| Methods Summary |
|---|
| public java.lang.String | getName()
return "AIFF Audio Multiplexer";
|
| public javax.media.Format | setInputFormat(javax.media.Format format, int trackID)
String reason = null;
if (!(format instanceof AudioFormat))
return null;
audioFormat = (AudioFormat) format;
String encodingString = audioFormat.getEncoding();
sampleSizeInBits = audioFormat.getSampleSizeInBits();
sampleRate = audioFormat.getSampleRate();
channels = audioFormat.getChannels();
blockAlign = channels * sampleSizeInBits / 8;
if (encodingString.equalsIgnoreCase(AudioFormat.LINEAR)) {
if (sampleSizeInBits > 8 &&
audioFormat.getEndian() == AudioFormat.LITTLE_ENDIAN)
return null;
if (audioFormat.getSigned() == AudioFormat.UNSIGNED)
return null;
if (audioFormat.getEndian() == AudioFormat.NOT_SPECIFIED ||
audioFormat.getSigned() == AudioFormat.NOT_SPECIFIED)
format = audioFormat.intersects(bigEndian);
// No compression: formType is AIFF
formType = "AIFF";
aiffEncoding = "NONE";
} else {
// Some compression: formType is AIFC
formType = "AIFC";
if (encodingString.equalsIgnoreCase(AudioFormat.ULAW))
aiffEncoding = "ulaw";
else if (encodingString.equalsIgnoreCase(AudioFormat.ALAW))
aiffEncoding = "alaw";
else if (encodingString.equalsIgnoreCase(AudioFormat.IMA4)) {
aiffEncoding = "ima4";
/**
* Each packet contains 64 samples. Each sample is 4 bits/channel.
* So 64 samples is 32 bytes/channel.
* The 2 in the equation refers two bytes that the Apple's
* IMA compressor puts at the front of each packet, which
* are referred to as predictor bytes
*/
blockAlign = (32 + 2) * channels;
} else if (encodingString.equalsIgnoreCase(AudioFormat.MAC3)) {
aiffEncoding = encodingString;
// 2 bytes represent 6 samples
blockAlign = 2;
} else if (encodingString.equalsIgnoreCase(AudioFormat.MAC6)) {
aiffEncoding = encodingString;
// 1 byte represent 6 samples
blockAlign = 1;
// TODO: gsm
// } else if (encodingString.equalsIgnoreCase(AudioFormat.GSM)) {
// aiffEncoding = "???";
// /**
// * Each frame that consists of 160 speech samples
// * requires 33 bytes
// */
// blockAlign = 33;
} else {
reason = "Cannot handle encoding " + encodingString;
}
}
if (reason == null) {
inputs[0] = format;
return format;
} else
return null;
|
| public int | setNumTracks(int nTracks)
if (nTracks != 1)
return 1;
else
return super.setNumTracks(nTracks);
|
| protected void | writeFooter()
byte [] dummy = new byte[] { 0 };
dataSize = filePointer - headerSize;
if ((filePointer & 1) != 0) {
// add a padding byte
write(dummy, 0, 1);
}
bufClear();
seek(4);
bufWriteInt(fileSize);
bufFlush();
bufClear();
seek(maxFramesOffset);
maxFrames = dataSize / blockAlign;
// System.out.println("maxFrames is " + maxFrames);
bufWriteInt(maxFrames);
bufFlush();
bufClear();
seek(dataSizeOffset);
bufWriteInt(dataSize + 8); // 8 is for offset and blockSize
bufFlush();
|
| protected void | writeHeader()
bufClear();
bufWriteBytes(FormID);
bufWriteInt(0); // This is filled in later when filesize is known
bufWriteBytes(formType);
if (formType.equals("AIFC")) {
bufWriteBytes(FormatVersionID);
bufWriteInt(4);
bufWriteInt(AIFCVersion1);
}
bufWriteBytes(CommonID);
int commonIDSize = CommonIDSize;
if (formType.equals("AIFC")) {
commonIDSize += 8; // for 2 4cc strings representing
// Compression type and name.
}
bufWriteInt(commonIDSize);
bufWriteShort((short) channels);
maxFramesOffset = (int) filePointer;
bufWriteInt(maxFrames); // To be filled in later
bufWriteShort((short) sampleSizeInBits);
// Write sample rate as IEEE extended.
// For now write the integer portion of sampleRate
// TODO: Verify this calculation
int exponent = 16398;
double highMantissa;
highMantissa = sampleRate;
while (highMantissa < 44000) {
highMantissa *= 2;
exponent--;
}
bufWriteShort((short) exponent); // Exponent
bufWriteInt( ((int) highMantissa) << 16);
bufWriteInt(0); // low Mantissa
// Note: Since we use 4cc codes, Compression Type
// and Compression Name take up 8 bytes
if (formType.equals("AIFC")) {
bufWriteBytes(aiffEncoding); // Compression Type
bufWriteBytes(aiffEncoding); // Compression Name
}
bufWriteBytes(SoundDataID);
dataSizeOffset = filePointer;
bufWriteInt(0); // This is filled in later when datasize is known
// Both offset and blocksize set to 0 upon recommendation in
// "Sound Manager" Chapter in "Inside Macintosh Sound:, page 2-87
bufWriteInt(0); // offset
bufWriteInt(0); // blocksize
bufFlush();
headerSize = filePointer;
// fileSize =
//System.out.println("fileSize size after header is done: " + fileSize);
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