| /* |
| * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
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| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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| */ |
| |
| package javax.sound.sampled; |
| |
| /** |
| * A target data line is a type of {@link DataLine} from which audio data can be |
| * read. The most common example is a data line that gets its data from an audio |
| * capture device. (The device is implemented as a mixer that writes to the |
| * target data line.) |
| * <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 |
| * target data line may act as a source for audio data. |
| * <p> |
| * The target 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 TargetDataLine} interface provides a method for reading the |
| * captured data from the target data line's buffer. Applications that record |
| * audio should read data from the target data line quickly enough to keep the |
| * buffer from overflowing, which could cause discontinuities in the captured |
| * data 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. If the buffer does overflow, the oldest queued data is discarded and |
| * replaced by new data. |
| * |
| * @author Kara Kytle |
| * @see Mixer |
| * @see DataLine |
| * @see SourceDataLine |
| * @since 1.3 |
| */ |
| public interface TargetDataLine extends DataLine { |
| |
| /** |
| * Opens the line with the specified format and requested 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 that is already open is illegal and may |
| * result in an {@code IllegalStateException}. |
| * <p> |
| * 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, in bytes |
| * @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 that is already open is illegal and may |
| * result in an {@code IllegalStateException}. |
| * <p> |
| * 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; |
| |
| /** |
| * Reads audio data from the data line's input buffer. The requested number |
| * of bytes is read into the specified array, starting at the specified |
| * offset into the array in bytes. This method blocks until the requested |
| * amount of data has been read. However, if the data line is closed, |
| * stopped, drained, or flushed before the requested amount has been read, |
| * the method no longer blocks, but returns the number of bytes read thus |
| * far. |
| * <p> |
| * The number of bytes that can be read 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 read without blocking, there is no guarantee that attempts |
| * to read additional data will block.) |
| * <p> |
| * The number of bytes to be read must represent an integral number of |
| * sample frames, such that: |
| * <br> |
| * <center>{@code [ bytes read ] % [frame size in bytes ] == 0}</center> |
| * <br> |
| * The return value will always meet this requirement. A request to read a |
| * number of bytes representing a non-integral number of sample frames |
| * cannot be fulfilled and may result in an IllegalArgumentException. |
| * |
| * @param b a byte array that will contain the requested input data when |
| * this method returns |
| * @param off the offset from the beginning of the array, in bytes |
| * @param len the requested number of bytes to read |
| * @return the number of bytes actually read |
| * @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 SourceDataLine#write |
| * @see DataLine#available |
| */ |
| int read(byte[] b, int off, int len); |
| |
| /** |
| * Obtains the number of sample frames of audio data that can be read from |
| * the target data line without blocking. Note that the return value |
| * measures sample frames, not bytes. |
| * |
| * @return the number of sample frames currently available for reading |
| * @see SourceDataLine#availableWrite |
| */ |
| //public int availableRead(); |
| } |
