src/share/classes/javax/sound/sampled/SourceDataLine.java
Print this page
*** 23,203 ****
* questions.
*/
package javax.sound.sampled;
-
/**
! * A source data line is a data line to which data may be written. It acts as
! * a source to its mixer. An application writes audio bytes to a source data line,
! * which handles the buffering of the bytes and delivers them to the mixer.
! * The mixer may mix the samples with those from other sources and then deliver
! * the mix to a target such as an output port (which may represent an audio output
* device on a sound card).
* <p>
* Note that the naming convention for this interface reflects the relationship
! * between the line and its mixer. From the perspective of an application,
! * a source data line may act as a target for audio data.
* <p>
* A source data line can be obtained from a mixer by invoking the
! * <code>{@link Mixer#getLine getLine}</code> method of <code>Mixer</code> with
! * an appropriate <code>{@link DataLine.Info}</code> object.
* <p>
! * The <code>SourceDataLine</code> interface provides a method for writing
! * audio data to the data line's buffer. Applications that play or mix
! * audio should write data to the source data line quickly enough to keep the
! * buffer from underflowing (emptying), which could cause discontinuities in
! * the audio that are perceived as clicks. Applications can use the
! * <code>{@link DataLine#available available}</code> method defined in the
! * <code>DataLine</code> interface to determine the amount of data currently
! * queued in the data line's buffer. The amount of data which can be written
! * to the buffer without blocking is the difference between the buffer size
! * and the amount of queued data. If the delivery of audio output
! * stops due to underflow, a <code>{@link LineEvent.Type#STOP STOP}</code> event is
! * generated. A <code>{@link LineEvent.Type#START START}</code> event is generated
! * when the audio output resumes.
*
* @author Kara Kytle
* @see Mixer
* @see DataLine
* @see TargetDataLine
* @since 1.3
*/
public interface SourceDataLine extends DataLine {
-
/**
* Opens the line with the specified format and suggested buffer size,
! * causing the line to acquire any required
! * system resources and become operational.
* <p>
* The buffer size is specified in bytes, but must represent an integral
* number of sample frames. Invoking this method with a requested buffer
* size that does not meet this requirement may result in an
! * IllegalArgumentException. The actual buffer size for the open line may
! * differ from the requested buffer size. The value actually set may be
! * queried by subsequently calling <code>{@link DataLine#getBufferSize}</code>.
* <p>
* If this operation succeeds, the line is marked as open, and an
! * <code>{@link LineEvent.Type#OPEN OPEN}</code> event is dispatched to the
! * line's listeners.
* <p>
! * Invoking this method on a line which is already open is illegal
! * and may result in an <code>IllegalStateException</code>.
* <p>
! * Note that some lines, once closed, cannot be reopened. Attempts
! * to reopen such a line will always result in a
! * <code>LineUnavailableException</code>.
*
* @param format the desired audio format
* @param bufferSize the desired buffer size
! * @throws LineUnavailableException if the line cannot be
! * opened due to resource restrictions
! * @throws IllegalArgumentException if the buffer size does not represent
! * an integral number of sample frames,
! * or if <code>format</code> is not fully specified or invalid
* @throws IllegalStateException if the line is already open
! * @throws SecurityException if the line cannot be
! * opened due to security restrictions
! *
* @see #open(AudioFormat)
* @see Line#open
* @see Line#close
* @see Line#isOpen
* @see LineEvent
*/
! public void open(AudioFormat format, int bufferSize) throws LineUnavailableException;
!
/**
* Opens the line with the specified format, causing the line to acquire any
* required system resources and become operational.
- *
* <p>
* The implementation chooses a buffer size, which is measured in bytes but
* which encompasses an integral number of sample frames. The buffer size
* that the system has chosen may be queried by subsequently calling
! * <code>{@link DataLine#getBufferSize}</code>.
* <p>
* If this operation succeeds, the line is marked as open, and an
! * <code>{@link LineEvent.Type#OPEN OPEN}</code> event is dispatched to the
! * line's listeners.
* <p>
! * Invoking this method on a line which is already open is illegal
! * and may result in an <code>IllegalStateException</code>.
* <p>
! * Note that some lines, once closed, cannot be reopened. Attempts
! * to reopen such a line will always result in a
! * <code>LineUnavailableException</code>.
*
* @param format the desired audio format
! * @throws LineUnavailableException if the line cannot be
! * opened due to resource restrictions
! * @throws IllegalArgumentException if <code>format</code>
! * is not fully specified or invalid
* @throws IllegalStateException if the line is already open
! * @throws SecurityException if the line cannot be
! * opened due to security restrictions
! *
* @see #open(AudioFormat, int)
* @see Line#open
* @see Line#close
* @see Line#isOpen
* @see LineEvent
*/
! public void open(AudioFormat format) throws LineUnavailableException;
!
/**
* Writes audio data to the mixer via this source data line. The requested
! * number of bytes of data are read from the specified array,
! * starting at the given offset into the array, and written to the data
! * line's buffer. If the caller attempts to write more data than can
! * currently be written (see <code>{@link DataLine#available available}</code>),
! * this method blocks until the requested amount of data has been written.
! * This applies even if the requested amount of data to write is greater
! * than the data line's buffer size. However, if the data line is closed,
! * stopped, or flushed before the requested amount has been written,
! * the method no longer blocks, but returns the number of bytes
! * written thus far.
! * <p>
! * The number of bytes that can be written without blocking can be ascertained
! * using the <code>{@link DataLine#available available}</code> method of the
! * <code>DataLine</code> interface. (While it is guaranteed that
! * this number of bytes can be written without blocking, there is no guarantee
! * that attempts to write additional data will block.)
* <p>
! * The number of bytes to write must represent an integral number of
! * sample frames, such that:
* <br>
! * <center><code>[ bytes written ] % [frame size in bytes ] == 0</code></center>
* <br>
* The return value will always meet this requirement. A request to write a
! * number of bytes representing a non-integral number of sample frames cannot
! * be fulfilled and may result in an <code>IllegalArgumentException</code>.
*
* @param b a byte array containing data to be written to the data line
! * @param len the length, in bytes, of the valid data in the array
! * (in other words, the requested amount of data to write, in bytes)
* @param off the offset from the beginning of the array, in bytes
* @return the number of bytes actually written
* @throws IllegalArgumentException if the requested number of bytes does
! * not represent an integral number of sample frames,
! * or if <code>len</code> is negative
! * @throws ArrayIndexOutOfBoundsException if <code>off</code> is negative,
! * or <code>off+len</code> is greater than the length of the array
! * <code>b</code>.
! *
* @see TargetDataLine#read
* @see DataLine#available
*/
! public int write(byte[] b, int off, int len);
/**
* Obtains the number of sample frames of audio data that can be written to
* the mixer, via this data line, without blocking. Note that the return
* value measures sample frames, not bytes.
* @return the number of sample frames currently available for writing
* @see TargetDataLine#availableRead
*/
//public int availableWrite();
}
--- 23,194 ----
* questions.
*/
package javax.sound.sampled;
/**
! * A source data line is a data line to which data may be written. It acts as a
! * source to its mixer. An application writes audio bytes to a source data line,
! * which handles the buffering of the bytes and delivers them to the mixer. The
! * mixer may mix the samples with those from other sources and then deliver the
! * mix to a target such as an output port (which may represent an audio output
* device on a sound card).
* <p>
* Note that the naming convention for this interface reflects the relationship
! * between the line and its mixer. From the perspective of an application, a
! * source data line may act as a target for audio data.
* <p>
* A source data line can be obtained from a mixer by invoking the
! * {@link Mixer#getLine getLine} method of {@code Mixer} with an appropriate
! * {@link DataLine.Info} object.
* <p>
! * The {@code SourceDataLine} interface provides a method for writing audio data
! * to the data line's buffer. Applications that play or mix audio should write
! * data to the source data line quickly enough to keep the buffer from
! * underflowing (emptying), which could cause discontinuities in the audio that
! * are perceived as clicks. Applications can use the
! * {@link DataLine#available available} method defined in the {@code DataLine}
! * interface to determine the amount of data currently queued in the data line's
! * buffer. The amount of data which can be written to the buffer without
! * blocking is the difference between the buffer size and the amount of queued
! * data. If the delivery of audio output stops due to underflow, a
! * {@link LineEvent.Type#STOP STOP} event is generated. A
! * {@link LineEvent.Type#START START} event is generated when the audio output
! * resumes.
*
* @author Kara Kytle
* @see Mixer
* @see DataLine
* @see TargetDataLine
* @since 1.3
*/
public interface SourceDataLine extends DataLine {
/**
* Opens the line with the specified format and suggested buffer size,
! * causing the line to acquire any required system resources and become
! * operational.
* <p>
* The buffer size is specified in bytes, but must represent an integral
* number of sample frames. Invoking this method with a requested buffer
* size that does not meet this requirement may result in an
! * {@code IllegalArgumentException}. The actual buffer size for the open
! * line may differ from the requested buffer size. The value actually set
! * may be queried by subsequently calling {@link DataLine#getBufferSize}.
* <p>
* If this operation succeeds, the line is marked as open, and an
! * {@link LineEvent.Type#OPEN OPEN} event is dispatched to the line's
! * listeners.
* <p>
! * Invoking this method on a line which is already open is illegal and may
! * result in an {@code IllegalStateException}.
* <p>
! * Note that some lines, once closed, cannot be reopened. Attempts to reopen
! * such a line will always result in a {@code LineUnavailableException}.
*
* @param format the desired audio format
* @param bufferSize the desired buffer size
! * @throws LineUnavailableException if the line cannot be opened due to
! * resource restrictions
! * @throws IllegalArgumentException if the buffer size does not represent an
! * integral number of sample frames, or if {@code format} is not
! * fully specified or invalid
* @throws IllegalStateException if the line is already open
! * @throws SecurityException if the line cannot be opened due to security
! * restrictions
* @see #open(AudioFormat)
* @see Line#open
* @see Line#close
* @see Line#isOpen
* @see LineEvent
*/
! void open(AudioFormat format, int bufferSize)
! throws LineUnavailableException;
/**
* Opens the line with the specified format, causing the line to acquire any
* required system resources and become operational.
* <p>
* The implementation chooses a buffer size, which is measured in bytes but
* which encompasses an integral number of sample frames. The buffer size
* that the system has chosen may be queried by subsequently calling
! * {@link DataLine#getBufferSize}.
* <p>
* If this operation succeeds, the line is marked as open, and an
! * {@link LineEvent.Type#OPEN OPEN} event is dispatched to the line's
! * listeners.
* <p>
! * Invoking this method on a line which is already open is illegal and may
! * result in an {@code IllegalStateException}.
* <p>
! * Note that some lines, once closed, cannot be reopened. Attempts to reopen
! * such a line will always result in a {@code LineUnavailableException}.
*
* @param format the desired audio format
! * @throws LineUnavailableException if the line cannot be opened due to
! * resource restrictions
! * @throws IllegalArgumentException if {@code format} is not fully specified
! * or invalid
* @throws IllegalStateException if the line is already open
! * @throws SecurityException if the line cannot be opened due to security
! * restrictions
* @see #open(AudioFormat, int)
* @see Line#open
* @see Line#close
* @see Line#isOpen
* @see LineEvent
*/
! void open(AudioFormat format) throws LineUnavailableException;
/**
* Writes audio data to the mixer via this source data line. The requested
! * number of bytes of data are read from the specified array, starting at
! * the given offset into the array, and written to the data line's buffer.
! * If the caller attempts to write more data than can currently be written
! * (see {@link DataLine#available available}), this method blocks until the
! * requested amount of data has been written. This applies even if the
! * requested amount of data to write is greater than the data line's buffer
! * size. However, if the data line is closed, stopped, or flushed before the
! * requested amount has been written, the method no longer blocks, but
! * returns the number of bytes written thus far.
! * <p>
! * The number of bytes that can be written without blocking can be
! * ascertained using the {@link DataLine#available available} method of the
! * {@code DataLine} interface. (While it is guaranteed that this number of
! * bytes can be written without blocking, there is no guarantee that
! * attempts to write additional data will block.)
* <p>
! * The number of bytes to write must represent an integral number of sample
! * frames, such that:
* <br>
! * <center>{@code [ bytes written ] % [frame size in bytes ] == 0}</center>
* <br>
* The return value will always meet this requirement. A request to write a
! * number of bytes representing a non-integral number of sample frames
! * cannot be fulfilled and may result in an
! * {@code IllegalArgumentException}.
*
* @param b a byte array containing data to be written to the data line
! * @param len the length, in bytes, of the valid data in the array (in
! * other words, the requested amount of data to write, in bytes)
* @param off the offset from the beginning of the array, in bytes
* @return the number of bytes actually written
* @throws IllegalArgumentException if the requested number of bytes does
! * not represent an integral number of sample frames, or if
! * {@code len} is negative
! * @throws ArrayIndexOutOfBoundsException if {@code off} is negative, or
! * {@code off+len} is greater than the length of the array {@code b}
* @see TargetDataLine#read
* @see DataLine#available
*/
! int write(byte[] b, int off, int len);
/**
* Obtains the number of sample frames of audio data that can be written to
* the mixer, via this data line, without blocking. Note that the return
* value measures sample frames, not bytes.
+ *
* @return the number of sample frames currently available for writing
* @see TargetDataLine#availableRead
*/
//public int availableWrite();
}