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// Copyright 2015 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// SSE2 variant of alpha filters
//
// Author: Skal (pascal.massimino@gmail.com)
#include "./dsp.h"
#if defined(WEBP_USE_SSE2)
#include <assert.h>
#include <emmintrin.h>
#include <stdlib.h>
#include <string.h>
//------------------------------------------------------------------------------
// Helpful macro.
# define SANITY_CHECK(in, out) \
assert(in != NULL); \
assert(out != NULL); \
assert(width > 0); \
assert(height > 0); \
assert(stride >= width); \
assert(row >= 0 && num_rows > 0 && row + num_rows <= height); \
(void)height; // Silence unused warning.
static void PredictLineTop(const uint8_t* src, const uint8_t* pred,
uint8_t* dst, int length, int inverse) {
int i;
const int max_pos = length & ~31;
assert(length >= 0);
if (inverse) {
for (i = 0; i < max_pos; i += 32) {
const __m128i A0 = _mm_loadu_si128((const __m128i*)&src[i + 0]);
const __m128i A1 = _mm_loadu_si128((const __m128i*)&src[i + 16]);
const __m128i B0 = _mm_loadu_si128((const __m128i*)&pred[i + 0]);
const __m128i B1 = _mm_loadu_si128((const __m128i*)&pred[i + 16]);
const __m128i C0 = _mm_add_epi8(A0, B0);
const __m128i C1 = _mm_add_epi8(A1, B1);
_mm_storeu_si128((__m128i*)&dst[i + 0], C0);
_mm_storeu_si128((__m128i*)&dst[i + 16], C1);
}
for (; i < length; ++i) dst[i] = src[i] + pred[i];
} else {
for (i = 0; i < max_pos; i += 32) {
const __m128i A0 = _mm_loadu_si128((const __m128i*)&src[i + 0]);
const __m128i A1 = _mm_loadu_si128((const __m128i*)&src[i + 16]);
const __m128i B0 = _mm_loadu_si128((const __m128i*)&pred[i + 0]);
const __m128i B1 = _mm_loadu_si128((const __m128i*)&pred[i + 16]);
const __m128i C0 = _mm_sub_epi8(A0, B0);
const __m128i C1 = _mm_sub_epi8(A1, B1);
_mm_storeu_si128((__m128i*)&dst[i + 0], C0);
_mm_storeu_si128((__m128i*)&dst[i + 16], C1);
}
for (; i < length; ++i) dst[i] = src[i] - pred[i];
}
}
// Special case for left-based prediction (when preds==dst-1 or preds==src-1).
static void PredictLineLeft(const uint8_t* src, uint8_t* dst, int length,
int inverse) {
int i;
if (length <= 0) return;
if (inverse) {
const int max_pos = length & ~7;
__m128i last = _mm_set_epi32(0, 0, 0, dst[-1]);
for (i = 0; i < max_pos; i += 8) {
const __m128i A0 = _mm_loadl_epi64((const __m128i*)(src + i));
const __m128i A1 = _mm_add_epi8(A0, last);
const __m128i A2 = _mm_slli_si128(A1, 1);
const __m128i A3 = _mm_add_epi8(A1, A2);
const __m128i A4 = _mm_slli_si128(A3, 2);
const __m128i A5 = _mm_add_epi8(A3, A4);
const __m128i A6 = _mm_slli_si128(A5, 4);
const __m128i A7 = _mm_add_epi8(A5, A6);
_mm_storel_epi64((__m128i*)(dst + i), A7);
last = _mm_srli_epi64(A7, 56);
}
for (; i < length; ++i) dst[i] = src[i] + dst[i - 1];
} else {
const int max_pos = length & ~31;
for (i = 0; i < max_pos; i += 32) {
const __m128i A0 = _mm_loadu_si128((const __m128i*)(src + i + 0 ));
const __m128i B0 = _mm_loadu_si128((const __m128i*)(src + i + 0 - 1));
const __m128i A1 = _mm_loadu_si128((const __m128i*)(src + i + 16 ));
const __m128i B1 = _mm_loadu_si128((const __m128i*)(src + i + 16 - 1));
const __m128i C0 = _mm_sub_epi8(A0, B0);
const __m128i C1 = _mm_sub_epi8(A1, B1);
_mm_storeu_si128((__m128i*)(dst + i + 0), C0);
_mm_storeu_si128((__m128i*)(dst + i + 16), C1);
}
for (; i < length; ++i) dst[i] = src[i] - src[i - 1];
}
}
static void PredictLineC(const uint8_t* src, const uint8_t* pred,
uint8_t* dst, int length, int inverse) {
int i;
if (inverse) {
for (i = 0; i < length; ++i) dst[i] = src[i] + pred[i];
} else {
for (i = 0; i < length; ++i) dst[i] = src[i] - pred[i];
}
}
//------------------------------------------------------------------------------
// Horizontal filter.
static WEBP_INLINE void DoHorizontalFilter(const uint8_t* in,
int width, int height, int stride,
int row, int num_rows,
int inverse, uint8_t* out) {
const uint8_t* preds;
const size_t start_offset = row * stride;
const int last_row = row + num_rows;
SANITY_CHECK(in, out);
in += start_offset;
out += start_offset;
preds = inverse ? out : in;
if (row == 0) {
// Leftmost pixel is the same as input for topmost scanline.
out[0] = in[0];
PredictLineLeft(in + 1, out + 1, width - 1, inverse);
row = 1;
preds += stride;
in += stride;
out += stride;
}
// Filter line-by-line.
while (row < last_row) {
// Leftmost pixel is predicted from above.
PredictLineC(in, preds - stride, out, 1, inverse);
PredictLineLeft(in + 1, out + 1, width - 1, inverse);
++row;
preds += stride;
in += stride;
out += stride;
}
}
//------------------------------------------------------------------------------
// Vertical filter.
static WEBP_INLINE void DoVerticalFilter(const uint8_t* in,
int width, int height, int stride,
int row, int num_rows,
int inverse, uint8_t* out) {
const uint8_t* preds;
const size_t start_offset = row * stride;
const int last_row = row + num_rows;
SANITY_CHECK(in, out);
in += start_offset;
out += start_offset;
preds = inverse ? out : in;
if (row == 0) {
// Very first top-left pixel is copied.
out[0] = in[0];
// Rest of top scan-line is left-predicted.
PredictLineLeft(in + 1, out + 1, width - 1, inverse);
row = 1;
in += stride;
out += stride;
} else {
// We are starting from in-between. Make sure 'preds' points to prev row.
preds -= stride;
}
// Filter line-by-line.
while (row < last_row) {
PredictLineTop(in, preds, out, width, inverse);
++row;
preds += stride;
in += stride;
out += stride;
}
}
//------------------------------------------------------------------------------
// Gradient filter.
static WEBP_INLINE int GradientPredictorC(uint8_t a, uint8_t b, uint8_t c) {
const int g = a + b - c;
return ((g & ~0xff) == 0) ? g : (g < 0) ? 0 : 255; // clip to 8bit
}
static void GradientPredictDirect(const uint8_t* const row,
const uint8_t* const top,
uint8_t* const out, int length) {
const int max_pos = length & ~7;
int i;
const __m128i zero = _mm_setzero_si128();
for (i = 0; i < max_pos; i += 8) {
const __m128i A0 = _mm_loadl_epi64((const __m128i*)&row[i - 1]);
const __m128i B0 = _mm_loadl_epi64((const __m128i*)&top[i]);
const __m128i C0 = _mm_loadl_epi64((const __m128i*)&top[i - 1]);
const __m128i D = _mm_loadl_epi64((const __m128i*)&row[i]);
const __m128i A1 = _mm_unpacklo_epi8(A0, zero);
const __m128i B1 = _mm_unpacklo_epi8(B0, zero);
const __m128i C1 = _mm_unpacklo_epi8(C0, zero);
const __m128i E = _mm_add_epi16(A1, B1);
const __m128i F = _mm_sub_epi16(E, C1);
const __m128i G = _mm_packus_epi16(F, zero);
const __m128i H = _mm_sub_epi8(D, G);
_mm_storel_epi64((__m128i*)(out + i), H);
}
for (; i < length; ++i) {
out[i] = row[i] - GradientPredictorC(row[i - 1], top[i], top[i - 1]);
}
}
static void GradientPredictInverse(const uint8_t* const in,
const uint8_t* const top,
uint8_t* const row, int length) {
if (length > 0) {
int i;
const int max_pos = length & ~7;
const __m128i zero = _mm_setzero_si128();
__m128i A = _mm_set_epi32(0, 0, 0, row[-1]); // left sample
for (i = 0; i < max_pos; i += 8) {
const __m128i tmp0 = _mm_loadl_epi64((const __m128i*)&top[i]);
const __m128i tmp1 = _mm_loadl_epi64((const __m128i*)&top[i - 1]);
const __m128i B = _mm_unpacklo_epi8(tmp0, zero);
const __m128i C = _mm_unpacklo_epi8(tmp1, zero);
const __m128i tmp2 = _mm_loadl_epi64((const __m128i*)&in[i]);
const __m128i D = _mm_unpacklo_epi8(tmp2, zero); // base input
const __m128i E = _mm_sub_epi16(B, C); // unclipped gradient basis B - C
__m128i out = zero; // accumulator for output
__m128i mask_hi = _mm_set_epi32(0, 0, 0, 0xff);
int k = 8;
while (1) {
const __m128i tmp3 = _mm_add_epi16(A, E); // delta = A + B - C
const __m128i tmp4 = _mm_min_epi16(tmp3, mask_hi);
const __m128i tmp5 = _mm_max_epi16(tmp4, zero); // clipped delta
const __m128i tmp6 = _mm_add_epi16(tmp5, D); // add to in[] values
A = _mm_and_si128(tmp6, mask_hi); // 1-complement clip
out = _mm_or_si128(out, A); // accumulate output
if (--k == 0) break;
A = _mm_slli_si128(A, 2); // rotate left sample
mask_hi = _mm_slli_si128(mask_hi, 2); // rotate mask
}
A = _mm_srli_si128(A, 14); // prepare left sample for next iteration
_mm_storel_epi64((__m128i*)&row[i], _mm_packus_epi16(out, zero));
}
for (; i < length; ++i) {
row[i] = in[i] + GradientPredictorC(row[i - 1], top[i], top[i - 1]);
}
}
}
static WEBP_INLINE void DoGradientFilter(const uint8_t* in,
int width, int height, int stride,
int row, int num_rows,
int inverse, uint8_t* out) {
const size_t start_offset = row * stride;
const int last_row = row + num_rows;
SANITY_CHECK(in, out);
in += start_offset;
out += start_offset;
// left prediction for top scan-line
if (row == 0) {
out[0] = in[0];
PredictLineLeft(in + 1, out + 1, width - 1, inverse);
row = 1;
in += stride;
out += stride;
}
// Filter line-by-line.
while (row < last_row) {
if (inverse) {
PredictLineC(in, out - stride, out, 1, inverse); // predict from above
GradientPredictInverse(in + 1, out + 1 - stride, out + 1, width - 1);
} else {
PredictLineC(in, in - stride, out, 1, inverse);
GradientPredictDirect(in + 1, in + 1 - stride, out + 1, width - 1);
}
++row;
in += stride;
out += stride;
}
}
#undef SANITY_CHECK
//------------------------------------------------------------------------------
static void HorizontalFilter(const uint8_t* data, int width, int height,
int stride, uint8_t* filtered_data) {
DoHorizontalFilter(data, width, height, stride, 0, height, 0, filtered_data);
}
static void VerticalFilter(const uint8_t* data, int width, int height,
int stride, uint8_t* filtered_data) {
DoVerticalFilter(data, width, height, stride, 0, height, 0, filtered_data);
}
static void GradientFilter(const uint8_t* data, int width, int height,
int stride, uint8_t* filtered_data) {
DoGradientFilter(data, width, height, stride, 0, height, 0, filtered_data);
}
//------------------------------------------------------------------------------
static void VerticalUnfilter(int width, int height, int stride, int row,
int num_rows, uint8_t* data) {
DoVerticalFilter(data, width, height, stride, row, num_rows, 1, data);
}
static void HorizontalUnfilter(int width, int height, int stride, int row,
int num_rows, uint8_t* data) {
DoHorizontalFilter(data, width, height, stride, row, num_rows, 1, data);
}
static void GradientUnfilter(int width, int height, int stride, int row,
int num_rows, uint8_t* data) {
DoGradientFilter(data, width, height, stride, row, num_rows, 1, data);
}
//------------------------------------------------------------------------------
// Entry point
extern void VP8FiltersInitSSE2(void);
WEBP_TSAN_IGNORE_FUNCTION void VP8FiltersInitSSE2(void) {
WebPUnfilters[WEBP_FILTER_HORIZONTAL] = HorizontalUnfilter;
WebPUnfilters[WEBP_FILTER_VERTICAL] = VerticalUnfilter;
WebPUnfilters[WEBP_FILTER_GRADIENT] = GradientUnfilter;
WebPFilters[WEBP_FILTER_HORIZONTAL] = HorizontalFilter;
WebPFilters[WEBP_FILTER_VERTICAL] = VerticalFilter;
WebPFilters[WEBP_FILTER_GRADIENT] = GradientFilter;
}
#else // !WEBP_USE_SSE2
WEBP_DSP_INIT_STUB(VP8FiltersInitSSE2)
#endif // WEBP_USE_SSE2