1/*
2 * Copyright (C) 2013 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 "colorspace.h"
18
19#include <jni.h>
20#include <stdint.h>
21
22typedef uint8_t uint8;
23typedef uint32_t uint32;
24typedef int32_t int32;
25
26// RGBA helper struct allows access as int and individual channels
27// WARNING: int value depends on endianness and should not be used to analyze individual channels.
28union Rgba {
29  uint32 color;
30  uint8 channel[4];
31};
32
33// Channel index constants
34static const uint8 kRed = 0;
35static const uint8 kGreen = 1;
36static const uint8 kBlue = 2;
37static const uint8 kAlpha = 3;
38
39// Clamp to range 0-255
40static inline uint32 clamp(int32 x) {
41  return x > 255 ? 255 : (x < 0 ? 0 : x);
42}
43
44// Convert YUV to RGBA
45// This uses the ITU-R BT.601 coefficients.
46static inline Rgba convertYuvToRgba(int32 y, int32 u, int32 v) {
47  Rgba color;
48  color.channel[kRed] = clamp(y + static_cast<int>(1.402 * v));
49  color.channel[kGreen] = clamp(y - static_cast<int>(0.344 * u + 0.714 * v));
50  color.channel[kBlue] = clamp(y + static_cast<int>(1.772 * u));
51  color.channel[kAlpha] = 0xFF;
52  return color;
53}
54
55// Colorspace conversion functions /////////////////////////////////////////////////////////////////
56void JNI_COLORSPACE_METHOD(nativeYuv420pToRgba8888)(
57    JNIEnv* env, jclass clazz, jobject input, jobject output, jint width, jint height) {
58  uint8* const pInput = static_cast<uint8*>(env->GetDirectBufferAddress(input));
59  Rgba* const pOutput = static_cast<Rgba*>(env->GetDirectBufferAddress(output));
60
61  const int size = width * height;
62
63  uint8* pInY = pInput;
64  uint8* pInU = pInput + size;
65  uint8* pInV = pInput + size + size / 4;
66  Rgba* pOutColor = pOutput;
67
68  const int u_offset = size;
69  const int v_offset = u_offset + size / 4;
70
71  for (int y = 0; y < height; y += 2) {
72    for (int x = 0; x < width; x += 2) {
73      int u, v, y1, y2, y3, y4;
74
75      y1 = pInY[0];
76      y2 = pInY[1];
77      y3 = pInY[width];
78      y4 = pInY[width + 1];
79
80      u = *pInU - 128;
81      v = *pInV - 128;
82
83      pOutColor[0] = convertYuvToRgba(y1, u, v);
84      pOutColor[1] = convertYuvToRgba(y2, u, v);
85      pOutColor[width] = convertYuvToRgba(y3, u, v);
86      pOutColor[width + 1] = convertYuvToRgba(y4, u, v);
87
88      pInY += 2;
89      pInU++;
90      pInV++;
91      pOutColor += 2;
92    }
93    pInY += width;
94    pOutColor += width;
95  }
96}
97
98void JNI_COLORSPACE_METHOD(nativeArgb8888ToRgba8888)(
99    JNIEnv* env, jclass clazz, jobject input, jobject output, jint width, jint height) {
100  Rgba* pInput = static_cast<Rgba*>(env->GetDirectBufferAddress(input));
101  Rgba* pOutput = static_cast<Rgba*>(env->GetDirectBufferAddress(output));
102
103  for (int i = 0; i < width * height; ++i) {
104    Rgba color_in = *pInput++;
105    Rgba& color_out = *pOutput++;
106    color_out.channel[kRed] = color_in.channel[kGreen];
107    color_out.channel[kGreen] = color_in.channel[kBlue];
108    color_out.channel[kBlue] = color_in.channel[kAlpha];
109    color_out.channel[kAlpha] = color_in.channel[kRed];
110  }
111}
112
113void JNI_COLORSPACE_METHOD(nativeRgba8888ToHsva8888)(
114    JNIEnv* env, jclass clazz, jobject input, jobject output, jint width, jint height) {
115  Rgba* pInput = static_cast<Rgba*>(env->GetDirectBufferAddress(input));
116  Rgba* pOutput = static_cast<Rgba*>(env->GetDirectBufferAddress(output));
117
118  int r, g, b, a, h, s, v, c_max, c_min;
119  float delta;
120  for (int i = 0; i < width * height; ++i) {
121    Rgba color_in = *pInput++;
122    Rgba& color_out = *pOutput++;
123    r = color_in.channel[kRed];
124    g = color_in.channel[kGreen];
125    b = color_in.channel[kBlue];
126    a = color_in.channel[kAlpha];
127
128    if (r > g) {
129      c_min = (g > b) ? b : g;
130      c_max = (r > b) ? r : b;
131    } else {
132      c_min = (r > b) ? b : r;
133      c_max = (g > b) ? g : b;
134    }
135    delta = c_max -c_min;
136
137    float scaler = 255 * 60 / 360.0f;
138    if (c_max == r) {
139      h = (g > b) ? static_cast<int>(scaler * (g - b) / delta) :
140          static_cast<int>(scaler * ((g - b) / delta + 6));
141    } else if (c_max == g) {
142      h = static_cast<int>(scaler * ((b - r) / delta + 2));
143    } else {  // Cmax == b
144      h = static_cast<int>(scaler * ((r - g) / delta + 4));
145    }
146    s = (delta == 0.0f) ? 0 : static_cast<unsigned char>(delta / c_max * 255);
147    v = c_max;
148
149    color_out.channel[kRed] = h;
150    color_out.channel[kGreen] = s;
151    color_out.channel[kBlue] = v;
152    color_out.channel[kAlpha] = a;
153  }
154}
155
156void JNI_COLORSPACE_METHOD(nativeRgba8888ToYcbcra8888)(
157    JNIEnv* env, jclass clazz, jobject input, jobject output, jint width, jint height) {
158  Rgba* pInput = static_cast<Rgba*>(env->GetDirectBufferAddress(input));
159  Rgba* pOutput = static_cast<Rgba*>(env->GetDirectBufferAddress(output));
160
161  int r, g, b;
162  for (int i = 0; i < width * height; ++i) {
163    Rgba color_in = *pInput++;
164    Rgba& color_out = *pOutput++;
165    r = color_in.channel[kRed];
166    g = color_in.channel[kGreen];
167    b = color_in.channel[kBlue];
168
169    color_out.channel[kRed] =
170        static_cast<unsigned char>((65.738 * r + 129.057 * g + 25.064 * b) / 256 + 16);
171    color_out.channel[kGreen] =
172        static_cast<unsigned char>((-37.945 * r - 74.494 * g + 112.439 * b) / 256 + 128);
173    color_out.channel[kBlue] =
174        static_cast<unsigned char>((112.439 * r - 94.154 * g - 18.285 * b) / 256 + 128);
175    color_out.channel[kAlpha] = color_in.channel[kAlpha];
176  }
177}
178