[SDL] Re: Problem with small images and YUV overlay on Windows

[Robert Folland]

On 8/5/05, Bill May <wmay at cisco.com> wrote:
> Robert Folland wrote:
> > Hi, I'm new to the forum.
> >
> > I'm using SDL to display YUV images, and it works fine on both
> > Linux and Windows for images over a certain size. But on Windows
> > I get problems with image size 176x144 (QCIF). It works fine on Linux.
> > Exactly the same source file is used for Linux and Windows.
> >
> > Larges sizes (eg 352x288 and 704x576) work fine on both platforms.
> >
> > Is there a problem with allocating areas with dimensions not divisible by 32
> > on Windows?
> 
> Sometime width != image->pitches[], especially with small sizes:
> 
>        if (width != m_image->pitches[0]) {
>          // The width is not equal to the size in the SDL buffers -
>          // we need to copy a row at a time
>          to = (uint8_t *)m_image->pixels[0];
>          from = y;
>          for (ix = 0; ix < height; ix++) {
>            memcpy(to, from, width);
>            to += m_image->pitches[0];
>            from += width;
>          }
>        } else {
>          // Copy entire Y frame
>          memcpy(m_image->pixels[0],
>                 y,
>                 bufsize);
>        }
> 

I'm now reading single bytes at a time from file, still the same problem.