/// <summary>
/// 使用指定的音频流绘制波形图
/// </summary>
/// <param name="stream"></param>
/// <returns></returns>
public OptReturn Draw(WaveStream stream)
{
OptReturn optReturn = new OptReturn();
optReturn.Result = true;
optReturn.Code = Defines.RET_SUCCESS;
try
{
WaveStream reader = stream;
reader.Position = 0;
if (reader.WaveFormat.Encoding != WaveFormatEncoding.Pcm && reader.WaveFormat.Encoding != WaveFormatEncoding.IeeeFloat)
{
reader = WaveFormatConversionStream.CreatePcmStream(reader);
reader = new BlockAlignReductionStream(reader);
}
InitDraw();
var waveChannel = new SampleChannel(reader, true);
int samples = (int)(reader.TotalTime.TotalSeconds) * reader.WaveFormat.SampleRate / mPngWidth;
var postVolumeMeter = new MeteringSampleProvider(waveChannel, samples);
postVolumeMeter.StreamVolume += postVolumeMeter_StreamVolume;
var waveProvider = new SampleToWaveProvider(postVolumeMeter);
while (true)
{
byte[] buffer = new byte[waveProvider.WaveFormat.AverageBytesPerSecond];
int readcount = waveProvider.Read(buffer, 0, waveProvider.WaveFormat.AverageBytesPerSecond);
if (readcount <= 0)
{
break;
}
}
stream.Position = 0;
if (mIsSaveFile)
{
return(GenerateImageFile());
}
Bitmap[] bitmaps = new Bitmap[2];
bitmaps[0] = mBitmap;
bitmaps[1] = mBitmap1;
optReturn.Data = bitmaps;
return(optReturn);
}
catch (Exception ex)
{
optReturn.Result = false;
optReturn.Code = Defines.RET_FAIL;
optReturn.Message = ex.Message;
return(optReturn);
}
}
/// <summary>
/// Creates the reader stream, supporting all filetypes in the core NAudio library,
/// and ensuring we are in PCM format
/// </summary>
/// <param name="fileName">File Name</param>
private void CreateReaderStream(string fileName)
{
if (fileName.EndsWith(".wav", StringComparison.OrdinalIgnoreCase))
{
readerStream = new WaveFileReader(fileName);
if (readerStream.WaveFormat.Encoding != WaveFormatEncoding.Pcm && readerStream.WaveFormat.Encoding != WaveFormatEncoding.IeeeFloat)
{
readerStream = WaveFormatConversionStream.CreatePcmStream(readerStream);
readerStream = new BlockAlignReductionStream(readerStream);
}
}
else if (fileName.EndsWith(".mp3", StringComparison.OrdinalIgnoreCase))
{
readerStream = new Mp3FileReader(fileName);
}
else if (fileName.EndsWith(".aiff"))
{
readerStream = new AiffFileReader(fileName);
}
}
