Ejemplo n.º 1
0
/** Finds the best quantized 3-tap pitch predictor by analysis by synthesis */
int pitch_search_3tap(
    spx_word16_t target[],                 /* Target vector */
    spx_word16_t* sw,
    spx_coef_t ak[],                     /* LPCs for this subframe */
    spx_coef_t awk1[],                   /* Weighted LPCs #1 for this subframe */
    spx_coef_t awk2[],                   /* Weighted LPCs #2 for this subframe */
    spx_sig_t exc[],                    /* Excitation */
    const void* par,
    int   start,                    /* Smallest pitch value allowed */
    int   end,                      /* Largest pitch value allowed */
    spx_word16_t pitch_coef,               /* Voicing (pitch) coefficient */
    int   p,                        /* Number of LPC coeffs */
    int   nsf,                      /* Number of samples in subframe */
    SpeexBits* bits,
    char* stack,
    spx_word16_t* exc2,
    spx_word16_t* r,
    int complexity,
    int cdbk_offset,
    int plc_tuning,
    spx_word32_t* cumul_gain
) {
    int i;
    int cdbk_index, pitch = 0, best_gain_index = 0;
    VARDECL(spx_sig_t * best_exc);
    VARDECL(spx_word16_t * new_target);
    VARDECL(spx_word16_t * best_target);
    int best_pitch = 0;
    spx_word32_t err, best_err = -1;
    int N;
    const ltp_params* params;
    const signed char* gain_cdbk;
    int   gain_cdbk_size;
    int scaledown = 0;

    VARDECL(int * nbest);

    params = (const ltp_params*) par;
    gain_cdbk_size = 1 << params->gain_bits;
    gain_cdbk = params->gain_cdbk + 4 * gain_cdbk_size * cdbk_offset;

    N = complexity;
    if (N > 10)
        N = 10;
    if (N < 1)
        N = 1;

    ALLOC(nbest, N, int);
    params = (const ltp_params*) par;

    if (end < start) {
        speex_bits_pack(bits, 0, params->pitch_bits);
        speex_bits_pack(bits, 0, params->gain_bits);
        SPEEX_MEMSET(exc, 0, nsf);
        return start;
    }

#ifdef FIXED_POINT
    /* Check if we need to scale everything down in the pitch search to avoid overflows */
    for (i = 0; i < nsf; i++) {
        if (ABS16(target[i]) > 16383) {
            scaledown = 1;
            break;
        }
    }
    for (i = -end; i < nsf; i++) {
        if (ABS16(exc2[i]) > 16383) {
            scaledown = 1;
            break;
        }
    }
#endif
    if (N > end - start + 1)
        N = end - start + 1;
    if (end != start)
        open_loop_nbest_pitch(sw, start, end, nsf, nbest, NULL, N, stack);
    else
        nbest[0] = start;

    ALLOC(best_exc, nsf, spx_sig_t);
    ALLOC(new_target, nsf, spx_word16_t);
    ALLOC(best_target, nsf, spx_word16_t);

    for (i = 0; i < N; i++) {
        pitch = nbest[i];
        SPEEX_MEMSET(exc, 0, nsf);
        err = pitch_gain_search_3tap(target, ak, awk1, awk2, exc, gain_cdbk, gain_cdbk_size, pitch, p, nsf,
                                     bits, stack, exc2, r, new_target, &cdbk_index, plc_tuning, *cumul_gain, scaledown);
        if (err < best_err || best_err < 0) {
            SPEEX_COPY(best_exc, exc, nsf);
            SPEEX_COPY(best_target, new_target, nsf);
            best_err = err;
            best_pitch = pitch;
            best_gain_index = cdbk_index;
        }
    }
    /*printf ("pitch: %d %d\n", best_pitch, best_gain_index);*/
    speex_bits_pack(bits, best_pitch - start, params->pitch_bits);
    speex_bits_pack(bits, best_gain_index, params->gain_bits);
#ifdef FIXED_POINT
    *cumul_gain = MULT16_32_Q13(SHL16(params->gain_cdbk[4 * best_gain_index + 3], 8), MAX32(1024, *cumul_gain));
#else
    *cumul_gain = 0.03125 * MAX32(1024, *cumul_gain) * params->gain_cdbk[4 * best_gain_index + 3];
#endif
    /*printf ("%f\n", cumul_gain);*/
    /*printf ("encode pitch: %d %d\n", best_pitch, best_gain_index);*/
    SPEEX_COPY(exc, best_exc, nsf);
    SPEEX_COPY(target, best_target, nsf);
#ifdef FIXED_POINT
    /* Scale target back up if needed */
    if (scaledown) {
        for (i = 0; i < nsf; i++)
            target[i] = SHL16(target[i], 1);
    }
#endif
    return pitch;
}
Ejemplo n.º 2
0
Archivo: ltp.c Proyecto: Affix/fgcom
/** Finds the best quantized 3-tap pitch predictor by analysis by synthesis */
int pitch_search_3tap(
    spx_sig_t target[],                 /* Target vector */
    spx_sig_t *sw,
    spx_coef_t ak[],                     /* LPCs for this subframe */
    spx_coef_t awk1[],                   /* Weighted LPCs #1 for this subframe */
    spx_coef_t awk2[],                   /* Weighted LPCs #2 for this subframe */
    spx_sig_t exc[],                    /* Excitation */
    const void *par,
    int   start,                    /* Smallest pitch value allowed */
    int   end,                      /* Largest pitch value allowed */
    spx_word16_t pitch_coef,               /* Voicing (pitch) coefficient */
    int   p,                        /* Number of LPC coeffs */
    int   nsf,                      /* Number of samples in subframe */
    SpeexBits *bits,
    char *stack,
    spx_sig_t *exc2,
    spx_word16_t *r,
    int complexity,
    int cdbk_offset,
    int plc_tuning
)
{
    int i,j;
    int cdbk_index, pitch=0, best_gain_index=0;
    VARDECL(spx_sig_t *best_exc);
    VARDECL(spx_sig_t *new_target);
    VARDECL(spx_sig_t *best_target);
    int best_pitch=0;
    spx_word64_t err, best_err=-1;
    int N;
    const ltp_params *params;
    VARDECL(int *nbest);

    N=complexity;
    if (N>10)
        N=10;
    if (N<1)
        N=1;

    ALLOC(nbest, N, int);
    params = (const ltp_params*) par;

    if (end<start)
    {
        speex_bits_pack(bits, 0, params->pitch_bits);
        speex_bits_pack(bits, 0, params->gain_bits);
        for (i=0; i<nsf; i++)
            exc[i]=0;
        return start;
    }

    ALLOC(best_exc, nsf, spx_sig_t);
    ALLOC(new_target, nsf, spx_sig_t);
    ALLOC(best_target, nsf, spx_sig_t);

    if (N>end-start+1)
        N=end-start+1;
    open_loop_nbest_pitch(sw, start, end, nsf, nbest, NULL, N, stack);
    for (i=0; i<N; i++)
    {
        pitch=nbest[i];
        for (j=0; j<nsf; j++)
            exc[j]=0;
        err=pitch_gain_search_3tap(target, ak, awk1, awk2, exc, par, pitch, p, nsf,
                                   bits, stack, exc2, r, new_target, &cdbk_index, cdbk_offset, plc_tuning);
        if (err<best_err || best_err<0)
        {
            for (j=0; j<nsf; j++)
                best_exc[j]=exc[j];
            for (j=0; j<nsf; j++)
                best_target[j]=new_target[j];
            best_err=err;
            best_pitch=pitch;
            best_gain_index=cdbk_index;
        }
    }

    /*printf ("pitch: %d %d\n", best_pitch, best_gain_index);*/
    speex_bits_pack(bits, best_pitch-start, params->pitch_bits);
    speex_bits_pack(bits, best_gain_index, params->gain_bits);
    /*printf ("encode pitch: %d %d\n", best_pitch, best_gain_index);*/
    for (i=0; i<nsf; i++)
        exc[i]=best_exc[i];
    for (i=0; i<nsf; i++)
        target[i]=best_target[i];

    return pitch;
}