YUV到RGB转换和显示使用opengl es 2.0从android ndk使用着色器

我正在使用ffmpeg在Android上使用rtsp播放器来连接和解码视频流。我想使用OpenGL es 2.0将YUV框架转换为RGB框架并显示，但我被阻止(这是我第一次使用opengl)。

我会尽量解释我的问题。

从NDK android我初始化一个opengl上下文(从线程我想用来显示图像)使用这种方法：

//
EGLint attribs[] = {
        EGL_SURFACE_TYPE,EGL_WINDOW_BIT,EGL_RENDERABLE_TYPE,EGL_OPENGL_ES2_BIT,EGL_BLUE_SIZE,8,EGL_GREEN_SIZE,EGL_RED_SIZE,EGL_ALPHA_SIZE,EGL_NONE
};
EGLint contextAttrs[] = {
        EGL_CONTEXT_CLIENT_VERSION,2,EGL_NONE
};

LOGI("Initializing context");

if((display = eglGetdisplay(EGL_DEFAULT_disPLAY)) == EGL_NO_disPLAY)
{
    closeContext();
    return;
}

if(!eglInitialize(display,0))
{
    closeContext();
    return;
}

if(!eglChooseConfig(display,attribs,&config,1,&numConfigs))
{
    closeContext();
    return;
}

if(!eglGetConfigAttrib(display,config,EGL_NATIVE_VISUAL_ID,&format))
{
    closeContext();
    return;
}

ANativeWindow_setBuffersGeometry(window,format);

if(!(surface = eglCreateWindowSurface(display,window,0)))
{
    closeContext();
    return;
}

if(!(context = eglCreateContext(display,contextAttrs)))
{
    closeContext();
    return;
}

if(!eglMakeCurrent(display,surface,context))
{
    closeContext();
    return;
}

if(!eglQuerySurface(display,EGL_WIDTH,&width) || !eglQuerySurface(display,EGL_HEIGHT,&height))
{
    closeContext();
    return;
}

LOGI("EGLWIDTH : %d EGLHEIGHT : %d ",(int)width,(int)height);

isInitEGLContext = 1;

然后我使用这种方法设置图形：

//
//Load Vertex and Fragment Shader,attach shader and link program
 programId = createProgram(kVertexShader,kFragmentShader);
 LOGI("Program id : %d error :  %d",(int) programId,glGetError());


if(!programId)
{
    LOGI("Could not create program");
    return;
}
// get index of the generic vertex attribute bound to vPosition
positionObject = (int) glGetAttribLocation(programId,"vPosition");

 // get index of the generic vertex attribute bound to vTexCoord
texturePosition = (int) glGetAttribLocation(programId,"vTexCoord");

// get the location of yTexture within the program (corresponding to   program id)
yuv_texture_object[0] = glGetUniformlocation(programId,"yTexture");

// get the location of uTexture within the program
yuv_texture_object[1] = glGetUniformlocation(programId,"uTexture");

// get the location of vTexture within the program
yuv_texture_object[2] = glGetUniformlocation(programId,"vTexture");

// Setup width of each planes (display size)
stream_yuv_width[0] = 800;
stream_yuv_width[1] = 400;
stream_yuv_width[2] = 400;

// Setup height of each planes (display size)
stream_yuv_height[0] = 600;
stream_yuv_height[1] = 300;
stream_yuv_height[2] = 300;

//set the view port
glViewport(0,stream_yuv_width[0],stream_yuv_height[0]);
LOGI("glViewPort() %d ",glGetError());

我已经硬编码显示大小(现在)，直到我得到一些工作。

createProgram方法，加载着色器，创建程序，编译和链接着色器成功。

这是我的着色器：

const char kVertexShader[] =
"attribute vec4 vPosition;\n"
"attribute vec2 vTexCoord;\n"
"varying vec2 v_vTexCoord;\n"
"void main() {\n"
"gl_Position = vPosition;\n"
"v_vTexCoord = vTexCoord;\n"
"}\n";

const char kFragmentShader[] =
"precision mediump float; \n"
"varying vec2 v_vTexCoord;\n"
"uniform sampler2D yTexture;\n"
"uniform sampler2D uTexture;\n"
"uniform sampler2D vTexture;\n"
"void main() {\n"
"float nx,ny; \n"
"nx = v_vTexCoord.x; \n"
"ny = v_vTexCoord.y; \n"
"float y=texture2D(yTexture,v_vTexCoord).r;\n"
"float u=texture2D(uTexture,vec2(nx / 2.0,ny / 2.0)).r;\n"
"float v=texture2D(vTexture,ny / 2.0)).r;\n"
"y = 1.1643 * (y - 0.0625);\n"
"u = u - 0.5; \n"
"v = v - 0.5; \n"
"float r=y + 1.5958 * v;\n"
"float g=y - 0.39173 * u - 0.81290 * v;\n"
"float b=y + 2.017 * u;\n"
"gl_FragColor = vec4(r,g,b,1.0);\n"
"}\n";

const GLfloat kVertexinformation[] = {
    -1.0f,1.0f,// TexCoord 0 top left
    -1.0f,-1.0f,// TexCoord 1 bottom left
    1.0f,// TexCoord 2 bottom right
    1.0f,1.0f            // TexCoord 3 top right
};
const GLshort kTextureCoordinateinformation[] = {
    0,// TexCoord 0 top left
    0,// TexCoord 1 bottom left
    1,// TexCoord 2 bottom right
    1,0          // TexCoord 3 top right  
};
const gluint kStride = 0;//COORDS_PER_VERTEX * 4;
const GLshort kIndicesinformation[] = {
    0,3
};

然后我设置yuv纹理和渲染到纹理，此时yuv_width [i]和yuv_height [i]设置为正确的值：

void setupYUVTexture()
{
//Setup the pixel alignement
glPixelStorei(GL_UNPACK_ALIGNMENT,1);
LOGI("glPixelStorei() : %d ",glGetError());
int i = 0;

for(i = 0 ; i < 3 ; ++i)
{
    //Check if the texture already setup
    if(yuv_texture_id[i] != 0)
    {
        glDeleteTextures(1,&yuv_texture_id[i]);
        yuv_texture_id[i] = 0;
    }
    // Active the i texture
    glActiveTexture(GL_TEXTURE0 + i);

    //Generate the texture name
    glGenTextures(1,&yuv_texture_id[i]);

    // Bind the texture
    glBindTexture(GL_TEXTURE_2D,yuv_texture_id[i]);

   // Setup the texture parameters
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);  
    glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
    glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP_TO_EDGE);   
    glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP_TO_EDGE);


    //Define the texture image
    glTexImage2D(GL_TEXTURE_2D,GL_luminance,yuv_width[i],yuv_height[i],GL_UNSIGNED_BYTE,NULL);
    LOGI("glTexImage2D() %d ",glGetError());
}
}

void renderToTexture()
{
 // Generate framebuffer object name
    glGenFramebuffers(1,&frameBufferObject);
    //Bind the framebuffer
    glBindFramebuffer(GL_FRAMEBUFFER,frameBufferObject);


    //Generate render buffer object name
    glGenRenderbuffers(1,&renderBufferObject);

    //Bind render buffer
    glBindRenderbuffer(GL_RENDERBUFFER,renderBufferObject);

   //Create and initialize render buffer for display RGBA with the same size of the viewport
    glrenderbufferStorage(GL_RENDERBUFFER,GL_RGBA4,800,600);

    //Attach render buffer to frame buffer object
    glFramebufferRenderbuffer(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_RENDERBUFFER,renderBufferObject);

    //Attach y plane to frame buffer object
    glFramebufferTexture2D(GL_FRAMEBUFFER,GL_TEXTURE_2D,yuv_texture_id[0],0);

   //Attach u plane to frame buffer object
    glFramebufferTexture2D(GL_FRAMEBUFFER,yuv_texture_id[1],0);

     //Attach v plane to frame buffer object
    glFramebufferTexture2D(GL_FRAMEBUFFER,yuv_texture_id[2],0);

    // Bind the framebuffer
    glBindFramebuffer(GL_FRAMEBUFFER,0);

    //Check if the framebuffer is correctly setup
    GLint status = glCheckFramebufferStatus(GL_FRAMEBUFFER);

    if(status != GL_FRAMEBUFFER_COMPLETE)
    {
        LOGI(" FBO setting fault : %d ",status);
        return;
    }
}

要完成，我的画框方法：

void drawFrame()
{
LOGI("DrawFrame");
glBindFramebuffer(GL_FRAMEBUFFER,frameBufferObject);
printGLError("glBindFramebuffer");
gluseProgram(programId);
printGLError("gluseProgram");
int i = 0;
for(i = 0 ; i < 3 ; ++i)
{
    glActiveTexture(GL_TEXTURE0 + i);
    printGLError("glActiveTexture");

    glBindTexture(GL_TEXTURE_2D,yuv_texture_object[i]);
    printGLError("glBindTexture");

    gluniform1i(yuv_texture_object[i],i);
    printGLError("gluniform1i");            
    LOGI("Plan : %d Largeur : %d Hauteur : %d ",i,yuv_height[i]);
    glTexSubImage2D(GL_TEXTURE_2D,yuv_planes[i]);
            printGLError("glTexSubImage2D");

    }

    glVertexAttribPointer(positionObject,GL_FLOAT,GL_FALSE,kStride,kVertexinformation);
    printGLError("glVertexAttribPointer");

    glVertexAttribPointer(texturePosition,GL_SHORT,kTextureCoordinateinformation);
    printGLError("glVertexAttribPointer");

    glEnabLevertexAttribArray(positionObject);      
    printGLError("glVertexAttribArray");

    glEnabLevertexAttribArray(texturePosition);
    printGLError("glVertexAttribArray");

    glBindFramebuffer(GL_FRAMEBUFFER,0);
    printGLError("glBindFramebuffer");

    glDrawElements(GL_TRIANGLE_STRIP,6,GL_UNSIGNED_SHORT,kIndicesinformation);
    printGLError("glDrawElements");

    eglSwapBuffers(display,surface);
    printGLError("eglSwapBuffers");

}

一旦opengl纹理和其他必需的属性初始化，那么当一个帧被解码时，我将y缓冲区重新映射到yuv_planes [0]中的u缓冲区，yuv_planes [1]中的u缓冲区以及yuv_planes [2]中的v缓冲区。

一旦使用ffmpeg i正确地解码帧，我按以下顺序调用：
initContext()
– setupGraphics()
– setupYUVTexture()
– renderToTexture()

然后我调用drawFrame。当然，当一切都被初始化时，我在每个解码帧之后直接调用drawFrame。

有我现在的输出。

图像的大小是正确的，但现在我在这里阻止。我不明白为什么图像显示是绿色的！
有任何想法吗

解决方法

这是很多代码，很多事情可能会出错;)。要调试这些问题，我会一步步走。

>只输出红色(gl_FragColor = vec4(1.0,0.5,1.0))，以确保您的配置正常工作。>尝试以灰度输出每个纹理。 (gl_FragColor = vec4(y，y，y，1.0))>如果所有这些都工作，那么它很可能意味着你的yuv => rgb转换是错误的地方。>如果这不工作，那么我会怀疑纹理映射中的某些东西。仔细检查你的glTexSubImage2D调用。您可能需要通过不同的步幅或使用不同的坐标系。

YUV到RGB转换和显示使用opengl es 2.0从android ndk使用着色器

解决方法

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