// Conversion routine the first
// (lame, libsndfile)
//
// Convert() default routine
// Handles WAV->MP3 encoding,
// !MP3->!MP3 audio encoding.
public void Convert(string inputFile, int convertFrom,
string outputFile, int convertTo, Reporter updateStatus)
{
// Verify existence of inputFilenm, throw
// exception if not exist
if (!System.IO.File.Exists(inputFile))
{
throw new FileNotFoundException(
"Cannot find file " + inputFile);
}
// Input file information
// (Set input file size)
FileInfo fi = new FileInfo(inputFile);
int soundFileSize = (int)fi.Length;
// Select conversion routines based
// on input/output file types
// If outfile = MP3 then use LameWriter
// to encode, using the settings in the
// structure mp3set (essentially the LHV1
// struct from LameWrapper):
if ((soundFormat)convertTo == soundFormat.MP3)
{
// File to convert from must be WAV
if ( !( (convertFrom >= (int)soundFormat.WAV) &&
(convertFrom < (int)soundFormat.AIFF) ) )
{
throw new Exception(
"Cannot encode to MP3 directly from this format ("
+ convertFrom + "). Convert to WAV first");
}
LameWriter mp3Writer = null;
// Instantiate LameWriter object
// with output filename
if (beConfig == null)
{
// Use default MP3 output settings
mp3Writer = new LameWriter(
new FileStream(outputFile, FileMode.Create),
inputFile);
}
else
{
// Use custom settings
mp3Writer = new LameWriter(
new FileStream(outputFile, FileMode.Create),
inputFile,
beConfig);
}
// open input file for binary reading
Stream s = new FileStream(inputFile,
FileMode.Open, FileAccess.Read);
BinaryReader br = new BinaryReader(s);
// setup byte buffer -- use mp3Writer.sampleSize
// to ensure correct buffer size
byte[] wavBuffer = new byte[mp3Writer.sampleSize];
// skip WAV header
s.Seek(LameWrapper.SKIP_WAV_HEADER, SeekOrigin.Begin);
// write mp3 file
int index = 0;
int processedBytes = 0;
while
((index = br.Read(wavBuffer, 0, mp3Writer.sampleSize)) > 0)
{
processedBytes += mp3Writer.sampleSize;
// Send to callback:
updateStatus(soundFileSize, processedBytes, this);
// Check for kill
if (this.killSwitch) break;
mp3Writer.Write(wavBuffer, 0, index);
}
// Finish up
mp3Writer.Close();
mp3Writer.WriteTags(outputFile);
}
// Assume libsndfile conversion:
else
{
// Check and make sure we are not
// trying to decode MP3->WAV
// Instantiate object
LibsndfileWrapper libSndFile = new LibsndfileWrapper();
LibsndfileWrapper.SF_INFO soundInfo =
new LibsndfileWrapper.SF_INFO();
// Calculate total frames to convert
int i = libSndFile.GetSoundFileType(inputFile, ref soundInfo);
// Each frame is 16bit:
long totalFrames = soundInfo.frames*2;
// Initialize
libSndFile.Initialize (inputFile,
outputFile, (LibsndfileWrapper.soundFormat)convertTo);
// The main decoding loop
long readCount;
long readIndex = 0;
while ( (readCount = libSndFile.Read()) > 0)
{
readIndex += readCount;
// Send update to delegate.
// Note that this is in
// libsndfile specific frames
// rather than in actual bytes.
//
// readIndex / totalFrames =
// percentage complete
updateStatus((int)totalFrames, (int)readIndex, this);
// Check for kill
if (this.killSwitch) break;
// Write to file
libSndFile.Write();
}
// Close up shop
libSndFile.Close();
}
}
// Initialize default settings
// for MP3 (call to initialize
// structure for customized MP3
// settings). After this call,
// settings are changed in the
// calling code. Takes the
// input WAV file.
public void SetMP3(string inputFile)
{
// Get information about inputFile,
// use to give beConfig initial
// values:
LibsndfileWrapper.SF_INFO soundInfo =
new LibsndfileWrapper.SF_INFO();
LibsndfileWrapper libSndFile = new LibsndfileWrapper();
libSndFile.GetSoundFileType(inputFile, ref soundInfo);
beConfig = new LameWrapper.BE_CONFIG(soundInfo);
}
// Given a file, return
// the sound file format
public soundFormat CheckSoundFormat(string inputFile)
{
// Verify existence of inputFilenm, throw
// exception if not exist
if (!System.IO.File.Exists(inputFile))
{
throw new FileNotFoundException(
"Cannot find file " + inputFile);
}
// Check for non-MP3 sound file
LibsndfileWrapper libSndFile = new LibsndfileWrapper();
LibsndfileWrapper.SF_INFO soundInfo =
new LibsndfileWrapper.SF_INFO();
int i = libSndFile.GetSoundFileType(inputFile, ref soundInfo);
// First check to see if it's an audio
// format !MP3. Then check for MP3.
// If no valid format found, throw
// exception.
if (soundInfo.format != 0)
{
return (soundFormat)soundInfo.format;
}
else
{
MP3Check verifyMP3 = new MP3Check(inputFile, 2);
if (!verifyMP3.Check())
{
throw new Exception("Cannot determine sound file type: " +
inputFile);
}
else
{
return soundFormat.MP3;
}
}
}
