// Copyright 2011 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 version of YUV to RGB upsampling functions.
//
// Author: somnath@google.com (Somnath Banerjee)
#include "./dsp.h"
#if defined(WEBP_USE_SSE2)
#include <assert.h>
#include <emmintrin.h>
#include <string.h>
#include "./yuv.h"
#ifdef FANCY_UPSAMPLING
// We compute (9*a + 3*b + 3*c + d + 8) / 16 as follows
// u = (9*a + 3*b + 3*c + d + 8) / 16
// = (a + (a + 3*b + 3*c + d) / 8 + 1) / 2
// = (a + m + 1) / 2
// where m = (a + 3*b + 3*c + d) / 8
// = ((a + b + c + d) / 2 + b + c) / 4
//
// Let's say k = (a + b + c + d) / 4.
// We can compute k as
// k = (s + t + 1) / 2 - ((a^d) | (b^c) | (s^t)) & 1
// where s = (a + d + 1) / 2 and t = (b + c + 1) / 2
//
// Then m can be written as
// m = (k + t + 1) / 2 - (((b^c) & (s^t)) | (k^t)) & 1
// Computes out = (k + in + 1) / 2 - ((ij & (s^t)) | (k^in)) & 1
#define GET_M(ij, in, out) do { \
const __m128i tmp0 = _mm_avg_epu8(k, (in)); /* (k + in + 1) / 2 */ \
const __m128i tmp1 = _mm_and_si128((ij), st); /* (ij) & (s^t) */ \
const __m128i tmp2 = _mm_xor_si128(k, (in)); /* (k^in) */ \
const __m128i tmp3 = _mm_or_si128(tmp1, tmp2); /* ((ij) & (s^t)) | (k^in) */\
const __m128i tmp4 = _mm_and_si128(tmp3, one); /* & 1 -> lsb_correction */ \
(out) = _mm_sub_epi8(tmp0, tmp4); /* (k + in + 1) / 2 - lsb_correction */ \
} while (0)
// pack and store two alternating pixel rows
#define PACK_AND_STORE(a, b, da, db, out) do { \
const __m128i t_a = _mm_avg_epu8(a, da); /* (9a + 3b + 3c + d + 8) / 16 */ \
const __m128i t_b = _mm_avg_epu8(b, db); /* (3a + 9b + c + 3d + 8) / 16 */ \
const __m128i t_1 = _mm_unpacklo_epi8(t_a, t_b); \
const __m128i t_2 = _mm_unpackhi_epi8(t_a, t_b); \
_mm_store_si128(((__m128i*)(out)) + 0, t_1); \
_mm_store_si128(((__m128i*)(out)) + 1, t_2); \
} while (0)
// Loads 17 pixels each from rows r1 and r2 and generates 32 pixels.
#define UPSAMPLE_32PIXELS(r1, r2, out) { \
const __m128i one = _mm_set1_epi8(1); \
const __m128i a = _mm_loadu_si128((__m128i*)&(r1)[0]); \
const __m128i b = _mm_loadu_si128((__m128i*)&(r1)[1]); \
const __m128i c = _mm_loadu_si128((__m128i*)&(r2)[0]); \
const __m128i d = _mm_loadu_si128((__m128i*)&(r2)[1]); \
\
const __m128i s = _mm_avg_epu8(a, d); /* s = (a + d + 1) / 2 */ \
const __m128i t = _mm_avg_epu8(b, c); /* t = (b + c + 1) / 2 */ \
const __m128i st = _mm_xor_si128(s, t); /* st = s^t */ \
\
const __m128i ad = _mm_xor_si128(a, d); /* ad = a^d */ \
const __m128i bc = _mm_xor_si128(b, c); /* bc = b^c */ \
\
const __m128i t1 = _mm_or_si128(ad, bc); /* (a^d) | (b^c) */ \
const __m128i t2 = _mm_or_si128(t1, st); /* (a^d) | (b^c) | (s^t) */ \
const __m128i t3 = _mm_and_si128(t2, one); /* (a^d) | (b^c) | (s^t) & 1 */ \
const __m128i t4 = _mm_avg_epu8(s, t); \
const __m128i k = _mm_sub_epi8(t4, t3); /* k = (a + b + c + d) / 4 */ \
__m128i diag1, diag2; \
\
GET_M(bc, t, diag1); /* diag1 = (a + 3b + 3c + d) / 8 */ \
GET_M(ad, s, diag2); /* diag2 = (3a + b + c + 3d) / 8 */ \
\
/* pack the alternate pixels */ \
PACK_AND_STORE(a, b, diag1, diag2, out + 0); /* store top */ \
PACK_AND_STORE(c, d, diag2, diag1, out + 2 * 32); /* store bottom */ \
}
// Turn the macro into a function for reducing code-size when non-critical
static void Upsample32Pixels(const uint8_t r1[], const uint8_t r2[],
uint8_t* const out) {
UPSAMPLE_32PIXELS(r1, r2, out);
}
#define UPSAMPLE_LAST_BLOCK(tb, bb, num_pixels, out) { \
uint8_t r1[17], r2[17]; \
memcpy(r1, (tb), (num_pixels)); \
memcpy(r2, (bb), (num_pixels)); \
/* replicate last byte */ \
memset(r1 + (num_pixels), r1[(num_pixels) - 1], 17 - (num_pixels)); \
memset(r2 + (num_pixels), r2[(num_pixels) - 1], 17 - (num_pixels)); \
/* using the shared function instead of the macro saves ~3k code size */ \
Upsample32Pixels(r1, r2, out); \
}
#define CONVERT2RGB(FUNC, XSTEP, top_y, bottom_y, \
top_dst, bottom_dst, cur_x, num_pixels) { \
int n; \
for (n = 0; n < (num_pixels); ++n) { \
FUNC(top_y[(cur_x) + n], r_u[n], r_v[n], \
top_dst + ((cur_x) + n) * XSTEP); \
} \
if (bottom_y != NULL) { \
for (n = 0; n < (num_pixels); ++n) { \
FUNC(bottom_y[(cur_x) + n], r_u[64 + n], r_v[64 + n], \
bottom_dst + ((cur_x) + n) * XSTEP); \
} \
} \
}
#define CONVERT2RGB_32(FUNC, XSTEP, top_y, bottom_y, \
top_dst, bottom_dst, cur_x) do { \
FUNC##32(top_y + (cur_x), r_u, r_v, top_dst + (cur_x) * XSTEP); \
if (bottom_y != NULL) { \
FUNC##32(bottom_y + (cur_x), r_u + 64, r_v + 64, \
bottom_dst + (cur_x) * XSTEP); \
} \
} while (0)
#define SSE2_UPSAMPLE_FUNC(FUNC_NAME, FUNC, XSTEP) \
static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bottom_y, \
const uint8_t* top_u, const uint8_t* top_v, \
const uint8_t* cur_u, const uint8_t* cur_v, \
uint8_t* top_dst, uint8_t* bottom_dst, int len) { \
int uv_pos, pos; \
/* 16byte-aligned array to cache reconstructed u and v */ \
uint8_t uv_buf[4 * 32 + 15]; \
uint8_t* const r_u = (uint8_t*)((uintptr_t)(uv_buf + 15) & ~15); \
uint8_t* const r_v = r_u + 32; \
\
assert(top_y != NULL); \
{ /* Treat the first pixel in regular way */ \
const int u_diag = ((top_u[0] + cur_u[0]) >> 1) + 1; \
const int v_diag = ((top_v[0] + cur_v[0]) >> 1) + 1; \
const int u0_t = (top_u[0] + u_diag) >> 1; \
const int v0_t = (top_v[0] + v_diag) >> 1; \
FUNC(top_y[0], u0_t, v0_t, top_dst); \
if (bottom_y != NULL) { \
const int u0_b = (cur_u[0] + u_diag) >> 1; \
const int v0_b = (cur_v[0] + v_diag) >> 1; \
FUNC(bottom_y[0], u0_b, v0_b, bottom_dst); \
} \
} \
/* For UPSAMPLE_32PIXELS, 17 u/v values must be read-able for each block */ \
for (pos = 1, uv_pos = 0; pos + 32 + 1 <= len; pos += 32, uv_pos += 16) { \
UPSAMPLE_32PIXELS(top_u + uv_pos, cur_u + uv_pos, r_u); \
UPSAMPLE_32PIXELS(top_v + uv_pos, cur_v + uv_pos, r_v); \
CONVERT2RGB_32(FUNC, XSTEP, top_y, bottom_y, top_dst, bottom_dst, pos); \
} \
if (len > 1) { \
const int left_over = ((len + 1) >> 1) - (pos >> 1); \
assert(left_over > 0); \
UPSAMPLE_LAST_BLOCK(top_u + uv_pos, cur_u + uv_pos, left_over, r_u); \
UPSAMPLE_LAST_BLOCK(top_v + uv_pos, cur_v + uv_pos, left_over, r_v); \
CONVERT2RGB(FUNC, XSTEP, top_y, bottom_y, top_dst, bottom_dst, \
pos, len - pos); \
} \
}
// SSE2 variants of the fancy upsampler.
SSE2_UPSAMPLE_FUNC(UpsampleRgbLinePairSSE2, VP8YuvToRgb, 3)
SSE2_UPSAMPLE_FUNC(UpsampleBgrLinePairSSE2, VP8YuvToBgr, 3)
SSE2_UPSAMPLE_FUNC(UpsampleRgbaLinePairSSE2, VP8YuvToRgba, 4)
SSE2_UPSAMPLE_FUNC(UpsampleBgraLinePairSSE2, VP8YuvToBgra, 4)
#undef GET_M
#undef PACK_AND_STORE
#undef UPSAMPLE_32PIXELS
#undef UPSAMPLE_LAST_BLOCK
#undef CONVERT2RGB
#undef CONVERT2RGB_32
#undef SSE2_UPSAMPLE_FUNC
#endif // FANCY_UPSAMPLING
#endif // WEBP_USE_SSE2
//------------------------------------------------------------------------------
#ifdef FANCY_UPSAMPLING
extern WebPUpsampleLinePairFunc WebPUpsamplers[/* MODE_LAST */];
void WebPInitUpsamplersSSE2(void) {
#if defined(WEBP_USE_SSE2)
VP8YUVInitSSE2();
WebPUpsamplers[MODE_RGB] = UpsampleRgbLinePairSSE2;
WebPUpsamplers[MODE_RGBA] = UpsampleRgbaLinePairSSE2;
WebPUpsamplers[MODE_BGR] = UpsampleBgrLinePairSSE2;
WebPUpsamplers[MODE_BGRA] = UpsampleBgraLinePairSSE2;
#endif // WEBP_USE_SSE2
}
void WebPInitPremultiplySSE2(void) {
#if defined(WEBP_USE_SSE2)
WebPUpsamplers[MODE_rgbA] = UpsampleRgbaLinePairSSE2;
WebPUpsamplers[MODE_bgrA] = UpsampleBgraLinePairSSE2;
#endif // WEBP_USE_SSE2
}
#else
// this empty function is to avoid an empty .o
void WebPInitPremultiplySSE2(void) {}
#endif // FANCY_UPSAMPLING