With multimedia redirection (MMR), the multimedia stream is decoded on the client system. The client system plays the media content so that the load on the ESXi host is reduced.

Remote desktops
For information about operating system requirements and other software requirements and configuration settings, see the topics about Windows Media Multimedia Redirection in the Configuring Remote Desktop Features in Horizon document.
Horizon Client computer or client access device

Windows 10

Supported media formats
Media formats that Windows Media Player supports, for example: M4V; MOV; MP4; MPEG-4 Part 2; WMV 7, 8, and 9; WMA; AVI; ACE; MP3.
MP3 is not supported when using MMS and RTSP.
Note: DRM-protected content is not redirected through Windows Media MMR.