public final class UlawEncoderInputStream extends InputStream
Constructor and Description |
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UlawEncoderInputStream(InputStream in,
int max)
Create an InputStream which takes 16 bit pcm data and produces ulaw data.
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Modifier and Type | Method and Description |
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int |
available()
Returns an estimated number of bytes that can be read or skipped without blocking for more
input.
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void |
close()
Closes this stream.
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static void |
encode(byte[] pcmBuf,
int pcmOffset,
byte[] ulawBuf,
int ulawOffset,
int length,
int max) |
static int |
maxAbsPcm(byte[] pcmBuf,
int offset,
int length)
Compute the maximum of the absolute value of the pcm samples.
|
int |
read()
Reads a single byte from this stream and returns it as an integer in the
range from 0 to 255.
|
int |
read(byte[] buf)
Equivalent to
read(buffer, 0, buffer.length) . |
int |
read(byte[] buf,
int offset,
int length)
Reads at most
length bytes from this stream and stores them in
the byte array b starting at offset . |
mark, markSupported, reset, skip
public UlawEncoderInputStream(InputStream in, int max)
in
- InputStream containing 16 bit pcm data.max
- pcm value corresponding to maximum ulaw value.public static void encode(byte[] pcmBuf, int pcmOffset, byte[] ulawBuf, int ulawOffset, int length, int max)
public static int maxAbsPcm(byte[] pcmBuf, int offset, int length)
pcmBuf
- array containing 16 bit pcm data.offset
- offset of start of 16 bit pcm data.length
- number of pcm samples (not number of input bytes)public int read(byte[] buf, int offset, int length) throws IOException
InputStream
length
bytes from this stream and stores them in
the byte array b
starting at offset
.read
in class InputStream
buf
- the byte array in which to store the bytes read.offset
- the initial position in buffer
to store the bytes read
from this stream.length
- the maximum number of bytes to store in b
.IOException
- if the stream is closed or another IOException occurs.public int read(byte[] buf) throws IOException
InputStream
read(buffer, 0, buffer.length)
.read
in class InputStream
IOException
public int read() throws IOException
InputStream
read
in class InputStream
IOException
- if the stream is closed or another IOException occurs.public void close() throws IOException
InputStream
close
in interface Closeable
close
in interface AutoCloseable
close
in class InputStream
IOException
- if an error occurs while closing this stream.public int available() throws IOException
InputStream
Note that this method provides such a weak guarantee that it is not very useful in practice.
Firstly, the guarantee is "without blocking for more input" rather than "without blocking": a read may still block waiting for I/O to complete — the guarantee is merely that it won't have to wait indefinitely for data to be written. The result of this method should not be used as a license to do I/O on a thread that shouldn't be blocked.
Secondly, the result is a conservative estimate and may be significantly smaller than the actual number of bytes available. In particular, an implementation that always returns 0 would be correct. In general, callers should only use this method if they'd be satisfied with treating the result as a boolean yes or no answer to the question "is there definitely data ready?".
Thirdly, the fact that a given number of bytes is "available" does not guarantee that a read or skip will actually read or skip that many bytes: they may read or skip fewer.
It is particularly important to realize that you must not use this method to
size a container and assume that you can read the entirety of the stream without needing
to resize the container. Such callers should probably write everything they read to a
ByteArrayOutputStream
and convert that to a byte array. Alternatively, if you're
reading from a file, File.length()
returns the current length of the file (though
assuming the file's length can't change may be incorrect, reading a file is inherently
racy).
The default implementation of this method in InputStream
always returns 0.
Subclasses should override this method if they are able to indicate the number of bytes
available.
available
in class InputStream
IOException
- if this stream is closed or an error occurs