This is a full virtual machine image containing a complete OS with the Alta software installed that can be imported into your VirtualBox based hypervisor. Subsequent software updates can typically be downloaded separately and do not require downloading this full image again.
This image is the Alta TS image, which receives MPEG-2 TS streams and outputs MPEG-2 TS streams with ancillary data stream including closed captioning and other data sources in various different formats.
This base VM includes Alta Core Components v2.68 and Web Components v2.44.
For the Alta image for use with Smpte-2110, see the main Alta 2110 product page - this is a separate base VM.