For testing purposes, I have my MediaTailor Ad Decision Server set to be a static VAST tag, which points to an .mp4 video hosted on an S3 bucket that I control.
The frame-rate of this .mp4 ad in the VAST response is 23.976.
However, MediaTailor is transcoding the ad and delivering the .ts files at a frame-rate of 30.
Why is it doing this and how I can correct it?
MediaTailor currently transcodes all ad assets to 30 fps as best practice. This is because MediaTailor looks at the HLS master manifest for transcoding attributes. In the HLS master manifest, only resolution, bitrate, and codec are required fields. As a result, those are customized to a content stream while all other low level encoding fields are set to optimal defaults.