PVRTC specs?

Target Platforms Mobile
1

Hi,

I was looking desperately for getting specs on the PVRTC format but just couldn’t find any good ones. What I found was that apparently there is a 4bpp (bits per pixel) and 2 bpp mode.
What I wonder: Assuming I have 3 channels (RGB) does that make it a total of 3*4 bits per pixel or does it stay at 4 bit for RGB.
In that case, whats the memory size when using RGBA?

Also, does anybody know if it’s possible to have at least 2 2048x2048 sized textures loaded for use in a scene?

2

PVRTC is texture compression based on wavelet principles. There are two levels of compression: PVRTC4 which stores 4 bits per pixel and PVRTC2 which uses 2 bits per pixel.

On the PowerVR MBX the maximum texture size is 1024x1024. While the PowerVR SGX (in the 3GS devices) is 2048x2048. I believe the SGX uses a Unified Memory Architecture so there’s enough RAM for 2 2048x2048 textures.