Libav
Functions

AMR pitch LPC coefficient decoding functions

Functions

static void lsf2lsp (const float *lsf, double *lsp)
 Convert an lsf vector into an lsp vector.
static void interpolate_lsf (float lsf_q[4][LP_FILTER_ORDER], float *lsf_new)
 Interpolate the LSF vector (used for fixed gain smoothing).
static void lsf2lsp_for_mode12k2 (AMRContext *p, double lsp[LP_FILTER_ORDER], const float lsf_no_r[LP_FILTER_ORDER], const int16_t *lsf_quantizer[5], const int quantizer_offset, const int sign, const int update)
 Decode a set of 5 split-matrix quantized lsf indexes into an lsp vector.
static void lsf2lsp_5 (AMRContext *p)
 Decode a set of 5 split-matrix quantized lsf indexes into 2 lsp vectors.
static void lsf2lsp_3 (AMRContext *p)
 Decode a set of 3 split-matrix quantized lsf indexes into an lsp vector.

Function Documentation

static void interpolate_lsf ( float  lsf_q[4][LP_FILTER_ORDER],
float *  lsf_new 
) [static]

Interpolate the LSF vector (used for fixed gain smoothing).

The interpolation is done over all four subframes even in MODE_12k2.

Parameters:
[in,out]lsf_qLSFs in [0,1] for each subframe
[in]lsf_newNew LSFs in [0,1] for subframe 4

Definition at line 245 of file amrnbdec.c.

Referenced by lsf2lsp_3(), and lsf2lsp_for_mode12k2().

static void lsf2lsp ( const float *  lsf,
double *  lsp 
) [static]

Convert an lsf vector into an lsp vector.

Parameters:
lsfinput lsf vector
lspoutput lsp vector

Definition at line 230 of file amrnbdec.c.

Referenced by lsf2lsp_3(), and lsf2lsp_for_mode12k2().

static void lsf2lsp_3 ( AMRContext p) [static]

Decode a set of 3 split-matrix quantized lsf indexes into an lsp vector.

Parameters:
ppointer to the AMRContext

Definition at line 333 of file amrnbdec.c.

Referenced by amrnb_decode_frame().

static void lsf2lsp_5 ( AMRContext p) [static]

Decode a set of 5 split-matrix quantized lsf indexes into 2 lsp vectors.

Parameters:
ppointer to the AMRContext

Definition at line 304 of file amrnbdec.c.

Referenced by amrnb_decode_frame().

static void lsf2lsp_for_mode12k2 ( AMRContext p,
double  lsp[LP_FILTER_ORDER],
const float  lsf_no_r[LP_FILTER_ORDER],
const int16_t *  lsf_quantizer[5],
const int  quantizer_offset,
const int  sign,
const int  update 
) [static]

Decode a set of 5 split-matrix quantized lsf indexes into an lsp vector.

Parameters:
pthe context
lspoutput LSP vector
lsf_no_rLSF vector without the residual vector added
lsf_quantizerpointers to LSF dictionary tables
quantizer_offsetoffset in tables
signfor the 3 dictionary table
updatestore data for computing the next frame's LSFs

Definition at line 266 of file amrnbdec.c.

Referenced by lsf2lsp_5().