diff options
| -rw-r--r-- | libavcodec/lsp.c | 26 | ||||
| -rw-r--r-- | libavcodec/lsp.h | 5 | ||||
| -rw-r--r-- | libavcodec/sipr.c | 28 |
3 files changed, 32 insertions, 27 deletions
diff --git a/libavcodec/lsp.c b/libavcodec/lsp.c index fa7152737a..98ca490a76 100644 --- a/libavcodec/lsp.c +++ b/libavcodec/lsp.c @@ -117,6 +117,32 @@ void ff_acelp_lsp2lpc(int16_t* lp, const int16_t* lsp, int lp_half_order) } } +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) diff --git a/libavcodec/lsp.h b/libavcodec/lsp.h index 2c22058062..e3af30d300 100644 --- a/libavcodec/lsp.h +++ b/libavcodec/lsp.h @@ -76,6 +76,11 @@ void ff_acelp_lsf2lspd(double *lsp, const float *lsf, int lp_order); 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) diff --git a/libavcodec/sipr.c b/libavcodec/sipr.c index aa798340bb..ba274e6c80 100644 --- a/libavcodec/sipr.c +++ b/libavcodec/sipr.c @@ -209,32 +209,6 @@ static void decode_parameters(SiprParameters* parms, GetBitContext *pgb, } } -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) { @@ -247,7 +221,7 @@ static void sipr_decode_lp(float *lsfnew, const float *lsfold, float *Az, 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; } |