US Patent 9894130 Video quality enhancement

Technology for supporting dynamic adaptive streaming over hypertext transfer protocol (DASH) is disclosed. A quality metric may be determined, at a network device, for each of a plurality of media content segments in a defined representation that are described in a media presentation description (MPD) file. Media content segments may be identified in the defined representation in which the determined quality metric is below a selected threshold. The identified media content segments may be replaced with corresponding media content segments from a different representation that are described in the MPD file to form a modified MPD file, wherein the quality metric for the corresponding media content segments is greater than the selected threshold in order to provide a substantially constant quality playback of the media content segments in the defined representation.