我已设法使用找到的代码here从麦克风发送音频。
但是我无法使用NAudio执行此操作。
CodeProject的代码具有明确的编码和解码代码，例如：
G711.Encode_aLaw
G711.Decode_uLaw
转换并返回要通过网络发送的字节。
是否可以为上面的CodeProject应用程序获取NAudio的示例代码？
答案 0 :(得分：1)
这是我使用NAudio，麦克风输入，扬声器输出，u-Law或A-Law编码编写的快速C＃控制台应用程序。 NAudio.Codecs命名空间包含A-Law和u-Law编码器和解码器。
这个程序不通过网络发送数据（这不难做，我只是不想在这里做）。我会留给你的。相反，它包含“发件人”线程和“接收器”线程。
麦克风DataAvailable事件处理程序只是将字节缓冲区放入队列中（它生成缓冲区的副本 - 您不想保留事件中的实际缓冲区）。 “Sender”线程抓取排队的缓冲区，将PCM数据转换为g.711并将其放入第二个队列。这个“进入第二个队列”部分是您发送到特定应用程序的远程UDP目标的位置。
“Receiver”线程从第二个队列读取数据，将其转换回PCM，然后将其提供给WaveOut（扬声器）设备正在使用的BufferedWaveProvider。您可以使用网络应用程序的UDP套接字接收替换此输入。
请注意，该程序可确保PCM输入和输出（麦克风和扬声器）使用相同的WaveFormat。这也是你必须为网络端点做的事情。
无论如何，它有效。所以这是代码。我不会详细介绍。有很多评论试图帮助理解正在发生的事情：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using NAudio.Wave;
using NAudio.Codecs;
namespace G711MicStream
{
class Program
{
delegate byte EncoderMethod( short _raw );
delegate short DecoderMethod( byte _encoded );
// Change these to their ALaw equivalent if you want.
static EncoderMethod Encoder = MuLawEncoder.LinearToMuLawSample;
static DecoderMethod Decoder = MuLawDecoder.MuLawToLinearSample;
static void Main(string[] args)
{
// Fire off our Sender thread.
Thread sender = new Thread(new ThreadStart(Sender));
sender.Start();
// And receiver...
Thread receiver = new Thread(new ThreadStart(Receiver));
receiver.Start();
// We're going to try for 16-bit PCM, 8KHz sampling, 1 channel.
// This should align nicely with u-law
CommonFormat = new WaveFormat(16000, 16, 1);
// Prep the input.
IWaveIn wavein = new WaveInEvent();
wavein.WaveFormat = CommonFormat;
wavein.DataAvailable += new EventHandler<WaveInEventArgs>(wavein_DataAvailable);
wavein.StartRecording();
// Prep the output. The Provider gets the same formatting.
WaveOut waveout = new WaveOut();
OutProvider = new BufferedWaveProvider(CommonFormat);
waveout.Init(OutProvider);
waveout.Play();
// Now we can just run until the user hits the <X> button.
Console.WriteLine("Running g.711 audio test. Hit <X> to quit.");
for( ; ; )
{
Thread.Sleep(100);
if( !Console.KeyAvailable ) continue;
ConsoleKeyInfo info = Console.ReadKey(false);
if( (info.Modifiers & ConsoleModifiers.Alt) != 0 ) continue;
if( (info.Modifiers & ConsoleModifiers.Control) != 0 ) continue;
// Quit looping on non-Alt, non-Ctrl X
if( info.Key == ConsoleKey.X ) break;
}
Console.WriteLine("Stopping...");
// Shut down the mic and kick the thread semaphore (without putting
// anything in the queue). This will (eventually) stop the thread
// (which also signals the receiver thread to stop).
wavein.StopRecording();
try{ wavein.Dispose(); } catch(Exception){}
SenderKick.Release();
// Wait for both threads to exit.
sender.Join();
receiver.Join();
// And close down the output.
waveout.Stop();
try{ waveout.Dispose(); } catch(Exception) {}
// Sleep a little. This seems to be accepted practice when shutting
// down these audio components.
Thread.Sleep(500);
}
/// <summary>
/// Grabs the mic data and just queues it up for the Sender.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
static void wavein_DataAvailable(object sender, WaveInEventArgs e)
{
// Create a local copy buffer.
byte [] buffer = new byte [e.BytesRecorded];
System.Buffer.BlockCopy(e.Buffer, 0, buffer, 0, e.BytesRecorded);
// Drop it into the queue. We'll need to lock for this.
Lock.WaitOne();
SenderQueue.AddLast(buffer);
Lock.ReleaseMutex();
// and kick the thread.
SenderKick.Release();
}
static
void
Sender()
{
// Holds the data from the DataAvailable event.
byte [] qbuffer = null;
for( ; ; )
{
// Wait for a 'kick'...
SenderKick.WaitOne();
// Lock...
Lock.WaitOne();
bool dataavailable = ( SenderQueue.Count != 0 );
if( dataavailable )
{
qbuffer = SenderQueue.First.Value;
SenderQueue.RemoveFirst();
}
Lock.ReleaseMutex();
// If the queue was empty on a kick, then that's our signal to
// exit.
if( !dataavailable ) break;
// Convert each 16-bit PCM sample to its 1-byte u-law equivalent.
int numsamples = qbuffer.Length / sizeof(short);
byte [] g711buff = new byte [numsamples];
// I like unsafe for this kind of stuff!
unsafe
{
fixed( byte * inbytes = &qbuffer[0] )
fixed( byte * outbytes = &g711buff[0] )
{
// Recast input buffer to short[]
short * buff = (short *)inbytes;
// And loop over the samples. Since both input and
// output are 16-bit, we can use the same index.
for( int index = 0; index < numsamples; ++index )
{
outbytes[index] = Encoder(buff[index]);
}
}
}
// This gets passed off to the reciver. We'll queue it for now.
Lock.WaitOne();
ReceiverQueue.AddLast(g711buff);
Lock.ReleaseMutex();
ReceiverKick.Release();
}
// Log it. We'll also kick the receiver (with no queue addition)
// to force it to exit.
Console.WriteLine("Sender: Exiting.");
ReceiverKick.Release();
}
static
void
Receiver()
{
byte [] qbuffer = null;
for( ; ; )
{
// Wait for a 'kick'...
ReceiverKick.WaitOne();
// Lock...
Lock.WaitOne();
bool dataavailable = ( ReceiverQueue.Count != 0 );
if( dataavailable )
{
qbuffer = ReceiverQueue.First.Value;
ReceiverQueue.RemoveFirst();
}
Lock.ReleaseMutex();
// Exit on kick with no data.
if( !dataavailable ) break;
// As above, but we convert in reverse, from 1-byte u-law
// samples to 2-byte PCM samples.
int numsamples = qbuffer.Length;
byte [] outbuff = new byte [qbuffer.Length * 2];
unsafe
{
fixed( byte * inbytes = &qbuffer[0] )
fixed( byte * outbytes = &outbuff[0] )
{
// Recast the output to short[]
short * outpcm = (short *)outbytes;
// And loop over the u-las samples.
for( int index = 0; index < numsamples; ++index )
{
outpcm[index] = Decoder(inbytes[index]);
}
}
}
// And write the output buffer to the Provider buffer for the
// WaveOut devices.
OutProvider.AddSamples(outbuff, 0, outbuff.Length);
}
Console.Write("Receiver: Exiting.");
}
/// <summary>Lock for the sender queue.</summary>
static Mutex Lock = new Mutex();
static WaveFormat CommonFormat;
/// <summary>"Kick" semaphore for the sender queue.</summary>
static Semaphore SenderKick = new Semaphore(0, int.MaxValue);
/// <summary>Queue of byte buffers from the DataAvailable event.</summary>
static LinkedList<byte []> SenderQueue = new LinkedList<byte[]>();
static Semaphore ReceiverKick = new Semaphore(0, int.MaxValue);
static LinkedList<byte []> ReceiverQueue = new LinkedList<byte[]>();
/// <summary>WaveProvider for the output.</summary>
static BufferedWaveProvider OutProvider;
}
}