The format of texture used now is .pvr.ccz which is packed using TexturePacker. There is one 2048*2048, one 1024*2048, two 1024*1024 and some other small textures. It seems the memory is exhausting! RGBA4 is not work on WP8, that it will be converted to RGBA8 in the memory.
So how to use compressed texture to reduce the memory usage? Thanks!