// 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.
// -----------------------------------------------------------------------------
//
// YUV to RGB upsampling functions.
//
// Author: somnath@google.com (Somnath Banerjee)
#include "./dsp.h"
#include "./yuv.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
//------------------------------------------------------------------------------
// Fancy upsampler
#ifdef FANCY_UPSAMPLING
// Fancy upsampling functions to convert YUV to RGB
WebPUpsampleLinePairFunc WebPUpsamplers[MODE_LAST];
// Given samples laid out in a square as:
// [a b]
// [c d]
// we interpolate u/v as:
// ([9*a + 3*b + 3*c + d 3*a + 9*b + 3*c + d] + [8 8]) / 16
// ([3*a + b + 9*c + 3*d a + 3*b + 3*c + 9*d] [8 8]) / 16
// We process u and v together stashed into 32bit (16bit each).
#define LOAD_UV(u, v) ((u) | ((v) << 16))
#define 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 x; \
const int last_pixel_pair = (len - 1) >> 1; \
uint32_t tl_uv = LOAD_UV(top_u[0], top_v[0]); /* top-left sample */ \
uint32_t l_uv = LOAD_UV(cur_u[0], cur_v[0]); /* left-sample */ \
if (top_y) { \
const uint32_t uv0 = (3 * tl_uv + l_uv + 0x00020002u) >> 2; \
FUNC(top_y[0], uv0 & 0xff, (uv0 >> 16), top_dst); \
} \
if (bottom_y) { \
const uint32_t uv0 = (3 * l_uv + tl_uv + 0x00020002u) >> 2; \
FUNC(bottom_y[0], uv0 & 0xff, (uv0 >> 16), bottom_dst); \
} \
for (x = 1; x <= last_pixel_pair; ++x) { \
const uint32_t t_uv = LOAD_UV(top_u[x], top_v[x]); /* top sample */ \
const uint32_t uv = LOAD_UV(cur_u[x], cur_v[x]); /* sample */ \
/* precompute invariant values associated with first and second diagonals*/\
const uint32_t avg = tl_uv + t_uv + l_uv + uv + 0x00080008u; \
const uint32_t diag_12 = (avg + 2 * (t_uv + l_uv)) >> 3; \
const uint32_t diag_03 = (avg + 2 * (tl_uv + uv)) >> 3; \
if (top_y) { \
const uint32_t uv0 = (diag_12 + tl_uv) >> 1; \
const uint32_t uv1 = (diag_03 + t_uv) >> 1; \
FUNC(top_y[2 * x - 1], uv0 & 0xff, (uv0 >> 16), \
top_dst + (2 * x - 1) * XSTEP); \
FUNC(top_y[2 * x - 0], uv1 & 0xff, (uv1 >> 16), \
top_dst + (2 * x - 0) * XSTEP); \
} \
if (bottom_y) { \
const uint32_t uv0 = (diag_03 + l_uv) >> 1; \
const uint32_t uv1 = (diag_12 + uv) >> 1; \
FUNC(bottom_y[2 * x - 1], uv0 & 0xff, (uv0 >> 16), \
bottom_dst + (2 * x - 1) * XSTEP); \
FUNC(bottom_y[2 * x + 0], uv1 & 0xff, (uv1 >> 16), \
bottom_dst + (2 * x + 0) * XSTEP); \
} \
tl_uv = t_uv; \
l_uv = uv; \
} \
if (!(len & 1)) { \
if (top_y) { \
const uint32_t uv0 = (3 * tl_uv + l_uv + 0x00020002u) >> 2; \
FUNC(top_y[len - 1], uv0 & 0xff, (uv0 >> 16), \
top_dst + (len - 1) * XSTEP); \
} \
if (bottom_y) { \
const uint32_t uv0 = (3 * l_uv + tl_uv + 0x00020002u) >> 2; \
FUNC(bottom_y[len - 1], uv0 & 0xff, (uv0 >> 16), \
bottom_dst + (len - 1) * XSTEP); \
} \
} \
}
// All variants implemented.
UPSAMPLE_FUNC(UpsampleRgbLinePair, VP8YuvToRgb, 3)
UPSAMPLE_FUNC(UpsampleBgrLinePair, VP8YuvToBgr, 3)
UPSAMPLE_FUNC(UpsampleRgbaLinePair, VP8YuvToRgba, 4)
UPSAMPLE_FUNC(UpsampleBgraLinePair, VP8YuvToBgra, 4)
UPSAMPLE_FUNC(UpsampleArgbLinePair, VP8YuvToArgb, 4)
UPSAMPLE_FUNC(UpsampleRgba4444LinePair, VP8YuvToRgba4444, 2)
UPSAMPLE_FUNC(UpsampleRgb565LinePair, VP8YuvToRgb565, 2)
#undef LOAD_UV
#undef UPSAMPLE_FUNC
#endif // FANCY_UPSAMPLING
//------------------------------------------------------------------------------
// simple point-sampling
#define SAMPLE_FUNC(FUNC_NAME, FUNC, XSTEP) \
static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bottom_y, \
const uint8_t* u, const uint8_t* v, \
uint8_t* top_dst, uint8_t* bottom_dst, int len) { \
int i; \
for (i = 0; i < len - 1; i += 2) { \
FUNC(top_y[0], u[0], v[0], top_dst); \
FUNC(top_y[1], u[0], v[0], top_dst + XSTEP); \
FUNC(bottom_y[0], u[0], v[0], bottom_dst); \
FUNC(bottom_y[1], u[0], v[0], bottom_dst + XSTEP); \
top_y += 2; \
bottom_y += 2; \
u++; \
v++; \
top_dst += 2 * XSTEP; \
bottom_dst += 2 * XSTEP; \
} \
if (i == len - 1) { /* last one */ \
FUNC(top_y[0], u[0], v[0], top_dst); \
FUNC(bottom_y[0], u[0], v[0], bottom_dst); \
} \
}
// All variants implemented.
SAMPLE_FUNC(SampleRgbLinePair, VP8YuvToRgb, 3)
SAMPLE_FUNC(SampleBgrLinePair, VP8YuvToBgr, 3)
SAMPLE_FUNC(SampleRgbaLinePair, VP8YuvToRgba, 4)
SAMPLE_FUNC(SampleBgraLinePair, VP8YuvToBgra, 4)
SAMPLE_FUNC(SampleArgbLinePair, VP8YuvToArgb, 4)
SAMPLE_FUNC(SampleRgba4444LinePair, VP8YuvToRgba4444, 2)
SAMPLE_FUNC(SampleRgb565LinePair, VP8YuvToRgb565, 2)
#undef SAMPLE_FUNC
const WebPSampleLinePairFunc WebPSamplers[MODE_LAST] = {
SampleRgbLinePair, // MODE_RGB
SampleRgbaLinePair, // MODE_RGBA
SampleBgrLinePair, // MODE_BGR
SampleBgraLinePair, // MODE_BGRA
SampleArgbLinePair, // MODE_ARGB
SampleRgba4444LinePair, // MODE_RGBA_4444
SampleRgb565LinePair, // MODE_RGB_565
SampleRgbaLinePair, // MODE_rgbA
SampleBgraLinePair, // MODE_bgrA
SampleArgbLinePair, // MODE_Argb
SampleRgba4444LinePair // MODE_rgbA_4444
};
//------------------------------------------------------------------------------
#if !defined(FANCY_UPSAMPLING)
#define DUAL_SAMPLE_FUNC(FUNC_NAME, FUNC) \
static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bot_y, \
const uint8_t* top_u, const uint8_t* top_v, \
const uint8_t* bot_u, const uint8_t* bot_v, \
uint8_t* top_dst, uint8_t* bot_dst, int len) { \
const int half_len = len >> 1; \
int x; \
if (top_dst != NULL) { \
for (x = 0; x < half_len; ++x) { \
FUNC(top_y[2 * x + 0], top_u[x], top_v[x], top_dst + 8 * x + 0); \
FUNC(top_y[2 * x + 1], top_u[x], top_v[x], top_dst + 8 * x + 4); \
} \
if (len & 1) FUNC(top_y[2 * x + 0], top_u[x], top_v[x], top_dst + 8 * x); \
} \
if (bot_dst != NULL) { \
for (x = 0; x < half_len; ++x) { \
FUNC(bot_y[2 * x + 0], bot_u[x], bot_v[x], bot_dst + 8 * x + 0); \
FUNC(bot_y[2 * x + 1], bot_u[x], bot_v[x], bot_dst + 8 * x + 4); \
} \
if (len & 1) FUNC(bot_y[2 * x + 0], bot_u[x], bot_v[x], bot_dst + 8 * x); \
} \
}
DUAL_SAMPLE_FUNC(DualLineSamplerBGRA, VP8YuvToBgra)
DUAL_SAMPLE_FUNC(DualLineSamplerARGB, VP8YuvToArgb)
#undef DUAL_SAMPLE_FUNC
#endif // !FANCY_UPSAMPLING
WebPUpsampleLinePairFunc WebPGetLinePairConverter(int alpha_is_last) {
WebPInitUpsamplers();
VP8YUVInit();
#ifdef FANCY_UPSAMPLING
return WebPUpsamplers[alpha_is_last ? MODE_BGRA : MODE_ARGB];
#else
return (alpha_is_last ? DualLineSamplerBGRA : DualLineSamplerARGB);
#endif
}
//------------------------------------------------------------------------------
// YUV444 converter
#define YUV444_FUNC(FUNC_NAME, FUNC, XSTEP) \
static void FUNC_NAME(const uint8_t* y, const uint8_t* u, const uint8_t* v, \
uint8_t* dst, int len) { \
int i; \
for (i = 0; i < len; ++i) FUNC(y[i], u[i], v[i], &dst[i * XSTEP]); \
}
YUV444_FUNC(Yuv444ToRgb, VP8YuvToRgb, 3)
YUV444_FUNC(Yuv444ToBgr, VP8YuvToBgr, 3)
YUV444_FUNC(Yuv444ToRgba, VP8YuvToRgba, 4)
YUV444_FUNC(Yuv444ToBgra, VP8YuvToBgra, 4)
YUV444_FUNC(Yuv444ToArgb, VP8YuvToArgb, 4)
YUV444_FUNC(Yuv444ToRgba4444, VP8YuvToRgba4444, 2)
YUV444_FUNC(Yuv444ToRgb565, VP8YuvToRgb565, 2)
#undef YUV444_FUNC
const WebPYUV444Converter WebPYUV444Converters[MODE_LAST] = {
Yuv444ToRgb, // MODE_RGB
Yuv444ToRgba, // MODE_RGBA
Yuv444ToBgr, // MODE_BGR
Yuv444ToBgra, // MODE_BGRA
Yuv444ToArgb, // MODE_ARGB
Yuv444ToRgba4444, // MODE_RGBA_4444
Yuv444ToRgb565, // MODE_RGB_565
Yuv444ToRgba, // MODE_rgbA
Yuv444ToBgra, // MODE_bgrA
Yuv444ToArgb, // MODE_Argb
Yuv444ToRgba4444 // MODE_rgbA_4444
};
//------------------------------------------------------------------------------
// Premultiplied modes
// non dithered-modes
// (x * a * 32897) >> 23 is bit-wise equivalent to (int)(x * a / 255.)
// for all 8bit x or a. For bit-wise equivalence to (int)(x * a / 255. + .5),
// one can use instead: (x * a * 65793 + (1 << 23)) >> 24
#if 1 // (int)(x * a / 255.)
#define MULTIPLIER(a) ((a) * 32897UL)
#define PREMULTIPLY(x, m) (((x) * (m)) >> 23)
#else // (int)(x * a / 255. + .5)
#define MULTIPLIER(a) ((a) * 65793UL)
#define PREMULTIPLY(x, m) (((x) * (m) + (1UL << 23)) >> 24)
#endif
static void ApplyAlphaMultiply(uint8_t* rgba, int alpha_first,
int w, int h, int stride) {
while (h-- > 0) {
uint8_t* const rgb = rgba + (alpha_first ? 1 : 0);
const uint8_t* const alpha = rgba + (alpha_first ? 0 : 3);
int i;
for (i = 0; i < w; ++i) {
const uint32_t a = alpha[4 * i];
if (a != 0xff) {
const uint32_t mult = MULTIPLIER(a);
rgb[4 * i + 0] = PREMULTIPLY(rgb[4 * i + 0], mult);
rgb[4 * i + 1] = PREMULTIPLY(rgb[4 * i + 1], mult);
rgb[4 * i + 2] = PREMULTIPLY(rgb[4 * i + 2], mult);
}
}
rgba += stride;
}
}
#undef MULTIPLIER
#undef PREMULTIPLY
// rgbA4444
#define MULTIPLIER(a) ((a) * 0x1111) // 0x1111 ~= (1 << 16) / 15
static WEBP_INLINE uint8_t dither_hi(uint8_t x) {
return (x & 0xf0) | (x >> 4);
}
static WEBP_INLINE uint8_t dither_lo(uint8_t x) {
return (x & 0x0f) | (x << 4);
}
static WEBP_INLINE uint8_t multiply(uint8_t x, uint32_t m) {
return (x * m) >> 16;
}
static void ApplyAlphaMultiply4444(uint8_t* rgba4444,
int w, int h, int stride) {
while (h-- > 0) {
int i;
for (i = 0; i < w; ++i) {
const uint8_t a = (rgba4444[2 * i + 1] & 0x0f);
const uint32_t mult = MULTIPLIER(a);
const uint8_t r = multiply(dither_hi(rgba4444[2 * i + 0]), mult);
const uint8_t g = multiply(dither_lo(rgba4444[2 * i + 0]), mult);
const uint8_t b = multiply(dither_hi(rgba4444[2 * i + 1]), mult);
rgba4444[2 * i + 0] = (r & 0xf0) | ((g >> 4) & 0x0f);
rgba4444[2 * i + 1] = (b & 0xf0) | a;
}
rgba4444 += stride;
}
}
#undef MULTIPLIER
void (*WebPApplyAlphaMultiply)(uint8_t*, int, int, int, int)
= ApplyAlphaMultiply;
void (*WebPApplyAlphaMultiply4444)(uint8_t*, int, int, int)
= ApplyAlphaMultiply4444;
//------------------------------------------------------------------------------
// Main call
void WebPInitUpsamplers(void) {
#ifdef FANCY_UPSAMPLING
WebPUpsamplers[MODE_RGB] = UpsampleRgbLinePair;
WebPUpsamplers[MODE_RGBA] = UpsampleRgbaLinePair;
WebPUpsamplers[MODE_BGR] = UpsampleBgrLinePair;
WebPUpsamplers[MODE_BGRA] = UpsampleBgraLinePair;
WebPUpsamplers[MODE_ARGB] = UpsampleArgbLinePair;
WebPUpsamplers[MODE_RGBA_4444] = UpsampleRgba4444LinePair;
WebPUpsamplers[MODE_RGB_565] = UpsampleRgb565LinePair;
// If defined, use CPUInfo() to overwrite some pointers with faster versions.
if (VP8GetCPUInfo != NULL) {
#if defined(WEBP_USE_SSE2)
if (VP8GetCPUInfo(kSSE2)) {
WebPInitUpsamplersSSE2();
}
#endif
#if defined(WEBP_USE_NEON)
if (VP8GetCPUInfo(kNEON)) {
WebPInitUpsamplersNEON();
}
#endif
}
#endif // FANCY_UPSAMPLING
}
void WebPInitPremultiply(void) {
WebPApplyAlphaMultiply = ApplyAlphaMultiply;
WebPApplyAlphaMultiply4444 = ApplyAlphaMultiply4444;
#ifdef FANCY_UPSAMPLING
WebPUpsamplers[MODE_rgbA] = UpsampleRgbaLinePair;
WebPUpsamplers[MODE_bgrA] = UpsampleBgraLinePair;
WebPUpsamplers[MODE_Argb] = UpsampleArgbLinePair;
WebPUpsamplers[MODE_rgbA_4444] = UpsampleRgba4444LinePair;
if (VP8GetCPUInfo != NULL) {
#if defined(WEBP_USE_SSE2)
if (VP8GetCPUInfo(kSSE2)) {
WebPInitPremultiplySSE2();
}
#endif
#if defined(WEBP_USE_NEON)
if (VP8GetCPUInfo(kNEON)) {
WebPInitPremultiplyNEON();
}
#endif
}
#endif // FANCY_UPSAMPLING
}
#if defined(__cplusplus) || defined(c_plusplus)
} // extern "C"
#endif