2012-03-26 120 views
3

我試圖用GLSL着色器將12位YUV幀(YUV420P)轉換爲24位RGB幀。 在Nvidia視頻卡上它工作正常,但在ATI視頻卡上它也在工作,但工作不正確。圖像不能正確繪製。顏色是不同的,圖像是全尺寸的四分之一。不同顯卡上的GLSL片段着色器

這裏是着色器的代碼:

uniform sampler2DRect y_texture, u_texture, v_texture; 
uniform float imageHeight; 

void main(void) { 
    float sx, sy, r, g, b, y, u, v; 
    sx = gl_TexCoord[0].x; 
    sy = imageHeight - gl_TexCoord[0].y; 
    y = texture2DRect(y_texture, vec2(sx/2.0, sy/2.0)).r; 
    u = texture2DRect(u_texture, vec2(sx/2.0, sy/2.0)).r; 
    v = texture2DRect(v_texture, vec2(sx/2.0, sy/2.0)).r; 
    y = 1.1643 * (y - 0.0625); 
    u = u - 0.5; 
    v = v - 0.5; 
    r = y + 1.5958 * v; 
    g = y - 0.39173 * u - 0.8129 * v; 
    b = y + 2.017 * u; 
    gl_FragColor = vec4(r, g, b, 1.0); 
} 

我怎樣才能修改(或創建新的)?

下面是示例代碼:

glEnable(GL_TEXTURE_RECTANGLE_ARB); 

//FrameHeight 
int i_imageHeight = glGetUniformLocation(handleProgram, "imageHeight"); 
glUniform1f(i_imageHeight, (float)frameHeight); 

//U 
glActiveTexture(GL_TEXTURE1); 
int i_u = glGetUniformLocationARB(handleProgram, "u_texture"); 
glUniform1iARB(i_u, 1); 
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 1); 

glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR); 
glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR); 
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); 
glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_LUMINANCE, frameWidth/2, frameHeight/2, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, uFrameData); 

//V 
glActiveTexture(GL_TEXTURE2); 
int i_v = glGetUniformLocationARB(handleProgram, "v_texture"); 
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 2); 
glUniform1iARB(i_v, 2); 

glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER,GL_LINEAR); 
glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER,GL_LINEAR); 
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); 
glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_LUMINANCE, frameWidth/2, frameHeight/2, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, vFrameData); 

//Y 
glActiveTexture(GL_TEXTURE0); 
int i_y = glGetUniformLocationARB(handleProgram, "y_texture"); 
glUniform1iARB(i_y, 3); 
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0); 

glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR); 
glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR); 
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); 
glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_LUMINANCE, frameWidth, frameHeight, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, yFrameData); 

//Draw 
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 

glBegin(GL_QUADS); 
    glTexCoord2i(0, 0); glVertex2i(0, 0); 
    glTexCoord2i(frameWidth, 0); glVertex2i(this->width, 0); 
    glTexCoord2i(frameWidth, frameHeight); glVertex2i(this->width, this->height); 
    glTexCoord2i(0, frameHeight); glVertex2i(0, this->height); 
glEnd(); 

glFlush(); 
SwapBuffers(hDC); 
+3

定義「不正確」。 – Bart 2012-03-26 09:44:07

+2

請同時發佈主機代碼。也許你在那裏使用GL_TEXTURE_2D而不是GL_TEXTURE_RECTANGLE_ARB? – sschuberth 2012-03-26 10:25:53

+0

我已經發布了代碼...同樣在着色器中: y = texture2DRect(y_texture,vec2(sx/2.0,sy/2.0))。r; 此行適用於ATI顯卡。在nVidia卡中: y = texture2DRect(y_texture,vec2(sx,sy))。r; – Alexander 2012-03-26 12:13:57

回答

0

您正在使用的紋理不正確。無處可見,您可以創建紋理對象(glGenTextures)。您需要先生成3個紋理對象,並將其傳遞給glBindTexture。相反,你正在做的是使用0,1和2索引,這也是不正確的,因爲0是不存在紋理的索引。我懷疑OpenGL在任何嘗試更改0紋理狀態時都會給出錯誤代碼。因此在兩次調用之間添加一些glError()檢查。從技術上講,你的程序是GL上的「未定義行爲」的一個例子,所以應該預期不同硬件/驅動程序的執行不同(直到你修復它)。

供您參考,紋理管理應該是這樣的:

GLuint textures[3]; 
glGenTextures(3,textures); 
... 
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, textures[1]); 
//initialize state of t1 
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, textures[2]); 
//initialize state of t2 
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, textures[0]); 
//initialize state of t0 

注意,你對glUniform和glActiveTexture通話仍然是正確的,所以沒必要來解決這些問題。