AMRWB decoder.
Patch by Marcelo Galvăo Póvoa.
Originally committed as revision 25062 to svn://svn.ffmpeg.org/ffmpeg/trunk
}
}
+void ff_amrwb_lsp2lpc(const double *lsp, float *lp, int lp_order)
+{
+ int lp_half_order = lp_order >> 1;
+ double buf[lp_half_order + 1];
+ double pa[lp_half_order + 1];
+ double *qa = buf + 1;
+ int i,j;
+
+ qa[-1] = 0.0;
+
+ ff_lsp2polyf(lsp , pa, lp_half_order );
+ ff_lsp2polyf(lsp + 1, qa, lp_half_order - 1);
+
+ for (i = 1, j = lp_order - 1; i < lp_half_order; i++, j--) {
+ double paf = pa[i] * (1 + lsp[lp_order - 1]);
+ double qaf = (qa[i] - qa[i-2]) * (1 - lsp[lp_order - 1]);
+ lp[i-1] = (paf + qaf) * 0.5;
+ lp[j-1] = (paf - qaf) * 0.5;
+ }
+
+ lp[lp_half_order - 1] = (1.0 + lsp[lp_order - 1]) *
+ pa[lp_half_order] * 0.5;
+
+ lp[lp_order - 1] = lsp[lp_order - 1];
+}
+
void ff_acelp_lp_decode(int16_t* lp_1st, int16_t* lp_2nd, const int16_t* lsp_2nd, const int16_t* lsp_prev, int lp_order)
{
int16_t lsp_1st[MAX_LP_ORDER]; // (0.15)
void ff_acelp_lsp2lpc(int16_t* lp, const int16_t* lsp, int lp_half_order);
/**
+ * LSP to LP conversion (5.2.4 of AMR-WB)
+ */
+void ff_amrwb_lsp2lpc(const double *lsp, float *lp, int lp_order);
+
+/**
* \brief Interpolate LSP for the first subframe and convert LSP -> LP for both subframes (3.2.5 and 3.2.6 of G.729)
* \param[out] lp_1st decoded LP coefficients for first subframe (-0x8000 <= (3.12) < 0x8000)
* \param[out] lp_2nd decoded LP coefficients for second subframe (-0x8000 <= (3.12) < 0x8000)
}
}
-static void lsp2lpc_sipr(const double *lsp, float *Az)
-{
- int lp_half_order = LP_FILTER_ORDER >> 1;
- double buf[(LP_FILTER_ORDER >> 1) + 1];
- double pa[(LP_FILTER_ORDER >> 1) + 1];
- double *qa = buf + 1;
- int i,j;
-
- qa[-1] = 0.0;
-
- ff_lsp2polyf(lsp , pa, lp_half_order );
- ff_lsp2polyf(lsp + 1, qa, lp_half_order - 1);
-
- for (i = 1, j = LP_FILTER_ORDER - 1; i < lp_half_order; i++, j--) {
- double paf = pa[i] * (1 + lsp[LP_FILTER_ORDER - 1]);
- double qaf = (qa[i] - qa[i-2]) * (1 - lsp[LP_FILTER_ORDER - 1]);
- Az[i-1] = (paf + qaf) * 0.5;
- Az[j-1] = (paf - qaf) * 0.5;
- }
-
- Az[lp_half_order - 1] = (1.0 + lsp[LP_FILTER_ORDER - 1]) *
- pa[lp_half_order] * 0.5;
-
- Az[LP_FILTER_ORDER - 1] = lsp[LP_FILTER_ORDER - 1];
-}
-
static void sipr_decode_lp(float *lsfnew, const float *lsfold, float *Az,
int num_subfr)
{
for (j = 0; j < LP_FILTER_ORDER; j++)
lsfint[j] = lsfold[j] * (1 - t) + t * lsfnew[j];
- lsp2lpc_sipr(lsfint, Az);
+ ff_amrwb_lsp2lpc(lsfint, Az, LP_FILTER_ORDER);
Az += LP_FILTER_ORDER;
t += t0;
}