How change the aspect ratio to fit a different aspect ratio.

DaVinci Resolve (originally known as da Vinci Resolve) is a color correction and non-linear video editing (NLE) application for macOS, Windows, and Linux, originally developed by da Vinci Systems, and now developed by Blackmagic Design following its acquisition in 2009. In addition to the commercial version of the software (known as DaVinci Resolve Studio), Blackmagic Design also distributes a free edition, with reduced functionality, simply named DaVinci Resolve (formerly known as DaVinci Resolve Lite). The software includes modules for video editing, color correction, audio mixing/effects (including Fairlight), and visual effects (including Fusion). It can either be used as an intermediary between other NLE software and Digital Cinema Package (DCP) creation software, or as a standalone end-to-end video editing application. For content delivery to services such as Netflix, Resolve provides functionality to create and validate IMF (Interoperable Master Format, standardized by SMPTE[47]) packages, known as IMPs (which comprise multiple components, such as MXF content, a composition playlist (CPL), and XML package data]), without the use of separate DCP software. Compatible file formats include video formats such as AVI, MP4, QuickTime, DNxHD, and XAVC data exchange formats such as XML, EDL, AAF, DCP, MXF, and CinemaDNG; audio formats such as AAC, AIFF, and WAVE; and image formats such as RAW, OpenEXR, TIFF, DPX, R3D, JPEG, and JPEG 2000. Supported plug-in types include OpenFX,VST, and AU. As of version 12.2 (December 2015), Resolve includes support for the Hybrid Log-Gamma (HLG) standard for a high dynamic range. Other supported capabilities include OpenCL and Intel Quick Sync Video.