📄 enc_main.c
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/* Find open loop pitch lag for whole speech frame */
if (*mode == MODE_7k)
{
/* Find open loop pitch lag for whole speech frame */
T_op = E_GAIN_open_loop_search(wsp, PIT_MIN / OPL_DECIM,
PIT_MAX / OPL_DECIM, L_FRAME / OPL_DECIM, st->mem_T0_med,
&(st->mem_ol_gain), st->mem_hf_wsp, st->mem_hp_wsp,
st->mem_ol_wght_flg);
}
else
{
/* Find open loop pitch lag for first 1/2 frame */
T_op = E_GAIN_open_loop_search(wsp, PIT_MIN / OPL_DECIM,
PIT_MAX / OPL_DECIM, (L_FRAME / 2) / OPL_DECIM, st->mem_T0_med,
&(st->mem_ol_gain), st->mem_hf_wsp, st->mem_hp_wsp,
st->mem_ol_wght_flg);
}
if (st->mem_ol_gain > 0.6)
{
st->mem_T0_med = E_GAIN_olag_median(T_op, st->mem_ol_lag);
st->mem_ada_w = 1.0F;
}
else
{
st->mem_ada_w = st->mem_ada_w * 0.9F;
}
if (st->mem_ada_w < 0.8)
{
st->mem_ol_wght_flg = 0;
}
else
{
st->mem_ol_wght_flg = 1;
}
E_DTX_pitch_tone_detection(st->vadSt, st->mem_ol_gain);
T_op *= OPL_DECIM;
if (*mode != MODE_7k)
{
/* Find open loop pitch lag for second 1/2 frame */
T_op2 = E_GAIN_open_loop_search(wsp + ((L_FRAME / 2) / OPL_DECIM),
PIT_MIN / OPL_DECIM, PIT_MAX / OPL_DECIM, (L_FRAME / 2) / OPL_DECIM,
st->mem_T0_med, &st->mem_ol_gain, st->mem_hf_wsp, st->mem_hp_wsp,
st->mem_ol_wght_flg);
if (st->mem_ol_gain > 0.6)
{
st->mem_T0_med = E_GAIN_olag_median(T_op2, st->mem_ol_lag);
st->mem_ada_w = 1.0F;
}
else
{
st->mem_ada_w = st->mem_ada_w * 0.9F;
}
if (st->mem_ada_w < 0.8)
{
st->mem_ol_wght_flg = 0;
}
else
{
st->mem_ol_wght_flg = 1;
}
E_DTX_pitch_tone_detection(st->vadSt, st->mem_ol_gain);
T_op2 *= OPL_DECIM;
}
else
{
T_op2 = T_op;
}
/*
* DTX-CNG
*/
if(*mode == MRDTX)
{
/* Buffer isf's and energy */
E_UTIL_residu(&A[3 * (M + 1)], speech, f_exc, L_FRAME);
f_tmp = 0.0;
for(i = 0; i < L_FRAME; i++)
{
f_tmp += f_exc[i] * f_exc[i];
}
E_DTX_buffer(st->dtx_encSt, isf, f_tmp, codec_mode);
/* Quantize and code the isfs */
E_DTX_exe(st->dtx_encSt, f_exc2, &prms);
/* reset speech coder memories */
E_MAIN_reset(st, 0);
/*
* Update signal for next frame.
* -> save past of speech[] and wsp[].
*/
memcpy(st->mem_speech, &st->mem_speech[L_FRAME],
(L_TOTAL - L_FRAME) * sizeof(Float32));
memcpy(st->mem_wsp, &st->mem_wsp[L_FRAME / OPL_DECIM],
(PIT_MAX / OPL_DECIM) * sizeof(Float32));
return(0);
}
/*
* ACELP
*/
/* Quantize and code the isfs */
if (*mode <= MODE_7k)
{
E_LPC_isf_2s3s_quantise(isf, isfq, st->mem_isf_q, indice, 4);
E_MAIN_parm_store((Word16)indice[0], &prms);
E_MAIN_parm_store((Word16)indice[1], &prms);
E_MAIN_parm_store((Word16)indice[2], &prms);
E_MAIN_parm_store((Word16)indice[3], &prms);
E_MAIN_parm_store((Word16)indice[4], &prms);
}
else
{
E_LPC_isf_2s5s_quantise(isf, isfq, st->mem_isf_q, indice, 4);
E_MAIN_parm_store((Word16)indice[0], &prms);
E_MAIN_parm_store((Word16)indice[1], &prms);
E_MAIN_parm_store((Word16)indice[2], &prms);
E_MAIN_parm_store((Word16)indice[3], &prms);
E_MAIN_parm_store((Word16)indice[4], &prms);
E_MAIN_parm_store((Word16)indice[5], &prms);
E_MAIN_parm_store((Word16)indice[6], &prms);
}
/* Convert isfs to the cosine domain */
E_LPC_isf_isp_conversion(isfq, ispnew_q, M);
if (*mode == MODE_24k)
{
/* Check stability on isf : distance between old isf and current isf */
f_tmp = 0.0F;
f_pt_tmp = st->mem_isf;
for (i=0; i < M - 1; i++)
{
f_tmp += (isf[i] - f_pt_tmp[i]) * (isf[i] - f_pt_tmp[i]);
}
stab_fac = (Float32)(1.25F - (f_tmp / 400000.0F));
if (stab_fac > 1.0F)
{
stab_fac = 1.0F;
}
if (stab_fac < 0.0F)
{
stab_fac = 0.0F;
}
memcpy(f_pt_tmp, isf, M * sizeof(Float32));
}
if (st->mem_first_frame == 1)
{
st->mem_first_frame = 0;
memcpy(st->mem_isp_q, ispnew_q, M * sizeof(Word16));
}
/* Find the interpolated isps and convert to a[] for all subframes */
E_LPC_int_isp_find(st->mem_isp_q, ispnew_q, E_ROM_interpol_frac, s_Aq);
for (i = 0; i < (NB_SUBFR * (M + 1)); i++)
{
Aq[i] = s_Aq[i] * 0.000244140625F; /* 1/4096 */
}
/* update isp memory for the next frame */
memcpy(st->mem_isp_q, ispnew_q, M * sizeof(Word16));
/*
* Find the best interpolation for quantized ISPs
*/
p_Aq = Aq;
for (i_subfr = 0; i_subfr < L_FRAME; i_subfr += L_SUBFR)
{
E_UTIL_residu(p_Aq, &speech[i_subfr], &f_exc[i_subfr], L_SUBFR);
p_Aq += (M + 1);
}
/* Buffer isf's and energy for dtx on non-speech frame */
if(vad_flag == 0)
{
f_tmp = 0.0F;
for(i = 0; i < L_FRAME; i++)
{
f_tmp += f_exc[i] * f_exc[i];
}
E_DTX_buffer(st->dtx_encSt, isf, f_tmp, codec_mode);
}
/* range for closed loop pitch search in 1st subframe */
T0_min = T_op - 8;
if (T0_min < PIT_MIN)
{
T0_min = PIT_MIN;
}
T0_max = T0_min + 15;
if (T0_max > PIT_MAX)
{
T0_max = PIT_MAX;
T0_min = T0_max - 15;
}
/*
* Loop for every subframe in the analysis frame
* ---------------------------------------------
* To find the pitch and innovation parameters. The subframe size is
* L_SUBFR and the loop is repeated L_FRAME/L_SUBFR times.
* - compute the target signal for pitch search
* - compute impulse response of weighted synthesis filter (h1[])
* - find the closed-loop pitch parameters
* - encode the pitch dealy
* - find 2 lt prediction (with / without LP filter for lt pred)
* - find 2 pitch gains and choose the best lt prediction.
* - find target vector for codebook search
* - update the impulse response h1[] for codebook search
* - correlation between target vector and impulse response
* - codebook search and encoding
* - VQ of pitch and codebook gains
* - find voicing factor and tilt of code for next subframe.
* - update states of weighting filter
* - find excitation and synthesis speech
*/
p_A = A;
p_Aq = Aq;
for (i_subfr = 0; i_subfr < L_FRAME; i_subfr += L_SUBFR)
{
pit_flag = i_subfr;
if ((i_subfr == (2 * L_SUBFR)) & (*mode > MODE_7k))
{
pit_flag = 0;
/* range for closed loop pitch search in 3rd subframe */
T0_min = T_op2 - 8;
if (T0_min < PIT_MIN)
{
T0_min = PIT_MIN;
}
T0_max = T0_min + 15;
if (T0_max > PIT_MAX)
{
T0_max = PIT_MAX;
T0_min = T0_max - 15;
}
}
/*
*
* Find the target vector for pitch search:
* ---------------------------------------
*
* |------| res[n]
* speech[n]---| A(z) |--------
* |------| | |--------| error[n] |------|
* zero -- (-)--| 1/A(z) |-----------| W(z) |-- target
* exc |--------| |------|
*
* Instead of subtracting the zero-input response of filters from
* the weighted input speech, the above configuration is used to
* compute the target vector.
*
*/
for (i = 0; i < M; i++)
{
error[i] = (Float32)(speech[i + i_subfr - 16] - st->mem_syn[i]);
}
E_UTIL_residu(p_Aq, &speech[i_subfr], &f_exc[i_subfr], L_SUBFR);
E_UTIL_synthesis(p_Aq, &f_exc[i_subfr], error + M, L_SUBFR, error, 0);
E_LPC_a_weight(p_A, Ap, GAMMA1, M);
E_UTIL_residu(Ap, error + M, xn, L_SUBFR);
E_UTIL_deemph(xn, TILT_FAC, L_SUBFR, &(st->mem_w0));
/*
* Find target in residual domain (cn[]) for innovation search.
*/
/* first half: xn[] --> cn[] */
memset(f_code, 0, M * sizeof(Float32));
memcpy(f_code + M, xn, (L_SUBFR / 2) * sizeof(Float32));
f_tmp = 0.0F;
E_UTIL_f_preemph(f_code + M, TILT_FAC, L_SUBFR / 2, &f_tmp);
E_LPC_a_weight(p_A, Ap, GAMMA1, M);
E_UTIL_synthesis(Ap, f_code + M, f_code + M, L_SUBFR / 2, f_code, 0);
E_UTIL_residu(p_Aq, f_code + M, cn, L_SUBFR / 2);
/* second half: res[] --> cn[] (approximated and faster) */
for(i = (L_SUBFR / 2); i < L_SUBFR; i++)
{
cn[i] = f_exc[i_subfr + i];
}
/*
* Compute impulse response, h1[], of weighted synthesis filter
*/
E_LPC_a_weight(p_A, Ap, GAMMA1, M);
memset(h1, 0, L_SUBFR * sizeof(Float32));
memcpy(h1, Ap, (M + 1) * sizeof(Float32));
E_UTIL_synthesis(p_Aq, h1, h1, L_SUBFR, h1 + (M + 1), 0);
f_tmp = 0.0;
E_UTIL_deemph(h1, TILT_FAC, L_SUBFR, &f_tmp);
/*
* Closed-loop fractional pitch search
*/
/* find closed loop fractional pitch lag */
if (*mode <= MODE_9k)
{
T0 = E_GAIN_closed_loop_search(&f_exc[i_subfr], xn, h1,
T0_min, T0_max, &T0_frac,
pit_flag, PIT_MIN, PIT_FR1_8b);
/* encode pitch lag */
if (pit_flag == 0) /* if 1st/3rd subframe */
{
/*
* The pitch range for the 1st/3rd subframe is encoded with
* 8 bits and is divided as follows:
* PIT_MIN to PIT_FR1-1 resolution 1/2 (frac = 0 or 2)
* PIT_FR1 to PIT_MAX resolution 1 (frac = 0)
*/
if (T0 < PIT_FR1_8b)
{
index = (Word16)(T0 * 2 + (T0_frac >> 1) - (PIT_MIN * 2));
}
else
{
index = (Word16)(T0 - PIT_FR1_8b + ((PIT_FR1_8b - PIT_MIN) * 2));
}
E_MAIN_parm_store(index, &prms);
/* find T0_min and T0_max for subframe 2 and 4 */
T0_min = T0 - 8;
if (T0_min < PIT_MIN)
{
T0_min = PIT_MIN;
}
T0_max = T0_min + 15;
if (T0_max > PIT_MAX)
{
T0_max = PIT_MAX;
T0_min = T0_max - 15;
}
}
else /* if subframe 2 or 4 */
{
/*
* The pitch range for subframe 2 or 4 is encoded with 6 bits:
* T0_min to T0_max resolution 1/2 (frac = 0 or 2)
*/
i = T0 - T0_min;
index = (Word16)(i * 2 + (T0_frac >> 1));
E_MAIN_parm_store(index, &prms);
}
}
else
{
T0 = E_GAIN_closed_loop_search(&f_exc[i_subfr], xn, h1,
T0_min, T0_max, &T0_frac,
pit_flag, PIT_FR2, PIT_FR1_9b);
/* encode pitch lag */
if (pit_flag == 0) /* if 1st/3rd subframe */
{
/*
* The pitch range for the 1st/3rd subframe is encoded with
* 9 bits and is divided as follows:
* PIT_MIN to PIT_FR2-1 resolution 1/4 (frac = 0,1,2 or 3)
* PIT_FR2 to PIT_FR1-1 resolution 1/2 (frac = 0 or 2)
* PIT_FR1 to PIT_MAX resolution 1 (frac = 0)
*/
if (T0 < PIT_FR2)
{
index = (Word16)(T0 * 4 + T0_frac - (PIT_MIN * 4));
}
else if (T0 < PIT_FR1_9b)
{
index = (Word16)(T0 * 2 + (T0_frac >> 1) - (PIT_FR2 * 2) + ((PIT_FR2 - PIT_MIN) * 4));
}
else
{
index = (Word16)(T0 - PIT_FR1_9b + ((PIT_FR2 - PIT_MIN) * 4) + ((PIT_FR1_9b - PIT_FR2) * 2));
}
E_MAIN_parm_store(index, &prms);
/* find T0_min and T0_max for subframe 2 and 4 */
T0_min = T0 - 8;
if (T0_min < PIT_MIN)
{
T0_min = PIT_MIN;
}
T0_max = T0_min + 15;
if (T0_max > PIT_MAX)
{
T0_max = PIT_MAX;
T0_min = T0_max - 15;
}
}
else /* if subframe 2 or 4 */
{
/*
* The pitch range for subframe 2 or 4 is encoded with 6 bits:
* T0_min to T0_max resolution 1/4 (frac = 0,1,2 or 3)
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