我有一个程序可以生成音频信号,这些信号应该同时播放。为此,我在每个100毫秒周期中播放100毫秒的音频流间隔。但是,在每个100毫秒音频流的开头和结尾都会出现不期望的信号(因为直流偏置),导致输出声音不平滑,即使信号值相同也是如此。我的代码附在下面。请帮我找出正确实时音频所需的解决方法。
using System;
using System.Windows.Forms;
using Microsoft.DirectX.DirectSound;
using System.IO;
namespace TestSound
{
class CSound : Form
{
const int HEADER_SIZE = 44;
const bool FLAG_STEREO = true;
const short BITS_PER_SAMPLE = 16;
const int SAMPLE_RATE = 44100;
int numberOfSamples;
MemoryStream stream;
BinaryWriter writer;
Device ApplicationDevice = null;
SecondaryBuffer buffer = null;
BufferDescription description;
public CSound()
{
try
{
ApplicationDevice = new Device();
}
catch
{
MessageBox.Show("Unable to create sound device.");
ApplicationDevice = null;
return;
}
ApplicationDevice.SetCooperativeLevel(this, CooperativeLevel.Priority);
description = new BufferDescription();
description.ControlEffects = false;
stream = new MemoryStream();
writer = new BinaryWriter(stream);
}
private void AddHeader()
{
stream.Position = 0;
writer.Write(0x46464952); // "RIFF" in ASCII
writer.Write((int)(HEADER_SIZE + (numberOfSamples * BITS_PER_SAMPLE * (FLAG_STEREO ? 2 : 1) / 8)) - 8);
writer.Write(0x45564157); // "WAVE" in ASCII
writer.Write(0x20746d66); // "fmt " in ASCII
writer.Write(16);
writer.Write((short)1);
writer.Write((short)(FLAG_STEREO ? 2 : 1));
writer.Write(SAMPLE_RATE);
writer.Write(SAMPLE_RATE * (FLAG_STEREO ? 2 : 1) * BITS_PER_SAMPLE / 8);
writer.Write((short)((FLAG_STEREO ? 2 : 1) * BITS_PER_SAMPLE / 8));
writer.Write(BITS_PER_SAMPLE);
writer.Write(0x61746164); // "data" in ASCII
writer.Write((int)(numberOfSamples * BITS_PER_SAMPLE * (FLAG_STEREO ? 2 : 1) / 8));
}
public void Play(short[] samples)
{
if (ApplicationDevice == null)
return;
stream.Position = HEADER_SIZE;
numberOfSamples = samples.Length;
for (int i = 0; i < numberOfSamples; i++)
{
writer.Write(samples[i]);
if (FLAG_STEREO)
writer.Write(samples[i]);
}
AddHeader();
stream.Position = 0;
try
{
if (buffer != null)
{
buffer.Dispose();
buffer = null;
}
buffer = new SecondaryBuffer(stream, description, ApplicationDevice);
buffer.Play(0, BufferPlayFlags.Default);
}
catch (Exception e)
{
MessageBox.Show(e.Message);
}
}
static short[] samples = new short[4410]; // 100 ms
static CSound sound;
static void Main()
{
Form form = new Form();
form.Show();
sound = new CSound();
Random random = new Random();
for (int i = 0; i < samples.Length; i++)
samples[i] = 1000; // constant value
while (true)
{
sound.Play(samples);
System.Threading.Thread.Sleep(100); // 100 ms
}
}
}
}