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* fix off-by-one zthresh calculation

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* remove the sharpening for non luma-AC coeffs
* adjust the bias a little bit to compensate for this

Using the multiply-by-reciprocal doesn't always give the same result
as the exact divide, given the QFIX fixed-point precision we use.
-> removed few now-unneeded SSE2 instructions (and checked for
bit-exactness using -noasm)

Change-Id: Ib68057cbdd69c4e589af56a01a8e7085db762c24
This commit is contained in:
skal
2013-12-09 13:56:04 +01:00
parent ad9dec0c24
commit d513bb62bc
2 changed files with 13 additions and 24 deletions
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15
src/dsp/enc_sse2.c
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@ -830,8 +830,6 @@ static int QuantizeBlockSSE2(int16_t in[16], int16_t out[16],
const __m128i bias8 = _mm_loadu_si128((__m128i*)&mtx->bias_[8]);
const __m128i q0 = _mm_loadu_si128((__m128i*)&mtx->q_[0]);
const __m128i q8 = _mm_loadu_si128((__m128i*)&mtx->q_[8]);
const __m128i zthresh0 = _mm_loadu_si128((__m128i*)&mtx->zthresh_[0]);
const __m128i zthresh8 = _mm_loadu_si128((__m128i*)&mtx->zthresh_[8]);
// sign(in) = in >> 15 (0x0000 if positive, 0xffff if negative)
const __m128i sign0 = _mm_srai_epi16(in0, 15);
@ -894,17 +892,8 @@ static int QuantizeBlockSSE2(int16_t in[16], int16_t out[16],
in0 = _mm_mullo_epi16(out0, q0);
in8 = _mm_mullo_epi16(out8, q8);
// if (coeff <= mtx->zthresh_) {in=0; out=0;}
{
__m128i cmp0 = _mm_cmpgt_epi16(coeff0, zthresh0);
__m128i cmp8 = _mm_cmpgt_epi16(coeff8, zthresh8);
in0 = _mm_and_si128(in0, cmp0);
in8 = _mm_and_si128(in8, cmp8);
_mm_storeu_si128((__m128i*)&in[0], in0);
_mm_storeu_si128((__m128i*)&in[8], in8);
out0 = _mm_and_si128(out0, cmp0);
out8 = _mm_and_si128(out8, cmp8);
}
_mm_storeu_si128((__m128i*)&in[0], in0);
_mm_storeu_si128((__m128i*)&in[8], in8);
// zigzag the output before storing it.
//