I am compressing video so i have come across following Export Presets
AVAssetExportPresetLowQuality
AVAssetExportPresetMediumQuality
AVAssetExportPresetHighestQuality
AVAssetExportPreset640x480
AVAssetExportPreset960x540
AVAssetExportPreset1280x720
AVAssetExportPreset1920x1080
AVAssetExportPreset3840x2160
I have read about all of them in apple documents and found that second list compressed in given fixed dimensions but found nothing about first list , i am confused that why it has 2 lists one with low, medium and high quality and other with fixed sizes and which one is better to use?