Xamarin：播放声音一分钟

Question

我正在尝试播放一分钟的声音。我可以这样做，但我这样做的方式会首先生成声音缓冲区然后播放它，这需要太多时间，有很大的延迟。所以现在我正在尝试在播放时生成声音缓冲区。所以不会有延迟。它播放了 4 秒然后停止，但我无法再次单击我的按钮一分钟。所以我认为即使我什么都听不见，代码仍在运行。

这是我的代码：

public void play()
    {   
        short[] buffer = new short[44100];
        track = new AudioTrack (Stream.Music, 44100, ChannelOut.Mono, Encoding.Pcm16bit, 5292000, AudioTrackMode.Static);
        track.SetPlaybackRate (44100);
        while (n2 < 5292000) {
            for (int n = 0; n < 44100; n++) {

                float temp1 = (float)( Amplitude * Math.Sin ((2 * Math.PI * Frequency * n2) / 44100D));
                byte[] bytes = BitConverter.GetBytes (temp1);
                buffer [n] = (short)(temp1 * short.MaxValue);
                n2++;
            }
            int buffer_number = track.Write (buffer, 0, buffer.Length);
            track.Play();
        }

        track.Release();
    }

我尝试使用 AudioTrackMode Stream 但是当程序到达 Track.play 时会抛出运行时错误： play() 在未初始化的 AudioTrack 上调用。

那我做错了什么？

Answer 1

以下是我如何在 c# 中使用基于 android 示例的压缩版本：

http://marblemice.blogspot.fr/2010/04/generate-and-play-tone-in-android.html

public void playSound()
        {   
            var duration = 1;
            var sampleRate = 8000;
            var numSamples = duration * sampleRate;
            var sample = new double[numSamples];
            var freqOfTone = 1900;
            byte[] generatedSnd = new byte[2 * numSamples];

            for (int i = 0; i < numSamples; ++i) {
                sample[i] = Math.Sin(2 * Math.PI * i / (sampleRate/freqOfTone));
            }

            int idx = 0;
            foreach (double dVal in sample) {
                short val = (short) (dVal * 32767);
                generatedSnd[idx++] = (byte) (val & 0x00ff);
                generatedSnd[idx++] = (byte) ((val & 0xff00) >> 8);
            }

            var track = new AudioTrack (global::Android.Media.Stream.Music, sampleRate, ChannelOut.Mono, Encoding.Pcm16bit, numSamples, AudioTrackMode.Static);
            track.Write(generatedSnd, 0, numSamples);
            track.Play ();
        }

根据您的需要调整duration和`freqOfTone``。