| /* |
| * Copyright (c) 1999, 2017, 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 |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.sound.sampled; |
| |
| import java.util.Arrays; |
| |
| /** |
| * {@code DataLine} adds media-related functionality to its superinterface, |
| * {@code Line}. This functionality includes transport-control methods that |
| * start, stop, drain, and flush the audio data that passes through the line. A |
| * data line can also report the current position, volume, and audio format of |
| * the media. Data lines are used for output of audio by means of the |
| * subinterfaces {@link SourceDataLine} or {@link Clip}, which allow an |
| * application program to write data. Similarly, audio input is handled by the |
| * subinterface {@link TargetDataLine}, which allows data to be read. |
| * <p> |
| * A data line has an internal buffer in which the incoming or outgoing audio |
| * data is queued. The {@link #drain()} method blocks until this internal buffer |
| * becomes empty, usually because all queued data has been processed. The |
| * {@link #flush()} method discards any available queued data from the internal |
| * buffer. |
| * <p> |
| * A data line produces {@link LineEvent.Type#START START} and |
| * {@link LineEvent.Type#STOP STOP} events whenever it begins or ceases active |
| * presentation or capture of data. These events can be generated in response to |
| * specific requests, or as a result of less direct state changes. For example, |
| * if {@link #start()} is called on an inactive data line, and data is available |
| * for capture or playback, a {@code START} event will be generated shortly, |
| * when data playback or capture actually begins. Or, if the flow of data to an |
| * active data line is constricted so that a gap occurs in the presentation of |
| * data, a {@code STOP} event is generated. |
| * <p> |
| * Mixers often support synchronized control of multiple data lines. |
| * Synchronization can be established through the {@code Mixer} interface's |
| * {@link Mixer#synchronize synchronize} method. See the description of the |
| * {@link Mixer Mixer} interface for a more complete description. |
| * |
| * @author Kara Kytle |
| * @see LineEvent |
| * @since 1.3 |
| */ |
| public interface DataLine extends Line { |
| |
| /** |
| * Drains queued data from the line by continuing data I/O until the data |
| * line's internal buffer has been emptied. This method blocks until the |
| * draining is complete. Because this is a blocking method, it should be |
| * used with care. If {@code drain()} is invoked on a stopped line that has |
| * data in its queue, the method will block until the line is running and |
| * the data queue becomes empty. If {@code drain()} is invoked by one |
| * thread, and another continues to fill the data queue, the operation will |
| * not complete. This method always returns when the data line is closed. |
| * |
| * @see #flush() |
| */ |
| void drain(); |
| |
| /** |
| * Flushes queued data from the line. The flushed data is discarded. In some |
| * cases, not all queued data can be discarded. For example, a mixer can |
| * flush data from the buffer for a specific input line, but any unplayed |
| * data already in the output buffer (the result of the mix) will still be |
| * played. You can invoke this method after pausing a line (the normal case) |
| * if you want to skip the "stale" data when you restart playback or |
| * capture. (It is legal to flush a line that is not stopped, but doing so |
| * on an active line is likely to cause a discontinuity in the data, |
| * resulting in a perceptible click.) |
| * |
| * @see #stop() |
| * @see #drain() |
| */ |
| void flush(); |
| |
| /** |
| * Allows a line to engage in data I/O. If invoked on a line that is already |
| * running, this method does nothing. Unless the data in the buffer has been |
| * flushed, the line resumes I/O starting with the first frame that was |
| * unprocessed at the time the line was stopped. When audio capture or |
| * playback starts, a {@link LineEvent.Type#START START} event is generated. |
| * |
| * @see #stop() |
| * @see #isRunning() |
| * @see LineEvent |
| */ |
| void start(); |
| |
| /** |
| * Stops the line. A stopped line should cease I/O activity. If the line is |
| * open and running, however, it should retain the resources required to |
| * resume activity. A stopped line should retain any audio data in its |
| * buffer instead of discarding it, so that upon resumption the I/O can |
| * continue where it left off, if possible. (This doesn't guarantee that |
| * there will never be discontinuities beyond the current buffer, of course; |
| * if the stopped condition continues for too long, input or output samples |
| * might be dropped.) If desired, the retained data can be discarded by |
| * invoking the {@code flush} method. When audio capture or playback stops, |
| * a {@link LineEvent.Type#STOP STOP} event is generated. |
| * |
| * @see #start() |
| * @see #isRunning() |
| * @see #flush() |
| * @see LineEvent |
| */ |
| void stop(); |
| |
| /** |
| * Indicates whether the line is running. The default is {@code false}. An |
| * open line begins running when the first data is presented in response to |
| * an invocation of the {@code start} method, and continues until |
| * presentation ceases in response to a call to {@code stop} or because |
| * playback completes. |
| * |
| * @return {@code true} if the line is running, otherwise {@code false} |
| * @see #start() |
| * @see #stop() |
| */ |
| boolean isRunning(); |
| |
| /** |
| * Indicates whether the line is engaging in active I/O (such as playback or |
| * capture). When an inactive line becomes active, it sends a |
| * {@link LineEvent.Type#START START} event to its listeners. Similarly, |
| * when an active line becomes inactive, it sends a |
| * {@link LineEvent.Type#STOP STOP} event. |
| * |
| * @return {@code true} if the line is actively capturing or rendering |
| * sound, otherwise {@code false} |
| * @see #isOpen |
| * @see #addLineListener |
| * @see #removeLineListener |
| * @see LineEvent |
| * @see LineListener |
| */ |
| boolean isActive(); |
| |
| /** |
| * Obtains the current format (encoding, sample rate, number of channels, |
| * etc.) of the data line's audio data. |
| * <p> |
| * If the line is not open and has never been opened, it returns the default |
| * format. The default format is an implementation specific audio format, |
| * or, if the {@code DataLine.Info} object, which was used to retrieve this |
| * {@code DataLine}, specifies at least one fully qualified audio format, |
| * the last one will be used as the default format. Opening the line with a |
| * specific audio format (e.g. {@link SourceDataLine#open(AudioFormat)}) |
| * will override the default format. |
| * |
| * @return current audio data format |
| * @see AudioFormat |
| */ |
| AudioFormat getFormat(); |
| |
| /** |
| * Obtains the maximum number of bytes of data that will fit in the data |
| * line's internal buffer. For a source data line, this is the size of the |
| * buffer to which data can be written. For a target data line, it is the |
| * size of the buffer from which data can be read. Note that the units used |
| * are bytes, but will always correspond to an integral number of sample |
| * frames of audio data. |
| * |
| * @return the size of the buffer, in bytes |
| */ |
| int getBufferSize(); |
| |
| /** |
| * Obtains the number of bytes of data currently available to the |
| * application for processing in the data line's internal buffer. For a |
| * source data line, this is the amount of data that can be written to the |
| * buffer without blocking. For a target data line, this is the amount of |
| * data available to be read by the application. For a clip, this value is |
| * always 0 because the audio data is loaded into the buffer when the clip |
| * is opened, and persists without modification until the clip is closed. |
| * <p> |
| * Note that the units used are bytes, but will always correspond to an |
| * integral number of sample frames of audio data. |
| * <p> |
| * An application is guaranteed that a read or write operation of up to the |
| * number of bytes returned from {@code available()} will not block; |
| * however, there is no guarantee that attempts to read or write more data |
| * will block. |
| * |
| * @return the amount of data available, in bytes |
| */ |
| int available(); |
| |
| /** |
| * Obtains the current position in the audio data, in sample frames. The |
| * frame position measures the number of sample frames captured by, or |
| * rendered from, the line since it was opened. This return value will wrap |
| * around after 2^31 frames. It is recommended to use |
| * {@code getLongFramePosition} instead. |
| * |
| * @return the number of frames already processed since the line was opened |
| * @see #getLongFramePosition() |
| */ |
| int getFramePosition(); |
| |
| /** |
| * Obtains the current position in the audio data, in sample frames. The |
| * frame position measures the number of sample frames captured by, or |
| * rendered from, the line since it was opened. |
| * |
| * @return the number of frames already processed since the line was opened |
| * @since 1.5 |
| */ |
| long getLongFramePosition(); |
| |
| /** |
| * Obtains the current position in the audio data, in microseconds. The |
| * microsecond position measures the time corresponding to the number of |
| * sample frames captured by, or rendered from, the line since it was |
| * opened. The level of precision is not guaranteed. For example, an |
| * implementation might calculate the microsecond position from the current |
| * frame position and the audio sample frame rate. The precision in |
| * microseconds would then be limited to the number of microseconds per |
| * sample frame. |
| * |
| * @return the number of microseconds of data processed since the line was |
| * opened |
| */ |
| long getMicrosecondPosition(); |
| |
| /** |
| * Obtains the current volume level for the line. This level is a measure of |
| * the signal's current amplitude, and should not be confused with the |
| * current setting of a gain control. The range is from 0.0 (silence) to 1.0 |
| * (maximum possible amplitude for the sound waveform). The units measure |
| * linear amplitude, not decibels. |
| * |
| * @return the current amplitude of the signal in this line, or |
| * {@link AudioSystem#NOT_SPECIFIED} |
| */ |
| float getLevel(); |
| |
| /** |
| * Besides the class information inherited from its superclass, |
| * {@code DataLine.Info} provides additional information specific to data |
| * lines. This information includes: |
| * <ul> |
| * <li>the audio formats supported by the data line |
| * <li>the minimum and maximum sizes of its internal buffer |
| * </ul> |
| * Because a {@code Line.Info} knows the class of the line its describes, a |
| * {@code DataLine.Info} object can describe {@code DataLine} subinterfaces |
| * such as {@link SourceDataLine}, {@link TargetDataLine}, and {@link Clip}. |
| * You can query a mixer for lines of any of these types, passing an |
| * appropriate instance of {@code DataLine.Info} as the argument to a method |
| * such as {@link Mixer#getLine(Line.Info)}. |
| * |
| * @author Kara Kytle |
| * @see Line.Info |
| * @since 1.3 |
| */ |
| class Info extends Line.Info { |
| |
| /** |
| * The set of supported formats. |
| */ |
| private final AudioFormat[] formats; |
| |
| /** |
| * Minimum buffer size supported by the data line, in bytes. |
| */ |
| private final int minBufferSize; |
| |
| /** |
| * Maximum buffer size supported by the data line, in bytes. |
| */ |
| private final int maxBufferSize; |
| |
| /** |
| * Constructs a data line's info object from the specified information, |
| * which includes a set of supported audio formats and a range for the |
| * buffer size. This constructor is typically used by mixer |
| * implementations when returning information about a supported line. |
| * |
| * @param lineClass the class of the data line described by the info |
| * object |
| * @param formats set of formats supported |
| * @param minBufferSize minimum buffer size supported by the data line, |
| * in bytes |
| * @param maxBufferSize maximum buffer size supported by the data line, |
| * in bytes |
| */ |
| public Info(Class<?> lineClass, AudioFormat[] formats, int minBufferSize, int maxBufferSize) { |
| |
| super(lineClass); |
| |
| if (formats == null) { |
| this.formats = new AudioFormat[0]; |
| } else { |
| this.formats = Arrays.copyOf(formats, formats.length); |
| } |
| |
| this.minBufferSize = minBufferSize; |
| this.maxBufferSize = maxBufferSize; |
| } |
| |
| /** |
| * Constructs a data line's info object from the specified information, |
| * which includes a single audio format and a desired buffer size. This |
| * constructor is typically used by an application to describe a desired |
| * line. |
| * |
| * @param lineClass the class of the data line described by the info |
| * object |
| * @param format desired format |
| * @param bufferSize desired buffer size, in bytes |
| */ |
| public Info(Class<?> lineClass, AudioFormat format, int bufferSize) { |
| |
| super(lineClass); |
| |
| if (format == null) { |
| this.formats = new AudioFormat[0]; |
| } else { |
| this.formats = new AudioFormat[]{format}; |
| } |
| |
| this.minBufferSize = bufferSize; |
| this.maxBufferSize = bufferSize; |
| } |
| |
| /** |
| * Constructs a data line's info object from the specified information, |
| * which includes a single audio format. This constructor is typically |
| * used by an application to describe a desired line. |
| * |
| * @param lineClass the class of the data line described by the info |
| * object |
| * @param format desired format |
| */ |
| public Info(Class<?> lineClass, AudioFormat format) { |
| this(lineClass, format, AudioSystem.NOT_SPECIFIED); |
| } |
| |
| /** |
| * Obtains a set of audio formats supported by the data line. Note that |
| * {@code isFormatSupported(AudioFormat)} might return {@code true} for |
| * certain additional formats that are missing from the set returned by |
| * {@code getFormats()}. The reverse is not the case: |
| * {@code isFormatSupported(AudioFormat)} is guaranteed to return |
| * {@code true} for all formats returned by {@code getFormats()}. |
| * <p> |
| * Some fields in the {@code AudioFormat} instances can be set to |
| * {@link AudioSystem#NOT_SPECIFIED NOT_SPECIFIED} if that field does |
| * not apply to the format, or if the format supports a wide range of |
| * values for that field. For example, a multi-channel device supporting |
| * up to 64 channels, could set the channel field in the |
| * {@code AudioFormat} instances returned by this method to |
| * {@code NOT_SPECIFIED}. |
| * |
| * @return a set of supported audio formats |
| * @see #isFormatSupported(AudioFormat) |
| */ |
| public AudioFormat[] getFormats() { |
| return Arrays.copyOf(formats, formats.length); |
| } |
| |
| /** |
| * Indicates whether this data line supports a particular audio format. |
| * The default implementation of this method simply returns {@code true} |
| * if the specified format matches any of the supported formats. |
| * |
| * @param format the audio format for which support is queried |
| * @return {@code true} if the format is supported, otherwise |
| * {@code false} |
| * @see #getFormats |
| * @see AudioFormat#matches |
| */ |
| public boolean isFormatSupported(AudioFormat format) { |
| |
| for (int i = 0; i < formats.length; i++) { |
| if (format.matches(formats[i])) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Obtains the minimum buffer size supported by the data line. |
| * |
| * @return minimum buffer size in bytes, or |
| * {@code AudioSystem.NOT_SPECIFIED} |
| */ |
| public int getMinBufferSize() { |
| return minBufferSize; |
| } |
| |
| /** |
| * Obtains the maximum buffer size supported by the data line. |
| * |
| * @return maximum buffer size in bytes, or |
| * {@code AudioSystem.NOT_SPECIFIED} |
| */ |
| public int getMaxBufferSize() { |
| return maxBufferSize; |
| } |
| |
| /** |
| * Determines whether the specified info object matches this one. To |
| * match, the superclass match requirements must be met. In addition, |
| * this object's minimum buffer size must be at least as large as that |
| * of the object specified, its maximum buffer size must be at most as |
| * large as that of the object specified, and all of its formats must |
| * match formats supported by the object specified. |
| * |
| * @param info the info object which is being compared to this one |
| * @return {@code true} if this object matches the one specified, |
| * otherwise {@code false} |
| */ |
| @Override |
| public boolean matches(Line.Info info) { |
| |
| if (! (super.matches(info)) ) { |
| return false; |
| } |
| |
| Info dataLineInfo = (Info)info; |
| |
| // treat anything < 0 as NOT_SPECIFIED |
| // demo code in old Java Sound Demo used a wrong buffer calculation |
| // that would lead to arbitrary negative values |
| if ((getMaxBufferSize() >= 0) && (dataLineInfo.getMaxBufferSize() >= 0)) { |
| if (getMaxBufferSize() > dataLineInfo.getMaxBufferSize()) { |
| return false; |
| } |
| } |
| |
| if ((getMinBufferSize() >= 0) && (dataLineInfo.getMinBufferSize() >= 0)) { |
| if (getMinBufferSize() < dataLineInfo.getMinBufferSize()) { |
| return false; |
| } |
| } |
| |
| AudioFormat[] localFormats = getFormats(); |
| |
| if (localFormats != null) { |
| |
| for (int i = 0; i < localFormats.length; i++) { |
| if (! (localFormats[i] == null) ) { |
| if (! (dataLineInfo.isFormatSupported(localFormats[i])) ) { |
| return false; |
| } |
| } |
| } |
| } |
| |
| return true; |
| } |
| |
| /** |
| * Obtains a textual description of the data line info. |
| * |
| * @return a string description |
| */ |
| @Override |
| public String toString() { |
| |
| StringBuilder sb = new StringBuilder(); |
| |
| if ( (formats.length == 1) && (formats[0] != null) ) { |
| sb.append(" supporting format " + formats[0]); |
| } else if (getFormats().length > 1) { |
| sb.append(" supporting " + getFormats().length + " audio formats"); |
| } |
| |
| if ( (minBufferSize != AudioSystem.NOT_SPECIFIED) && (maxBufferSize != AudioSystem.NOT_SPECIFIED) ) { |
| sb.append(", and buffers of " + minBufferSize + " to " + maxBufferSize + " bytes"); |
| } else if ( (minBufferSize != AudioSystem.NOT_SPECIFIED) && (minBufferSize > 0) ) { |
| sb.append(", and buffers of at least " + minBufferSize + " bytes"); |
| } else if (maxBufferSize != AudioSystem.NOT_SPECIFIED) { |
| sb.append(", and buffers of up to " + minBufferSize + " bytes"); |
| } |
| |
| return new String(super.toString() + sb); |
| } |
| } |
| } |
