| Methods Summary |
|---|
| public java.lang.String | getName()
return "WAVE Audio Multiplexer";
|
| public javax.media.Format | setInputFormat(javax.media.Format input, int trackID)
if (!(input instanceof AudioFormat))
return null;
AudioFormat format = (AudioFormat) input;
sampleRate = format.getSampleRate();
String reason = null;
// Check to see if some of these restrictions can be removed
/*if (format.getEndian() == AudioFormat.BIG_ENDIAN)
reason = "Endian should be LITTLE_ENDIAN";
/*
else if ( Math.abs(sampleRate - 8000.0) > epsilon )
reason = "Sample rate should be 8000. Cannot handle sample rate " + sampleRate;
else if (format.getFrameSizeInBits() != (33*8))
reason = "framesize should be 33 bytes";
else if (format.getChannels() != 1)
reason = "Number of channels should be 1";
*/
audioFormat = (AudioFormat) format;
if (format instanceof WavAudioFormat) {
wavAudioFormat = (WavAudioFormat) format;
}
String encodingString = audioFormat.getEncoding();
sampleSizeInBits = audioFormat.getSampleSizeInBits();
if (encodingString.equalsIgnoreCase(AudioFormat.LINEAR)) {
if ( sampleSizeInBits > 8 ) {
if (audioFormat.getEndian() == AudioFormat.BIG_ENDIAN)
return null;
if (audioFormat.getSigned() == AudioFormat.UNSIGNED)
return null;
// Data has to be little endian and signed.
if (audioFormat.getEndian() == AudioFormat.NOT_SPECIFIED ||
audioFormat.getSigned() == AudioFormat.NOT_SPECIFIED) {
format = (AudioFormat)audioFormat.intersects(signed);
}
} else {
if (audioFormat.getSigned() == AudioFormat.SIGNED)
return null;
// Data has to be unsigned.
if (audioFormat.getEndian() == AudioFormat.NOT_SPECIFIED ||
audioFormat.getSigned() == AudioFormat.NOT_SPECIFIED) {
format = (AudioFormat)audioFormat.intersects(unsigned);
}
}
}
Integer formatTag =
(Integer)
WavAudioFormat.reverseFormatMapper.get(encodingString.toLowerCase());
if (formatTag == null) {
reason = "Cannot handle format";
return null;
}
// For certain encodings additional encoding-specific information
// is required which can only be obtained thru WavAudioFormat
wFormatTag = formatTag.shortValue();
switch (wFormatTag) {
case WavAudioFormat.WAVE_FORMAT_ADPCM:
case WavAudioFormat.WAVE_FORMAT_DVI_ADPCM:
case WavAudioFormat.WAVE_FORMAT_GSM610:
if (wavAudioFormat == null) {
reason = "A WavAudioFormat is required " +
" to provide encoding specific information for this " +
"encoding " + wFormatTag;
}
}
if (wavAudioFormat != null) {
codecSpecificHeader = wavAudioFormat.getCodecSpecificHeader();
bytesPerSecond = wavAudioFormat.getAverageBytesPerSecond();
}
sampleRate = audioFormat.getSampleRate();
channels = audioFormat.getChannels();
if (reason != null) {
return null;
} else {
inputs[0] = format;
return format;
}
|
| public int | setNumTracks(int nTracks)
if (nTracks != 1)
return 1;
else
return super.setNumTracks(nTracks);
|
| protected void | writeFooter()
// Write the file size
seek(4);
bufClear();
bufWriteIntLittleEndian(fileSize - 8); // -8 since we should skip the first
// two ints
bufFlush();
// Write the data size
seek(dataSizeOffset);
bufClear();
int dataSize = fileSize - (dataSizeOffset + 4);
bufWriteIntLittleEndian(dataSize);
bufFlush();
if (factChunkLength > 0) {
// Has a Fact chunk
// Calculate numberOfSamples
// bytesPerSecond won't be zero
float duration = (float) dataSize / bytesPerSecond;
int numberOfSamples = (int) (duration * sampleRate);
seek(numberOfSamplesOffset);
bufClear();
bufWriteIntLittleEndian(numberOfSamples);
bufFlush();
}
|
| protected void | writeHeader()
int formatSize = 16; // Minimum formatSize
bufClear();
audioFormat = (AudioFormat) inputs[0];
codecSpecificHeader = null;
if (audioFormat instanceof WavAudioFormat)
codecSpecificHeader = ((WavAudioFormat)audioFormat).getCodecSpecificHeader();
if (codecSpecificHeader != null) {
formatSize += ( 2 + // for extra field size)
codecSpecificHeader.length);
} else if (wFormatTag == WavAudioFormat.WAVE_FORMAT_MPEG_LAYER3) {
formatSize += ( 2 + // for extra field size)
12); // Extra info for mp3 is 12
}
bufWriteBytes("RIFF");
bufWriteInt(0); // This is filled in later when filesize is known
bufWriteBytes("WAVE");
bufWriteBytes("fmt "); // Format Chunk
bufWriteIntLittleEndian(formatSize);
int frameSizeInBits = audioFormat.getFrameSizeInBits();
if (frameSizeInBits > 0) {
blockAlign = frameSizeInBits / 8;
} else {
blockAlign = (sampleSizeInBits / 8) * channels;
}
bufWriteShortLittleEndian(wFormatTag); // encoding
bufWriteShortLittleEndian((short) channels);
bufWriteIntLittleEndian((int) sampleRate);
int frameRate = Format.NOT_SPECIFIED;
if (wFormatTag == WavAudioFormat.WAVE_FORMAT_MPEG_LAYER3) {
blockAlign = 1;
frameRate = (int) audioFormat.getFrameRate();
if (frameRate != Format.NOT_SPECIFIED) {
bytesPerSecond = frameRate;
}
}
if (bytesPerSecond <= 0) {
bytesPerSecond = channels * sampleSizeInBits * (int) sampleRate / 8;
}
bufWriteIntLittleEndian(bytesPerSecond);
bufWriteShortLittleEndian((short) blockAlign);
if (wFormatTag == WavAudioFormat.WAVE_FORMAT_MPEG_LAYER3) {
bufWriteShortLittleEndian((short) 0);
} else {
bufWriteShortLittleEndian((short) sampleSizeInBits);
}
if (codecSpecificHeader != null) {
bufWriteShortLittleEndian((short) codecSpecificHeader.length);
bufWriteBytes(codecSpecificHeader);
} else if (wFormatTag == WavAudioFormat.WAVE_FORMAT_MPEG_LAYER3) {
/**
* Note: TODO: Info on the extra fields in WAVE_FORMAT_MPEG_LAYER3
* not available. After looking at several wav files, the wID,
* fdwFlags, nFramesPerBlock and nCodecDelay always have the
* value 1, 2, 1 and 1393
* Only the nBlockSize value varies from file to file
* Setting these value until I can get the meaning of
* these fields in codecSpecificHeader
*/
/*
8kbit 8000 mono 72
16kbit 8000 mono 144
8kbit 11025 mono 52
16kbit 11025 mono 104
32kbit 11025 stereo 208
16kbit 11025 mono 104
16kbit 16000 mono 72
24kbit 22050 mono 78
32kbit 8000 stereo 288
128kbit 44100 stereo 417??
56k 24000 stereo 168
*/
int blockSize;
if (frameRate > 0) {
float temp = (72F * frameRate * 8) / 8000F;
temp *= (8000F / sampleRate);
blockSize = (int) temp;
} else {
blockSize = 417; // ???
}
bufWriteShortLittleEndian((short) 12); // Length of extra data
bufWriteShortLittleEndian((short)1); // wID
bufWriteIntLittleEndian(2); // fdwFlags
bufWriteShortLittleEndian((short) blockSize); // nBlockSize
bufWriteShortLittleEndian((short)1); // nFramesPerBlock
bufWriteShortLittleEndian((short)1393); // nCodecDelay
}
factChunkLength = 0;
if (wFormatTag != WavAudioFormat.WAVE_FORMAT_PCM) {
// Compressed formats require a FACT chunk
bufWriteBytes("fact"); // Fact Chunk
bufWriteIntLittleEndian(4);
numberOfSamplesOffset = filePointer;
bufWriteInt(0); // This is filled in later when numberOfSamples is known
factChunkLength = 12;
}
bufWriteBytes("data"); // Data Chunk
dataSizeOffset = (int) filePointer;
bufWriteInt(0); // This is filled in later when datasize is known
/*
fileSize = 4 + // for RIFF
4 + // file length
4 + // for WAVE
4 + // 'fmt ' chunk id
4 + // 'fmt ' chunk size field
formatSize +
4 + // 'data' chunk id
4; // 'data' chunk size field
*/
bufFlush();
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