In one aspect of the present invention, a network gateway is configured to facilitate on line and off line bi-directional communication between a number of near end data and telephony devices with far end data termination devices via a hybrid fiber coaxial network and a cable modem termination system. The described network gateway combines a QAM receiver, a transmitter, a DOCSIS MAC, a CPU, a voice and audio processor, an Ethernet MAC, and a USB controller to provide high performance and robust operation.

Gateway with voice

Various techniques and tools for encoding and decoding (e.g., in a video encoder/decoder) binary information (e.g., skipped macroblock information) are described. In some embodiments, the binary information is arranged in a bit plane, and the bit plane is coded at the picture/frame layer. The encoder and decoder process the binary information and, in some embodiments, switch coding modes. For example, the encoder and decoder use normal, row-skip, column-skip, or differential modes, or other and/or additional modes. In some embodiments, the encoder and decoder define a skipped macroblock as a predicted macroblock whose motion is equal to its causally predicted motion and which has zero residual error. In some embodiments, the encoder and decoder use a raw coding mode to allow for low-latency applications.

Skip macroblock coding

Video decoding innovations for multithreading implementations and graphics processor unit (“GPU”) implementations are described. For example, for multithreaded decoding, a decoder uses innovations in the areas of layered data structures, picture extent discovery, a picture command queue, and/or task scheduling for multithreading. Or, for a GPU implementation, a decoder uses innovations in the areas of inverse transforms, inverse quantization, fractional interpolation, intra prediction using waves, loop filtering using waves, memory usage and/or performance-adaptive loop filtering. Innovations are also described in the areas of error handling and recovery, determination of neighbor availability for operations such as context modeling and intra prediction, CABAC decoding, computation of collocated information for direct mode macroblocks in B slices, reduction of memory consumption, implementation of trick play modes, and picture dropping for quality adjustment.

Computing collocated macroblock information for direct mode macroblocks

The present invention is a system on chip architecture having scalable, distributed processing and memory capabilities through a plurality of processing layers. In a preferred embodiment, a distributed processing layer processor comprises a plurality of processing layers, a processing layer controller, and a central direct memory access controller. The processing layer controller manages the scheduling of tasks and distribution of processing tasks to each processing layer. Within each processing layer, a plurality of pipelined processing units (PUs), specially designed for conducting a defined set of processing tasks, are in communication with a plurality of program memories and data memories. One application of the present invention is in a media gateway that is designed to enable the communication of media across circuit switched and packet switched networks. The hardware system architecture of the said novel gateway is comprised of a plurality of DPLPs, referred to as Media Engines that are interconnected with a Host Processor or Packet Engine, which, in turn, is in communication with interfaces to networks. Each of the PUs within the processing layers of the Media Engines are specially designed to perform a class of media processing specific tasks, such as line echo cancellation, encoding or decoding data, or tone signaling.

Distributed processing architecture with scalable processing layers

Disclosed are methods that enable communications to be established regardless of the presence of communications blockers, e.g., firewalls and NATs, in the path between two computing devices. Two devices each establish communications with a rendezvous service. Through the service, the devices signal each other to set up direct, peer-to-peer communications between themselves. If the devices fail to establish direct communications, then they invoke a relay service that provides the illusion of direct communications. In another aspect, an originating device attempts to establish communications with a recipient, using an address and port number associated with the recipient. If that attempts fails, possibly because a firewall is blocking communications, then the originating device retries using a port normally held open by firewalls. If this attempt also fails, then the originating device invokes the services of a proxy to negotiate a port acceptable for use by the recipient and by any intervening firewalls.

Methods and systems for establishing communications through firewalls and network address translators

A compression system and process include adaptive quantization for selection of one quantizer, for each video frame or frame portion, from a group of quantizers, where each quantizer is a set of predefined quantizer values, and coding of the quantized values using a common entropy coding table for all quantizers, or a separate entropy coding table for each quantizer. The entropy coding tables are obtained during a training procedure. The selection of the quantizer is based on a formula which takes into account the distortion and bit rate characteristics of each quantizer. A similar formula, based on the distortion and bit rate characteristics, is used to select the particular quantizer value within the chosen quantizer for each video signal value being coded.

Adaptive entropy coding in adaptive quantization framework for video signal coding systems and processes

A network echo canceller for integrated telecommunications processing. The network echo canceller processes echoes in multiple communication channels over a packet network. The network echo canceller adapts a least means squared finite impulse response filter to each communication channel in order to estimate an echo therein. The echo estimation is subtracted from signals that are being sent over each communication channel. The echo canceller includes a residual error suppressor to suppress non-linear sources of echo when desired. The echo canceller includes a double talk detector to inhibit filter adaptation during double talk. The network echo canceller is programmable into a digital signal processor and can be flexibly controlled through messaging.

Network echo canceller for integrated telecommunications processing

Disclosed is an integrated voice activation detector for detecting whether voice is present. In one embodiment, the integrated voice activation detector includes a semiconductor integrated circuit having at least one signal processing unit to perform voice detection and a storage device to store signal processing instructions for execution by the at least one signal processing unit to: detect whether noise is present to determine whether a noise flag should be set, detect a predetermined number of zero crossing to determine whether a zero crossing flag should be set, detect whether a threshold amount of energy is present to determine whether an energy flag should be set, and detect whether instantaneous energy is present to determine whether an instantaneous energy flag should be set. Utilizing a combination of the noise, zero crossing, energy, and instantaneous energy flags the integrated voice activation detector determines whether voice is present.

Voice activity detector for integrated telecommunications processing

Disclosed is an integrated tone detection processor for discriminating between tone and voice signals and determining the tones. The tone detection processor performs Automatic Gain Control (AGC) to normalize the power of the tone or voice signal. Further, the energy of the tone or voice signals are determined at specific frequencies utilizing a Goertzel Filter process. The tone detection processor determines whether or not a tone is present, and if a tone exists, determines the type of tone. Based upon determining the two maximum energy levels of the Goertzel filtered tone, whether the tone is a single tone, dual tone, silence, or other (e.g. speech) can be discriminated. The tone can then be identified by a user-defined dictionary of tones. Based upon various ON and OFF cadence checks in combination with the use of TONE ON and TONE OFF counters, tones can be declared.

Tone detection for integrated telecommunications processing

A method and apparatus for compressing and transmitting variable amounts of video data in real time over a channel having a fixed bandwidth. A trellis having a plurality of nodes is provided. Each of the plurality of nodes has an associated quantization parameter and bit number. The bit number associated with each node corresponds to a quantity of bits consumed in reaching that node. For each of the plurality of blocks, a minimum path through the trellis is selected. A quantization parameter associated with the selected minimum path is selected. A number of bits is assigned to each of the plurality of blocks in accordance with the selected quantization parameter. A substantially fixed number of bits is distributed among the plurality of blocks which make up each of the plurality of frames in accordance with the selected quantization parameter. The number of bits per frame is substantially constant for each of the plurality of frames, and the distribution of bits within each of the plurality of frames varies in accordance with the content of the frame.

Anurag Bist

Papers

Adaptive entropy coding in adaptive quantization framework for video signal coding systems and processes

Network echo canceller for integrated telecommunications processing

Voice activity detector for integrated telecommunications processing

Tone detection for integrated telecommunications processing

A perceptually motivated trellis based rate control method and apparatus for low bit rate video coding