通过opengl es 2.0来实现yuv(NV21)的显示
基本思路参考如下文章，用opengles2.0 来实现yuv（NV21）的显示。
http://blog.csdn.net/fu_shuwu/article/details/72972312
public static String VERTEX_SHADER =
"attribute vec4 vPosition; \n"+
"attribute vec2 a_texCoord; \n"+
"varying vec2 tc; \n"+
"void main() \n"+
"{ \n"+
" gl_Position = vPosition; \n"+
" tc = a_texCoord; \n"+
"} \n";
public static String FRAG_SHADER =
"precision mediump float;\n"+
"varying vec2 tc; \n"+
"uniform sampler2D SamplerY; \n"+
"uniform sampler2D SamplerUV; \n"+
"const float PI = 3.14159265; \n"+
"const mat3 convertMat = mat3( 1.0, 1.0, 1.0, 0.0, -0.39465, 2.03211, 1.13983, -0.58060, 0.0 );\n"+
"void main(void) \n"+
"{ \n"+
"vec3 yuv; \n"+
"yuv.x = texture2D(SamplerY, tc).r; \n"+
"yuv.z = texture2D(SamplerUV, tc).r - 0.5; \n"+
"yuv.y = texture2D(SamplerUV, tc).a - 0.5; \n"+
"vec3 color = convertMat * yuv; \n"+
"vec4 mainColor = vec4(color, 1.0); \n"+
"gl_FragColor =mainColor; \n"+
"} \n";
//设置opengl 渲染的坐标系统，从[-1，1]
public static float squareVertices[] = { //rotate 90
1.0f, 1.0f,//rt
1.0f, -1.0f,//rb
-1.0f, 1.0f,//lt
-1.0f, -1.0f,//lb
};
//设置纹理基本坐标
public static float coordVertices[] = {
0.0f, 0.0f,//lb
1.0f, 0.0f,//rb
0.0f, 1.0f,//lt
1.0f, 1.0f,//rt
};
// 创建纹理
private void createTexture(int width, int height, int format, int[] textureId)
{
//创建纹理
GLES20.glGenTextures(1, textureId, 0);
//绑定纹理
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId[0]);
//设置纹理属性
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, format, width, height, 0, format, GLES20.GL_UNSIGNED_BYTE, null);
}
//GLSurface Render 子类相关部分
private void InitShader()
{
programHandleMain = util.createShaderProgram();
if ( programHandleMain != -1 )
{
//启动纹理
GLES20.glEnable(GLES20.GL_TEXTURE_2D);
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
// 获取VertexShader变量
aPositionMain = getShaderHandle(programHandleMain, "vPosition");
aTexCoordMain = getShaderHandle(programHandleMain, "a_texCoord");
// 获取FrameShader变量
uYTextureMain = getShaderHandle(programHandleMain, "SamplerY");
uUVTextureMain = getShaderHandle(programHandleMain, "SamplerUV");
// 使用滤镜着色器程序
GLES20.glUseProgram(programHandleMain);
//给变量赋值
GLES20.glUniform1i(uYTextureMain, 0);
GLES20.glUniform1i(uUVTextureMain, 1);
GLES20.glEnableVertexAttribArray(aPositionMain);
GLES20.glEnableVertexAttribArray(aTexCoordMain);
// 设置Vertex Shader数据
squareVertices.position(0);
GLES20.glVertexAttribPointer(aPositionMain, 2, GLES20.GL_FLOAT, false, 0, squareVertices);
coordVertices.position(0);
GLES20.glVertexAttribPointer(aTexCoordMain, 2, GLES20.GL_FLOAT, false, 0, coordVertices);
//创建yuv纹理
createTexture(frameWidth, frameHeight, GLES20.GL_LUMINANCE, Ytexture);
createTexture(frameWidth >> 1, frameHeight >> 1, GLES20.GL_LUMINANCE_ALPHA, UVtexture);
}
}
public void onDrawFrame(GL10 unused)
{
// 重绘背景色
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
if ( yBuf != null )
{
//y
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, Ytexture[0]);
GLES20.glTexSubImage2D(GLES20.GL_TEXTURE_2D,
0,
0,
0,
frameWidth,
frameHeight,
GLES20.GL_LUMINANCE,
GLES20.GL_UNSIGNED_BYTE,
yBuf);
//uv
GLES20.glActiveTexture(GLES20.GL_TEXTURE2);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, UVtexture[0]);
GLES20.glTexSubImage2D(GLES20.GL_TEXTURE_2D,
0,
0,
0,
frameWidth >> 1,
frameHeight >> 1,
GLES20.GL_LUMINANCE_ALPHA,
GLES20.GL_UNSIGNED_BYTE,
uvBuf);
}
//绘制
GLES20.glViewport(0, 0, viewWidth, viewHeight);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
}
public void onSurfaceCreated(GL10 unused, EGLConfig config)
{
//设置背景的颜色为黑色
GLES20.glClearColor(0.f, 0.f, 0.f, 1.0f);
InitShader();
}
public void onSurfaceChanged(GL10 unused, int width, int height)
{
viewWidth = width;
viewHeight = height;
GLES20.glViewport(0, 0, viewWidth, viewHeight);
}
camera preview那边一旦有数据callback frame 来，设置这样一个回调接口。
public void onNewFrames(byte[] data, int length)
{
if ( length != 0 )
{
yBuf.clear();
uvBuf.clear();
copyYUV(data, length);;//填充camera preview数据到opengl requestRender();//请求opengl 刷新屏幕一次
}
}
public void copyYUV(byte[] src,int ilen)
{
int len =(ilen<<1)/3;
yBuf.put(src,0,len).position(0);
uvBuf.put(src,len,len>>1).position(0);
}