我正在开展一个音乐项目，我需要加入几个WAV文件。我的代码工作正常，但你清楚地听到两个加入的WAV文件之间的咔嗒声。这是一个很大的问题。
我是音频工程师。当我工作时，例如DAW（数字音频工作站）中的连续样本，我想防止两个WAV样本之间的这种咔嗒声，然后我必须创建一个交叉淡入淡出（基本上这是第一个样本的淡出和下一个样本的淡入）。
因此我的问题是，如果我可以在连接两个WAV文件时创建这样的交叉淡入淡出。我需要摆脱连接波形文件之间的点击噪音。
我在下面提供了如何连接WAV文件的C＃代码。这适用于格式相同的WAV文件＆＃34;。我在（How to join 2 or more .WAV files together programatically?）上找到了这段代码。此外，我发现了这个FadeIn/FadeOut possibility，但我不知道如何在代码上应用它。此外，我不知道这是否会阻止咔哒声。
感谢您的建议和解决方案。希望Mark Heath读到这个:)。
祝你好运， 亚历
Wavefile格式：
AverageBytesPerSecond：264600 | BitsPerSample：24 | BlockAlign：6 | 频道：2 | 编码：PCM | 额外尺寸：0 | SampleRate：44100 |
public static void Concatenate(string outputFile, IEnumerable<string> sourceFiles)
{
byte[] buffer = new byte[6]; //1024 was the original. but my wave file format has the blockAlign 6. So 1024 was not working for me. 6 does.
WaveFileWriter waveFileWriter = null;
try
{
foreach (string sourceFile in sourceFiles)
{
using (WaveFileReader reader = new WaveFileReader(sourceFile))
{
if (waveFileWriter == null)
{
// first time in create new Writer
waveFileWriter = new WaveFileWriter(outputFile, reader.WaveFormat);
}
else
{
if (!reader.WaveFormat.Equals(waveFileWriter.WaveFormat))
{
throw new InvalidOperationException("Can't concatenate WAV Files that don't share the same format");
}
}
int read;
while ((read = reader.Read(buffer, 0, buffer.Length)) > 0)
{
waveFileWriter.WriteData(buffer, 0, read);
}
}
}
}
finally
{
if (waveFileWriter != null)
{
waveFileWriter.Dispose();
}
}
}
答案 0 :(得分：0)
听起来很有趣：）
这是我写的一个例子。它接受输入文件名模式列表（假定当前目录）和输出文件的名称。它将文件拼接在一起，在一个文件的末尾淡出约1秒，然后在下一个文件的约1秒内淡出，依此类推。注意：它不会混合~1秒重叠。不喜欢这样做:)）
我使用WaveFileReader上的ReadNextSampleFrame方法将数据读取为IEEE浮点样本（每个通道一个浮点数）。这使得单方面应用音量调节变得更加容易，而不必担心实际的输入PCM表示。在输出上，它使用编写器上的WriteSamples来编写调整后的样本。
我第一次使用NAudio FadeInFadeOutSampleProvider。但是当你有多个音频通道时，我发现了一个奇怪的错误。
因此，代码会手动将卷应用于每个样本读取，在每个文件的开头（第一个除外）将卷从0.0增加到1.0。然后直接复制文件的“中间”。然后在文件结束前大约1秒钟（实际上，（WaveFormat.SampleRate * WaveFormat.Channels）在文件结束之前采样），它将音量从1.0f减少到0.0f。 / p>
我通过使用sox测试它来生成一个5秒长的440Hz正弦波文件，采样率= 96K，立体声，如下：
sox -n -c 2 -r 96000 -b 24 sine.wav synth 5 sine 440
测试如下：
FadeWeaver.FadeWeave("weaved.wav", "sine.wav", "sine.wav", "sine.wav");
这是代码：
public class FadeWeaver
{
static
public
void
FadeWeave( string _outfilename,
params string [] _inpatterns )
{
WaveFileWriter output = null;
WaveFormat waveformat = null;
float [] sample = null;
float volume = 1.0f;
float volumemod = 0.0f;
// Add .wav extension to the output if not specified.
string extension = Path.GetExtension(_outfilename);
if( string.Compare(extension, ".wav", true) != 0 ) _outfilename += ".wav";
// Assume we're using the current directory. Let's get the
// list of filenames.
List<string> filenames = new List<string>();
foreach( string pattern in _inpatterns )
{
filenames.AddRange(Directory.GetFiles(Directory.GetCurrentDirectory(), pattern));
}
try
{
// Alrighty. Let's march over them. We'll index them (rather than
// foreach'ing) so that we can monitor first/last file.
for( int index = 0; index < filenames.Count; ++index )
{
// Grab the file and use an 'audiofilereader' to load it.
string filename = filenames[index];
using( WaveFileReader reader = new WaveFileReader(filename) )
{
// Get our first/last flags.
bool firstfile = (index == 0 );
bool lastfile = (index == filenames.Count - 1);
// If it's the first...
if( firstfile )
{
// Initialize the writer.
waveformat = reader.WaveFormat;
output = new WaveFileWriter(_outfilename, waveformat);
}
else
{
// All files must have a matching format.
if( !reader.WaveFormat.Equals(waveformat) )
{
throw new InvalidOperationException("Different formats");
}
}
long fadeinsamples = 0;
if( !firstfile )
{
// Assume 1 second of fade in, but set it to total size
// if the file is less than one second.
fadeinsamples = waveformat.SampleRate;
if( fadeinsamples > reader.SampleCount ) fadeinsamples = reader.SampleCount;
}
// Initialize volume and read from the start of the file to
// the 'fadeinsamples' count (which may be 0, if it's the first
// file).
volume = 0.0f;
volumemod = 1.0f / (float)fadeinsamples;
int sampleix = 0;
while( sampleix < (long)fadeinsamples )
{
sample = reader.ReadNextSampleFrame();
for( int floatix = 0; floatix < waveformat.Channels; ++floatix )
{
sample[floatix] = sample[floatix] * volume;
}
// Add modifier to volume. We'll make sure it isn't over
// 1.0!
if( (volume = (volume + volumemod)) > 1.0f ) volume = 1.0f;
// Write them to the output and bump the index.
output.WriteSamples(sample, 0, sample.Length);
++sampleix;
}
// Now for the time between fade-in and fade-out.
// Determine when to start.
long fadeoutstartsample = reader.SampleCount;
//if( !lastfile )
{
// We fade out every file except the last. Move the
// sample counter back by one second.
fadeoutstartsample -= waveformat.SampleRate;
if( fadeoutstartsample < sampleix )
{
// We've actually crossed over into our fade-in
// timeframe. We'll have to adjust the actual
// fade-out time accordingly.
fadeoutstartsample = reader.SampleCount - sampleix;
}
}
// Ok, now copy everything between fade-in and fade-out.
// We don't mess with the volume here.
while( sampleix < (int)fadeoutstartsample )
{
sample = reader.ReadNextSampleFrame();
output.WriteSamples(sample, 0, sample.Length);
++sampleix;
}
// Fade out is next. Initialize the volume. Note that
// we use a bit-shorter of a time frame just to make sure
// we hit 0.0f as our ending volume.
long samplesleft = reader.SampleCount - fadeoutstartsample;
volume = 1.0f;
volumemod = 1.0f / ((float)samplesleft * 0.95f);
// And loop over the reamaining samples
while( sampleix < (int)reader.SampleCount )
{
// Grab a sample (one float per channel) and adjust by
// volume.
sample = reader.ReadNextSampleFrame();
for( int floatix = 0; floatix < waveformat.Channels; ++floatix )
{
sample[floatix] = sample[floatix] * volume;
}
// Subtract modifier from volume. We'll make sure it doesn't
// accidentally go below 0.
if( (volume = (volume - volumemod)) < 0.0f ) volume = 0.0f;
// Write them to the output and bump the index.
output.WriteSamples(sample, 0, sample.Length);
++sampleix;
}
}
}
}
catch( Exception _ex )
{
Console.WriteLine("Exception: {0}", _ex.Message);
}
finally
{
if( output != null ) try{ output.Dispose(); } catch(Exception){}
}
}
}