1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
/*
* Copyright 2017 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE 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.
*/
#import "RTCDefaultShader.h"
#if TARGET_OS_IPHONE
#import <OpenGLES/ES3/gl.h>
#else
#import <OpenGL/gl3.h>
#endif
#import "RTCOpenGLDefines.h"
#import "RTCShader.h"
#import "base/RTCLogging.h"
#include "absl/types/optional.h"
static const int kYTextureUnit = 0;
static const int kUTextureUnit = 1;
static const int kVTextureUnit = 2;
static const int kUvTextureUnit = 1;
// Fragment shader converts YUV values from input textures into a final RGB
// pixel. The conversion formula is from http://www.fourcc.org/fccyvrgb.php.
static const char kI420FragmentShaderSource[] =
SHADER_VERSION
"precision highp float;"
FRAGMENT_SHADER_IN " vec2 v_texcoord;\n"
"uniform lowp sampler2D s_textureY;\n"
"uniform lowp sampler2D s_textureU;\n"
"uniform lowp sampler2D s_textureV;\n"
FRAGMENT_SHADER_OUT
"void main() {\n"
" float y, u, v, r, g, b;\n"
" y = " FRAGMENT_SHADER_TEXTURE "(s_textureY, v_texcoord).r;\n"
" u = " FRAGMENT_SHADER_TEXTURE "(s_textureU, v_texcoord).r;\n"
" v = " FRAGMENT_SHADER_TEXTURE "(s_textureV, v_texcoord).r;\n"
" u = u - 0.5;\n"
" v = v - 0.5;\n"
" r = y + 1.403 * v;\n"
" g = y - 0.344 * u - 0.714 * v;\n"
" b = y + 1.770 * u;\n"
" " FRAGMENT_SHADER_COLOR " = vec4(r, g, b, 1.0);\n"
" }\n";
static const char kNV12FragmentShaderSource[] =
SHADER_VERSION
"precision mediump float;"
FRAGMENT_SHADER_IN " vec2 v_texcoord;\n"
"uniform lowp sampler2D s_textureY;\n"
"uniform lowp sampler2D s_textureUV;\n"
FRAGMENT_SHADER_OUT
"void main() {\n"
" mediump float y;\n"
" mediump vec2 uv;\n"
" y = " FRAGMENT_SHADER_TEXTURE "(s_textureY, v_texcoord).r;\n"
" uv = " FRAGMENT_SHADER_TEXTURE "(s_textureUV, v_texcoord).ra -\n"
" vec2(0.5, 0.5);\n"
" " FRAGMENT_SHADER_COLOR " = vec4(y + 1.403 * uv.y,\n"
" y - 0.344 * uv.x - 0.714 * uv.y,\n"
" y + 1.770 * uv.x,\n"
" 1.0);\n"
" }\n";
@implementation RTCDefaultShader {
GLuint _vertexBuffer;
GLuint _vertexArray;
// Store current rotation and only upload new vertex data when rotation changes.
absl::optional<RTCVideoRotation> _currentRotation;
GLuint _i420Program;
GLuint _nv12Program;
}
- (void)dealloc {
glDeleteProgram(_i420Program);
glDeleteProgram(_nv12Program);
glDeleteBuffers(1, &_vertexBuffer);
glDeleteVertexArrays(1, &_vertexArray);
}
- (BOOL)createAndSetupI420Program {
NSAssert(!_i420Program, @"I420 program already created");
_i420Program = RTCCreateProgramFromFragmentSource(kI420FragmentShaderSource);
if (!_i420Program) {
return NO;
}
GLint ySampler = glGetUniformLocation(_i420Program, "s_textureY");
GLint uSampler = glGetUniformLocation(_i420Program, "s_textureU");
GLint vSampler = glGetUniformLocation(_i420Program, "s_textureV");
if (ySampler < 0 || uSampler < 0 || vSampler < 0) {
RTCLog(@"Failed to get uniform variable locations in I420 shader");
glDeleteProgram(_i420Program);
_i420Program = 0;
return NO;
}
glUseProgram(_i420Program);
glUniform1i(ySampler, kYTextureUnit);
glUniform1i(uSampler, kUTextureUnit);
glUniform1i(vSampler, kVTextureUnit);
return YES;
}
- (BOOL)createAndSetupNV12Program {
NSAssert(!_nv12Program, @"NV12 program already created");
_nv12Program = RTCCreateProgramFromFragmentSource(kNV12FragmentShaderSource);
if (!_nv12Program) {
return NO;
}
GLint ySampler = glGetUniformLocation(_nv12Program, "s_textureY");
GLint uvSampler = glGetUniformLocation(_nv12Program, "s_textureUV");
if (ySampler < 0 || uvSampler < 0) {
RTCLog(@"Failed to get uniform variable locations in NV12 shader");
glDeleteProgram(_nv12Program);
_nv12Program = 0;
return NO;
}
glUseProgram(_nv12Program);
glUniform1i(ySampler, kYTextureUnit);
glUniform1i(uvSampler, kUvTextureUnit);
return YES;
}
- (BOOL)prepareVertexBufferWithRotation:(RTCVideoRotation)rotation {
if (!_vertexBuffer && !RTCCreateVertexBuffer(&_vertexBuffer, &_vertexArray)) {
RTCLog(@"Failed to setup vertex buffer");
return NO;
}
#if !TARGET_OS_IPHONE
glBindVertexArray(_vertexArray);
#endif
glBindBuffer(GL_ARRAY_BUFFER, _vertexBuffer);
if (!_currentRotation || rotation != *_currentRotation) {
_currentRotation = absl::optional<RTCVideoRotation>(rotation);
RTCSetVertexData(*_currentRotation);
}
return YES;
}
- (void)applyShadingForFrameWithWidth:(int)width
height:(int)height
rotation:(RTCVideoRotation)rotation
yPlane:(GLuint)yPlane
uPlane:(GLuint)uPlane
vPlane:(GLuint)vPlane {
if (![self prepareVertexBufferWithRotation:rotation]) {
return;
}
if (!_i420Program && ![self createAndSetupI420Program]) {
RTCLog(@"Failed to setup I420 program");
return;
}
glUseProgram(_i420Program);
glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + kYTextureUnit));
glBindTexture(GL_TEXTURE_2D, yPlane);
glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + kUTextureUnit));
glBindTexture(GL_TEXTURE_2D, uPlane);
glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + kVTextureUnit));
glBindTexture(GL_TEXTURE_2D, vPlane);
glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
}
- (void)applyShadingForFrameWithWidth:(int)width
height:(int)height
rotation:(RTCVideoRotation)rotation
yPlane:(GLuint)yPlane
uvPlane:(GLuint)uvPlane {
if (![self prepareVertexBufferWithRotation:rotation]) {
return;
}
if (!_nv12Program && ![self createAndSetupNV12Program]) {
RTCLog(@"Failed to setup NV12 shader");
return;
}
glUseProgram(_nv12Program);
glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + kYTextureUnit));
glBindTexture(GL_TEXTURE_2D, yPlane);
glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + kUvTextureUnit));
glBindTexture(GL_TEXTURE_2D, uvPlane);
glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
}
@end
|
