// Copyright 2014 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.
// -----------------------------------------------------------------------------
//
// NEON variant of methods for lossless decoder
//
// Author: Skal (pascal.massimino@gmail.com)
#include "./dsp.h"
#if defined(WEBP_USE_NEON)
#include <arm_neon.h>
#include "./lossless.h"
#include "./neon.h"
//------------------------------------------------------------------------------
// Colorspace conversion functions
#if !defined(WORK_AROUND_GCC)
// gcc 4.6.0 had some trouble (NDK-r9) with this code. We only use it for
// gcc-4.8.x at least.
static void ConvertBGRAToRGBA(const uint32_t* src,
int num_pixels, uint8_t* dst) {
const uint32_t* const end = src + (num_pixels & ~15);
for (; src < end; src += 16) {
uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
// swap B and R. (VSWP d0,d2 has no intrinsics equivalent!)
const uint8x16_t tmp = pixel.val[0];
pixel.val[0] = pixel.val[2];
pixel.val[2] = tmp;
vst4q_u8(dst, pixel);
dst += 64;
}
VP8LConvertBGRAToRGBA_C(src, num_pixels & 15, dst); // left-overs
}
static void ConvertBGRAToBGR(const uint32_t* src,
int num_pixels, uint8_t* dst) {
const uint32_t* const end = src + (num_pixels & ~15);
for (; src < end; src += 16) {
const uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
const uint8x16x3_t tmp = { { pixel.val[0], pixel.val[1], pixel.val[2] } };
vst3q_u8(dst, tmp);
dst += 48;
}
VP8LConvertBGRAToBGR_C(src, num_pixels & 15, dst); // left-overs
}
static void ConvertBGRAToRGB(const uint32_t* src,
int num_pixels, uint8_t* dst) {
const uint32_t* const end = src + (num_pixels & ~15);
for (; src < end; src += 16) {
const uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
const uint8x16x3_t tmp = { { pixel.val[2], pixel.val[1], pixel.val[0] } };
vst3q_u8(dst, tmp);
dst += 48;
}
VP8LConvertBGRAToRGB_C(src, num_pixels & 15, dst); // left-overs
}
#else // WORK_AROUND_GCC
// gcc-4.6.0 fallback
static const uint8_t kRGBAShuffle[8] = { 2, 1, 0, 3, 6, 5, 4, 7 };
static void ConvertBGRAToRGBA(const uint32_t* src,
int num_pixels, uint8_t* dst) {
const uint32_t* const end = src + (num_pixels & ~1);
const uint8x8_t shuffle = vld1_u8(kRGBAShuffle);
for (; src < end; src += 2) {
const uint8x8_t pixels = vld1_u8((uint8_t*)src);
vst1_u8(dst, vtbl1_u8(pixels, shuffle));
dst += 8;
}
VP8LConvertBGRAToRGBA_C(src, num_pixels & 1, dst); // left-overs
}
static const uint8_t kBGRShuffle[3][8] = {
{ 0, 1, 2, 4, 5, 6, 8, 9 },
{ 10, 12, 13, 14, 16, 17, 18, 20 },
{ 21, 22, 24, 25, 26, 28, 29, 30 }
};
static void ConvertBGRAToBGR(const uint32_t* src,
int num_pixels, uint8_t* dst) {
const uint32_t* const end = src + (num_pixels & ~7);
const uint8x8_t shuffle0 = vld1_u8(kBGRShuffle[0]);
const uint8x8_t shuffle1 = vld1_u8(kBGRShuffle[1]);
const uint8x8_t shuffle2 = vld1_u8(kBGRShuffle[2]);
for (; src < end; src += 8) {
uint8x8x4_t pixels;
INIT_VECTOR4(pixels,
vld1_u8((const uint8_t*)(src + 0)),
vld1_u8((const uint8_t*)(src + 2)),
vld1_u8((const uint8_t*)(src + 4)),
vld1_u8((const uint8_t*)(src + 6)));
vst1_u8(dst + 0, vtbl4_u8(pixels, shuffle0));
vst1_u8(dst + 8, vtbl4_u8(pixels, shuffle1));
vst1_u8(dst + 16, vtbl4_u8(pixels, shuffle2));
dst += 8 * 3;
}
VP8LConvertBGRAToBGR_C(src, num_pixels & 7, dst); // left-overs
}
static const uint8_t kRGBShuffle[3][8] = {
{ 2, 1, 0, 6, 5, 4, 10, 9 },
{ 8, 14, 13, 12, 18, 17, 16, 22 },
{ 21, 20, 26, 25, 24, 30, 29, 28 }
};
static void ConvertBGRAToRGB(const uint32_t* src,
int num_pixels, uint8_t* dst) {
const uint32_t* const end = src + (num_pixels & ~7);
const uint8x8_t shuffle0 = vld1_u8(kRGBShuffle[0]);
const uint8x8_t shuffle1 = vld1_u8(kRGBShuffle[1]);
const uint8x8_t shuffle2 = vld1_u8(kRGBShuffle[2]);
for (; src < end; src += 8) {
uint8x8x4_t pixels;
INIT_VECTOR4(pixels,
vld1_u8((const uint8_t*)(src + 0)),
vld1_u8((const uint8_t*)(src + 2)),
vld1_u8((const uint8_t*)(src + 4)),
vld1_u8((const uint8_t*)(src + 6)));
vst1_u8(dst + 0, vtbl4_u8(pixels, shuffle0));
vst1_u8(dst + 8, vtbl4_u8(pixels, shuffle1));
vst1_u8(dst + 16, vtbl4_u8(pixels, shuffle2));
dst += 8 * 3;
}
VP8LConvertBGRAToRGB_C(src, num_pixels & 7, dst); // left-overs
}
#endif // !WORK_AROUND_GCC
//------------------------------------------------------------------------------
#ifdef USE_INTRINSICS
static WEBP_INLINE uint32_t Average2(const uint32_t* const a,
const uint32_t* const b) {
const uint8x8_t a0 = vreinterpret_u8_u64(vcreate_u64(*a));
const uint8x8_t b0 = vreinterpret_u8_u64(vcreate_u64(*b));
const uint8x8_t avg = vhadd_u8(a0, b0);
return vget_lane_u32(vreinterpret_u32_u8(avg), 0);
}
static WEBP_INLINE uint32_t Average3(const uint32_t* const a,
const uint32_t* const b,
const uint32_t* const c) {
const uint8x8_t a0 = vreinterpret_u8_u64(vcreate_u64(*a));
const uint8x8_t b0 = vreinterpret_u8_u64(vcreate_u64(*b));
const uint8x8_t c0 = vreinterpret_u8_u64(vcreate_u64(*c));
const uint8x8_t avg1 = vhadd_u8(a0, c0);
const uint8x8_t avg2 = vhadd_u8(avg1, b0);
return vget_lane_u32(vreinterpret_u32_u8(avg2), 0);
}
static WEBP_INLINE uint32_t Average4(const uint32_t* const a,
const uint32_t* const b,
const uint32_t* const c,
const uint32_t* const d) {
const uint8x8_t a0 = vreinterpret_u8_u64(vcreate_u64(*a));
const uint8x8_t b0 = vreinterpret_u8_u64(vcreate_u64(*b));
const uint8x8_t c0 = vreinterpret_u8_u64(vcreate_u64(*c));
const uint8x8_t d0 = vreinterpret_u8_u64(vcreate_u64(*d));
const uint8x8_t avg1 = vhadd_u8(a0, b0);
const uint8x8_t avg2 = vhadd_u8(c0, d0);
const uint8x8_t avg3 = vhadd_u8(avg1, avg2);
return vget_lane_u32(vreinterpret_u32_u8(avg3), 0);
}
static uint32_t Predictor5(uint32_t left, const uint32_t* const top) {
return Average3(&left, top + 0, top + 1);
}
static uint32_t Predictor6(uint32_t left, const uint32_t* const top) {
return Average2(&left, top - 1);
}
static uint32_t Predictor7(uint32_t left, const uint32_t* const top) {
return Average2(&left, top + 0);
}
static uint32_t Predictor8(uint32_t left, const uint32_t* const top) {
(void)left;
return Average2(top - 1, top + 0);
}
static uint32_t Predictor9(uint32_t left, const uint32_t* const top) {
(void)left;
return Average2(top + 0, top + 1);
}
static uint32_t Predictor10(uint32_t left, const uint32_t* const top) {
return Average4(&left, top - 1, top + 0, top + 1);
}
//------------------------------------------------------------------------------
static WEBP_INLINE uint32_t Select(const uint32_t* const c0,
const uint32_t* const c1,
const uint32_t* const c2) {
const uint8x8_t p0 = vreinterpret_u8_u64(vcreate_u64(*c0));
const uint8x8_t p1 = vreinterpret_u8_u64(vcreate_u64(*c1));
const uint8x8_t p2 = vreinterpret_u8_u64(vcreate_u64(*c2));
const uint8x8_t bc = vabd_u8(p1, p2); // |b-c|
const uint8x8_t ac = vabd_u8(p0, p2); // |a-c|
const int16x4_t sum_bc = vreinterpret_s16_u16(vpaddl_u8(bc));
const int16x4_t sum_ac = vreinterpret_s16_u16(vpaddl_u8(ac));
const int32x2_t diff = vpaddl_s16(vsub_s16(sum_bc, sum_ac));
const int32_t pa_minus_pb = vget_lane_s32(diff, 0);
return (pa_minus_pb <= 0) ? *c0 : *c1;
}
static uint32_t Predictor11(uint32_t left, const uint32_t* const top) {
return Select(top + 0, &left, top - 1);
}
static WEBP_INLINE uint32_t ClampedAddSubtractFull(const uint32_t* const c0,
const uint32_t* const c1,
const uint32_t* const c2) {
const uint8x8_t p0 = vreinterpret_u8_u64(vcreate_u64(*c0));
const uint8x8_t p1 = vreinterpret_u8_u64(vcreate_u64(*c1));
const uint8x8_t p2 = vreinterpret_u8_u64(vcreate_u64(*c2));
const uint16x8_t sum0 = vaddl_u8(p0, p1); // add and widen
const uint16x8_t sum1 = vqsubq_u16(sum0, vmovl_u8(p2)); // widen and subtract
const uint8x8_t out = vqmovn_u16(sum1); // narrow and clamp
return vget_lane_u32(vreinterpret_u32_u8(out), 0);
}
static uint32_t Predictor12(uint32_t left, const uint32_t* const top) {
return ClampedAddSubtractFull(&left, top + 0, top - 1);
}
static WEBP_INLINE uint32_t ClampedAddSubtractHalf(const uint32_t* const c0,
const uint32_t* const c1,
const uint32_t* const c2) {
const uint8x8_t p0 = vreinterpret_u8_u64(vcreate_u64(*c0));
const uint8x8_t p1 = vreinterpret_u8_u64(vcreate_u64(*c1));
const uint8x8_t p2 = vreinterpret_u8_u64(vcreate_u64(*c2));
const uint8x8_t avg = vhadd_u8(p0, p1); // Average(c0,c1)
const uint8x8_t ab = vshr_n_u8(vqsub_u8(avg, p2), 1); // (a-b)>>1 saturated
const uint8x8_t ba = vshr_n_u8(vqsub_u8(p2, avg), 1); // (b-a)>>1 saturated
const uint8x8_t out = vqsub_u8(vqadd_u8(avg, ab), ba);
return vget_lane_u32(vreinterpret_u32_u8(out), 0);
}
static uint32_t Predictor13(uint32_t left, const uint32_t* const top) {
return ClampedAddSubtractHalf(&left, top + 0, top - 1);
}
//------------------------------------------------------------------------------
// Subtract-Green Transform
// vtbl?_u8 are marked unavailable for iOS arm64 with Xcode < 6.3, use
// non-standard versions there.
#if defined(__APPLE__) && defined(__aarch64__) && \
defined(__apple_build_version__) && (__apple_build_version__< 6020037)
#define USE_VTBLQ
#endif
#ifdef USE_VTBLQ
// 255 = byte will be zeroed
static const uint8_t kGreenShuffle[16] = {
1, 255, 1, 255, 5, 255, 5, 255, 9, 255, 9, 255, 13, 255, 13, 255
};
static WEBP_INLINE uint8x16_t DoGreenShuffle(const uint8x16_t argb,
const uint8x16_t shuffle) {
return vcombine_u8(vtbl1q_u8(argb, vget_low_u8(shuffle)),
vtbl1q_u8(argb, vget_high_u8(shuffle)));
}
#else // !USE_VTBLQ
// 255 = byte will be zeroed
static const uint8_t kGreenShuffle[8] = { 1, 255, 1, 255, 5, 255, 5, 255 };
static WEBP_INLINE uint8x16_t DoGreenShuffle(const uint8x16_t argb,
const uint8x8_t shuffle) {
return vcombine_u8(vtbl1_u8(vget_low_u8(argb), shuffle),
vtbl1_u8(vget_high_u8(argb), shuffle));
}
#endif // USE_VTBLQ
static void SubtractGreenFromBlueAndRed(uint32_t* argb_data, int num_pixels) {
const uint32_t* const end = argb_data + (num_pixels & ~3);
#ifdef USE_VTBLQ
const uint8x16_t shuffle = vld1q_u8(kGreenShuffle);
#else
const uint8x8_t shuffle = vld1_u8(kGreenShuffle);
#endif
for (; argb_data < end; argb_data += 4) {
const uint8x16_t argb = vld1q_u8((uint8_t*)argb_data);
const uint8x16_t greens = DoGreenShuffle(argb, shuffle);
vst1q_u8((uint8_t*)argb_data, vsubq_u8(argb, greens));
}
// fallthrough and finish off with plain-C
VP8LSubtractGreenFromBlueAndRed_C(argb_data, num_pixels & 3);
}
static void AddGreenToBlueAndRed(uint32_t* argb_data, int num_pixels) {
const uint32_t* const end = argb_data + (num_pixels & ~3);
#ifdef USE_VTBLQ
const uint8x16_t shuffle = vld1q_u8(kGreenShuffle);
#else
const uint8x8_t shuffle = vld1_u8(kGreenShuffle);
#endif
for (; argb_data < end; argb_data += 4) {
const uint8x16_t argb = vld1q_u8((uint8_t*)argb_data);
const uint8x16_t greens = DoGreenShuffle(argb, shuffle);
vst1q_u8((uint8_t*)argb_data, vaddq_u8(argb, greens));
}
// fallthrough and finish off with plain-C
VP8LAddGreenToBlueAndRed_C(argb_data, num_pixels & 3);
}
#undef USE_VTBLQ
#endif // USE_INTRINSICS
#endif // WEBP_USE_NEON
//------------------------------------------------------------------------------
extern void VP8LDspInitNEON(void);
void VP8LDspInitNEON(void) {
#if defined(WEBP_USE_NEON)
VP8LConvertBGRAToRGBA = ConvertBGRAToRGBA;
VP8LConvertBGRAToBGR = ConvertBGRAToBGR;
VP8LConvertBGRAToRGB = ConvertBGRAToRGB;
#ifdef USE_INTRINSICS
VP8LPredictors[5] = Predictor5;
VP8LPredictors[6] = Predictor6;
VP8LPredictors[7] = Predictor7;
VP8LPredictors[8] = Predictor8;
VP8LPredictors[9] = Predictor9;
VP8LPredictors[10] = Predictor10;
VP8LPredictors[11] = Predictor11;
VP8LPredictors[12] = Predictor12;
VP8LPredictors[13] = Predictor13;
VP8LSubtractGreenFromBlueAndRed = SubtractGreenFromBlueAndRed;
VP8LAddGreenToBlueAndRed = AddGreenToBlueAndRed;
#endif
#endif // WEBP_USE_NEON
}
//------------------------------------------------------------------------------