/*-------------------------------------------------------------------------- * init_decod_ld8k - Initialization of variables for the decoder section. *-------------------------------------------------------------------------- */ public void init_decod_ld8k() { /* Initialize static pointer */ exc = 0 + LD8KConstants.PIT_MAX + LD8KConstants.L_INTERPOL; /* Static vectors to zero */ Util.set_zero(old_exc_array, LD8KConstants.PIT_MAX + LD8KConstants.L_INTERPOL); Util.set_zero(mem_syn, LD8KConstants.M); sharp = LD8KConstants.SHARPMIN; old_t0 = 60; gain_code.value = (float) 0.; gain_pitch.value = (float) 0.; lspDec.lsp_decw_reset(); return; }
/*-------------------------------------------------------------------------- * decod_ld8k - decoder *-------------------------------------------------------------------------- */ public void decod_ld8k( int parm[], int parms, /* * input : synthesis parameters (parm[0] = bfi) */ int voicing, /* input : voicing decision from previous frame */ float synth[], int ss, /* output: synthesized speech */ float A_t[], /* output: two sets of A(z) coefficients length=2*MP1 */ IntegerPointer t0_first /* output: integer delay of first subframe */) { int Az; /* Pointer to A_t (LPC coefficients) */ float lsp_new[] = new float[LD8KConstants.M]; /* LSPs */ float code[] = new float[LD8KConstants.L_SUBFR]; /* algebraic codevector */ /* Scalars */ int i, i_subfr; int index; IntegerPointer t0 = new IntegerPointer(), t0_frac = new IntegerPointer(); int bfi; int bad_pitch; /* Test bad frame indicator (bfi) */ bfi = parm[parms++]; /* Decode the LSPs */ lspDec.d_lsp(parm, parms, lsp_new, bfi); parms += 2; /* Advance synthesis parameters pointer */ /* Interpolation of LPC for the 2 subframes */ LpcFunc.int_qlpc(lsp_old, lsp_new, A_t); /* update the LSFs for the next frame */ Util.copy(lsp_new, lsp_old, LD8KConstants.M); /*------------------------------------------------------------------------* * Loop for every subframe in the analysis frame * *------------------------------------------------------------------------* * The subframe size is L_SUBFR and the loop is repeated L_FRAME/L_SUBFR * * times * * - decode the pitch delay * * - decode algebraic code * * - decode pitch and codebook gains * * - find the excitation and compute synthesis speech * *------------------------------------------------------------------------*/ Az = 0; // A_t; /* pointer to interpolated LPC parameters */ for (i_subfr = 0; i_subfr < LD8KConstants.L_FRAME; i_subfr += LD8KConstants.L_SUBFR) { index = parm[parms++]; /* pitch index */ if (i_subfr == 0) { /* if first subframe */ i = parm[parms++]; /* get parity check result */ bad_pitch = bfi + i; if (bad_pitch == 0) { DecLag.dec_lag3( index, LD8KConstants.PIT_MIN, LD8KConstants.PIT_MAX, i_subfr, t0, t0_frac); old_t0 = t0.value; } else /* Bad frame, or parity error */ { t0.value = old_t0; t0_frac.value = 0; old_t0++; if (old_t0 > LD8KConstants.PIT_MAX) { old_t0 = LD8KConstants.PIT_MAX; } } t0_first.value = t0.value; /* If first frame */ } else /* second subframe */ { if (bfi == 0) { DecLag.dec_lag3( index, LD8KConstants.PIT_MIN, LD8KConstants.PIT_MAX, i_subfr, t0, t0_frac); old_t0 = t0.value; } else { t0.value = old_t0; t0_frac.value = 0; old_t0++; if (old_t0 > LD8KConstants.PIT_MAX) { old_t0 = LD8KConstants.PIT_MAX; } } } /*-------------------------------------------------* * - Find the adaptive codebook vector. * *--------------------------------------------------*/ PredLt.pred_lt_3( old_exc_array, exc + i_subfr, t0.value, t0_frac.value, LD8KConstants.L_SUBFR); /*-------------------------------------------------------* * - Decode innovative codebook. * * - Add the fixed-gain pitch contribution to code[]. * *-------------------------------------------------------*/ if (bfi != 0) { /* Bad Frame Error Concealment */ parm[parms + 0] = (int) (Util.random_g729() & 0x1fff); /* * 13 bits random */ parm[parms + 1] = (int) (Util.random_g729() & 0x000f); /* * 4 bits random */ } DecAcelp.decod_ACELP(parm[parms + 1], parm[parms + 0], code); parms += 2; for (i = t0.value; i < LD8KConstants.L_SUBFR; i++) code[i] += sharp * code[i - t0.value]; /*-------------------------------------------------* * - Decode pitch and codebook gains. * *-------------------------------------------------*/ index = parm[parms++]; /* index of energy VQ */ decGain.dec_gain(index, code, LD8KConstants.L_SUBFR, bfi, gain_pitch, gain_code); /*-------------------------------------------------------------* * - Update pitch sharpening "sharp" with quantized gain_pitch * *-------------------------------------------------------------*/ sharp = gain_pitch.value; if (sharp > LD8KConstants.SHARPMAX) sharp = LD8KConstants.SHARPMAX; if (sharp < LD8KConstants.SHARPMIN) sharp = LD8KConstants.SHARPMIN; /*-------------------------------------------------------* * - Find the total excitation. * *-------------------------------------------------------*/ if (bfi != 0) { if (voicing == 0) { /* for unvoiced frame */ for (i = 0; i < LD8KConstants.L_SUBFR; i++) { old_exc_array[exc + i + i_subfr] = gain_code.value * code[i]; } } else { /* for voiced frame */ for (i = 0; i < LD8KConstants.L_SUBFR; i++) { old_exc_array[exc + i + i_subfr] = gain_pitch.value * old_exc_array[exc + i + i_subfr]; } } } else { /* No frame errors */ for (i = 0; i < LD8KConstants.L_SUBFR; i++) { old_exc_array[exc + i + i_subfr] = gain_pitch.value * old_exc_array[exc + i + i_subfr] + gain_code.value * code[i]; } } /*-------------------------------------------------------* * - Find synthesis speech corresponding to exc[]. * *-------------------------------------------------------*/ Filter.syn_filt( A_t, Az, old_exc_array, exc + i_subfr, synth, ss + i_subfr, LD8KConstants.L_SUBFR, mem_syn, 0, 1); Az += LD8KConstants.MP1; /* * interpolated LPC parameters for next subframe */ } /*--------------------------------------------------* * Update signal for next frame. * * -> shift to the left by L_FRAME exc[] * *--------------------------------------------------*/ Util.copy( old_exc_array, LD8KConstants.L_FRAME, old_exc_array, 0, LD8KConstants.PIT_MAX + LD8KConstants.L_INTERPOL); return; }