Adaptive streaming to multicast and constrained-fidelity constant bit rate encoding

Abstract

This disclosure describes and adaptive bit rate encoding and distribution techniques for conserving bandwidth usage in a channel. The invention comprises, an encoder or transcoder, a video fragmenter, a video-quality analyzer that output complexity values, a streaming server, a process by which individual fragments are selected for distribution, a video-quality threshold, and, optionally a bandwidth reclamation factor. A video-quality analyzer inspects any combination of the input and output of the encoder, transcoder, or fragmenter, and produces a video-quality metric for each fragment. A fragment-selection process responds to request from a client device. If the video-quality value of the fragment requested exceeds the video-quality threshold, a different fragment having a lower vide-quality value is selected instead. Otherwise, the fragment that would have been selected is selected. In some embodiments, the video-quality threshold can be dynamically adjusted to permit varying amounts of bandwidth reclamation.

1 . A method for joint management of video quality and bandwidth in adaptive bitrate streaming, the method comprising:
 encoding base band, via an encoder, or pre-encoding video to produce one or more bit streams;   creating chunks or fragments, via a fragmenter, consistent with one or more adaptive streaming protocols;   inspecting any combination of the input and output of the encoder, a transcoder, or fragmenter; and   producing a video-quality metric for each fragment,   wherein a fragment-selection process responds to request from a client device,   wherein if the video-quality value of the fragment requested exceeds the video-quality threshold, a different fragment having a lower vide-quality value is selected instead,   wherein otherwise, the fragment that would have been selected is selected.   
     
     
         2 . A method of  claim 1 , wherein individual fragments are recombined and repackaged into an unfragmented real time delivery protocol. 
     
     
         3 . The method of  claim 1 , wherein the video-quality threshold is dynamically adjusted to permit varying amounts of bandwidth reclamation. 
     
     
         4 . The method of  claim 1 , wherein the video-quality metric can be determined by inspection of bitstreams or fragments to discover quantization coefficients. 
     
     
         5 . The method of  claim 1 , wherein the video-quality metric can be determined by analysis of motion vectors. 
     
     
         6 . The method of  claim 1 , wherein the video-quality metric can be determined by analysis of the level of spatial detail. 
     
     
         7 . The method of  claim 1 , wherein the video-quality metric can be determined by one of full-reference, partial-reference, and no-reference video-quality assessment techniques. 
     
     
         8 . The method of  claim 1 , wherein the video-quality metric can be determined by analysis of coding complexity 
     
     
         9 . The method of  claim 1 , wherein the video-quality metric can be determined by a model of human visual perception 
     
     
         10 . The method of  claim 1 , wherein the video-quality metric is determined on-the-fly (at the same time or near the same time that a request for a fragment is processed.). 
     
     
         11 . The method  claim 1 , wherein the video-quality metric is determined ahead of time and stored in a manner that associates individual video-quality metrics with individual fragments. 
     
     
         12 . The method of  claim 1 , wherein individual fragments are recombined and repackaged into an MPEG2 transport stream. 
     
     
         13 . A system, the system comprising:
 an encoder or transcoder for receiving media content;   a video fragmenter, for dividing the content into fragments;   a video-quality analyzer that output complexity values for logically dividing the media content into fragments;   a streaming server,   a process by which individual fragments are selected for distribution,   a video-quality threshold.   
     
     
         14 . The system of  claim 12 , wherein the system further comprises a bandwidth reclamation factor. 
     
     
         15 . The system of  claim 12 , wherein the system further comprises a process of storing and associating video-quality metrics and fragments. 
     
     
         16 . The system of  claim 12 , the system further comprising a process for combining and/or repackaging individual fragments. 
     
     
         17 . The system of  claim 12 , the system further comprising a process for distributing fragments to HTTP clients. 
     
     
         18 . The system of  claim 12 , the system further comprising a process for distributing repackaged fragments to MPEG2 TS clients. 
     
     
         19 . The system of  claim 12 , the system further comprising a process for distributing to HTTP clients and to MPEG2 TS clients.