74 results about "Video multicast" patented technology

Layered Video Multicast with Retransmissions (LVMR) is a system for distributing video content using layered coding over the Internet. The two key contributions of the system are (1) improving the quality of reception within each layer by retransmitting lost packets given an upper bound on recovery time and applying an adaptive playback point scheme to help achieve more successful retransmission, and (2) adapting to network congestion and heterogeneity using a hierarchical rate control mechanism. A hierarchical rate control system and method is disclosed for regulating the flow of video information in a network by establishing subnet agents for each subnet, and by establishing intermediate agents for each domain. The subnet agents gather information concerning add-layer experiments conducted by receivers in a subnet, and the information is provided to intermediate agents of the domains for regulating data traffic.

The client application provides VCR functionality in a data-centered video multicast network (36) through active prefetching of the fragments from broadcast channels. The player (10) has a user interface (12) that supports a plurality of VCR functions (14–26). Plural buffers (32) and their associated loaders (34) download video data under control of a manager module (38). The manager module accesses the playback pointer (40) and employs feasible point calculation module (42) to cause the loaders to selectively download segments so that VCR functions can be supported while maintaining continuous playback after the VCR function is performed.

A method and apparatus for estimating packet loss rate are described including calculating a real packet loss rate in a time slot at the end of the time slot, estimating average packet loss rate for a subsequent time slot, estimating variance of packet loss rate for the subsequent time slot and estimating the packet loss rate for the subsequent time slot. A method and apparatus and also described for dynamically allocating available bandwidth for video multicast including selecting an intra-frame rate, determining a packet loss rate threshold, receiving user topology information, receiving channel conditions for each user, determining an optimal operation point for encoding and transmitting video frames in a subsequent time slot, adapting dynamically quantization parameters and a forward error correction code rate, encoding the video frames using the quantization parameters and applying forward error correction code with the forward error correction code rate to data packets of the video frames to generate forward error correction packets.

Improved distribution of video information in an infrastructure-based wireless network is provided. A wireless channel condition between the video server node and each of the plurality of receiver nodes is measured (or accepted, or otherwise determined). Each of the plurality of receiver nodes are assigned into one of a first group and a second group using the measured wireless channel conditions, wherein receiver nodes assigned to the first group have, on average (e.g., on average over time), a better measured wireless channel condition than that of receiver nodes assigned to the second group. At least some (e.g., one or more) of the receiver nodes of the first group of nodes are selected to serve as relay nodes. Video information (e.g., N layers) is then transmitted wirelessly from the video server node for reception by each of the receiver nodes assigned to the first group. Each of the selected relay nodes then transmit at least a part (e.g., M≦N layers) of the video information for reception by at least some of the receiver nodes of the second group such that the relay nodes collectively transmit the at least a part of the video information to all of the receiver nodes of the second group. Receiver nodes assigned to the first group receive, decode and render the received video information. Similarly, receiver nodes assigned to the second group, receive, decode and render the received at least a part of the video information. The receiver nodes assigned to the second group may also use the (1) video information transmitted wirelessly by the source node and/or (2) copies of the at least a part of the video information transmitted by other relay nodes (that is, relay nodes not assigned to it), to the extent such information is received.

The disclosed method is realized based on video multicast by using Internet group management protocol (IGMP) Proxy/Snooping. The method includes following operations: (1) for each optical network unit (ONU), the system defines their ID i.e. ONU ID, and defines each multicast ID for multicast group of video service stream in different content; (2) using structure from point to multipoint of Ethernet passive optical network (EPON), the method combines IGMP with down going broadcast mechanism of EPON network to realize single copy multicast of same video service stream in EPON network. Overcoming disadvantages of low use ratio of multicast bandwidth, the method reproduces only one piece of video service stream for each group on OLT for users in same group share. The invention saves network bandwidth, lowers network load. Features are: easy of implementation, forward compactable and easy to realize intercommunication with multicast protocol of data network IGMP.

A federated media server system. The federated media server system may include a plurality of media servers. A first media server may be coupled to a second media server over a network. The first media server may also be coupled to a third media server over the network. Additionally, the second and third media servers may be coupled to a plurality of respective clients. The first media server may be configured to record video, e.g., videoconferences, and stream recordings to clients and/or the second and third media servers. The second and third media servers may assist in performing video recording, transcoding, storage of recordings, multicasting, etc.

Video multicast over Wireless Local Area Networks (WLANs) faces many challenges due to varying channel conditions and limited bandwidth. A promising solution to this problem is the use of packet level Forward Error Correction (FEC) mechanisms. However, the adjustment of the FEC rate is not a trivial issue due to the dynamic wireless environment. This decision becomes more complicated if one considers the multi-rate capability of the existing wireless LAN technology. A novel method which dynamically adapts the transmission rate and FEC for video multicast over multi-rate wireless networks is described. In order to evaluate the system experimentally, a prototype using open source drivers and socket programming was implemented. Experimental results show that the proposed system significantly improves the multicast system performance.

The present invention provides a system and method for optimizing utility in a wireless data system. A connection is first established with a plurality of receiver devices. After the connection has been established, feedback is received from the receiver devices at periodic intervals, wherein the feedback includes channel quality information. A map is computed for each of a plurality of modulation and coding schemes (MCSs) using the received feedback, wherein the map associated with each MCS reflects the set of receiver devices capable of receiving that particular MCS. Once the MCSs have been mapped, one of the MCSs is assigned to each of a plurality of variable-sized layers of at least one video session for optimizing total system utility. If the wireless system has multiple sessions, resources are also allocated among the different sessions in a manner which further optimizes system utility.

The invention discloses a video frame structure and D2D (Device-to-Device) communication based video multicast method. The video frame structure and D2D communication based video multicast method comprises steps that a base station announces a video multicast service, and all the interested users in a cell join in the service to form a multicast cluster; the base station carries out video stream multicast for the users in the cluster by regarding the transmission time of one basic unit GOP (Group of Pictures) in a video code as a cycle; the users check received information and report sequence numbers of frames having packet loss in the GOP to the base station after the multicast sub time slot is ended; the base station after receiving feedback information of the users establishes a sequence list based on the priorities of to-be-restored frames and establishes a CQI matrix of a D2D link between target frames ACK-devices and NACK-devices; relay selection and grouping are performed based on the CQI matrix and the time Tm required for transmission of the target frame m is calculated; and after the transmission is finished, the sequence number of the current target frame in the sequence list is deleted. The video frame structure and D2D communication based video multicast method efficiently overcomes the problem that the multicast rate in the multimedia multicast is always affected by the worst fading channel in the cluster, and greatly improves the video quality within limited spectrum resources from the perspective of the user.

The invention discloses a method for realizing digital fingerprint encrypted video multicast transmission. The method comprises digital fingerprint encrypted transmission and digital fingerprint encrypted receiving. The digital fingerprint encrypted transmission comprises the following steps of: performing moving picture experts group-2 (MPEG-2) standard compression on carrier information source data of images and videos; processing image-based or video-based digital fingerprint data to finally form digital fingerprint data; deciding the energy magnitudes of digital fingerprint embedding and the relation of the energy magnitudes according to the probability of different branches of a tree structure to mutually generate collusion attack; processing by code division multiple access/time division multiple address (CDMA/TDMA) combined quadrature modulation to form blended data; enabling the blended data to form an encrypted data stream; and finally transmitting through a channel. The digital fingerprint encrypted receiving comprises the following steps of: deciphering and compressing according to a secret key K<m>, K<(i)>; recovering the information source data of the images and the videos; meanwhile, performing demodulation and processing on the information source data of the images and the videos, detecting the collusion attack generated among all levels of the tree structure by correlation functions to finally obtain the digital fingerprint data. The method for realizing the digital fingerprint encrypted video multicast transmission has the advantages that the safety is high; the communication cost is reduced; and meanwhile, the right and the validity of a system to track lawbreakers are enhanced.

Methods and systems for scheduling multicast transmissions that includes scheduling layered data for one or more multicast transmissions across a plurality of sub-channels using multi-resolution modulation. The sub-channels for each transmission may have diverse or uniform capacities. Scheduling includes allocating sub-channels to the layers of the layered data.

The invention discloses a reliable video transmission method based on network coding to mainly solve the problem of lower video reconstruction quality of a receiving end caused by packet loss or error codes in a general video transmission method. The reliable video transmission method based on network coding comprises the following steps of: adding corresponding redundant information to a layered code stream used for performing the scalable video coding for each picture group of original video information, and packing the layered code stream to complete code rate distribution; performing the random linear network coding on data packets subjected to code rate distribution by using a designed global coding matrix with a nonstringent lower triangular structure; and transmitting coded information to the receiving end through a transmission channel, and decoding a network coding code stream at the receiving end by using a Gaussian elimination method, and restoring the original video information. The reliable video transmission method based on network coding has the advantages of improving the problem of lower video reconstruction quality of the receiving end caused by packet loss and time delay in the transmission process, and realizing the unequal error protection of an H. 264/SVC (scalable video coding) code stream and the high-reliability video multicast.

A method for video multicast delivery for 4g wireless networks includes collecting client feedback and obtaining supportable modulation and coding scheme MCS for each client over a base station of wireless network, prioritizing video packets for said clients and setting a utility for each of the video packets; performing a radio resource allocation for determining a utility optimization for transmitted frames of the video packets; and assigning an MCS to each transmitted frame of the video packets, responsive to step performing a radio resource allocation

The invention discloses a method, a device and a communication system for forwarding scalable video coded data message, belonging to the communication technology field. The method comprises: receiving the scalable video multicast coded data message encapsulated by real time transmission protocol; selecting the data message suitable for downstream node from the data message to form the multicast data stream to be forwarded, wherein the real time transmission protocol serial numbers of the data message in the multicast data stream are discontinuous; updating the discontinuous real time transmission protocol serial numbers of the data message in the multicast data stream into continuous real time transmission protocol serial numbers; forwarding the multicast data stream formed by the data message with the updated continuous real time transmission protocol serial numbers to the downstream node. According to the technical scheme provided by the embodiment of the invention, the serial numbers of the RTP-encapsulated SVC multicast data stream sent by the network equipment are continuous.

The invention relates to a channel switching accelerating method and a channel ethnic group marking method in a video multicast network system. The channel switching accelerating method includes the steps of frame interpolation, rebound, construction and transmission in advance. A user sends out a switching request, and a terminal informs a switch of joining in a corresponding multicast group; an accelerating module executes corresponding actions according to the position or the operation stage, where a current image frame is located, of a group of video pictures (GOP); in the front part of the GOP, overdue frames are supplemented to be complete; in the front middle of the GOP, only reference frames are recalled; in the rear middle of the GOP, new I frames are constructed; in the tail of the COP, transmission is performed in advance. In addition, keys on a terminal control panel are not increased, one certain key or a certain group of keys are defined to have different functions under different states, and the operation functions of channel ethnic group marking and scanning type automatic switching in groups are achieved. Channel switching of video multicast can be accelerated, the possibility of jamming of the backbone network is lowered, and instant large fluctuations of network flow are avoided.

The invention discloses an audio and video multicast broadcast method based on a virtual desktop, comprising the following steps: when a first multicast component of a first virtual machine is started, generating multicast address information, and getting a second virtual machine list which have started a second multicast component in multicast; broadcasting the multicast address information in a multicast manner to a predetermined second virtual machine according to the second virtual machine list; sending the multicast address information received by the second multicast component of the predetermined second virtual machine to a first terminal through a desktop agent so the first terminal can join a multicast group according to the multicast address information; and broadcasting audio and video data in a multicast manner to the first terminal through the first multicast component of the first virtual machine so the first terminal can broadcast corresponding audio and video content after receiving the audio and video data. The invention further discloses an audio and video multicast broadcast device and an audio and video multicast broadcast system based on a virtual desktop. The problem that audio and video broadcast on a terminal may be stuck is solved.

There are provided methods and apparatus for measuring a received quality of at least one of a video multicast and a video broadcast for a plurality of users. A method includes receiving (225) data from the plurality of users regarding the received quality, and increasing (235) a weight of the data for any of the plurality of users having the received quality greater than a threshold.

The invention discloses a method and device for realizing multicast demanding under a ring network environment, and relates to the technology of video control. The method disclosed by the invention comprises the following steps: starting the PIM reverse demanding mode of a multicast source interface in a multicast source switch; under the PIM reverse demanding mode, sending a first IGMP reporting message to a node switch in the same ring network by the multicast source switch, and determining a two-layer multicast forwarding table according to the first IGMP reporting message by the node switch; when no output interface matched with the multicast group number of a multicast source exists in the multicast forwarding table, sending a first IGMP leaving message to the node switch by the multicast source switch, updating the two-layer multicast forwarding table according to the first IGMMP leaving message by the node switch, and isolating a multicast video stream sent by the multicast source. According to the invention, arbitrary flooding of video multicast messages can be rejected in the video monitoring ring network, so that the link bandwidth is greatly reduced, and the shock pressure of the multicast source port of the multicast source switch is reduced.

The invention discloses a view angle prediction method of a panoramic video multicast stream based on limited view field feedback, which comprises the following steps of: 1, constructing a significance detection model based on spherical convolution, and extracting significance features from a panoramic video by using the significance detection model; 2, constructing a memory network model based on spherical convolution, and mining causal relevance and features of user view sequences of a small number of users by using the memory network model based on spherical convolution; and 3, finally, combining the space-time saliency characteristics of the video and the visual angle characteristics of a small number of users to obtain a predicted visual angle of all the users. According to the method, the mapping distortion problem of the panoramic video is considered, and saliency detection and a small number of visual angles are combined to obtain the final predicted user visual angle, so that relatively high prediction accuracy can be realized.

The invention discloses a video multicast transmission method based on a TV white frequency band. The video multicast transmission method comprises the five steps: building a wireless video multicasttransmission network, performing SVC encoding processing on the video by a CR base station, performing spectrum detection and realizing the optimal resource scheduling. The utilization rate of the TVwhite frequency band is improved by using the cognitive radio technology. The SVC technology is applied to encode the video so that the user can obtain the video matching the channel quality. The AMCchannel encoding technology and the video encoding SVC technology are matched in the physical layer to ensure the link quality. The heuristic algorithm of the binary particle swarm optimization algorithm with low complexity is applied to obtain the sub-optimal solution of the optimal resource scheduling and solve the resource scheduling problem based on the maximum proportional fairness as the resource scheduling criterion. The method improves the throughput of the system and the quality of the received video and realizes the purpose of receiving the matching high-quality video according to the user channel quality.

The invention provides a WebRTC-based multi-terminal multi-channel real-time video monitoring method. The method comprises the following steps of: 1, configuring camera information according to an access mode of a camera video stream; 2, starting all back-end service programs to respond to a front-end video request, providing a unified video stream monitoring control service for a front end, and processing abnormal exit of a client; and 3, loading the configuration information and analyzing the configuration information into a configuration object by the front end, completing identity metadata interaction with the rear end, establishing end-to-end video data transmission based on WebRTC and completing video control; on the basis of the WebRTC protocol and the HTML5 technology, a unified and universal video protocol conversion service is provided, and various video data are converted into the WebRTC protocol to be directly used for a WEB page to play a video without a plug-in; and various video applications such as video inspection, video multicast, video carousel, video analysis and the like can be better completed.

The embodiment of the invention provides a panoramic video multicast method and device in a satellite-ground fusion network. The method comprises the following steps: grouping user terminals accordingto main view angle prediction information of the user terminals to obtain multiple pieces of bottom-layer user terminal grouping information; performing bandwidth allocation according to the groupinginformation of the plurality of underlying user terminals to obtain bandwidth allocation information of the user terminals; and splicing the high-quality user terminal main view angle patch information and the low-quality user terminal auxiliary view angle patch information to obtain a panoramic VR video, and performing multicast real-time transmission on the panoramic VR video according to the user terminal bandwidth allocation information. According to the method, secondary grouping is carried out, bandwidth allocation is carried out by taking a group as a unit according to a grouping result, spectrum sharing is carried out by taking the group as a unit, network utility maximization is realized, and user utility is effectively improved and VR wireless use experience of a user terminal is improved through a multicast transmission method on the premise of the same bandwidth.