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Code Issues Releases Activity

Simplify implementation and use of dec2()

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Originally committed as revision 13498 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Vitor Sessak 2008-05-28 18:59:09 +00:00
parent 3fb53d55db
commit 121ec9e55a
1 changed files with 18 additions and 13 deletions
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31
libavcodec/ra144.c
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@ -289,20 +289,29 @@ static int eq(const int16_t *in, int *target)
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;
decsp[x] = (a * ractx->lpc_coef[x] + b * ractx->lpc_coef_old[x])>> 2;
if (eq(decsp, work))
return dec1(decsp, data, inp, f);
else
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) */
@ -337,13 +346,9 @@ static int ra144_decode_frame(AVCodecContext * avctx,
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 */