Android上使用OpenGLES2.0显示YUV数据

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Android上使用OpenGLES2.0显示YUV数据

2024-08-16 05:34:15 221人阅读

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。

mGLSurface = (GLFrameSurface) findViewById(R.id.glsurface);  mGLSurface.setEGLContextClientVersion(2);  mGLFRenderer = new GLFrameRenderer(this, mGLSurface);  mGLSurface.setRenderer(mGLFRenderer);

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 }

View Code

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

View Code

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。

首页 > 代码库 > Android上使用OpenGLES2.0显示YUV数据

Android上使用OpenGLES2.0显示YUV数据

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