The present invention provides a device (200, 300), system (400, 500) and method for real-time streaming of a multimedia file stored in a remote server over a packet network to a multimedia client connected to the same network via a low-speed access link such as an analog telephone line. The invention operates to provide significantly improved QoS with respect to both quality and delay.

Device, system and method of real-time multimedia streaming

A personal media broadcasting system enables video distribution over a computer network and allows a user to view and control media sources over a computer network from a remote location. A personal broadcaster receives an input from one or more types of media sources, digitizes and compresses the content, and streams the compressed media over a computer network to a media player running on any of a wide range of client devices for viewing the media. The system may allow the user to issue control commands (e.g., “channel up”) from the media player to the broadcaster, causing the source device to execute the commands. The broadcaster and the media player may employ several techniques for buffering, transmitting, and viewing the content to improve the user's experience.

Personal media broadcasting system with output buffer

A media device allows users to watch and capture portions from a media stream. Users may then share the captured media content with other users. In one embodiment, the media device receives a media stream, plays the media stream, and caches a portion of the media stream as it is being played. A user can define a media clip by selecting its boundaries in the cached portion of the media stream. The media device creates the media clip based on the user's input and enables the user to transmit the media clip to another system, such as a community website for sharing it with other users.

Capturing and sharing media content

A method for effectively implementing a multi-room television system includes a digital base station that processes and combines various program sources to produce a processed stream. A communications processor then responsively transmits the processed stream as a local composite output stream to various wired and wireless display devices for flexible viewing at variable remote locations. The transmission path performance is used to determine the video encoding process, and special attention is taken to assure that all users have low-latency interactive capabilities.

Method for effectively implementing a multi-room television system

A multimedia compression system for generating frame rate scalable data in the case of video, and, more generally, universally scalable data Universally scalable data is scalable across all of the relevant characteristics of the data. In the case of video, these characteristics include frame rate, resolution, and quality. The scalable data generated by the compression system is comprised of multiple additive layers for each characteristic across which the data is scalable. In the case of video, the frame rate layers are additive temporal layers, the resolution layers are additive base and enhancement layers, and the quality layers are additive index planes of embedded codes. Various techniques can be used for generating each of these layers (e.g., Laplacian pyramid decomposition or wavelet decomposition for generating the resolution layers; tree structured vector quantization or tree structured-scalar quantization for generating the quality layers). The compression system further provides for embedded inter-frame compression in the context of frame rate scalability, and non-redundant layered multicast network delivery of the scalable data.

Multimedia compression system with adaptive block sizes

A method and apparatus for selecting a quantizer scale (170) to maintain the overall quality of the video image while optimizing the coding rate. A quantizer scale is selected for each macroblock such that the target bit rate for the picture is achieved while an optimal quantization scale ratio is maintained for successive macroblocks to produce a uniform visual quality over the entire picture. One embodiment applies the method to the frame level while another embodiment applies the method in conjunction with a wavelet transform.

Apparatus and method for optimizing the rate control in a coding system

An apparatus and concomitant method for selecting a macroblock coding mode based upon the quantization scale selected for the macroblock. The total number of bits needed to code each macroblock consists of two parts, bits needed for coding motion vectors (320) and bits for coding the predictive residual (330). The number of bits for coding the motion vectors is generally obtained from a look-up table. The number of bits for coding the predictive residual is obtained by an estimation which assumes that the number of bits for encoding the predictive residuals is directly proportional to the value of its variance and inversely proportional to the value of quantizer steps (quantizer scale). Using this estimation, the total number of bits necessary to code a macroblock is calculated (340) and compared for each coding mode (350). By selecting the coding mode with the least number of bits, a near-optimal solution of low complexity for practical implementation is acquired.

Apparatus and method for selecting a coding mode in a block-based coding system

A video decompression system includes block error concealment means for generating substitute data for lost blocks of pixel data. An interpolator generates both spatially and temporally interpolated or predicted blocks of data for concealing a lost block. Pixel data in the respective blocks of spatially and interpolated data are transformed to coefficients representing frequency spectra. A substitute block of coefficients is assembled from coefficients from both the transformed blocks, according to a predetermined criteria. The substitute block is transformed back to the spatial domain for substitution of lost pixel values.

Temporal-spatial error concealment apparatus and method for video signal processors

A rate control algorithm for delivery of digital video traffic on local area networks that results on uniform video quality during normal traffic conditions and graceful degradation during periods of congestion is proposed. The algorithm controls a dual rate-control-mode MPEG-2 encoder. This encoder operates in either variable bit-rate (VBR) or joint rate controlled VBR mode.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Rate control for VBR MPEG video on local area networks

A joint rate control algorithm for variable bit rate(VBR) MPEG-compressed digital video on point-to-point permanent virtual circuit (PVC) ATM links is proposed.The algorithm controls the encoding mode of a numberof video encoders that operate either on VBR or constantbit rate (CBR) mode. The algorithm selects the encodingmode based on the buffer occupancy of a multiplexer co-located with the encoders that interfaces them to the PVClink. VBR encoding is the predominant encoding mode usedduring congestion-free periods. CBR mode is used only during congested periods. When CBR is selected, new bit ratesare jointly assigned to the encoders based on their relativeencoding complexities. The bit rate assigned to the encodersare enforced by a CBR rate control local to each encoder.The performance of the joint rate control algorithm is evaluated through simulation of a packet multiplexer, where anumber of connections are multiplexed onto a fixed-capacity channel. The performance is compared to that of multiplexing conventional CBR and open-loop VBR from the videoquality and bandwidth efficiency points of view. Simulation results show that the proposed algorithm improves performance over multiplexed conventional CBR or open-loop VBR MPEG video, without significantly increasing implementation complexity. The application of the algorithm, tovideo-on-demand over ATM is discussed.

Wilson Kwok

Papers

Apparatus and method for optimizing the rate control in a coding system

Apparatus and method for selecting a coding mode in a block-based coding system

Temporal-spatial error concealment apparatus and method for video signal processors

Rate control for VBR MPEG video on local area networks

Joint rate control for VBR MPEG video on PVC ATM links