Ensure the base layer is HDR (BT.2020). If the base layer is SDR (rare in P7, but possible in other profiles), converting to P8 requires tone mapping. For this specific P7->P8 request, we assume the Base Layer is already HDR.

The Old Way (Circa 2021-2023): Users had to extract the BL+EL+RPU, then use complex command lines to merge the enhancement layer into the base layer before converting to Profile 8. This often broke FEL content or resulted in sync issues.

The "New" Method (2024–Present): Thanks to the incredible updates to dovi_tool (by quietvoid) and mkvtoolnix, we can now convert Profile 7 to Profile 8 without losing the dynamic metadata, and without complex EL merging. The new method simply rewrites the RPU (Reference Processing Unit) to Profile 8 compatibility while keeping the video stream intact.

To understand the conversion, we first have to understand the container.