|Constructor and Description|
Create an InputStream which takes 16 bit pcm data and produces ulaw data.
|Modifier and Type||Method and Description|
Returns an estimated number of bytes that can be read or skipped without blocking for more input.
Closes this stream.
Compute the maximum of the absolute value of the pcm samples.
Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.
Reads at most
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
lengthbytes from this stream and stores them in the byte array
buf- the byte array in which to store the bytes read.
offset- the initial position in
bufferto store the bytes read from this stream.
length- the maximum number of bytes to store in
IOException- if the stream is closed or another IOException occurs.
public int read(byte buf) throws IOException
read(buffer, 0, buffer.length).
public int read() throws IOException
public void close() throws IOException
public int available() throws IOException
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
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