Here's an example that writes 2 seconds of silence *
* PcmWaveWriter s_wsw = new PcmWaveWriter(2, 44100);
* byte[] silence = new byte[16*2*44100];
* wsw.Open("C:\\out.wav");
* wsw.WriteHeader();
* wsw.WriteData(silence, 0, silence.length);
* wsw.WriteData(silence, 0, silence.length);
* wsw.Close();
*
*
* @author Jim Lawrence, helloNetwork.com
* @author Marc Gimpel, Wimba S.A. (mgimpel@horizonwimba.com)
* @version $Revision: 1.2 $
*/
public class PcmWaveWriter
extends AudioFileWriter
{
/** Wave type code of PCM */
public static final short WAVE_FORMAT_PCM = (short) 0x01;
/** Wave type code of Speex */
public static final short WAVE_FORMAT_SPEEX = (short) 0xa109;
/**
* Table describing the number of frames per packet in a Speex Wave file,
* depending on its mode-1 (1=NB, 2=WB, 3=UWB), channels-1 (1=mono, 2=stereo)
* and the quality setting (0 to 10).
* See end of file for exerpt from SpeexACM code for more explanations.
*/
public static final int[][][] WAVE_FRAME_SIZES = new int[][][]
{{{8, 8, 8, 1, 1, 2, 2, 2, 2, 2, 2}, // NB mono
{2, 1, 1, 7, 7, 8, 8, 8, 8, 3, 3}}, // NB stereo
{{8, 8, 8, 2, 1, 1, 2, 2, 2, 2, 2}, // WB mono
{1, 2, 2, 8, 7, 6, 3, 3, 3, 3, 3}}, // WB stereo
{{8, 8, 8, 1, 2, 2, 1, 1, 1, 1, 1}, // UWB mono
{2, 1, 1, 7, 8, 3, 6, 6, 5, 5, 5}}}; // UWB stereo
/**
* Table describing the number of bit per Speex frame, depending on its
* mode-1 (1=NB, 2=WB, 3=UWB), channels-1 (1=mono, 2=stereo) and the quality
* setting (0 to 10).
* See end of file for exerpt from SpeexACM code for more explanations.
*/
public static final int[][][] WAVE_BITS_PER_FRAME = new int[][][]
{{{ 43, 79, 119, 160, 160, 220, 220, 300, 300, 364, 492}, // NB mono
{ 60, 96, 136, 177, 177, 237, 237, 317, 317, 381, 509}}, // NB stereo
{{ 79, 115, 155, 196, 256, 336, 412, 476, 556, 684, 844}, // WB mono
{ 96, 132, 172, 213, 273, 353, 429, 493, 573, 701, 861}}, // WB stereo
{{ 83, 151, 191, 232, 292, 372, 448, 512, 592, 720, 880}, // UWB mono
{100, 168, 208, 249, 309, 389, 465, 529, 609, 737, 897}}}; // UWB stereo
private RandomAccessFile raf;
/** Defines the encoder mode (0=NB, 1=WB and 2-UWB). */
private int mode;
/** */
private int quality;
/** Defines the sampling rate of the audio input. */
private int sampleRate;
/** Defines the number of channels of the audio input (1=mono, 2=stereo). */
private int channels;
/** Defines the number of frames per speex packet. */
private int nframes;
/** Defines whether or not to use VBR (Variable Bit Rate). */
private boolean vbr;
/** */
private int size;
/** */
private boolean isPCM;
/**
* Constructor.
*/
public PcmWaveWriter()
{
size = 0;
}
/**
* Constructor.
* @param sampleRate the number of samples per second.
* @param channels the number of audio channels (1=mono, 2=stereo, ...).
*/
public PcmWaveWriter(final int sampleRate, final int channels)
{
this();
setPCMFormat(sampleRate, channels);
}
/**
* Constructor.
* @param mode the mode of the encoder (0=NB, 1=WB, 2=UWB).
* @param quality
* @param sampleRate the number of samples per second.
* @param channels the number of audio channels (1=mono, 2=stereo, ...).
* @param nframes the number of frames per speex packet.
* @param vbr
*/
public PcmWaveWriter(final int mode,
final int quality,
final int sampleRate,
final int channels,
final int nframes,
final boolean vbr)
{
this();
setSpeexFormat(mode, quality, sampleRate, channels, nframes, vbr);
}
/**
* Sets the output format for a PCM Wave file.
* Must be called before WriteHeader().
* @param sampleRate the number of samples per second.
* @param channels the number of audio channels (1=mono, 2=stereo, ...).
*/
private void setPCMFormat(final int sampleRate, final int channels)
{
this.channels = channels;
this.sampleRate = sampleRate;
isPCM = true;
}
/**
* Sets the output format for a Speex Wave file.
* Must be called before WriteHeader().
* @param mode the mode of the encoder (0=NB, 1=WB, 2=UWB).
* @param quality
* @param sampleRate the number of samples per second.
* @param channels the number of audio channels (1=mono, 2=stereo, ...).
* @param nframes the number of frames per speex packet.
* @param vbr
*/
private void setSpeexFormat(final int mode,
final int quality,
final int sampleRate,
final int channels,
final int nframes,
final boolean vbr)
{
this.mode = mode;
this.quality = quality;
this.sampleRate = sampleRate;
this.channels = channels;
this.nframes = nframes;
this.vbr = vbr;
isPCM = false;
}
/**
* Closes the output file.
* MUST be called to have a correct stream.
* @exception IOException if there was an exception closing the Audio Writer.
*/
public void close()
throws IOException
{
/* update the total file length field from RIFF chunk */
raf.seek(4);
int fileLength = (int) raf.length() - 8;
writeInt(raf, fileLength);
/* update the data chunk length size */
raf.seek(40);
writeInt(raf, size);
/* close the output file */
raf.close();
}
/**
* Open the output file.
* @param file - file to open.
* @exception IOException if there was an exception opening the Audio Writer.
*/
public void open(final File file)
throws IOException
{
file.delete();
raf = new RandomAccessFile(file, "rw");
size = 0;
}
/**
* Open the output file.
* @param filename filename to open.
* @exception IOException if there was an exception opening the Audio Writer.
*/
public void open(final String filename)
throws IOException
{
open(new File(filename));
}
/**
* Writes the initial data chunks that start the wave file.
* Prepares file for data samples to written.
* @param comment ignored by the WAV header.
* @exception IOException
*/
public void writeHeader(final String comment)
throws IOException
{
/* writes the RIFF chunk indicating wave format */
byte[] chkid = "RIFF".getBytes();
raf.write(chkid, 0, chkid.length);
writeInt(raf, 0); /* total length must be blank */
chkid = "WAVE".getBytes();
raf.write(chkid, 0, chkid.length);
/* format subchunk: of size 16 */
chkid = "fmt ".getBytes();
raf.write(chkid, 0, chkid.length);
if (isPCM) {
writeInt(raf, 16); // Size of format chunk
writeShort(raf, WAVE_FORMAT_PCM); // Format tag: PCM
writeShort(raf, (short)channels); // Number of channels
writeInt(raf, sampleRate); // Sampling frequency
writeInt(raf, sampleRate*channels*2); // Average bytes per second
writeShort(raf, (short) (channels*2)); // Blocksize of data
writeShort(raf, (short) 16); // Bits per sample
}
else {
int length = comment.length();
writeInt(raf, (short) (18+2+80+length)); // Size of format chunk
writeShort(raf, WAVE_FORMAT_SPEEX); // Format tag: Speex
writeShort(raf, (short)channels); // Number of channels
writeInt(raf, sampleRate); // Sampling frequency
writeInt(raf, (calculateEffectiveBitrate(mode, channels, quality) + 7) >> 3); // Average bytes per second
writeShort(raf, (short) calculateBlockSize(mode, channels, quality)); // Blocksize of data
writeShort(raf, (short) quality); // Bits per sample
writeShort(raf, (short) (2+80+length)); // The count in bytes of the extra size
raf.writeByte(0xff & 1); // ACM major version number
raf.writeByte(0xff & 0); // ACM minor version number
raf.write(buildSpeexHeader(sampleRate, mode, channels, vbr, nframes));
raf.writeBytes(comment);
}
/* write the start of data chunk */
chkid = "data".getBytes();
raf.write(chkid, 0, chkid.length);
writeInt(raf, 0);
}
/**
* Writes a packet of audio.
* @param data audio data
* @param offset the offset from which to start reading the data.
* @param len the length of data to read.
* @exception IOException
*/
public void writePacket(final byte[] data,
final int offset,
final int len)
throws IOException
{
raf.write(data, offset, len);
size+= len;
}
/**
* Calculates effective bitrate (considering padding).
* See end of file for exerpt from SpeexACM code for more explanations.
* @param mode
* @param channels
* @param quality
* @return effective bitrate (considering padding).
*/
private static final int calculateEffectiveBitrate(final int mode,
final int channels,
final int quality)
{
return ((((WAVE_FRAME_SIZES[mode-1][channels-1][quality] *
WAVE_BITS_PER_FRAME[mode-1][channels-1][quality]) + 7) >> 3) *
50 * 8) / WAVE_BITS_PER_FRAME[mode-1][channels-1][quality];
}
/**
* Calculates block size (considering padding).
* See end of file for exerpt from SpeexACM code for more explanations.
* @param mode
* @param channels
* @param quality
* @return block size (considering padding).
*/
private static final int calculateBlockSize(final int mode,
final int channels,
final int quality)
{
return (((WAVE_FRAME_SIZES[mode-1][channels-1][quality] *
WAVE_BITS_PER_FRAME[mode-1][channels-1][quality]) + 7) >> 3);
}
}
// The following is taken from the SpeexACM 1.0.1.1 Source code (codec.c file).
//
// This array describes how many bits are required by an encoded audio frame.
// It also specifies the optimal framesperblock parameter to minimize
// padding loss. It also lists the effective bitrate (considering padding).
//
// The array indices are rate, channels, quality (each as a 0 based index)
//
/*
struct tagQualityInfo {
UINT nBitsPerFrame;
UINT nFrameSize;
UINT nFramesPerBlock;
UINT nEffectiveBitrate;
} QualityInfo[3][2][11] = {
43, 160, 8, 2150, // 8000 1 0
79, 160, 8, 3950, // 8000 1 1
119, 160, 8, 5950, // 8000 1 2
160, 160, 1, 8000, // 8000 1 3
160, 160, 1, 8000, // 8000 1 4
220, 160, 2, 11000, // 8000 1 5
220, 160, 2, 11000, // 8000 1 6
300, 160, 2, 15000, // 8000 1 7
300, 160, 2, 15000, // 8000 1 8
364, 160, 2, 18200, // 8000 1 9
492, 160, 2, 24600, // 8000 1 10
60, 160, 2, 3000, // 8000 2 0
96, 160, 1, 4800, // 8000 2 1
136, 160, 1, 6800, // 8000 2 2
177, 160, 7, 8857, // 8000 2 3
177, 160, 7, 8857, // 8000 2 4
237, 160, 8, 11850, // 8000 2 5
237, 160, 8, 11850, // 8000 2 6
317, 160, 8, 15850, // 8000 2 7
317, 160, 8, 15850, // 8000 2 8
381, 160, 3, 19066, // 8000 2 9
509, 160, 3, 25466, // 8000 2 10
79, 320, 8, 3950, // 16000 1 0
115, 320, 8, 5750, // 16000 1 1
155, 320, 8, 7750, // 16000 1 2
196, 320, 2, 9800, // 16000 1 3
256, 320, 1, 12800, // 16000 1 4
336, 320, 1, 16800, // 16000 1 5
412, 320, 2, 20600, // 16000 1 6
476, 320, 2, 23800, // 16000 1 7
556, 320, 2, 27800, // 16000 1 8
684, 320, 2, 34200, // 16000 1 9
844, 320, 2, 42200, // 16000 1 10
96, 320, 1, 4800, // 16000 2 0
132, 320, 2, 6600, // 16000 2 1
172, 320, 2, 8600, // 16000 2 2
213, 320, 8, 10650, // 16000 2 3
273, 320, 7, 13657, // 16000 2 4
353, 320, 6, 17666, // 16000 2 5
429, 320, 3, 21466, // 16000 2 6
493, 320, 3, 24666, // 16000 2 7
573, 320, 3, 28666, // 16000 2 8
701, 320, 3, 35066, // 16000 2 9
861, 320, 3, 43066, // 16000 2 10
83, 640, 8, 4150, // 32000 1 0
151, 640, 8, 7550, // 32000 1 1
191, 640, 8, 9550, // 32000 1 2
232, 640, 1, 11600, // 32000 1 3
292, 640, 2, 14600, // 32000 1 4
372, 640, 2, 18600, // 32000 1 5
448, 640, 1, 22400, // 32000 1 6
512, 640, 1, 25600, // 32000 1 7
592, 640, 1, 29600, // 32000 1 8
720, 640, 1, 36000, // 32000 1 9
880, 640, 1, 44000, // 32000 1 10
100, 640, 2, 5000, // 32000 2 0
168, 640, 1, 8400, // 32000 2 1
208, 640, 1, 10400, // 32000 2 2
249, 640, 7, 12457, // 32000 2 3
309, 640, 8, 15450, // 32000 2 4
389, 640, 3, 19466, // 32000 2 5
465, 640, 6, 23266, // 32000 2 6
529, 640, 6, 26466, // 32000 2 7
609, 640, 5, 30480, // 32000 2 8
737, 640, 5, 36880, // 32000 2 9
897, 640, 5, 44880, // 32000 2 10
};
*/