diff options
author | Christian Schneppe <christian@pix-art.de> | 2016-08-28 21:53:23 +0200 |
---|---|---|
committer | Christian Schneppe <christian@pix-art.de> | 2016-08-28 21:53:23 +0200 |
commit | 084faa3a6277f7270882209468e65dd38f10cdd5 (patch) | |
tree | de593d7dd066af3f4a0915f37afb5c3cbff5d996 /src/main/jni/libwebp/dsp/yuv.h | |
parent | 1aca12fdfdcbb334e279583de0d70d611d22af6a (diff) | |
parent | b3b3475e93a9b08f9e35edbf74673728b560ad3b (diff) |
Merge remote-tracking branch 'refs/remotes/origin/video-compression'
Diffstat (limited to 'src/main/jni/libwebp/dsp/yuv.h')
-rw-r--r-- | src/main/jni/libwebp/dsp/yuv.h | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/src/main/jni/libwebp/dsp/yuv.h b/src/main/jni/libwebp/dsp/yuv.h new file mode 100644 index 000000000..8a47edd82 --- /dev/null +++ b/src/main/jni/libwebp/dsp/yuv.h @@ -0,0 +1,321 @@ +// Copyright 2010 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. +// ----------------------------------------------------------------------------- +// +// inline YUV<->RGB conversion function +// +// The exact naming is Y'CbCr, following the ITU-R BT.601 standard. +// More information at: http://en.wikipedia.org/wiki/YCbCr +// Y = 0.2569 * R + 0.5044 * G + 0.0979 * B + 16 +// U = -0.1483 * R - 0.2911 * G + 0.4394 * B + 128 +// V = 0.4394 * R - 0.3679 * G - 0.0715 * B + 128 +// We use 16bit fixed point operations for RGB->YUV conversion (YUV_FIX). +// +// For the Y'CbCr to RGB conversion, the BT.601 specification reads: +// R = 1.164 * (Y-16) + 1.596 * (V-128) +// G = 1.164 * (Y-16) - 0.813 * (V-128) - 0.391 * (U-128) +// B = 1.164 * (Y-16) + 2.018 * (U-128) +// where Y is in the [16,235] range, and U/V in the [16,240] range. +// In the table-lookup version (WEBP_YUV_USE_TABLE), the common factor +// "1.164 * (Y-16)" can be handled as an offset in the VP8kClip[] table. +// So in this case the formulae should read: +// R = 1.164 * [Y + 1.371 * (V-128) ] - 18.624 +// G = 1.164 * [Y - 0.698 * (V-128) - 0.336 * (U-128)] - 18.624 +// B = 1.164 * [Y + 1.733 * (U-128)] - 18.624 +// once factorized. +// For YUV->RGB conversion, only 14bit fixed precision is used (YUV_FIX2). +// That's the maximum possible for a convenient ARM implementation. +// +// Author: Skal (pascal.massimino@gmail.com) + +#ifndef WEBP_DSP_YUV_H_ +#define WEBP_DSP_YUV_H_ + +#include "./dsp.h" +#include "../dec/decode_vp8.h" + +// Define the following to use the LUT-based code: +// #define WEBP_YUV_USE_TABLE + +#if defined(WEBP_EXPERIMENTAL_FEATURES) +// Do NOT activate this feature for real compression. This is only experimental! +// This flag is for comparison purpose against JPEG's "YUVj" natural colorspace. +// This colorspace is close to Rec.601's Y'CbCr model with the notable +// difference of allowing larger range for luma/chroma. +// See http://en.wikipedia.org/wiki/YCbCr#JPEG_conversion paragraph, and its +// difference with http://en.wikipedia.org/wiki/YCbCr#ITU-R_BT.601_conversion +// #define USE_YUVj +#endif + +//------------------------------------------------------------------------------ +// YUV -> RGB conversion + +#ifdef __cplusplus +extern "C" { +#endif + +enum { + YUV_FIX = 16, // fixed-point precision for RGB->YUV + YUV_HALF = 1 << (YUV_FIX - 1), + YUV_MASK = (256 << YUV_FIX) - 1, + YUV_RANGE_MIN = -227, // min value of r/g/b output + YUV_RANGE_MAX = 256 + 226, // max value of r/g/b output + + YUV_FIX2 = 14, // fixed-point precision for YUV->RGB + YUV_HALF2 = 1 << (YUV_FIX2 - 1), + YUV_MASK2 = (256 << YUV_FIX2) - 1 +}; + +// These constants are 14b fixed-point version of ITU-R BT.601 constants. +#define kYScale 19077 // 1.164 = 255 / 219 +#define kVToR 26149 // 1.596 = 255 / 112 * 0.701 +#define kUToG 6419 // 0.391 = 255 / 112 * 0.886 * 0.114 / 0.587 +#define kVToG 13320 // 0.813 = 255 / 112 * 0.701 * 0.299 / 0.587 +#define kUToB 33050 // 2.018 = 255 / 112 * 0.886 +#define kRCst (-kYScale * 16 - kVToR * 128 + YUV_HALF2) +#define kGCst (-kYScale * 16 + kUToG * 128 + kVToG * 128 + YUV_HALF2) +#define kBCst (-kYScale * 16 - kUToB * 128 + YUV_HALF2) + +//------------------------------------------------------------------------------ + +#if !defined(WEBP_YUV_USE_TABLE) + +// slower on x86 by ~7-8%, but bit-exact with the SSE2 version + +static WEBP_INLINE int VP8Clip8(int v) { + return ((v & ~YUV_MASK2) == 0) ? (v >> YUV_FIX2) : (v < 0) ? 0 : 255; +} + +static WEBP_INLINE int VP8YUVToR(int y, int v) { + return VP8Clip8(kYScale * y + kVToR * v + kRCst); +} + +static WEBP_INLINE int VP8YUVToG(int y, int u, int v) { + return VP8Clip8(kYScale * y - kUToG * u - kVToG * v + kGCst); +} + +static WEBP_INLINE int VP8YUVToB(int y, int u) { + return VP8Clip8(kYScale * y + kUToB * u + kBCst); +} + +static WEBP_INLINE void VP8YuvToRgb(int y, int u, int v, + uint8_t* const rgb) { + rgb[0] = VP8YUVToR(y, v); + rgb[1] = VP8YUVToG(y, u, v); + rgb[2] = VP8YUVToB(y, u); +} + +static WEBP_INLINE void VP8YuvToBgr(int y, int u, int v, + uint8_t* const bgr) { + bgr[0] = VP8YUVToB(y, u); + bgr[1] = VP8YUVToG(y, u, v); + bgr[2] = VP8YUVToR(y, v); +} + +static WEBP_INLINE void VP8YuvToRgb565(int y, int u, int v, + uint8_t* const rgb) { + const int r = VP8YUVToR(y, v); // 5 usable bits + const int g = VP8YUVToG(y, u, v); // 6 usable bits + const int b = VP8YUVToB(y, u); // 5 usable bits + const int rg = (r & 0xf8) | (g >> 5); + const int gb = ((g << 3) & 0xe0) | (b >> 3); +#ifdef WEBP_SWAP_16BIT_CSP + rgb[0] = gb; + rgb[1] = rg; +#else + rgb[0] = rg; + rgb[1] = gb; +#endif +} + +static WEBP_INLINE void VP8YuvToRgba4444(int y, int u, int v, + uint8_t* const argb) { + const int r = VP8YUVToR(y, v); // 4 usable bits + const int g = VP8YUVToG(y, u, v); // 4 usable bits + const int b = VP8YUVToB(y, u); // 4 usable bits + const int rg = (r & 0xf0) | (g >> 4); + const int ba = (b & 0xf0) | 0x0f; // overwrite the lower 4 bits +#ifdef WEBP_SWAP_16BIT_CSP + argb[0] = ba; + argb[1] = rg; +#else + argb[0] = rg; + argb[1] = ba; +#endif +} + +#else + +// Table-based version, not totally equivalent to the SSE2 version. +// Rounding diff is only +/-1 though. + +extern int16_t VP8kVToR[256], VP8kUToB[256]; +extern int32_t VP8kVToG[256], VP8kUToG[256]; +extern uint8_t VP8kClip[YUV_RANGE_MAX - YUV_RANGE_MIN]; +extern uint8_t VP8kClip4Bits[YUV_RANGE_MAX - YUV_RANGE_MIN]; + +static WEBP_INLINE void VP8YuvToRgb(int y, int u, int v, + uint8_t* const rgb) { + const int r_off = VP8kVToR[v]; + const int g_off = (VP8kVToG[v] + VP8kUToG[u]) >> YUV_FIX; + const int b_off = VP8kUToB[u]; + rgb[0] = VP8kClip[y + r_off - YUV_RANGE_MIN]; + rgb[1] = VP8kClip[y + g_off - YUV_RANGE_MIN]; + rgb[2] = VP8kClip[y + b_off - YUV_RANGE_MIN]; +} + +static WEBP_INLINE void VP8YuvToBgr(int y, int u, int v, + uint8_t* const bgr) { + const int r_off = VP8kVToR[v]; + const int g_off = (VP8kVToG[v] + VP8kUToG[u]) >> YUV_FIX; + const int b_off = VP8kUToB[u]; + bgr[0] = VP8kClip[y + b_off - YUV_RANGE_MIN]; + bgr[1] = VP8kClip[y + g_off - YUV_RANGE_MIN]; + bgr[2] = VP8kClip[y + r_off - YUV_RANGE_MIN]; +} + +static WEBP_INLINE void VP8YuvToRgb565(int y, int u, int v, + uint8_t* const rgb) { + const int r_off = VP8kVToR[v]; + const int g_off = (VP8kVToG[v] + VP8kUToG[u]) >> YUV_FIX; + const int b_off = VP8kUToB[u]; + const int rg = ((VP8kClip[y + r_off - YUV_RANGE_MIN] & 0xf8) | + (VP8kClip[y + g_off - YUV_RANGE_MIN] >> 5)); + const int gb = (((VP8kClip[y + g_off - YUV_RANGE_MIN] << 3) & 0xe0) | + (VP8kClip[y + b_off - YUV_RANGE_MIN] >> 3)); +#ifdef WEBP_SWAP_16BIT_CSP + rgb[0] = gb; + rgb[1] = rg; +#else + rgb[0] = rg; + rgb[1] = gb; +#endif +} + +static WEBP_INLINE void VP8YuvToRgba4444(int y, int u, int v, + uint8_t* const argb) { + const int r_off = VP8kVToR[v]; + const int g_off = (VP8kVToG[v] + VP8kUToG[u]) >> YUV_FIX; + const int b_off = VP8kUToB[u]; + const int rg = ((VP8kClip4Bits[y + r_off - YUV_RANGE_MIN] << 4) | + VP8kClip4Bits[y + g_off - YUV_RANGE_MIN]); + const int ba = (VP8kClip4Bits[y + b_off - YUV_RANGE_MIN] << 4) | 0x0f; +#ifdef WEBP_SWAP_16BIT_CSP + argb[0] = ba; + argb[1] = rg; +#else + argb[0] = rg; + argb[1] = ba; +#endif +} + +#endif // WEBP_YUV_USE_TABLE + +//----------------------------------------------------------------------------- +// Alpha handling variants + +static WEBP_INLINE void VP8YuvToArgb(uint8_t y, uint8_t u, uint8_t v, + uint8_t* const argb) { + argb[0] = 0xff; + VP8YuvToRgb(y, u, v, argb + 1); +} + +static WEBP_INLINE void VP8YuvToBgra(uint8_t y, uint8_t u, uint8_t v, + uint8_t* const bgra) { + VP8YuvToBgr(y, u, v, bgra); + bgra[3] = 0xff; +} + +static WEBP_INLINE void VP8YuvToRgba(uint8_t y, uint8_t u, uint8_t v, + uint8_t* const rgba) { + VP8YuvToRgb(y, u, v, rgba); + rgba[3] = 0xff; +} + +// Must be called before everything, to initialize the tables. +void VP8YUVInit(void); + +//----------------------------------------------------------------------------- +// SSE2 extra functions (mostly for upsampling_sse2.c) + +#if defined(WEBP_USE_SSE2) + +// When the following is defined, tables are initialized statically, adding ~12k +// to the binary size. Otherwise, they are initialized at run-time (small cost). +#define WEBP_YUV_USE_SSE2_TABLES + +#if defined(FANCY_UPSAMPLING) +// Process 32 pixels and store the result (24b or 32b per pixel) in *dst. +void VP8YuvToRgba32(const uint8_t* y, const uint8_t* u, const uint8_t* v, + uint8_t* dst); +void VP8YuvToRgb32(const uint8_t* y, const uint8_t* u, const uint8_t* v, + uint8_t* dst); +void VP8YuvToBgra32(const uint8_t* y, const uint8_t* u, const uint8_t* v, + uint8_t* dst); +void VP8YuvToBgr32(const uint8_t* y, const uint8_t* u, const uint8_t* v, + uint8_t* dst); +#endif // FANCY_UPSAMPLING + +// Must be called to initialize tables before using the functions. +void VP8YUVInitSSE2(void); + +#endif // WEBP_USE_SSE2 + +//------------------------------------------------------------------------------ +// RGB -> YUV conversion + +// Stub functions that can be called with various rounding values: +static WEBP_INLINE int VP8ClipUV(int uv, int rounding) { + uv = (uv + rounding + (128 << (YUV_FIX + 2))) >> (YUV_FIX + 2); + return ((uv & ~0xff) == 0) ? uv : (uv < 0) ? 0 : 255; +} + +#ifndef USE_YUVj + +static WEBP_INLINE int VP8RGBToY(int r, int g, int b, int rounding) { + const int luma = 16839 * r + 33059 * g + 6420 * b; + return (luma + rounding + (16 << YUV_FIX)) >> YUV_FIX; // no need to clip +} + +static WEBP_INLINE int VP8RGBToU(int r, int g, int b, int rounding) { + const int u = -9719 * r - 19081 * g + 28800 * b; + return VP8ClipUV(u, rounding); +} + +static WEBP_INLINE int VP8RGBToV(int r, int g, int b, int rounding) { + const int v = +28800 * r - 24116 * g - 4684 * b; + return VP8ClipUV(v, rounding); +} + +#else + +// This JPEG-YUV colorspace, only for comparison! +// These are also 16bit precision coefficients from Rec.601, but with full +// [0..255] output range. +static WEBP_INLINE int VP8RGBToY(int r, int g, int b, int rounding) { + const int luma = 19595 * r + 38470 * g + 7471 * b; + return (luma + rounding) >> YUV_FIX; // no need to clip +} + +static WEBP_INLINE int VP8RGBToU(int r, int g, int b, int rounding) { + const int u = -11058 * r - 21710 * g + 32768 * b; + return VP8ClipUV(u, rounding); +} + +static WEBP_INLINE int VP8RGBToV(int r, int g, int b, int rounding) { + const int v = 32768 * r - 27439 * g - 5329 * b; + return VP8ClipUV(v, rounding); +} + +#endif // USE_YUVj + +#ifdef __cplusplus +} // extern "C" +#endif + +#endif /* WEBP_DSP_YUV_H_ */ |