问NAudio峰值音量计

EN

public MainWindow()
    {
        int waveInDevices = WaveIn.DeviceCount;
        for (int waveInDevice = 0; waveInDevice < waveInDevices; waveInDevice++)
        {
            WaveInCapabilities deviceInfo = WaveIn.GetCapabilities(waveInDevice);
            Console.WriteLine("Device {0}: {1}, {2} channels",
                waveInDevice, deviceInfo.ProductName, deviceInfo.Channels);

            WaveIn waveIn = new WaveIn();
            waveIn.DeviceNumber = 0; //TODO: Let the user choose which device, this comes from the device numbers above
            waveIn.DataAvailable += waveIn_DataAvailable;
            int sampleRate = SAMPLE_RATE; // 8 kHz
            int channels = 1; // mono
            waveIn.WaveFormat = new WaveFormat(sampleRate, channels);
            waveIn.StartRecording();
        }
    }

    void waveIn_DataAvailable(object sender, WaveInEventArgs e)
    {
        for (int index = 0; index < e.BytesRecorded; index += 2)
        {
            short sample = (short)((e.Buffer[index + 1] << 8) |
                                    e.Buffer[index + 0]);
            float sample32 = sample / 32768f;
            ProcessSample(sample32);
        }           

    }

    void ProcessSample(float sample1)
    {
        samplenumber += 1;

        if (sample1 > maxval)
        {
            maxval = sample1;
        }

        if (sample1 < minval)
        {
            minval = sample1;
        }


        //Run updateView every few loops

        if (samplenumber > (double)SAMPLE_RATE / DISPLAY_UPDATE_RATE)
        {
            samplenumber = 0;
            updateView(); //needs to be fast!
        }
    }

    void updateView()
    {
        Console.WriteLine(maxval);
        Console.WriteLine(minval);
        progressBar1.Value = (maxval - minval)*50;

        maxval = 0;
        minval = 0;
    }