/// <summary>
/// Adjusts the volume level of a WAV file, saving the adjusted file as a separate file.
/// </summary>
/// <param name="pSrcFilename">The name of the WAV file to adjust</param>
/// <param name="pDestFilename">The name to use for the volume-adjusted WAV file</param>
/// <param name="pMultiplier">The value by which to multiply the audio samples</param>
public static void AdjustVolume_Copy(String pSrcFilename, String pDestFilename, double pMultiplier)
{
// If an empty source or destination file were passed in, then throw an exception.
if (pSrcFilename == "")
throw new WAVFileReadException("Blank filename specified.", "WAVFile.AdjustVolume_Copy()");
if (pDestFilename == "")
throw new WAVFileWriteException("Blank filename specified.", "WAVFile.AdjustVolume_Copy()");
// Open the srouce file
WAVFile srcFile = new WAVFile();
String retval = srcFile.Open(pSrcFilename, WAVFileMode.READ);
if (retval == "")
{
// Check to make sure the input file has a supported number of bits/sample and sample rate. If
// not, then throw an exception.
if (!SupportedBitsPerSample(srcFile.BitsPerSample))
{
WAVFileBitsPerSampleException exc = new WAVFileBitsPerSampleException(pSrcFilename +
" has unsupported bits/sample ("
+ srcFile.BitsPerSample.ToString() + ")",
"WAVFile.AdjustVolume_Copy()", srcFile.BitsPerSample);
srcFile.Close();
throw exc;
}
// Open the destination file and start copying the adjusted audio data to it.
WAVFile destFile = new WAVFile();
destFile.Create(pDestFilename, srcFile.IsStereo, srcFile.SampleRateHz, srcFile.BitsPerSample);
if (srcFile.BitsPerSample == 8)
{
byte sample = 0;
for (int i = 0; i < srcFile.NumSamples; ++i)
{
// Note: Only multiply the sample if pMultiplier is not 1.0 (if the multiplier is
// 1.0, then it would be good to avoid any binary roundoff error).
sample = srcFile.GetNextSample_8bit();
if (pMultiplier != 1.0)
sample = (byte)((double)sample * pMultiplier);
destFile.AddSample_8bit(sample);
}
}
else if (srcFile.BitsPerSample == 16)
{
short sample = 0;
for (int i = 0; i < srcFile.NumSamples; ++i)
{
// Note: Only multiply the sample if pMultiplier is not 1.0 (if the multiplier is
// 1.0, then it would be good to avoid any binary roundoff error).
sample = srcFile.GetNextSample_16bit();
if (pMultiplier != 1.0)
sample = (short)((double)sample * pMultiplier);
destFile.AddSample_16bit(sample);
}
}
srcFile.Close();
destFile.Close();
}
else
throw new WAVFileReadException(retval, "WAVFile.AdjustVolume_Copy()");
}
/// <summary>
/// For 8-bit WAV files: Adjusts the volume level and converts it to a 16-bit audio file.
/// The converted data is saved to a separate file.
/// </summary>
/// <param name="pSrcFilename">The name of the WAV file to convert</param>
/// <param name="pDestFilename">The name to use for the converted WAV file</param>
/// <param name="pMultiplier">The volume multiplier</param>
public static void AdjustVolume_Copy_8BitTo16Bit(String pSrcFilename, String pDestFilename, double pMultiplier)
{
// If an empty source or destination file were passed in, then throw an exception.
if (pSrcFilename == "")
throw new WAVFileReadException("Blank filename specified.", "WAVFile.AdjustVolume_Copy_8BitTo16Bit()");
if (pDestFilename == "")
throw new WAVFileWriteException("Blank filename specified.", "WAVFile.AdjustVolume_Copy_8BitTo16Bit()");
// Open the srouce file
WAVFile srcFile = new WAVFile();
String retval = srcFile.Open(pSrcFilename, WAVFileMode.READ);
if (retval == "")
{
// Check to make sure the input file has 8 bits per sample. If not, then throw an exception.
if (srcFile.BitsPerSample != 8)
{
WAVFileBitsPerSampleException exc = new WAVFileBitsPerSampleException(pSrcFilename +
": 8 bits per sample required, and the file has " +
srcFile.BitsPerSample.ToString() + " bits per sample.",
"WAVFile.AdjustVolume_Copy_8BitTo16Bit()",
srcFile.BitsPerSample);
srcFile.Close();
throw exc;
}
// Open the destination file
WAVFile destFile = new WAVFile();
destFile.Create(pDestFilename, srcFile.IsStereo, srcFile.SampleRateHz, 16, true);
// Copy the data
short sample_16bit = 0;
while (srcFile.NumSamplesRemaining > 0)
{
// Scale the sample from 8-bit to 16 bits
sample_16bit = ScaleByteToShort(srcFile.GetNextSample_8bit());
// Now, apply pMultiplier if it is not 1.0
if (pMultiplier != 1.0)
sample_16bit = (short)((double)sample_16bit * pMultiplier);
// Save the sample to the destination file
destFile.AddSample_16bit(sample_16bit);
}
srcFile.Close();
destFile.Close();
}
else
throw new WAVFileReadException(retval, "WAVFile.AdjustVolume_Copy_8BitTo16Bit()");
}