theora dev - Mar 2005 - question from beginner (YCbCr to RGB)

Hello, i'm sorry for my English is not good.

I need help with convert yuv_buffer data (YCbCr) to RGB without SDL.
I write:
        BYTE *frame=new BYTE[YUV_BUFFER.y_height*YUV_BUFFER.y_width*4];

        for(int cc=0; cc<YUV_BUFFER.y_height*YUV_BUFFER.y_width; cc++)
        {

                frame[cc*4+0]=YUV_BUFFER.y[cc]+1.371*(YUV_BUFFER.v[cc]-128);
               
frame[cc*4+1]=YUV_BUFFER.y[cc]-0.698*(YUV_BUFFER.v[cc]-128)-0.336*(YUV_BUFFER.u[cc]-128);
                frame[cc*4+2]=YUV_BUFFER.y[cc]+1.732*(YUV_BUFFER.u[cc]-128);
                frame[cc*4+3]=255;

                //R = Y + 1.371(CR - 128)
                //G = Y - 0.698(CR - 128) - 0.336(CB - 128)
                //B = Y + 1.732(CB - 128)
                //A = 255

        }

But it seems to me that this code is incorrect, because don't use y_stride,
uv_height, uv_width, uv_stride fields.

File libtheora-1.0alpha4.pdf doesn't contain enough useful information
concerning these fields: y_stride, uv_height, uv_width, uv_stride.

Please, write an example-code for needeed YCbCr to RGB convertion or
give me link where wrote about that.

Thanks!
ls, russian enthusiast.

On Tue, Mar 15, 2005 at 10:06:42AM +0500, LS PLOTINKA wrote:
> I need help with convert yuv_buffer data (YCbCr) to RGB without SDL.
You need to loop over each row of the video buffer separately, and
advance the Y and U,V pointers by their respective strides between
rows. You're also not taking into account the chroma subsampling:
the CR and CB values may have only 1/2 or 1/4 the number of pixels
of the Y and RGB values.

HTH,
 -r