To better control resolution and aspect ratio of output videos, we recommend that
            you                use the values  CopyC#
CopyC#MaxWidth
 CopyC#
CopyC#MaxHeight
 CopyC#
CopyC#SizingPolicy
 CopyC#
CopyC#PaddingPolicy
 CopyC#
CopyC#DisplayAspectRatio
 CopyC#
CopyC#Resolution
 CopyC#
CopyC#AspectRatio
The display aspect ratio of the video in the output file. Valid values include:
 CopyC#
CopyC#auto
 CopyC#
CopyC#1:1
 CopyC#
CopyC#4:3
 CopyC#
CopyC#3:2
 CopyC#
CopyC#16:9
            If you specify  CopyC#
CopyC#auto
If you specify an aspect ratio for the output file that differs from aspect ratio of the input file, Elastic Transcoder adds pillarboxing (black bars on the sides) or letterboxing (black bars on the top and bottom) to maintain the aspect ratio of the active region of the video.
 Declaration Syntax
 Declaration Syntax| C# | 
public string AspectRatio { get; set; }