AutoCloseable
, DataLine
, Line
public interface SourceDataLine extends DataLine
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.
A source data line can be obtained from a mixer by invoking the getLine
method of Mixer
with an appropriate DataLine.Info
object.
The 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 available
method defined in the 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 STOP
event is generated. A START
event is generated when the audio output resumes.
DataLine.Info
Modifier and Type | Method | Description |
---|---|---|
void |
open |
Opens the line with the specified format, causing the line to acquire any required system resources and become operational. |
void |
open |
Opens the line with the specified format and suggested buffer size, causing the line to acquire any required system resources and become operational. |
int |
write |
Writes audio data to the mixer via this source data line. |
available, drain, flush, getBufferSize, getFormat, getFramePosition, getLevel, getLongFramePosition, getMicrosecondPosition, isActive, isRunning, start, stop
addLineListener, close, getControl, getControls, getLineInfo, isControlSupported, isOpen, open, removeLineListener
void open(AudioFormat format, int bufferSize) throws LineUnavailableException
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 DataLine.getBufferSize()
.
If this operation succeeds, the line is marked as open, and an OPEN
event is dispatched to the line's listeners.
Invoking this method on a line which is already open is illegal and may result in an IllegalStateException
.
Note that some lines, once closed, cannot be reopened. Attempts to reopen such a line will always result in a LineUnavailableException
.
format
- the desired audio formatbufferSize
- the desired buffer sizeLineUnavailableException
- if the line cannot be opened due to resource restrictionsIllegalArgumentException
- if the buffer size does not represent an integral number of sample frames, or if format
is not fully specified or invalidIllegalStateException
- if the line is already openSecurityException
- if the line cannot be opened due to security restrictionsvoid open(AudioFormat format) throws LineUnavailableException
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 DataLine.getBufferSize()
.
If this operation succeeds, the line is marked as open, and an OPEN
event is dispatched to the line's listeners.
Invoking this method on a line which is already open is illegal and may result in an IllegalStateException
.
Note that some lines, once closed, cannot be reopened. Attempts to reopen such a line will always result in a LineUnavailableException
.
format
- the desired audio formatLineUnavailableException
- if the line cannot be opened due to resource restrictionsIllegalArgumentException
- if format
is not fully specified or invalidIllegalStateException
- if the line is already openSecurityException
- if the line cannot be opened due to security restrictionsint write(byte[] b, int off, int len)
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. The number of bytes that can be written without blocking can be ascertained using the available
method of the 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.)
The number of bytes to write must represent an integral number of sample frames, such that:
[ bytes written ] % [frame size in bytes ] == 0
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 IllegalArgumentException
.
b
- a byte array containing data to be written to the data lineoff
- the offset from the beginning of the array, in byteslen
- the length, in bytes, of the valid data in the array (in other words, the requested amount of data to write, in bytes)IllegalArgumentException
- if the requested number of bytes does not represent an integral number of sample frames, or if len
is negativeArrayIndexOutOfBoundsException
- if off
is negative, or off+len
is greater than the length of the array b
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/javax/sound/sampled/SourceDataLine.html