Imagination Technologies Limited

Kaam LLC

Senthil Kumar Mani

Bala Manikya Prasad Puram

Srinivas Akella

Gandhi Namani

Sowmya Mannava

Sai Ravi Teja Pulugurtha

Anupama Ghantasala

Harish Rajamani

Prasad Puram

Tejaswini Dudyala

Srivally Munnangi

Ghandhi Namani

Bala Monikya Prasad Puram

A method of estimating available bandwidth for a network comprising a transmitting device and a receiving device, the method comprising: transmitting a media packet stream over the network to the receiving device, the media packets comprising media data for streaming media at the receiving device; transmitting one or more probe packets over the network so as to test the available bandwidth of the network, wherein the probe packets comprise duplicate data of the media packet stream; and determining, during transmission of the probe packets, a measure of network bandwidth availability in dependence on one or more metrics associated with receiving the media packet stream at the receiving device.

Estimating network bandwidth using probe packets

A method of transmitting data determines a measure of consecutive packet loss in a network; a ratio of a number of data packets and a number of error correction packets is selected in dependence on the measure. A stream of data packets is generated, and a stream of error correction packets is generated in dependence on the stream of data packets such that the proportion of error correction packets generated to the data packets generated is commensurate with the selected ratio.

Method and device for transmitting a data stream with selectable ratio of error correction packets to data packets

An echo cancellation detector for controlling an acoustic echo canceller that is configured to cancel an echo of a far-end signal in a near-end signal in a telephony system, the echo cancellation detector comprising a comparison generator configured to compare the far-end signal with the near-end signal, a decision unit configured to make a determination about a first acoustic echo canceller based on that comparison and a controller configured to control an operation of a second acoustic echo canceller in dependence on the determination.

Detection of acoustic echo cancellation

Bandwidth management

Voice data transmission with adaptive redundancy creates a voice data packet by packetizing the voice data payload and a number of redundant payloads selected from a set of previous voice data payloads. The voice data from the voice data payload is analysed to determine whether it is a critical or non-critical payload by classifying the received voice data as voiced or unvoiced. If at least a portion of the voice data is classified as unvoiced, the voice data payload is determined to be a critical payload. If it is a critical payload, then the voice data payload is added to the set of previous voice data payloads for inclusion as a redundant payload in subsequent voice data packets. The voice data packet is then forwarded for transmission over the network.

Voice data transmission with adaptive redundancy

A video packet stream is transmitted from a transmitting device to a receiving device over a network, by transmitting an audio packet stream to the receiving device, determining a measure of network bandwidth in dependence on one or more metrics associated with receiving the audio packet stream at the receiving device, and enabling a video packet stream in dependence on the determined measure.

Method and apparatus for processing a received sequence of data packets by removing unsuitable error correction packets from the sequence

A gain control system for controlling gain applied to an audio signal includes a power estimator configured to estimate the power of a digital signal derived from the audio signal, a digital gain estimator configured to determine, in dependence on the estimated power, a digital gain which would modify the power of the digital signal so as to reach a target power level, and a gain controller configured to adjust an analogue gain applied to the audio signal in dependence on the determined digital gain.

Controlling analogue gain of an audio signal using digital gain estimation and voice detection

A controller for an acoustic echo canceller includes a noise estimator configured to estimate a level of noise that is comprised in a microphone signal relative to an echo component, estimated by the acoustic echo canceller, comprised in the microphone signal. The controller further includes a control module configured to control the acoustic echo canceller in dependence on that estimate.

Estimating averaged noise component in a microphone signal

A signal processing apparatus that handles an adaptive enhancement of a speech signal, receives a first signal and a second signal from a determined source. At least one of a speech signal or at least one noise signal is present in the first signal or the second signal. The first signal and the received second signal are processed to obtain a processed signal for amplification of a gain associated with the speech signal present in the first signal and the second signal by a determined factor. A signal-to-noise ratio (SNR) associated with the processed signal is greater than or equal to a threshold value. A reference noise signal is obtained from the second signal based on subtraction of an estimated the speech signal present in the received second signal from the processed signal. A processed speech signal is determined based on filtration of the obtained reference noise signal.

Adaptive enhancement of speech signals

A system that handles direction of arrival (DOA) estimation for acoustic signals using sub-array selection, identifies a plurality of microphone sub-arrays from the plurality of microphones in the microphone-array, selects a set of microphone sub-arrays from the plurality of microphone sub-arrays, and computes a relative time-delay for arrival of the acoustic signals between each pair of microphones of the selected set of microphone sub-arrays. The selection is based on a maximum distance between each pair of microphones of the identified plurality of microphone sub-arrays of the microphone-array. A first microphone sub-array is determined from the selected set of microphone sub-arrays and the DOA of the acoustic signals is estimated with reference to the determined first microphone sub-array. The estimation of the direction of arrival of the acoustic signals is based on the computed relative time-delay for the determined first microphone sub-array of the microphone-array.

Direction of arrival estimation of acoustic-signals from acoustic source using sub-array selection

A method of transmitting a stream of packets over a network, the method comprising the steps of: a transmitting device maintaining a measure of network quality; analyzing the measure of network quality so as to determine whether the bandwidth of the network is degrading, beyond a predetermined threshold, the network quality for a transmission over the network; the transmitting device determining a transmission bitrate and a proportion of redundancy in dependence on the analysis; the transmitting device packetising media data and redundancy data in dependence on the determined proportion to generate a stream of packets; and the transmitting device transmitting the generated stream at a rate commensurate with the determined transmission bitrate.

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Hyderabad Telangana, India

Senthil Kumar Mani