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lavu/tx: add DCT-III implementation

This commit is contained in:
Lynne 2022-11-20 03:44:29 +01:00
parent 504b7bec1a
commit a56d7e0ca3
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GPG Key ID: A2FEA5F03F034464
1 changed files with 70 additions and 2 deletions
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72
libavutil/tx_template.c
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@ -1737,6 +1737,11 @@ static av_cold int TX_NAME(ff_tx_dct_init)(AVTXContext *s,
TXSample *tab;
SCALE_TYPE rsc = *((SCALE_TYPE *)scale);
if (inv) {
len *= 2;
s->len *= 2;
rsc *= 0.5;
}
if ((ret = ff_tx_init_subtx(s, TX_TYPE(RDFT), flags, NULL, len, inv, &rsc)))
return ret;
@ -1752,8 +1757,13 @@ static av_cold int TX_NAME(ff_tx_dct_init)(AVTXContext *s,
for (int i = 0; i < len; i++)
tab[i] = RESCALE(cos(i*freq)*(!inv + 1));
for (int i = 0; i < len/2; i++)
tab[len + i] = RESCALE(cos((len - 2*i - 1)*freq));
if (inv) {
for (int i = 0; i < len/2; i++)
tab[len + i] = RESCALE(0.5 / sin((2*i + 1)*freq));
} else {
for (int i = 0; i < len/2; i++)
tab[len + i] = RESCALE(cos((len - 2*i - 1)*freq));
}
return 0;
}
@ -1818,6 +1828,49 @@ static void TX_NAME(ff_tx_dctII)(AVTXContext *s, void *_dst,
dst[1] = next;
}
static void TX_NAME(ff_tx_dctIII)(AVTXContext *s, void *_dst,
void *_src, ptrdiff_t stride)
{
TXSample *dst = _dst;
TXSample *src = _src;
const int len = s->len;
const int len2 = len >> 1;
const TXSample *exp = (void *)s->exp;
#ifdef TX_INT32
int64_t tmp1, tmp2 = src[len - 1];
tmp2 = (2*tmp2 + 0x40000000) >> 31;
#else
TXSample tmp1, tmp2 = 2*src[len - 1];
#endif
src[len] = tmp2;
for (int i = len - 2; i >= 2; i -= 2) {
TXSample val1 = src[i - 0];
TXSample val2 = src[i - 1] - src[i + 1];
CMUL(src[i + 1], src[i], exp[len - i], exp[i], val1, val2);
}
s->fn[0](&s->sub[0], dst, src, sizeof(float));
for (int i = 0; i < len2; i++) {
TXSample in1 = dst[i];
TXSample in2 = dst[len - i - 1];
TXSample c = exp[len + i];
tmp1 = in1 + in2;
tmp2 = in1 - in2;
tmp2 *= c;
#ifdef TX_INT32
tmp2 = (tmp2 + 0x40000000) >> 31;
#endif
dst[i] = tmp1 + tmp2;
dst[len - i - 1] = tmp1 - tmp2;
}
}
static const FFTXCodelet TX_NAME(ff_tx_dctII_def) = {
.name = TX_NAME_STR("dctII"),
.function = TX_NAME(ff_tx_dctII),
@ -1832,6 +1885,20 @@ static const FFTXCodelet TX_NAME(ff_tx_dctII_def) = {
.prio = FF_TX_PRIO_BASE,
};
static const FFTXCodelet TX_NAME(ff_tx_dctIII_def) = {
.name = TX_NAME_STR("dctIII"),
.function = TX_NAME(ff_tx_dctIII),
.type = TX_TYPE(DCT),
.flags = AV_TX_UNALIGNED | AV_TX_INPLACE |
FF_TX_OUT_OF_PLACE | FF_TX_INVERSE_ONLY,
.factors = { 2, TX_FACTOR_ANY },
.min_len = 2,
.max_len = TX_LEN_UNLIMITED,
.init = TX_NAME(ff_tx_dct_init),
.cpu_flags = FF_TX_CPU_FLAGS_ALL,
.prio = FF_TX_PRIO_BASE,
};
int TX_TAB(ff_tx_mdct_gen_exp)(AVTXContext *s, int *pre_tab)
{
int off = 0;
@ -1920,6 +1987,7 @@ const FFTXCodelet * const TX_NAME(ff_tx_codelet_list)[] = {
&TX_NAME(ff_tx_rdft_r2c_def),
&TX_NAME(ff_tx_rdft_c2r_def),
&TX_NAME(ff_tx_dctII_def),
&TX_NAME(ff_tx_dctIII_def),
NULL,
};