Android上使用OpenGLES2.0显示YUV数据
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在Android上用OpenGLES来显示YUV图像，之所以这样做，是因为：
1.android本身也不能直接显示YUV图像，YUV转成RGB还是必要的；
2.YUV手动转RGB会占用大量的CPU资源，如果以这样的形式播放视频，手机会很热，所以我们尽量让GPU来做这件事；
3.OpenGLES是Android集成到自身框架里的第三方库，它有很多的可取之处。
博主的C/C++不是很好，所以整个过程是在Java层实现的，大家见笑，我主要参考（但不限于）以下文章，十分感谢这些朋友的分享：
1. http://blog.csdn.NET/xiaoguaihai/article/details/8672631
2.http://chenshun87.blog.163.com/blog/static/18859389201232011727615/
3.http://blog.csdn.net/ypist/article/details/8950903
4.http://blog.csdn.net/wanglang3081/article/details/8480281
5.http://blog.csdn.net/xdljf/article/details/7178620
一、首先我先说一下这个解决方案是怎么运行的，给大家一个概念
1.显示在哪 -> GLSurfaceVIew
2.谁来把数据贴到GLSurfaceVIew上 -> Renderer
3.谁来负责YUV数据转换成RGB -> GL中的Program/Shader
一句话说明白就是：GL的Program/Shader把用户传过来的YUV数据，转换成RGB数据后，通过Renderer贴在GLSurfaceView上。
二、怎么检查你的手机是不是支持GLES2.0呢，使用下面的代码段就行了：
一般的手机，都是会支持GLES2.0的，大家不必担心。
public static boolean detectOpenGLES20(Context context) { ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE); ConfigurationInfo info = am.getDeviceConfigurationInfo(); return (info.reqGlEsVersion >= 0x20000); }
三、开搞
A 先要有一个GLSurfaceView，把它放入你的布局中就好了。
找到这个家伙，对它进行简单的设置，并为它设置一个Renderer。
Renderer的作用就是在GLSurfaceView上画出图像。
B 再就是看下GLFrameRenderer怎么来写了
1 public class GLFrameRenderer implements Renderer { 2 3 private ISimplePlayer mParentAct; //请无视之 4 private GLSurfaceView mTargetSurface; 5 private GLProgram prog = new GLProgram(0); 6 private int mVideoWidth = -1, mVideoHeight = -1; 7 private ByteBuffer y; 8 private ByteBuffer u; 9 private ByteBuffer v; 10 11 public GLFrameRenderer(ISimplePlayer callback, GLSurfaceView surface) { 12 mParentAct = callback; //请无视之 13 mTargetSurface = surface; 14 } 15 16 @Override 17 public void onSurfaceCreated(GL10 gl, EGLConfig config) { 18 Utils.LOGD("GLFrameRenderer :: onSurfaceCreated"); 19 if (!prog.isProgramBuilt()) { 20 prog.buildProgram(); 21 Utils.LOGD("GLFrameRenderer :: buildProgram done"); 22 } 23 } 24 25 @Override 26 public void onSurfaceChanged(GL10 gl, int width, int height) { 27 Utils.LOGD("GLFrameRenderer :: onSurfaceChanged"); 28 GLES20.glViewport(0, 0, width, height); 29 } 30 31 @Override 32 public void onDrawFrame(GL10 gl) { 33 synchronized (this) { 34 if (y != null) { 35 // reset position, have to be done 36 y.position(0); 37 u.position(0); 38 v.position(0); 39 prog.buildTextures(y, u, v, mVideoWidth, mVideoHeight); 40 GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f); 41 GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT); 42 prog.drawFrame(); 43 } 44 } 45 } 46 47 /** 48 * this method will be called from native code, it happens when the video is about to play or 49 * the video size changes. 50 */ 51 public void update(int w, int h) { 52 Utils.LOGD("INIT E"); 53 if (w > 0 && h > 0) { 54 if (w != mVideoWidth && h != mVideoHeight) { 55 this.mVideoWidth = w; 56 this.mVideoHeight = h; 57 int yarraySize = w * h; 58 int uvarraySize = yarraySize / 4; 59 synchronized (this) { 60 y = ByteBuffer.allocate(yarraySize); 61 u = ByteBuffer.allocate(uvarraySize); 62 v = ByteBuffer.allocate(uvarraySize); 63 } 64 } 65 } 66 67 mParentAct.onPlayStart(); //请无视之 68 Utils.LOGD("INIT X"); 69 } 70 71 /** 72 * this method will be called from native code, it‘s used for passing yuv data to me. 73 */ 74 public void update(byte[] ydata, byte[] udata, byte[] vdata) { 75 synchronized (this) { 76 y.clear(); 77 u.clear(); 78 v.clear(); 79 y.put(ydata, 0, ydata.length); 80 u.put(udata, 0, udata.length); 81 v.put(vdata, 0, vdata.length); 82 } 83 84 // request to render 85 mTargetSurface.requestRender(); 86 } 87 }
代码很简单，Renderer主要处理这么几个事：
1.Surface create的时候，我初始化了一些需要用到的Program/Shader，因为马上就要用到它们了；
2.Surface change的时候，重置一下画面；
3.onDrawFrame()时，把数据真正地“画”上去；
4.至于两个update方法，是用来把图像的宽高/数据传过来的。
C 看GLProgram是怎么写的，它的作用是向Renderer提供计算单元，你所有对数据的处理，都在这儿了。
1 public boolean isProgramBuilt() { 2 return isProgBuilt; 3 } 4 5 public void buildProgram() { 6 createBuffers(_vertices, coordVertices); 7 if (_program <= 0) { 8 _program = createProgram(VERTEX_SHADER, FRAGMENT_SHADER); 9 } 10 Utils.LOGD("_program = " + _program); 11 12 /* 13 * get handle for "vPosition" and "a_texCoord" 14 */ 15 _positionHandle = GLES20.glGetAttribLocation(_program, "vPosition"); 16 Utils.LOGD("_positionHandle = " + _positionHandle); 17 checkGlError("glGetAttribLocation vPosition"); 18 if (_positionHandle == -1) { 19 throw new RuntimeException("Could not get attribute location for vPosition"); 20 } 21 _coordHandle = GLES20.glGetAttribLocation(_program, "a_texCoord"); 22 Utils.LOGD("_coordHandle = " + _coordHandle); 23 checkGlError("glGetAttribLocation a_texCoord"); 24 if (_coordHandle == -1) { 25 throw new RuntimeException("Could not get attribute location for a_texCoord"); 26 } 27 28 /* 29 * get uniform location for y/u/v, we pass data through these uniforms 30 */ 31 _yhandle = GLES20.glGetUniformLocation(_program, "tex_y"); 32 Utils.LOGD("_yhandle = " + _yhandle); 33 checkGlError("glGetUniformLocation tex_y"); 34 if (_yhandle == -1) { 35 throw new RuntimeException("Could not get uniform location for tex_y"); 36 } 37 _uhandle = GLES20.glGetUniformLocation(_program, "tex_u"); 38 Utils.LOGD("_uhandle = " + _uhandle); 39 checkGlError("glGetUniformLocation tex_u"); 40 if (_uhandle == -1) { 41 throw new RuntimeException("Could not get uniform location for tex_u"); 42 } 43 _vhandle = GLES20.glGetUniformLocation(_program, "tex_v"); 44 Utils.LOGD("_vhandle = " + _vhandle); 45 checkGlError("glGetUniformLocation tex_v"); 46 if (_vhandle == -1) { 47 throw new RuntimeException("Could not get uniform location for tex_v"); 48 } 49 50 isProgBuilt = true; 51 } 52 53 /** 54 * build a set of textures, one for Y, one for U, and one for V. 55 */ 56 public void buildTextures(Buffer y, Buffer u, Buffer v, int width, int height) { 57 boolean videoSizeChanged = (width != _video_width || height != _video_height); 58 if (videoSizeChanged) { 59 _video_width = width; 60 _video_height = height; 61 Utils.LOGD("buildTextures videoSizeChanged: w=" + _video_width + " h=" + _video_height); 62 } 63 64 // building texture for Y data 65 if (_ytid < 0 || videoSizeChanged) { 66 if (_ytid >= 0) { 67 Utils.LOGD("glDeleteTextures Y"); 68 GLES20.glDeleteTextures(1, new int[] { _ytid }, 0); 69 checkGlError("glDeleteTextures"); 70 } 71 // GLES20.glPixelStorei(GLES20.GL_UNPACK_ALIGNMENT, 1); 72 int[] textures = new int[1]; 73 GLES20.glGenTextures(1, textures, 0); 74 checkGlError("glGenTextures"); 75 _ytid = textures[0]; 76 Utils.LOGD("glGenTextures Y = " + _ytid); 77 } 78 GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, _ytid); 79 checkGlError("glBindTexture"); 80 GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_LUMINANCE, _video_width, _video_height, 0, 81 GLES20.GL_LUMINANCE, GLES20.GL_UNSIGNED_BYTE, y); 82 checkGlError("glTexImage2D"); 83 GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST); 84 GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR); 85 GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE); 86 GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE); 87 88 // building texture for U data 89 if (_utid < 0 || videoSizeChanged) { 90 if (_utid >= 0) { 91 Utils.LOGD("glDeleteTextures U"); 92 GLES20.glDeleteTextures(1, new int[] { _utid }, 0); 93 checkGlError("glDeleteTextures"); 94 } 95 int[] textures = new int[1]; 96 GLES20.glGenTextures(1, textures, 0); 97 checkGlError("glGenTextures"); 98 _utid = textures[0]; 99 Utils.LOGD("glGenTextures U = " + _utid); 100 } 101 GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, _utid); 102 GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_LUMINANCE, _video_width / 2, _video_height / 2, 0, 103 GLES20.GL_LUMINANCE, GLES20.GL_UNSIGNED_BYTE, u); 104 GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST); 105 GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR); 106 GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE); 107 GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE); 108 109 // building texture for V data 110 if (_vtid < 0 || videoSizeChanged) { 111 if (_vtid >= 0) { 112 Utils.LOGD("glDeleteTextures V"); 113 GLES20.glDeleteTextures(1, new int[] { _vtid }, 0); 114 checkGlError("glDeleteTextures"); 115 } 116 int[] textures = new int[1]; 117 GLES20.glGenTextures(1, textures, 0); 118 checkGlError("glGenTextures"); 119 _vtid = textures[0]; 120 Utils.LOGD("glGenTextures V = " + _vtid); 121 } 122 GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, _vtid); 123 GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_LUMINANCE, _video_width / 2, _video_height / 2, 0, 124 GLES20.GL_LUMINANCE, GLES20.GL_UNSIGNED_BYTE, v); 125 GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST); 126 GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR); 127 GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE); 128 GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE); 129 } 130 131 /** 132 * render the frame 133 * the YUV data will be converted to RGB by shader. 134 */ 135 public void drawFrame() { 136 GLES20.glUseProgram(_program); 137 checkGlError("glUseProgram"); 138 139 GLES20.glVertexAttribPointer(_positionHandle, 2, GLES20.GL_FLOAT, false, 8, _vertice_buffer); 140 checkGlError("glVertexAttribPointer mPositionHandle"); 141 GLES20.glEnableVertexAttribArray(_positionHandle); 142 143 GLES20.glVertexAttribPointer(_coordHandle, 2, GLES20.GL_FLOAT, false, 8, _coord_buffer); 144 checkGlError("glVertexAttribPointer maTextureHandle"); 145 GLES20.glEnableVertexAttribArray(_coordHandle); 146 147 // bind textures 148 GLES20.glActiveTexture(_textureI); 149 GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, _ytid); 150 GLES20.glUniform1i(_yhandle, _tIindex); 151 152 GLES20.glActiveTexture(_textureII); 153 GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, _utid); 154 GLES20.glUniform1i(_uhandle, _tIIindex); 155 156 GLES20.glActiveTexture(_textureIII); 157 GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, _vtid); 158 GLES20.glUniform1i(_vhandle, _tIIIindex); 159 160 GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4); 161 GLES20.glFinish(); 162 163 GLES20.glDisableVertexAttribArray(_positionHandle); 164 GLES20.glDisableVertexAttribArray(_coordHandle); 165 } 166 167 /** 168 * create program and load shaders, fragment shader is very important. 169 */ 170 public int createProgram(String vertexSource, String fragmentSource) { 171 // create shaders 172 int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexSource); 173 int pixelShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource); 174 // just check 175 Utils.LOGD("vertexShader = " + vertexShader); 176 Utils.LOGD("pixelShader = " + pixelShader); 177 178 int program = GLES20.glCreateProgram(); 179 if (program != 0) { 180 GLES20.glAttachShader(program, vertexShader); 181 checkGlError("glAttachShader"); 182 GLES20.glAttachShader(program, pixelShader); 183 checkGlError("glAttachShader"); 184 GLES20.glLinkProgram(program); 185 int[] linkStatus = new int[1]; 186 GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linkStatus, 0); 187 if (linkStatus[0] != GLES20.GL_TRUE) { 188 Utils.LOGE("Could not link program: ", null); 189 Utils.LOGE(GLES20.glGetProgramInfoLog(program), null); 190 GLES20.glDeleteProgram(program); 191 program = 0; 192 } 193 } 194 return program; 195 } 196 197 /** 198 * create shader with given source. 199 */ 200 private int loadShader(int shaderType, String source) { 201 int shader = GLES20.glCreateShader(shaderType); 202 if (shader != 0) { 203 GLES20.glShaderSource(shader, source); 204 GLES20.glCompileShader(shader); 205 int[] compiled = new int[1]; 206 GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compiled, 0); 207 if (compiled[0] == 0) { 208 Utils.LOGE("Could not compile shader " + shaderType + ":", null); 209 Utils.LOGE(GLES20.glGetShaderInfoLog(shader), null); 210 GLES20.glDeleteShader(shader); 211 shader = 0; 212 } 213 } 214 return shader; 215 } 216 217 /** 218 * these two buffers are used for holding vertices, screen vertices and texture vertices. 219 */ 220 private void createBuffers(float[] vert, float[] coord) { 221 _vertice_buffer = ByteBuffer.allocateDirect(vert.length * 4); 222 _vertice_buffer.order(ByteOrder.nativeOrder()); 223 _vertice_buffer.asFloatBuffer().put(vert); 224 _vertice_buffer.position(0); 225 226 if (_coord_buffer == null) { 227 _coord_buffer = ByteBuffer.allocateDirect(coord.length * 4); 228 _coord_buffer.order(ByteOrder.nativeOrder()); 229 _coord_buffer.asFloatBuffer().put(coord); 230 _coord_buffer.position(0); 231 } 232 } 233 234 private void checkGlError(String op) { 235 int error; 236 while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) { 237 Utils.LOGE("***** " + op + ": glError " + error, null); 238 throw new RuntimeException(op + ": glError " + error); 239 } 240 } 241 242 private static float[] squareVertices = { -1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f, }; // fullscreen 243 244 private static float[] coordVertices = { 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, };// whole-texture 245 246 private static final String VERTEX_SHADER = "attribute vec4 vPosition;\n" + "attribute vec2 a_texCoord;\n" 247 + "varying vec2 tc;\n" + "void main() {\n" + "gl_Position = vPosition;\n" + "tc = a_texCoord;\n" + "}\n"; 248 249 private static final String FRAGMENT_SHADER = "precision mediump float;\n" + "uniform sampler2D tex_y;\n" 250 + "uniform sampler2D tex_u;\n" + "uniform sampler2D tex_v;\n" + "varying vec2 tc;\n" + "void main() {\n" 251 + "vec4 c = vec4((texture2D(tex_y, tc).r - 16./255.) * 1.164);\n" 252 + "vec4 U = vec4(texture2D(tex_u, tc).r - 128./255.);\n" 253 + "vec4 V = vec4(texture2D(tex_v, tc).r - 128./255.);\n" + "c += V * vec4(1.596, -0.813, 0, 0);\n" 254 + "c += U * vec4(0, -0.392, 2.017, 0);\n" + "c.a = 1.0;\n" + "gl_FragColor = c;\n" + "}\n"; 255
这里面代码比较复杂，我在这里稍作解释：
1.首先，buildProgram()目的要生成一个program，作用是用来将YUV->RGB，其中用到了2个shader（shader就相当于一个小运算器，它运行一段代码），第1个shader运行VERTEX_SHADER里的代码，目的是将坐标作为参数传入第2个shader；第2个shader来做YUV->RGB的运算。
2.buildTextures()是要生成3个贴图，分别为了显示R/G/B数据，三个贴图重合在一起，显示出来的就是彩色的图片。
3.drawFrame()是使用program来做运算，并真正去做画这个动作了。
至此，就可以将YUV图片也好，视频也可，给显示在Android上了，而且速度不慢哦！希望能帮到大家。
相关代码下载链接：
http://download.csdn.net/detail/ueryueryuery/7144851
本文来自：http://blog.csdn.net/ueryueryuery/article/details/17608185#comments
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