Patent ID: 7936815
Filing Date: 2011-05-03
Classification: H04L,H04N

Abstract:
1. A method for client-executed search and retrieval of video information in a shared network resource, particularly search and retrieval of a desired frame (F x ) in a video stream, wherein the shared network resource particularly is Internet, an intranet or extranet, wherein the video information is stored in form of an encoded video file on HTTP servers in the shared network resource and accessed by clients via HTTP (Hypertext Transfer Protocol), wherein each client has a video decoder, wherein the encoded video file (Φ) is concatenated of multiple encoded video streams (IS) which contain the video signals of the video information compressed at an average bit rate t[c] which covers the client's expected channel bit rate σ, wherein each encoded video stream is divided into p packets (PC) with varying lengths q, wherein each packet (PC) comprises a header (H p ) and payload (PL), wherein the packets (PC) in a stream (IS) are provided in non-overlapping, successive groups (G) of two or more successive packets, such that each stream (IS) is divided in m groups of this kind, wherein the header (H PC ) of the first packet (PC k,1 ) of each group (G k , kεm) in addition to information of the number n of video frames which the packet contains and references to other packets and streams, is provided with information of a jump offset d j which corresponds to the combined lengths of the packets in the group and number j frames (F) which the jump offset d j and the first following packet (PC k+1,1 ) in the following group (G k+1 ) comprise, wherein the video file (Φ) further comprises a header (H Φ ) which contains information of the parameters of the streams (IS), wherein the information of the parameters of the streams (IS) includes the distances d k and d l , from the beginning of the video file (Φ) to respectively the beginning of each stream (IS) and to the end of the first packet (PC 1 ) in each stream (IS), wherein the transmission of video information takes place bandwidth-scalable over a version of HTTP which allows persistent connection and specification of byte range, and wherein the method is characterized by generating a request to the HTTP server for downloading the header (H pc ) of the first packet (PC k,1 ) in a group (G k , kεm) in a video stream (IS k , kεy), comparing the number x of the desired frame (F x ) with j, and if x εj, continuing the transmission and decoding of the video stream from and including the first frame of the packet wherein the frame (F x ) is located, this packet being one of the packets in the group (G k ) and the first packet (PC k+1,1 ) in the following group (G k+1 ), or, if x∉j, requesting the header (H PC ) of the first packet (PC k+1,1 ) in the following group (G k+1 ), and, as is the case, continuing the process until the desired frame (F x ) has been found, whereafter downloading and decoding of the stream (IS) are continued from and including the first frame in the packet where the desired frame (F x ) is located, such that a frame-based and packet-formatted search and retrieval of video information are realized with the use of a suitable version of HTTP as a transport protocol.