javazoom.jl.decoder

Class MP3Decoder

java.lang.Object

javazoom.jl.decoder.MP3Decoder

public class MP3Decoder
extends Object

The Decoder class encapsulates the details of decoding an MPEG audio frame.

Since:

0.0.5

Version:

0.0.7 12/12/99

Author:

MDM

Field Summary

Fields

Modifier and Type	Field and Description
static int	DECODER_ERROR The first decoder error code.
static int	ILLEGAL_SUBBAND_ALLOCATION Illegal allocation in subband layer.
static int	UNKNOWN_ERROR
static int	UNSUPPORTED_LAYER Layer not supported by the decoder.

Constructor Summary

Constructors

Constructor and Description
MP3Decoder() Creates a new Decoder instance with default parameters.

Method Summary

Methods

Modifier and Type	Method and Description
OutputBuffer	decodeFrame(Header header, Bitstream stream) Decodes one frame from an MPEG audio bitstream.
int	getOutputChannels() Retrieves the number of channels of PCM samples output by this decoder.
int	getOutputFrequency() Retrieves the sample frequency of the PCM samples output by this decoder.
protected DecoderException	newDecoderException(int errorcode)
protected DecoderException	newDecoderException(int errorcode, Throwable throwable)
protected FrameDecoder	retrieveDecoder(Header header, Bitstream stream, int layer)
void	setOutputBuffer(OutputBuffer out) Changes the output buffer.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DECODER_ERROR

public static final int DECODER_ERROR

The first decoder error code. See the DecoderErrors interface for other decoder error codes.

See Also:

Constant Field Values

UNKNOWN_ERROR

public static final int UNKNOWN_ERROR

See Also:

Constant Field Values

UNSUPPORTED_LAYER

public static final int UNSUPPORTED_LAYER

Layer not supported by the decoder.

See Also:

Constant Field Values

ILLEGAL_SUBBAND_ALLOCATION

public static final int ILLEGAL_SUBBAND_ALLOCATION

Illegal allocation in subband layer. Indicates a corrupt stream.

See Also:

Constant Field Values

Constructor Detail

MP3Decoder

public MP3Decoder()

Creates a new Decoder instance with default parameters.

Method Detail

decodeFrame

public OutputBuffer decodeFrame(Header header,
                       Bitstream stream)
                         throws DecoderException

Decodes one frame from an MPEG audio bitstream.

Parameters:

header - The header describing the frame to decode.

bitstream - The bistream that provides the bits for te body of the frame.

Returns:

A SampleBuffer containing the decoded samples.

Throws:

DecoderException

setOutputBuffer

public void setOutputBuffer(OutputBuffer out)

Changes the output buffer. This will take effect the next time decodeFrame() is called.

getOutputFrequency

public int getOutputFrequency()

Retrieves the sample frequency of the PCM samples output by this decoder. This typically corresponds to the sample rate encoded in the MPEG audio stream.

Parameters:

the - sample rate (in Hz) of the samples written to the output buffer when decoding.

getOutputChannels

public int getOutputChannels()

Retrieves the number of channels of PCM samples output by this decoder. This usually corresponds to the number of channels in the MPEG audio stream, although it may differ.

Returns:

The number of output channels in the decoded samples: 1 for mono, or 2 for stereo.

newDecoderException

protected DecoderException newDecoderException(int errorcode)

newDecoderException

protected DecoderException newDecoderException(int errorcode,
                                   Throwable throwable)

retrieveDecoder

protected FrameDecoder retrieveDecoder(Header header,
                           Bitstream stream,
                           int layer)
                                throws DecoderException

Throws:

DecoderException