javazoom.jl.decoder

Class Decoder

public class Decoder extends Object implements DecoderErrors

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

Since: 0.0.5

Version: 0.0.7 12/12/99

Nested Class Summary
static classDecoder.Params
The Params class presents the customizable aspects of the decoder.
Constructor Summary
Decoder()
Creates a new Decoder instance with default parameters.
Decoder(Decoder.Params params0)
Creates a new Decoder instance with default parameters.
Method Summary
ObufferdecodeFrame(Header header, Bitstream stream)
Decodes one frame from an MPEG audio bitstream.
static Decoder.ParamsgetDefaultParams()
intgetOutputBlockSize()
Retrieves the maximum number of samples that will be written to the output buffer when one frame is decoded.
intgetOutputChannels()
Retrieves the number of channels of PCM samples output by this decoder.
intgetOutputFrequency()
Retrieves the sample frequency of the PCM samples output by this decoder.
protected DecoderExceptionnewDecoderException(int errorcode)
protected DecoderExceptionnewDecoderException(int errorcode, Throwable throwable)
protected FrameDecoderretrieveDecoder(Header header, Bitstream stream, int layer)
voidsetEqualizer(Equalizer eq)
voidsetOutputBuffer(Obuffer out)
Changes the output buffer.

Constructor Detail

Decoder

public Decoder()
Creates a new Decoder instance with default parameters.

Decoder

public Decoder(Decoder.Params params0)
Creates a new Decoder instance with default parameters.

Parameters: params The Params instance that describes the customizable aspects of the decoder.

Method Detail

decodeFrame

public Obuffer decodeFrame(Header header, Bitstream stream)
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.

getDefaultParams

public static Decoder.Params getDefaultParams()

getOutputBlockSize

public int getOutputBlockSize()
Retrieves the maximum number of samples that will be written to the output buffer when one frame is decoded. This can be used to help calculate the size of other buffers whose size is based upon the number of samples written to the output buffer. NB: this is an upper bound and fewer samples may actually be written, depending upon the sample rate and number of channels.

Returns: The maximum number of samples that are written to the output buffer when decoding a single frame of MPEG audio.

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.

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.

newDecoderException

protected DecoderException newDecoderException(int errorcode)

newDecoderException

protected DecoderException newDecoderException(int errorcode, Throwable throwable)

retrieveDecoder

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

setEqualizer

public void setEqualizer(Equalizer eq)

setOutputBuffer

public void setOutputBuffer(Obuffer out)
Changes the output buffer. This will take effect the next time decodeFrame() is called.
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