Redream does not correctly interpret Non-Twiddled VQ Textures
Non-Twiddled VQ textures are a feature of the Dreamcast's PVR, which interpret the codebook of the VQ texture differently than the Twiddled version of these textures. In the non-twiddled variant, codebook entries are treated as a run of four horizontal pixels instead of as the usual square arrangement of those pixels.
An excellent test case for this is my VQ framebuffer example, which displays perlin noise scrolling from right to left on real Dreamcast hardware. Source code and a bootable CDI are available on my GitHub here:
https://github.com/maslevin/dreamcast-samples/tree/master/vqfb
Expected output can be found recorded on youtube here: