1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "FormatConvert.h"
18
19
20// Round up to the nearest multiple of the given alignment value
21template<unsigned alignment>
22int align(int value) {
23    static_assert((alignment && !(alignment & (alignment - 1))),
24                  "alignment must be a power of 2");
25
26    unsigned mask = alignment - 1;
27    return (value + mask) & ~mask;
28}
29
30
31// Limit the given value to the provided range.  :)
32static inline float clamp(float v, float min, float max) {
33    if (v < min) return min;
34    if (v > max) return max;
35    return v;
36}
37
38
39static uint32_t yuvToRgbx(const unsigned char Y, const unsigned char Uin, const unsigned char Vin) {
40    // Don't use this if you want to see the best performance.  :)
41    // Better to do this in a pixel shader if we really have to, but on actual
42    // embedded hardware we expect to be able to texture directly from the YUV data
43    float U = Uin - 128.0f;
44    float V = Vin - 128.0f;
45
46    float Rf = Y + 1.140f*V;
47    float Gf = Y - 0.395f*U - 0.581f*V;
48    float Bf = Y + 2.032f*U;
49    unsigned char R = (unsigned char)clamp(Rf, 0.0f, 255.0f);
50    unsigned char G = (unsigned char)clamp(Gf, 0.0f, 255.0f);
51    unsigned char B = (unsigned char)clamp(Bf, 0.0f, 255.0f);
52
53    return (R      ) |
54           (G <<  8) |
55           (B << 16) |
56           0xFF000000;  // Fill the alpha channel with ones
57}
58
59
60void copyNV21toRGB32(unsigned width, unsigned height,
61                     uint8_t* src,
62                     uint32_t* dst, unsigned dstStridePixels)
63{
64    // The NV21 format provides a Y array of 8bit values, followed by a 1/2 x 1/2 interleaved
65    // U/V array.  It assumes an even width and height for the overall image, and a horizontal
66    // stride that is an even multiple of 16 bytes for both the Y and UV arrays.
67    unsigned strideLum = align<16>(width);
68    unsigned sizeY = strideLum * height;
69    unsigned strideColor = strideLum;   // 1/2 the samples, but two interleaved channels
70    unsigned offsetUV = sizeY;
71
72    uint8_t* srcY = src;
73    uint8_t* srcUV = src+offsetUV;
74
75    for (unsigned r = 0; r < height; r++) {
76        // Note that we're walking the same UV row twice for even/odd luminance rows
77        uint8_t* rowY  = srcY  + r*strideLum;
78        uint8_t* rowUV = srcUV + (r/2 * strideColor);
79
80        uint32_t* rowDest = dst + r*dstStridePixels;
81
82        for (unsigned c = 0; c < width; c++) {
83            unsigned uCol = (c & ~1);   // uCol is always even and repeats 1:2 with Y values
84            unsigned vCol = uCol | 1;   // vCol is always odd
85            rowDest[c] = yuvToRgbx(rowY[c], rowUV[uCol], rowUV[vCol]);
86        }
87    }
88}
89
90
91void copyYV12toRGB32(unsigned width, unsigned height,
92                     uint8_t* src,
93                     uint32_t* dst, unsigned dstStridePixels)
94{
95    // The YV12 format provides a Y array of 8bit values, followed by a 1/2 x 1/2 U array, followed
96    // by another 1/2 x 1/2 V array.  It assumes an even width and height for the overall image,
97    // and a horizontal stride that is an even multiple of 16 bytes for each of the Y, U,
98    // and V arrays.
99    unsigned strideLum = align<16>(width);
100    unsigned sizeY = strideLum * height;
101    unsigned strideColor = align<16>(strideLum/2);
102    unsigned sizeColor = strideColor * height/2;
103    unsigned offsetU = sizeY;
104    unsigned offsetV = sizeY + sizeColor;
105
106    uint8_t* srcY = src;
107    uint8_t* srcU = src+offsetU;
108    uint8_t* srcV = src+offsetV;
109
110    for (unsigned r = 0; r < height; r++) {
111        // Note that we're walking the same U and V rows twice for even/odd luminance rows
112        uint8_t* rowY = srcY + r*strideLum;
113        uint8_t* rowU = srcU + (r/2 * strideColor);
114        uint8_t* rowV = srcV + (r/2 * strideColor);
115
116        uint32_t* rowDest = dst + r*dstStridePixels;
117
118        for (unsigned c = 0; c < width; c++) {
119            rowDest[c] = yuvToRgbx(rowY[c], rowU[c], rowV[c]);
120        }
121    }
122}
123
124
125void copyYUYVtoRGB32(unsigned width, unsigned height,
126                     uint8_t* src, unsigned srcStridePixels,
127                     uint32_t* dst, unsigned dstStridePixels)
128{
129    uint32_t* srcWords = (uint32_t*)src;
130
131    const int srcRowPadding32 = srcStridePixels/2 - width/2;  // 2 bytes per pixel, 4 bytes per word
132    const int dstRowPadding32 = dstStridePixels   - width;    // 4 bytes per pixel, 4 bytes per word
133
134    for (unsigned r = 0; r < height; r++) {
135        for (unsigned c = 0; c < width/2; c++) {
136            // Note:  we're walking two pixels at a time here (even/odd)
137            uint32_t srcPixel = *srcWords++;
138
139            uint8_t Y1 = (srcPixel)       & 0xFF;
140            uint8_t U  = (srcPixel >> 8)  & 0xFF;
141            uint8_t Y2 = (srcPixel >> 16) & 0xFF;
142            uint8_t V  = (srcPixel >> 24) & 0xFF;
143
144            // On the RGB output, we're writing one pixel at a time
145            *(dst+0) = yuvToRgbx(Y1, U, V);
146            *(dst+1) = yuvToRgbx(Y2, U, V);
147            dst += 2;
148        }
149
150        // Skip over any extra data or end of row alignment padding
151        srcWords += srcRowPadding32;
152        dst += dstRowPadding32;
153    }
154}
155
156
157void copyMatchedInterleavedFormats(unsigned width, unsigned height,
158                                   void* src, unsigned srcStridePixels,
159                                   void* dst, unsigned dstStridePixels,
160                                   unsigned pixelSize) {
161    for (unsigned row = 0; row < height; row++) {
162        // Copy the entire row of pixel data
163        memcpy(dst, src, width * pixelSize);
164
165        // Advance to the next row (keeping in mind that stride here is in units of pixels)
166        src = (uint8_t*)src + srcStridePixels * pixelSize;
167        dst = (uint8_t*)dst + dstStridePixels * pixelSize;
168    }
169}
170