TBItmap scanline

[marcov]

Also, 24-bit pixel format is not supported on any of the today's video cards.

Not internally, but it is as texture. If you don't use alpha, it is better to keep it 24-bit, and only expand during uploading, otherwise you afaik waste videocard bandwidth (example: showing images from camera's)

And effective texture upload sizes aren't getting faster as quickly as rendering.

[LP]

Not internally, but it is as texture. If you don't use alpha, it is better to keep it 24-bit, and only expand during uploading, otherwise you afaik waste videocard bandwidth (example: showing images from camera's)

You are wrong. If the texture format is not supported by video card (which is the case of 24-bit pixel format on most video hardware), then expanding it before uploading does not reduce bandwidth, it only saves disk space. In addition, converting 24-bit format to 32-bit upon loading is quite slow as pixel data is not memory aligned so you'll be wasting a lot of CPU power just to load the image. I would argument exactly the opposite, huge disk space is cheap these days so you'd better off storing 32-bit pixel format instead of inducing massive overhead just to avoid saving one additional byte per pixel on disk (and there are other more efficient ways to save disk space, e.g. compression).

P.S. If you have doubts, please download DirectX SDK and use Caps Viewer to see that effectively, no 24-bit texture format is supported, either "internally" (whatever you meant by that) or not.