/// <summary>
/// Returns the highest sample value in a WAV file, as a 16-bit value, regardless of
/// whether the file contains 8-bit or 16-bit audio. If the sample is coming from
/// an 8-bit audio file, the sample will be scaled up from 8-bit to 16-bit.
/// </summary>
/// <param name="pFilename">The audio file name</param>
/// <returns>The highest sample value from the file, as a 16-bit value</returns>
public static short HighestSampleValueAs16Bit(String pFilename)
{
short highestSample = 0;
try
{
WAVFile audioFile = new WAVFile();
if (audioFile.Open(pFilename, WAVFileMode.READ) == "")
{
if (audioFile.BitsPerSample == 8)
{
short sample = 0;
for (int i = 0; i < audioFile.NumSamples; ++i)
{
sample = ScaleByteToShort(audioFile.GetNextSample_8bit());
if (sample > highestSample)
highestSample = sample;
}
}
else if (audioFile.BitsPerSample == 16)
{
short sample = 0;
for (int i = 0; i < audioFile.NumSamples; ++i)
{
sample = audioFile.GetNextSample_16bit();
if (sample > highestSample)
highestSample = sample;
}
}
audioFile.Close();
}
}
catch (Exception)
{
}
return highestSample;
}
/// <summary>
/// Returns the highest number of channels in a set of audio files.
/// </summary>
/// <param name="pFilenames">An array containing the audio file names</param>
/// <returns>The highest number of channels in the set of audio files</returns>
public static byte HighestNumChannels(String[] pFilenames)
{
byte numChannels = 0;
if (pFilenames != null)
{
WAVFile audioFile = new WAVFile();
String retval = "";
foreach (String filename in pFilenames)
{
try
{
retval = audioFile.Open(filename, WAVFileMode.READ);
if (retval == "")
{
if (audioFile.NumChannels > numChannels)
numChannels = audioFile.NumChannels;
audioFile.Close();
}
}
catch (Exception)
{
}
}
}
return numChannels;
}
/// <summary>
/// Returns the highest sample value in a WAV audio file.
/// The return value is a byte array and will contain one
/// byte if the file contains 8-bit audio or 2 bytes if the file
/// contains 16-bit audio. The return value will be null if
/// the file cannot be opened. If it is known that the audio
/// file contains 16-bit samples, the byte array can be converted
/// to a 16-bit integer using BitConverter.ToInt16().
/// </summary>
/// <param name="pFilename">The name of the WAV file</param>
/// <param name="pBitsPerSample">This will contain the number of bits per sample, or 0 if the file wasn't loaded.</param>
/// <returns>A byte array containing the highest audio sample, or null if the file wasn't loaded.</returns>
public static byte[] HighestSampleValue(String pFilename, out short pBitsPerSample)
{
pBitsPerSample = 0;
byte[] highestSampleValue = null;
WAVFile audioFile = new WAVFile();
try
{
if (audioFile.Open(pFilename, WAVFileMode.READ) == "")
{
pBitsPerSample = audioFile.mBitsPerSample;
if (audioFile.mBitsPerSample == 8)
{
byte sample = 0;
byte highestSample = 0;
for (int i = 0; i < audioFile.NumSamples; ++i)
{
sample = audioFile.GetNextSample_8bit();
if (sample > highestSample)
highestSample = sample;
}
highestSampleValue = new byte[1];
highestSampleValue[0] = highestSample;
}
else if (audioFile.mBitsPerSample == 16)
{
short sample = 0;
short highestSample = 0;
for (int i = 0; i < audioFile.NumSamples; ++i)
{
sample = audioFile.GetNextSample_16bit();
if (sample > highestSample)
highestSample = sample;
}
highestSampleValue = BitConverter.GetBytes(highestSample);
if (!BitConverter.IsLittleEndian)
Array.Reverse(highestSampleValue);
}
audioFile.Close();
}
}
catch (Exception)
{
}
return (highestSampleValue);
}
/// <summary>
/// Returns a WAVFormat struct containing audio format information
/// (# channels, sample rate, and bits per sample) for a WAV file.
/// </summary>
/// <param name="pFilename">The name of the file about which to retrieve format information</param>
/// <returns>A WAVFormat struct object containing the audio format information for the open file</returns>
public static WAVFormat GetAudioFormat(String pFilename)
{
WAVFormat format = new WAVFormat();
WAVFile audioFile = new WAVFile();
if (audioFile.Open(pFilename, WAVFileMode.READ) == "")
{
format.BitsPerSample = audioFile.mBitsPerSample;
format.NumChannels = audioFile.mNumChannels;
format.SampleRateHz = audioFile.mSampleRateHz;
audioFile.Close();
}
return (format);
}
/// <summary>
/// Returns the highest number of bits per sample in a set of audio files.
/// </summary>
/// <param name="pFilenames">An array containing the audio file names</param>
/// <returns>The highest number of bits per sample in the set of audio files</returns>
public static short HighestBitsPerSample(String[] pFilenames)
{
short bitsPerSample = 0;
if (pFilenames != null)
{
WAVFile audioFile = new WAVFile();
String retval = "";
foreach (String filename in pFilenames)
{
try
{
retval = audioFile.Open(filename, WAVFileMode.READ);
if (retval == "")
{
if (audioFile.BitsPerSample > bitsPerSample)
bitsPerSample = audioFile.BitsPerSample;
audioFile.Close();
}
}
catch (Exception)
{
}
}
}
return bitsPerSample;
}
/// <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()");
}
/// <summary>
/// Converts a WAV file's bits/sample and number of channels to a separate WAV file.
/// </summary>
/// <param name="pSrcFilename">The name of the file to convert</param>
/// <param name="pDestFilename">The destination file name</param>
/// <param name="pBitsPerSample">The destination's number of bits/sample</param>
/// <param name="pStereo">Whether or not the destination should be stereo</param>
/// <param name="pVolumeMultiplier">A multiplier that can be used to adjust the volume of the output audio file</param>
public static void CopyAndConvert(String pSrcFilename, String pDestFilename, short pBitsPerSample, bool pStereo, double pVolumeMultiplier)
{
WAVFile srcFile = new WAVFile();
String retval = srcFile.Open(pSrcFilename, WAVFileMode.READ);
if (retval != "")
throw new WAVFileException(retval, "WAVFile.Convert_Copy()");
WAVFile destFile = new WAVFile();
destFile.Create(pDestFilename, pStereo, srcFile.SampleRateHz, pBitsPerSample);
if ((srcFile.BitsPerSample == 8) && (pBitsPerSample == 8))
{
byte sample = 0;
if (srcFile.IsStereo && !pStereo)
{
// 8-bit to 8-bit, stereo to mono: Average each 2 samples
while (srcFile.NumSamplesRemaining > 0)
{
sample = (byte)((short)((short)srcFile.GetNextSample_8bit() + (short)srcFile.GetNextSample_8bit()) / 2);
if (pVolumeMultiplier != 1.0)
sample = (byte)((double)sample * pVolumeMultiplier);
destFile.AddSample_8bit(sample);
}
}
else if ((srcFile.IsStereo && pStereo) || (!srcFile.IsStereo && !pStereo))
{
// 8-bit to 8-bit, stereo to stereo or mono to mono
while (srcFile.NumSamplesRemaining > 0)
{
sample = srcFile.GetNextSample_8bit();
if (pVolumeMultiplier != 1.0)
sample = (byte)((double)sample * pVolumeMultiplier);
destFile.AddSample_8bit(sample);
}
}
else if (!srcFile.IsStereo && pStereo)
{
// 8-bit to 8-bit, mono to stereo: Write each sample twice
while (srcFile.NumSamplesRemaining > 0)
{
sample = srcFile.GetNextSample_8bit();
if (pVolumeMultiplier != 1.0)
sample = (byte)((double)sample * pVolumeMultiplier);
destFile.AddSample_8bit(sample);
destFile.AddSample_8bit(sample);
}
}
}
else if ((srcFile.BitsPerSample == 8) && (pBitsPerSample == 16))
{
short sample = 0;
if (srcFile.IsStereo && !pStereo)
{
// 8-bit to 16 bit, stereo to mono: Average each 2 samples
while (srcFile.NumSamplesRemaining > 0)
{
sample = (short)((int)((int)srcFile.GetNextSampleAs16Bit() + (int)srcFile.GetNextSampleAs16Bit()) / 2);
if (pVolumeMultiplier != 1.0)
sample = (short)((double)sample * pVolumeMultiplier);
destFile.AddSample_16bit(sample);
}
}
else if ((srcFile.IsStereo && pStereo) || (!srcFile.IsStereo && !pStereo))
{
// 8-bit to 16 bit, stereo to stereo or mono to mono
while (srcFile.NumSamplesRemaining > 0)
{
sample = srcFile.GetNextSampleAs16Bit();
if (pVolumeMultiplier != 1.0)
sample = (short)((double)sample * pVolumeMultiplier);
destFile.AddSample_16bit(sample);
}
}
else if (!srcFile.IsStereo && pStereo)
{
// 8-bit to 16 bit, mono to stereo: Write each sample twice
while (srcFile.NumSamplesRemaining > 0)
{
sample = srcFile.GetNextSampleAs16Bit();
if (pVolumeMultiplier != 1.0)
sample = (short)((double)sample * pVolumeMultiplier);
destFile.AddSample_16bit(sample);
destFile.AddSample_16bit(sample);
}
}
}
else if ((srcFile.BitsPerSample == 16) && (pBitsPerSample == 8))
{
byte sample = 0;
if (srcFile.IsStereo && !pStereo)
{
// 16-bit to 8-bit, stereo to mono: Average each 2 samples
short sample_16bit = 0;
while (srcFile.NumSamplesRemaining > 0)
{
sample_16bit = (short)((int)srcFile.GetNextSample_16bit() + (int)srcFile.GetNextSample_16bit() / 2);
if (pVolumeMultiplier != 1.0)
sample_16bit = (short)((double)sample_16bit * pVolumeMultiplier);
sample = ScaleShortToByte(sample_16bit);
destFile.AddSample_8bit(sample);
}
}
else if ((srcFile.IsStereo && pStereo) || (!srcFile.IsStereo && !pStereo))
{
// 16-bit to 8-bit, stereo to stereo or mono to mono
while (srcFile.NumSamplesRemaining > 0)
{
sample = ScaleShortToByte(srcFile.GetNextSample_16bit());
if (pVolumeMultiplier != 1.0)
sample = (byte)((double)sample * pVolumeMultiplier);
destFile.AddSample_8bit(sample);
}
}
else if (!srcFile.IsStereo && pStereo)
{
// 16-bit to 8-bit, mono to stereo: Write each sample twice
while (srcFile.NumSamplesRemaining > 0)
{
sample = ScaleShortToByte(srcFile.GetNextSample_16bit());
if (pVolumeMultiplier != 1.0)
sample = (byte)((double)sample * pVolumeMultiplier);
destFile.AddSample_8bit(sample);
destFile.AddSample_8bit(sample);
}
}
}
else if ((srcFile.BitsPerSample == 16) && (pBitsPerSample == 16))
{
short sample = 0;
if (srcFile.IsStereo && !pStereo)
{
// 16-bit to 16-bit, stereo to mono: Average each 2 samples
while (srcFile.NumSamplesRemaining > 0)
{
sample = (short)((int)((int)srcFile.GetNextSample_16bit() + (int)srcFile.GetNextSample_16bit()) / 2);
if (pVolumeMultiplier != 1.0)
sample = (short)((double)sample * pVolumeMultiplier);
destFile.AddSample_16bit(sample);
}
}
else if ((srcFile.IsStereo && pStereo) || (!srcFile.IsStereo && !pStereo))
{
// 16-bit to 16-bit, stereo to stereo or mono to mono
while (srcFile.NumSamplesRemaining > 0)
{
sample = srcFile.GetNextSample_16bit();
if (pVolumeMultiplier != 1.0)
sample = (short)((double)sample * pVolumeMultiplier);
destFile.AddSample_16bit(sample);
}
}
else if (!srcFile.IsStereo && pStereo)
{
// 16-bit to 16-bit, mono to stereo: Write each sample twice
while (srcFile.NumSamplesRemaining > 0)
{
sample = srcFile.GetNextSample_16bit();
if (pVolumeMultiplier != 1.0)
sample = (short)((double)sample * pVolumeMultiplier);
destFile.AddSample_16bit(sample);
destFile.AddSample_16bit(sample);
}
}
}
destFile.Close();
srcFile.Close();
}
/// <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>
/// Changes the volume of a WAV file.
/// </summary>
/// <param name="pFilename">The name of the WAV file to adjust</param>
/// <param name="pMultiplier">The volume multiplier</param>
public static void AdjustVolumeInPlace(String pFilename, double pMultiplier)
{
// If pMultiplier is 1, then we don't need to do anything.
if (pMultiplier == 1.0)
return;
// Open the file
WAVFile audioFile = new WAVFile();
String retval = audioFile.Open(pFilename, WAVFileMode.READ_WRITE);
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(audioFile.BitsPerSample))
{
short bitsPerSample = audioFile.BitsPerSample;
audioFile.Close();
throw new WAVFileBitsPerSampleException(pFilename + " has unsupported bits/sample ("
+ bitsPerSample.ToString() + ")",
"WAVFile.AdjustVolumeInPlace()", bitsPerSample);
}
if (!SupportedSampleRate(audioFile.SampleRateHz))
{
int sampleRate = audioFile.SampleRateHz;
audioFile.Close();
throw new WAVFileSampleRateException(pFilename + " has unsupported sample rate ("
+ sampleRate.ToString() + ")",
"WAVFile.AdjustVolumeInPlace()", sampleRate);
}
// Adjust the file volume
if (audioFile.BitsPerSample == 8)
{
byte sample = 0;
for (int sampleNum = 0; sampleNum < audioFile.NumSamples; ++sampleNum)
{
sample = (byte)((double)audioFile.GetNextSample_8bit() * pMultiplier);
audioFile.SeekToAudioSample(sampleNum);
audioFile.AddSample_8bit(sample);
}
}
else if (audioFile.BitsPerSample == 16)
{
short sample = 0;
for (int sampleNum = 0; sampleNum < audioFile.NumSamples; ++sampleNum)
{
sample = (short)((double)audioFile.GetNextSample_16bit() * pMultiplier);
audioFile.SeekToAudioSample(sampleNum);
audioFile.AddSample_16bit(sample);
}
}
audioFile.Close();
}
else
throw new WAVFileReadException(retval, "WAVFile.AdjustVolumeInPlace()");
}
/// <summary>
/// Returns whether or not any audio samples are remaining to be read from an array of WAV files.
/// </summary>
/// <param name="WAVFileArray">An array of WAVFile objects that are currently open</param>
/// <returns>true if there are samples that can still be read from any of the files, or false if not.</returns>
private static bool SamplesRemain(WAVFile[] WAVFileArray)
{
bool samplesRemain = false;
if (WAVFileArray != null)
{
for (int i = 0; i < WAVFileArray.GetLength(0); ++i)
{
if (WAVFileArray[i].NumSamplesRemaining > 0)
{
samplesRemain = true;
break;
}
}
}
return (samplesRemain);
}
/// <summary>
/// Returns whether or not the WAV file format (mono/stereo,
/// sample rate, and bits per sampe) match another WAV file's
/// format.
/// </summary>
/// <param name="pWAVFile">Another WAVFile object to compare with</param>
/// <returns></returns>
public bool FormatMatches(WAVFile pWAVFile)
{
bool retval = false;
if (pWAVFile != null)
retval = ((mNumChannels == pWAVFile.mNumChannels) &&
(mSampleRateHz == pWAVFile.mSampleRateHz) &&
(mBitsPerSample == pWAVFile.mBitsPerSample));
return retval;
}
public static void MixAudioFiles(WAVInputFile[] pInputFiles, string pOutputFilename, string pTempDir)
{
amountDone = 0;
OnUpdated();
string[] pFileList = new string[pInputFiles.Length];
for (int i = 0; i < pInputFiles.Length; i++)
{
pFileList[i] = pInputFiles[i].ToString();
}
// If pFileList is null or empty, then just return.
if (pFileList == null)
return;
if (pFileList.GetLength(0) == 0)
return;
// Make sure all the audio files have the sample rate (we can merge 8-bit and 16-bit audio and
// convert mono to stereo). If the sample rates don't match, then throw an exception.
if (!SampleRatesEqual(pFileList))
throw new WAVFileAudioMergeException("The sample rates of the audio files differ.", "WAVFile.MergeAudioFiles()");
amountDone = 1;
OnUpdated();
// Check the audio format. If the number of bits/sample or sample rate is not
// supported, then throw an exception.
WAVFormat firstFileAudioFormat = GetAudioFormat(pFileList[0]);
if (!SupportedBitsPerSample(firstFileAudioFormat.BitsPerSample))
throw new WAVFileBitsPerSampleException("Unsupported number of bits per sample: " + firstFileAudioFormat.BitsPerSample.ToString(), "WAVFile.MergeAudioFiles()", firstFileAudioFormat.BitsPerSample);
if (!SupportedSampleRate(firstFileAudioFormat.SampleRateHz))
throw new WAVFileSampleRateException("Unsupported sample rate: " + firstFileAudioFormat.SampleRateHz.ToString(), "WAVFile.MergeAudioFiles()", firstFileAudioFormat.SampleRateHz);
amountDone = 2;
OnUpdated();
// 2. Create the temporary directory if it doesn't exist already. This checks for the
// existence of the temp directory and stores the result in tempDirExisted so that
// later, if the temp directory did not exist, we can delete it.
bool tempDirExisted = Directory.Exists(pTempDir);
if (!tempDirExisted)
{
try
{
Directory.CreateDirectory(pTempDir);
if (!Directory.Exists(pTempDir))
throw new WAVFileAudioMergeException("Unable to create temporary work directory (" + pTempDir + ")", "WAVFile.MergeAudioFiles()");
}
catch (System.Exception exc)
{
throw new WAVFileAudioMergeException("Unable to create temporary work directory (" + pTempDir + "): "
+ exc.Message, "WAVFile.MergeAudioFiles()");
}
}
amountDone = 3;
OnUpdated();
// 4. Find the highest sample value of all files, and calculate the sound
// multiplier based on this (all files will be scaled down by this amount).
int numTracks = pFileList.GetLength(0);
double multiplier = 0.0; // The multiplier for scaling down the audio files
short highestSampleValue = 0; // Will store the highest sample value (8-bit will be cast to short)
// Determine the highest # of bits per sample in all the audio files.
short highestBitsPerSample = HighestBitsPerSample(pFileList);
bool outputStereo = (HighestNumChannels(pFileList) > 1);
if (highestBitsPerSample == 8)
{
// Get the highest sample value of all of the WAV files
byte highestSample = HighestSampleValue_8bit(pFileList);
highestSampleValue = (short)highestSample;
byte difference = (byte)(highestSample - (byte.MaxValue / (byte)numTracks));
multiplier = 1.0 - ((double)difference / (double)highestSample);
}
else if (highestBitsPerSample == 16)
{
// Get the highest sample value of all of the WAV files
highestSampleValue = HighestSampleValueAs16Bit(pFileList);
short difference = (short)(highestSampleValue - (short.MaxValue / (short)numTracks));
multiplier = 1.0 - ((double)difference / (double)highestSampleValue);
}
if (double.IsInfinity(multiplier) || (multiplier == 0.0))
{
// If the temp dir did not exist, then remove it.
if (!tempDirExisted)
DeleteDir(pTempDir);
// Throw the exception
throw new WAVFileAudioMergeException("Could not calculate first volume multiplier.", "WAVFile.MergeAudioFiles()");
}
amountDone = 4;
OnUpdated();
if (multiplier < 0.0)
multiplier = -multiplier;
// 5. Scale down the audio levels of the source files, and save the output
// in the temp directory. Also change the path to the audio files in
// inputFilenames so that they point to the temp directory (we'll be
// combining the scaled audio files).
// This array (scaledAudioFiles) will contain WAVFile objects for the scaled audio files.
WAVFile[] scaledAudioFiles = new WAVFile[pFileList.GetLength(0)];
String filename = ""; // For the scaled-down WAV filename
WAVFile inputFile = new WAVFile();
WAVFile outputFile = new WAVFile();
for (int i = 0; i < pFileList.GetLength(0); ++i)
{
// pFileList[i] contains the fully-pathed filename. Using just the
// filename, construct the fully-pathed filename for the scaled-down
// version of the file in the temporary directory.
filename = pTempDir + "\\" + Path.GetFileName(pFileList[i]);
// Copy the file to the temp directory, adjusting its bits/sample and number of
// channels if necessary. And also ajust its volume using multiplier.
//CopyAndConvert(pFileList[i], filename, highestBitsPerSample, outputStereo, multiplier);
CopyAndConvert(pFileList[i], filename, highestBitsPerSample, outputStereo, 1.0f);
// Create the WAVFile object in the scaledAudioFiles array, and open the scaled
// audio file with it.
scaledAudioFiles[i] = new WAVFile();
scaledAudioFiles[i].Open(filename, WAVFileMode.READ);
}
amountDone = 5;
OnUpdated();
// 7. Now, create the final audio mix file.
outputFile.Create(pOutputFilename, outputStereo, firstFileAudioFormat.SampleRateHz,
highestBitsPerSample);
amountDone = 6;
OnUpdated();
// 8. Do the merging..
// The basic algorithm for doing the merging is as follows:
// while there is at least 1 sample remaining in any of the source files
// sample = 0
// for each source file
// if the source file has any samples remaining
// sample = sample + next available sample from the source file
// sample = sample / # of source files
// write the sample to the output file
if (highestBitsPerSample == 8)
{
byte sample = 0;
while (SamplesRemain(scaledAudioFiles))
{
sample = 0;
for (int i = 0; i < scaledAudioFiles.GetLength(0); ++i)
{
if (scaledAudioFiles[i].NumSamplesRemaining > 0)
sample += scaledAudioFiles[i].GetNextSample_8bit();
}
sample /= (byte)(scaledAudioFiles.GetLength(0));
outputFile.AddSample_8bit(sample);
}
}
else if (highestBitsPerSample == 16)
{
for (int i = 0; i < scaledAudioFiles.Length - 1; i++)
{
int currentAudioFile = i;
double totalFileTime = GetWavFileDuration(pFileList[currentAudioFile]).TotalSeconds;
double timePerSample = totalFileTime / scaledAudioFiles[currentAudioFile].NumSamples; // in seconds
double mixTime = totalFileTime - pInputFiles[currentAudioFile].FadeTime;
double timePast = (scaledAudioFiles[currentAudioFile].NumSamples - scaledAudioFiles[currentAudioFile].NumSamplesRemaining) * timePerSample;
while (scaledAudioFiles[currentAudioFile].NumSamplesRemaining > 0)
{
// Get the next sample from the current audio file
short sample = scaledAudioFiles[currentAudioFile].GetNextSampleAs16Bit();
// Find the mix time to mix the sample of the next audio file into there
if (timePast >= mixTime)
{
sample += scaledAudioFiles[currentAudioFile + 1].GetNextSampleAs16Bit();
}
// Devide the sample by the amount of samples
sample /= (short)(scaledAudioFiles.Length);
// Write the audio sample to the output file
outputFile.AddSample_16bit(sample);
// Add the time of the sample ot the total time
timePast += timePerSample;
}
amountDone = 94 / scaledAudioFiles.Length * (i + 1) + 6;
OnUpdated();
}
// Write the rest
while (scaledAudioFiles[scaledAudioFiles.Length -1].NumSamplesRemaining > 0)
{
short sample = scaledAudioFiles[scaledAudioFiles.Length - 1].GetNextSampleAs16Bit();
sample /= (short)(scaledAudioFiles.Length);
outputFile.AddSample_16bit(sample);
}
amountDone = 99;
OnUpdated();
}
PBBRenderer.Instance.ActiveStatus = 2;
OnUpdated();
outputFile.Close();
// 9. Remove the input files(to free up disk space.
foreach (WAVFile audioFile in scaledAudioFiles)
{
filename = audioFile.Filename;
audioFile.Close();
System.IO.File.Delete(filename);
}
// 10. Now, increase the volume level of the output file. (will first have
// to see if the inputs are 8-bit or 16-bit.)
// Adjust the volume level of the file so that its volume is
// the same as the volume of the input files. This is done by
// first finding the highest sample value of all files, then
// the highest sample value of the combined audio file, and
// scaling the audio of the output file to match the volume
// of the input files (such that the highest level of the output
// file is the same as the highest level of all files).
// For 16-bit audio, this works okay, but for 8-bit audio, the
// output seems to sound better if we adjust the volume so that
// the highest sample value is 3/4 of the maximum sample value
// for the # of bits/sample.
if (highestBitsPerSample == 8)
{
byte highestSampleVal = HighestSampleValue_8bit(pOutputFilename);
byte maxValue = byte.MaxValue / 4 * 3;
multiplier = (double)maxValue / (double)highestSampleVal;
}
else if (highestBitsPerSample == 16)
{
short finalMixFileHighestSample = HighestSampleValueAs16Bit(pOutputFilename);
// Calculate the multiplier for adjusting the audio of the final mix file.
//short difference = (short)(finalMixFileHighestSample - highestSampleValue);
//multiplier = 1.0 - ((double)difference / (double)finalMixFileHighestSample);
// This calculates the multiplier based on the highest sample value in the audio
// file and the highest possible 16-bit sample value.
multiplier = (double)short.MaxValue / (double)finalMixFileHighestSample;
}
if (multiplier < 0.0)
multiplier = -multiplier;
// Adjust the volume of the final mix file.
//AdjustVolumeInPlace(pOutputFilename, multiplier);
// If the temporary directory did not exist prior to this method being called, then
// delete it.
if (!tempDirExisted)
{
String retval = DeleteDir(pTempDir);
if (retval != "")
throw new WAVFileAudioMergeException("Unable to remove temp directory (" + pTempDir + "): " + retval,
"WAVFile.MergeAudioFiles()");
}
amountDone = 100;
}
