File	Doc	Category	Size	Date	Package
AudioInputStream.java	API Doc	Java SE 5 API	14280	Fri Aug 26 14:57:50 BST 2005	javax.sound.sampled

AudioInputStream

• java.lang.Object
  • java.io.InputStream

Fields Summary
private InputStream	stream The InputStream from which this AudioInputStream object was constructed.
protected AudioFormat	format The format of the audio data contained in the stream.
protected long	frameLength This stream's length, in sample frames.
protected int	frameSize The size of each frame, in bytes.
protected long	framePos The current position in this stream, in sample frames (zero-based).
private long	markpos The position where a mark was set.
private byte[]	pushBackBuffer When the underlying stream could only return a non-integral number of frames, store the remainder in a temporary buffer
private int	pushBackLen number of valid bytes in the pushBackBuffer
private byte[]	markPushBackBuffer MarkBuffer at mark position
private int	markPushBackLen number of valid bytes in the markPushBackBuffer

Constructors Summary
public AudioInputStream(InputStream stream, AudioFormat format, long length) Constructs an audio input stream that has the requested format and length in sample frames, using audio data from the specified input stream. param stream the stream on which this AudioInputStream object is based param format the format of this stream's audio data param length the length in sample frames of the data in this stream super(); this.format = format; this.frameLength = length; this.frameSize = format.getFrameSize(); // any frameSize that is not well-defined will // cause that this stream will be read in bytes if( this.frameSize == AudioSystem.NOT_SPECIFIED || frameSize <= 0) { this.frameSize = 1; } this.stream = stream; framePos = 0; markpos = 0;
public AudioInputStream(TargetDataLine line) Constructs an audio input stream that reads its data from the target data line indicated. The format of the stream is the same as that of the target data line, and the length is AudioSystem#NOT_SPECIFIED. param line the target data line from which this stream obtains its data. see AudioSystem#NOT_SPECIFIED TargetDataLineInputStream tstream = new TargetDataLineInputStream(line); format = line.getFormat(); frameLength = AudioSystem.NOT_SPECIFIED; frameSize = format.getFrameSize(); if( frameSize == AudioSystem.NOT_SPECIFIED || frameSize <= 0) { frameSize = 1; } this.stream = tstream; framePos = 0; markpos = 0;

Methods Summary
public int	available() Returns the maximum number of bytes that can be read (or skipped over) from this audio input stream without blocking. This limit applies only to the next invocation of a read or skip method for this audio input stream; the limit can vary each time these methods are invoked. Depending on the underlying stream,an IOException may be thrown if this stream is closed. return the number of bytes that can be read from this audio input stream without blocking throws IOException if an input or output error occurs see #read(byte[], int, int) see #read(byte[]) see #read() see #skip int temp = stream.available(); // don't return greater than our set length in frames if( (frameLength != AudioSystem.NOT_SPECIFIED) && ( (temp/frameSize) > (frameLength-framePos)) ) { return (int) (frameLength-framePos) * frameSize; } else { return temp; }
public void	close() Closes this audio input stream and releases any system resources associated with the stream. throws IOException if an input or output error occurs stream.close();
public javax.sound.sampled.AudioFormat	getFormat() Obtains the audio format of the sound data in this audio input stream. return an audio format object describing this stream's format return format;
public long	getFrameLength() Obtains the length of the stream, expressed in sample frames rather than bytes. return the length in sample frames return frameLength;
public void	mark(int readlimit) Marks the current position in this audio input stream. param readlimit the maximum number of bytes that can be read before the mark position becomes invalid. see #reset see #markSupported stream.mark(readlimit); if (markSupported()) { markpos = framePos; // remember the pushback buffer markPushBackLen = pushBackLen; if (markPushBackLen > 0) { if (markPushBackBuffer == null) { markPushBackBuffer = new byte[frameSize]; } System.arraycopy(pushBackBuffer, 0, markPushBackBuffer, 0, markPushBackLen); } }
public boolean	markSupported() Tests whether this audio input stream supports the mark and reset methods. return true if this stream supports the mark and reset methods; false otherwise see #mark see #reset return stream.markSupported();
public int	read() Reads the next byte of data from the audio input stream. The audio input stream's frame size must be one byte, or an IOException will be thrown. return the next byte of data, or -1 if the end of the stream is reached throws IOException if an input or output error occurs see #read(byte[], int, int) see #read(byte[]) see #available if( frameSize != 1 ) { throw new IOException("cannot read a single byte if frame size > 1"); } byte[] data = new byte[1]; int temp = read(data); if (temp <= 0) { // we have a weird situation if read(byte[]) returns 0! return -1; } return temp & 0xFF;
public int	read(byte[] b) Reads some number of bytes from the audio input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown. This method will always read an integral number of frames. If the length of the array is not an integral number of frames, a maximum of b.length - (b.length % frameSize) bytes will be read. param b the buffer into which the data is read return the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached throws IOException if an input or output error occurs see #read(byte[], int, int) see #read() see #available return read(b,0,b.length);
public int	read(byte[] b, int off, int len) Reads up to a specified maximum number of bytes of data from the audio stream, putting them into the given byte array. This method will always read an integral number of frames. If len does not specify an integral number of frames, a maximum of len - (len % frameSize) bytes will be read. param b the buffer into which the data is read param off the offset, from the beginning of array b, at which the data will be written param len the maximum number of bytes to read return the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached throws IOException if an input or output error occurs see #read(byte[]) see #read() see #skip see #available // make sure we don't read fractions of a frame. if( (len%frameSize) != 0 ) { len -= (len%frameSize); if (len == 0) { return 0; } } if( frameLength != AudioSystem.NOT_SPECIFIED ) { if( framePos >= frameLength ) { return -1; } else { // don't try to read beyond our own set length in frames if( (len/frameSize) > (frameLength-framePos) ) { len = (int) (frameLength-framePos) * frameSize; } } } int bytesRead = 0; int thisOff = off; // if we've bytes left from last call to read(), // use them first if (pushBackLen > 0 && len >= pushBackLen) { System.arraycopy(pushBackBuffer, 0, b, off, pushBackLen); thisOff += pushBackLen; len -= pushBackLen; bytesRead += pushBackLen; pushBackLen = 0; } int thisBytesRead = stream.read(b, thisOff, len); if (thisBytesRead == -1) { return -1; } if (thisBytesRead > 0) { bytesRead += thisBytesRead; } if (bytesRead > 0) { pushBackLen = bytesRead % frameSize; if (pushBackLen > 0) { // copy everything we got from the beginning of the frame // to our pushback buffer if (pushBackBuffer == null) { pushBackBuffer = new byte[frameSize]; } System.arraycopy(b, off + bytesRead - pushBackLen, pushBackBuffer, 0, pushBackLen); bytesRead -= pushBackLen; } // make sure to update our framePos framePos += bytesRead/frameSize; } return bytesRead;
public void	reset() Repositions this audio input stream to the position it had at the time its mark method was last invoked. throws IOException if an input or output error occurs. see #mark see #markSupported stream.reset(); framePos = markpos; // re-create the pushback buffer pushBackLen = markPushBackLen; if (pushBackLen > 0) { if (pushBackBuffer == null) { pushBackBuffer = new byte[frameSize - 1]; } System.arraycopy(markPushBackBuffer, 0, pushBackBuffer, 0, pushBackLen); }
public long	skip(long n) Skips over and discards a specified number of bytes from this audio input stream. param n the requested number of bytes to be skipped return the actual number of bytes skipped throws IOException if an input or output error occurs see #read see #available // make sure not to skip fractional frames if( (n%frameSize) != 0 ) { n -= (n%frameSize); } if( frameLength != AudioSystem.NOT_SPECIFIED ) { // don't skip more than our set length in frames. if( (n/frameSize) > (frameLength-framePos) ) { n = (frameLength-framePos) * frameSize; } } long temp = stream.skip(n); // if no error, update our position. if( temp%frameSize != 0 ) { // Throw an IOException if we've skipped a fractional number of frames throw new IOException("Could not skip an integer number of frames."); } if( temp >= 0 ) { framePos += temp/frameSize; } return temp;