点，但我不知道如何去了解这个从否则C＃/ XAML应用程序。我有一个看看，但它似乎并不具备的DirectSound，SecondaryBuffer，SecondaryBuffer类，我假设我需要使用。

我做了上述的一些假设。这可能是我找错了班或有从Windows 8应用产生任意的声音一个完全独立的方式。

我发现的播放WAV文件的例子。这似乎是有前途的，我只需要替换本地文件流我生成的音频缓冲。

    public void PlaySound()
    {
        XAudio2 xaudio;
        MasteringVoice masteringVoice;

        xaudio = new XAudio2();
        masteringVoice = new MasteringVoice(xaudio);

        var nativefilestream = new NativeFileStream(
            @"Assets\SpeechOn.wav",
            NativeFileMode.Open,
            NativeFileAccess.Read,
            NativeFileShare.Read);

        var soundstream = new SoundStream(nativefilestream);


        var waveFormat = soundstream.Format;
        var buffer = new AudioBuffer
        {
            Stream = soundstream.ToDataStream(),
            AudioBytes = (int)soundstream.Length,
            Flags = BufferFlags.EndOfStream
        };

        var sourceVoice = new SourceVoice(xaudio, waveFormat, true);

        // There is also support for shifting the frequency.
        sourceVoice.SetFrequencyRatio(0.5f);

        sourceVoice.SubmitSourceBuffer(buffer, soundstream.DecodedPacketsInfo);

        sourceVoice.Start();
    }

解决方案

The only way to generate dynamic sound in Win8RT is to use XAudio2, so you should be able to do this with SharpDX.XAudio2.

Instead of using NativeFileStream, just instantiate a DataStream directly giving your managed buffer (or you can use an unmanaged buffer or let DataStream instantiate one for you). The code would be like this:

// Initialization phase, keep this buffer during the life of your application
// Allocate 10s at 44.1Khz of stereo 16bit signals
var myBufferOfSamples = new short[44100 * 10 * 2];

// Create a DataStream with pinned managed buffer
var dataStream = DataStream.Create(myBufferOfSamples, true, true);

var buffer = new AudioBuffer
        {
            Stream = dataStream,
            AudioBytes = (int)dataStream.Length,
            Flags = BufferFlags.EndOfStream
        };

//...
// Fill myBufferOfSamples
//...

// PCM 44.1Khz stereo 16 bit format
var waveFormat = new WaveFormat();

XAudio2 xaudio = new XAudio2();
MasteringVoice masteringVoice = new MasteringVoice(xaudio);
var sourceVoice = new SourceVoice(xaudio, waveFormat, true);

// Submit the buffer
sourceVoice.SubmitSourceBuffer(buffer, null);

Sample method to fill the buffer with a Sine wave:

    private void FillBuffer(short[] buffer, int sampleRate, double frequency)
    {
        double totalTime = 0;

        for (int i = 0; i < buffer.Length - 1; i += 2)
        {
            double time = (double)totalTime / (double)sampleRate;
            short currentSample = (short)(Math.Sin(2 * Math.PI * frequency * time) * (double)short.MaxValue);

            buffer[i] = currentSample; //(short)(currentSample & 0xFF);
            buffer[i + 1] = currentSample; //(short)(currentSample >> 8);

            totalTime += 2;
        }

    }

这篇关于打从生成缓冲区声音Windows 8应用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！

datastream

打从生成缓冲区声音Windows 8应用

问题描述