You can setup video with different resolutions. Use resolutions parameter in data source. This should be used only for normal videos (non-hls, non-dash) to setup different qualities of the original video.
var dataSource = BetterPlayerDataSource(BetterPlayerDataSourceType.network,
"https://file-examples-com.github.io/uploads/2017/04/file_example_MP4_480_1_5MG.mp4",
resolutions: {
"LOW":
"https://file-examples-com.github.io/uploads/2017/04/file_example_MP4_480_1_5MG.mp4",
"MEDIUM":
"https://file-examples-com.github.io/uploads/2017/04/file_example_MP4_640_3MG.mp4",
"LARGE":
"https://file-examples-com.github.io/uploads/2017/04/file_example_MP4_1280_10MG.mp4",
"EXTRA_LARGE":
"https://file-examples-com.github.io/uploads/2017/04/file_example_MP4_1920_18MG.mp4"
});