SALVI is among the non-conventional ratio and differential vegetation indices.
SLAVI = (( Band 5))/(( Band 4+ Band 6)) for Landsat 8
SLAVI = (( Band 4))/(( Band 3+ Band 5)) for Landsat 7
This video used Landsat 8 image with the Layers 1, 2, 3, 4, 5, 6, and 7 stacked together. If you don't know how to layer stack watch the video https://www.youtube.com/watch?v=SCU8L...

This video is made after the individual bands are merged from Band 1 to 7.