return retval;
}
-static int dec2(int16_t *decsp, const int *data, const int *inp,
- int f, const int *inp2, int a)
+static int dec2(RA144Context *ractx, int16_t *decsp, int block_num,
+ int copynew, int f)
{
int work[10];
+ int a = block_num + 1;
int b = NBLOCKS - a;
int x;
+ // Interpolate block coefficients from the this frame forth block and
+ // last frame forth block
for (x=0; x<30; x++)
- decsp[x] = (a * inp[x] + b * inp2[x]) >> 2;
-
- if (eq(decsp, work))
- return dec1(decsp, data, inp, f);
- else
+ decsp[x] = (a * ractx->lpc_coef[x] + b * ractx->lpc_coef_old[x])>> 2;
+
+ if (eq(decsp, work)) {
+ // The interpolated coefficients are unstable, copy either new or old
+ // coefficients
+ if (copynew)
+ return dec1(decsp, ractx->lpc_refl, ractx->lpc_coef, f);
+ else
+ return dec1(decsp, ractx->lpc_refl_old, ractx->lpc_coef_old, f);
+ } else {
return rms(work, f);
+ }
}
/* Uncompress one block (20 bytes -> 160*2 bytes) */
energy = decodeval[get_bits(&gb, 5) << 1]; // Useless table entries?
a = t_sqrt(energy*ractx->old_energy) >> 12;
- gbuf1[0] = dec2(gbuf2[0], ractx->lpc_refl_old, ractx->lpc_coef_old, ractx->old_energy, ractx->lpc_coef, 3);
- if (ractx->old_energy < energy) {
- gbuf1[1] = dec2(gbuf2[1], ractx->lpc_refl, ractx->lpc_coef, a, ractx->lpc_coef_old, 2);
- } else {
- gbuf1[1] = dec2(gbuf2[1], ractx->lpc_refl_old, ractx->lpc_coef_old, a, ractx->lpc_coef, 2);
- }
- gbuf1[2] = dec2(gbuf2[2], ractx->lpc_refl, ractx->lpc_coef, energy, ractx->lpc_coef_old, 3);
+ gbuf1[0] = dec2(ractx, gbuf2[0], 0, 0, ractx->old_energy);
+ gbuf1[1] = dec2(ractx, gbuf2[1], 1, energy > ractx->old_energy, a);
+ gbuf1[2] = dec2(ractx, gbuf2[2], 2, 1, energy);
gbuf1[3] = dec1(gbuf2[3], ractx->lpc_refl, ractx->lpc_coef, energy);
/* do output */