Class NbCodec

java.lang.Object
javaforce.codec.speex.NbCodec
All Implemented Interfaces:
Codebook
Direct Known Subclasses:
NbDecoder, NbEncoder, SbCodec
public class NbCodec extends Object implements Codebook
Narrowband Codec. This class contains all the basic structures needed by the Narrowband encoder and decoder.
Version:
$Revision$
Author:
Marc Gimpel, Wimba S.A. (mgimpel@horizonwimba.com)

  • Field Details

    • VERY_SMALL

      public static final float VERY_SMALL
      Very small initial value for some of the buffers.
      See Also:

    • NB_FRAME_SIZE

      public static final int[] NB_FRAME_SIZE
      The Narrowband Frame Size gives the size in bits of a Narrowband frame for a given narrowband submode.

    • NB_SUBMODES

      public static final int NB_SUBMODES
      The Narrowband Submodes gives the number of submodes possible for the Narrowband codec.
      See Also:

    • NB_SUBMODE_BITS

      public static final int NB_SUBMODE_BITS
      The Narrowband Submodes Bits gives the number bits used to encode the Narrowband Submode
      See Also:

    • exc_gain_quant_scal1

      public static final float[] exc_gain_quant_scal1

    • exc_gain_quant_scal3

      public static final float[] exc_gain_quant_scal3

    • m_lsp

      protected final Lsp m_lsp

    • filters

      protected final Filters filters

    • submodes

      protected SubMode[] submodes

    • submodeID

      protected int submodeID
      Sub-mode data

    • first

      protected int first
      Activated sub-mode

    • frameSize

      protected int frameSize
      Is this the first frame?

    • subframeSize

      protected int subframeSize
      Size of frames

    • nbSubframes

      protected int nbSubframes
      Size of sub-frames

    • windowSize

      protected int windowSize
      Number of sub-frames

    • lpcSize

      protected int lpcSize
      Analysis (LPC) window length

    • bufSize

      protected int bufSize
      LPC order

    • min_pitch

      protected int min_pitch
      Buffer size

    • max_pitch

      protected int max_pitch
      Minimum pitch value allowed

    • gamma1

      protected float gamma1
      Maximum pitch value allowed

    • gamma2

      protected float gamma2
      Perceptual filter: A(z/gamma1)

    • lag_factor

      protected float lag_factor
      Perceptual filter: A(z/gamma2)

    • lpc_floor

      protected float lpc_floor
      Lag windowing Gaussian width

    • preemph

      protected float preemph
      Noise floor multiplier for A[0] in LPC analysis

    • pre_mem

      protected float pre_mem
      Pre-emphasis: P(z) = 1 - a*z^-1

    • frmBuf

      protected float[] frmBuf
      1-element memory for pre-emphasis

    • frmIdx

      protected int frmIdx
      Input buffer (original signal)

    • excBuf

      protected float[] excBuf

    • excIdx

      protected int excIdx
      Excitation buffer

    • innov

      protected float[] innov
      Start of excitation frame

    • lpc

      protected float[] lpc
      Innovation for the frame

    • qlsp

      protected float[] qlsp
      LPCs for current frame

    • old_qlsp

      protected float[] old_qlsp
      Quantized LSPs for current frame

    • interp_qlsp

      protected float[] interp_qlsp
      Quantized LSPs for previous frame

    • interp_qlpc

      protected float[] interp_qlpc
      Interpolated quantized LSPs

    • mem_sp

      protected float[] mem_sp
      Interpolated quantized LPCs

    • pi_gain

      protected float[] pi_gain
      Filter memory for synthesis signal

    • awk1

      protected float[] awk1
      Gain of LPC filter at theta=pi (fe/2)

    • awk2

      protected float[] awk2
      Gain of LPC filter at theta=pi (fe/2)

    • awk3

      protected float[] awk3
      Gain of LPC filter at theta=pi (fe/2)

    • voc_m1

      protected float voc_m1

    • voc_m2

      protected float voc_m2

    • voc_mean

      protected float voc_mean

    • voc_offset

      protected int voc_offset

    • dtx_enabled

      protected int dtx_enabled

  • Constructor Details

    • NbCodec

      public NbCodec()
      Constructor.

  • Method Details

    • nbinit

      public void nbinit()
      Narrowband initialisation.

    • init

      protected void init(int frameSize, int subframeSize, int lpcSize, int bufSize)
      Initialisation.
      Parameters:
      frameSize -
      subframeSize -
      lpcSize -
      bufSize -

    • getFrameSize

      public int getFrameSize()
      Returns the size of a frame (ex: 160 samples for a narrowband frame, 320 for wideband and 640 for ultra-wideband).
      Returns:
      the size of a frame (number of audio samples in a frame).

    • getDtx

      public boolean getDtx()
      Returns whether or not we are using Discontinuous Transmission encoding.
      Returns:
      whether or not we are using Discontinuous Transmission encoding.

    • getPiGain

      public float[] getPiGain()
      Returns the Pitch Gain array.
      Returns:
      the Pitch Gain array.

    • getExc

      public float[] getExc()
      Returns the excitation array.
      Returns:
      the excitation array.

    • getInnov

      public float[] getInnov()
      Returns the innovation array.
      Returns:
      the innovation array.