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
|
/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
#include "FrameworkFormats.h"
// The purpose of YUVConverter is to use
// OpenGL shaders to convert YUV images to RGB
// images that can be displayed on screen.
// Doing this on the GPU can be much faster than
// on the CPU.
// Usage:
// 0. Have a current OpenGL context working.
// 1. Constructing the YUVConverter object will allocate
// OpenGL resources needed to convert, given the desired
// |width| and |height| of the buffer.
// 2. To convert a given YUV buffer of |pixels|, call
// the drawConvert method (with x, y, width, and height
// arguments depicting the region to convert).
// The RGB version of the YUV buffer will be drawn
// to the current framebuffer. To retrieve
// the result, if the user of the result is an OpenGL texture,
// it suffices to have that texture be the color attachment
// of the framebuffer object. Or, if you want the results
// on the CPU, call glReadPixels() after the call to drawConvert().
class YUVConverter {
public:
// call ctor when creating a gralloc buffer
// with YUV format
YUVConverter(int width, int height, FrameworkFormat format);
// destroy when ColorBuffer is destroyed
~YUVConverter();
// call when gralloc_unlock updates
// the host color buffer
// (rcUpdateColorBuffer)
void drawConvert(int x, int y, int width, int height, char* pixels);
private:
// For dealing with n-pixel-aligned buffers
void updateCutoffs(float width, float ywidth, float halfwidth, float cwidth);
FrameworkFormat mFormat;
// We need the following GL objects:
GLuint mVshader = 0;
GLuint mFshader = 0; // Fragment shader (does actual conversion)
GLuint mProgram = 0;
GLuint mVbuf = 0;
GLuint mIbuf = 0;
GLuint mYtex = 0;
GLuint mUtex = 0;
GLuint mVtex = 0;
// shader uniform locations
GLint mYWidthCutoffLoc = -1;
GLint mCWidthCutoffLoc = -1;
GLint mYSamplerLoc = -1;
GLint mUSamplerLoc = -1;
GLint mVSamplerLoc = -1;
float mYWidthCutoff = 1.0;
float mCWidthCutoff = 1.0;
};
|
