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audio-resampler: keep precision

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Transpose and add before applying the cubic interpolation to avoid
overflows when using full precision.
This commit is contained in:
Wim Taymans 2016-03-01 16:31:18 +01:00
parent cc9d8594fe
commit 90a41b81dc
1 changed files with 17 additions and 18 deletions
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35
gst-libs/gst/audio/audio-resampler-x86.h
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@ -223,7 +223,7 @@ inner_product_gint16_cubic_1_sse2 (gint16 * o, const gint16 * a,
const gint16 * b, gint len, const gint16 * icoeff, gint bstride)
{
gint i = 0;
__m128i sum[4], t;
__m128i sum[4], t[4];
__m128i f = _mm_cvtsi64_si128 (*((long long*)icoeff));
const gint16 *c[4] = {(gint16*)((gint8*)b + 0*bstride),
(gint16*)((gint8*)b + 1*bstride),
@ -234,30 +234,29 @@ inner_product_gint16_cubic_1_sse2 (gint16 * o, const gint16 * a,
f = _mm_unpacklo_epi16 (f, sum[0]);
for (; i < len; i += 8) {
t = _mm_loadu_si128 ((__m128i *) (a + i));
sum[0] = _mm_add_epi32 (sum[0], _mm_madd_epi16 (t, _mm_load_si128 ((__m128i *) (c[0] + i))));
sum[1] = _mm_add_epi32 (sum[1], _mm_madd_epi16 (t, _mm_load_si128 ((__m128i *) (c[1] + i))));
sum[2] = _mm_add_epi32 (sum[2], _mm_madd_epi16 (t, _mm_load_si128 ((__m128i *) (c[2] + i))));
sum[3] = _mm_add_epi32 (sum[3], _mm_madd_epi16 (t, _mm_load_si128 ((__m128i *) (c[3] + i))));
t[0] = _mm_loadu_si128 ((__m128i *) (a + i));
sum[0] = _mm_add_epi32 (sum[0], _mm_madd_epi16 (t[0], _mm_load_si128 ((__m128i *) (c[0] + i))));
sum[1] = _mm_add_epi32 (sum[1], _mm_madd_epi16 (t[0], _mm_load_si128 ((__m128i *) (c[1] + i))));
sum[2] = _mm_add_epi32 (sum[2], _mm_madd_epi16 (t[0], _mm_load_si128 ((__m128i *) (c[2] + i))));
sum[3] = _mm_add_epi32 (sum[3], _mm_madd_epi16 (t[0], _mm_load_si128 ((__m128i *) (c[3] + i))));
}
sum[0] = _mm_srai_epi32 (sum[0], PRECISION_S16+1);
sum[1] = _mm_srai_epi32 (sum[1], PRECISION_S16+1);
sum[2] = _mm_srai_epi32 (sum[2], PRECISION_S16+1);
sum[3] = _mm_srai_epi32 (sum[3], PRECISION_S16+1);
t[0] = _mm_unpacklo_epi32 (sum[0], sum[1]);
t[1] = _mm_unpacklo_epi32 (sum[2], sum[3]);
t[2] = _mm_unpackhi_epi32 (sum[0], sum[1]);
t[3] = _mm_unpackhi_epi32 (sum[2], sum[3]);
sum[0] = _mm_madd_epi16 (sum[0], _mm_shuffle_epi32 (f, _MM_SHUFFLE (0, 0, 0, 0)));
sum[1] = _mm_madd_epi16 (sum[1], _mm_shuffle_epi32 (f, _MM_SHUFFLE (1, 1, 1, 1)));
sum[2] = _mm_madd_epi16 (sum[2], _mm_shuffle_epi32 (f, _MM_SHUFFLE (2, 2, 2, 2)));
sum[3] = _mm_madd_epi16 (sum[3], _mm_shuffle_epi32 (f, _MM_SHUFFLE (3, 3, 3, 3)));
sum[0] = _mm_add_epi32 (sum[0], sum[1]);
sum[2] = _mm_add_epi32 (sum[2], sum[3]);
sum[0] = _mm_add_epi32 (_mm_unpacklo_epi64(t[0], t[1]), _mm_unpackhi_epi64(t[0], t[1]));
sum[2] = _mm_add_epi32 (_mm_unpacklo_epi64(t[2], t[3]), _mm_unpackhi_epi64(t[2], t[3]));
sum[0] = _mm_add_epi32 (sum[0], sum[2]);
sum[0] = _mm_srai_epi32 (sum[0], PRECISION_S16);
sum[0] = _mm_madd_epi16 (sum[0], f);
sum[0] = _mm_add_epi32 (sum[0], _mm_shuffle_epi32 (sum[0], _MM_SHUFFLE (2, 3, 2, 3)));
sum[0] = _mm_add_epi32 (sum[0], _mm_shuffle_epi32 (sum[0], _MM_SHUFFLE (1, 1, 1, 1)));
sum[0] = _mm_add_epi32 (sum[0], _mm_set1_epi32 (1 << (PRECISION_S16 - 2)));
sum[0] = _mm_srai_epi32 (sum[0], PRECISION_S16-1);
sum[0] = _mm_add_epi32 (sum[0], _mm_set1_epi32 (1 << (PRECISION_S16 - 1)));
sum[0] = _mm_srai_epi32 (sum[0], PRECISION_S16);
sum[0] = _mm_packs_epi32 (sum[0], sum[0]);
*o = _mm_extract_epi16 (sum[0], 0);
}