Question

重新渲染所有数据后，我能够将视频流缓冲区打开到openGL。但是视频被反转并仅在整个纹理的一部分上呈现。

我正在从流式视频中捕捉帧并将它们渲染为纹理。这是我的顶点着色器

    static const char *kVertexShaderString =
    "#version 100\n"
    "\n"
    "uniform mat4 uMVP; \n"
    "uniform vec3 uPosition; \n"
    "attribute vec3 aVertex; \n"
    "attribute vec4 aColor;\n"
    "varying vec4 vColor;\n"
    "varying vec3 vGrid;  \n"
"attribute vec2 v_TextCoord;\n"
"varying  vec2 texCoord;\n"
    "void main(void) { \n"
    "  vGrid = aVertex + uPosition; \n"
    "  vec4 pos = vec4(vGrid, 1.0); \n"
    "  vColor = aColor;"
    "  gl_Position = uMVP * pos; \n"
"   texCoord = v_TextCoord;\n"
    "    \n"
    "}\n";

和片段着色器

static const char *kPassThroughFragmentShaderString =
    "#version 100\n"
    "\n"
    "#ifdef GL_ES\n"
    "precision mediump float;\n"
    "#endif\n"
    "varying vec4 vColor;\n"
"uniform sampler2D v_Texture;\n"
"varying lowp vec2 texCoord;\n"
    "\n"
    "void main(void) { \n"
    "gl_FragColor = texture2D(v_Texture, texCoord);\n"
    "}\n";

更新我的顶点后如下

-1.0f, -1.0f, -2.0f,
1.0f, -1.0f, -2.0f,
1.0f, 1.0f, -2.0f,
-1.0f, -1.0f, -2.0f,
1.0f, 1.0f, -2.0f,
-1.0f, 1.0f, -2.0f,

要创建视频纹理，我已经使用了

     - (GLuint)createVideoTexture
{
    GLuint handle;
    glGenTextures(1, &handle);
    glBindTexture(GL_TEXTURE_2D, handle);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);


    return handle;
}

在屏幕上画画我正在使用

CVPixelBufferRef pixelBuffer;



// If we have a valid buffer, lock the base address of its pixel buffer
//        if (NULL != latestSampleBuffer) {
//            pixelBuffer = CMSampleBufferGetImageBuffer(latestSampleBuffer);
pixelBuffer = [self.mOutput copyPixelBufferForItemTime:_player.currentItem.currentTime itemTimeForDisplay:nil];
unsigned char* pixelBufferBaseAddress = NULL;


CVPixelBufferLockBaseAddress(pixelBuffer, 0);
/// Address where image buffer starts
uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(pixelBuffer);

/// Read image parameters
size_t width = CVPixelBufferGetWidth(pixelBuffer);
size_t height = CVPixelBufferGetHeight(pixelBuffer);
// CVPixelBufferRef rotatedBuffer = [self correctBufferOrientation:pixelBuffer];
pixelBufferBaseAddress = (unsigned char*)CVPixelBufferGetBaseAddress(pixelBuffer) ;

const size_t bytesPerRow = CVPixelBufferGetBytesPerRow(pixelBuffer);
if(pixelBufferBaseAddress != NULL){

    if (0 == _floorTexture) {
        _floorTexture = [self createVideoTexture];
    }



    glBindTexture(GL_TEXTURE0, _floorTexture);
    GLsizei bufferHeight =  (GLsizei) CVPixelBufferGetHeight(pixelBuffer);
    GLsizei bufferWidth =  (GLsizei) CVPixelBufferGetWidth(pixelBuffer);
    if (bytesPerRow / BYTES_PER_TEXEL == videoSize.width) {
        // No padding between lines of decoded video

        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (GLsizei) width, (GLsizei) height, 0, GL_BGRA_EXT, GL_UNSIGNED_BYTE, pixelBufferBaseAddress);
    }
    else {
        // Decoded video contains padding between lines.  We must not
        // upload it to graphics memory as we do not want to display it

        // Allocate storage for the texture (correctly sized)
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (GLsizei) width, (GLsizei) height, 0, GL_BGRA_EXT, GL_UNSIGNED_BYTE, NULL);

        // Now upload each line of texture data as a sub-image
        for (int i = 0; i < videoSize.height; ++i) {
         GLubyte* line = pixelBufferBaseAddress + i * bytesPerRow;
         glTexSubImage2D(GL_TEXTURE_2D, 0, 0, i, (GLsizei) videoSize.width, 1, GL_BGRA, GL_UNSIGNED_BYTE, line);
         }

        //glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, bufferWidth/BYTES_PER_TEXEL,bufferHeight, 0, GL_BGRA_EXT, GL_UNSIGNED_BYTE, pixelBufferBaseAddress);
    }
}




//glVertexAttribPointer(_texCoordSlot, 2, GL_FLOAT, GL_FALSE,sizeof(float) * 4, 0);
glVertexAttribPointer(_texCoordSlot, 2, GL_FLOAT, 4*2, false, (GLvoid*) (sizeof(float) * 4));

glDrawArrays(GL_TRIANGLES, 0, NUM_CUBE_VERTICES / 3);
glBindTexture(GL_TEXTURE0, 0);
CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);

if (pixelBuffer) {
    CFRelease(pixelBuffer);
}

我也为_texCoords尝试了不同的顶点和不同的glVertexAttribPointer。

任何人都可以帮助识别我的方法中的问题吗？

iOS纹理倒置了，它也仅在纹理的一部分上渲染？

0 个答案: