Agora Lab, Inc.

Dts, Inc.

Zesen Zhuang

Jean-Marc Jot

Michael M Goodwin

Martin Walsh

Edward Stein

Suketu Kamdar

Sheng Zhong

Wei Dai

Zhonghou Zheng

Jian Lou

Qianzong Chen

Jiali Li

HuaMing Zhang

Tao Duan

Xiajun Gu

Mingyue Hao

A method for allocating bitrate in video communications is disclosed. The method includes encoding, via an encoder, a video stream that is partitioned into tiles associated with a viewing angle of the video stream, whereby encoding the video stream includes allocating each of the tiles a bitrate. The method also includes determining an image quality score associated with rendering of the tiles at a first iteration, whereby rendering of the tiles includes decoding and displaying the tiles at the first iteration in the viewing angle of the video stream with the bitrate. The method further includes, responsive to determining the image quality score, modifying the bitrate allocated to at least some of the tiles such that rendering of the tiles at a second iteration that is after the first iteration includes decoding and displaying the tiles with the modified bitrate.

Tile encoding bitrate allocation for low-latency video communication systems

A method includes maintaining a phase-out list that includes tiles of a current viewport of a wide-angle image that are predicted to no longer be in the viewport after a time duration d from a current time t. Tiles predicted to be viewed at a time that is later than the current time t are obtained. Those of the predicted tiles that are not in a receiver list are added to the receiver list. Tiles that form a current viewing area are rendered using the receiver list. Tiles of the receiver list and a phase-out list are associated with respective display times. Rendering the tiles includes decoding and displaying tiles of the receiver list having display times that are not larger than the current time t and stopping decoding and displaying tiles of the phase-out list associated with the display times that are not larger than the current time t.

Real-time wide-angle video communication system

Apparatus, method and non-transitory computer readable medium for bandwidth estimation for a network using traffic shaping detection are provided, including selecting periodically sampled packets from the network, bandwidth samples each having a delay jitter greater than a jitter threshold, the delay jitter of a packet determined as the difference between a delay for the packet in the network and a minimum delay for all packets sampled within a delay statistics window for the packet; updating a probability distribution of sampled bandwidth based on the selected bandwidth samples; determining whether traffic shaping is occurring in the network based on a density of the updated probability distribution of sampled bandwidth; and based on a determination that traffic shaping is occurring in the network, adjusting an upper limit of estimated bandwidth for the network based on an estimated traffic shaping rate, the estimated traffic shaping rate determined based on the updated probability distribution.

Traffic shaping detection and bandwidth estimation for a network

A system and method for determining the performance of a video codec for real-time communication applications. A set of network conditions is used to simulate certain typical real-world network conditions. A coded video stream is transmitted from the transmitting end to the receiving end under these conditions. The end-to-end latency and received video fluency are measured along with a set of existing video quality measures by a video codec performance evaluation system including a network model and a video codec quality analyzer. The decodable frame ratio, latency and video fluency are used as the performance metrics for real-time communication video quality evaluation. The video codec performance evaluation system does not send any video data over a network when it determines the real-time communication quality of the video codec.

System and method for determining video codec performance in real-time communication over internet

Embodiments of systems and methods are described for reducing undesired leakage energy produced by a non-front-facing speaker in a multi-speaker system. For example, the multi-speaker system can include an array of forward-facing speakers, one or more upward-facing speakers, and/or one or more side-facing speakers. Filters coupled to any two of the speakers in the multi-speaker system can generate audio signals output by the coupled speakers to reduce, attenuate, or cancel a portion of an audio signal output by one or more non-front-facing speakers that acoustically propagates along a direct path from the respective non-front-facing speaker to a listening position in a listening area in front of the multi-speaker system.

Multi-speaker method and apparatus for leakage cancellation

System and methods of managing reference frame adaptively for video communication under a network are provided. The system adaptively decides the interval between each I frame, the bitrate of the encoded bit steams, and the resolution of the encoded video to achieve quick connection. The system may set the appropriate reference frame(s) for the current frame, manage the reference frame(s) in the DPB to be long/short term reference frame(s) or mark them as unused for reference; mark the current frame to be a long term reference frame, a short term reference frame, unused for reference or skip encoding the current frame; adaptively change the ratio of long term reference frame(s) with respect to the short term reference frame(s) in the DPB; adaptively change the frequency ratio of marking the current frame as long term reference frame and marking the current frame as short term reference frame.

Method and apparatus for reference frame management for video communication

A method for encoding a video stream, including encoding, by a processor, a first slice of a first picture of the video stream; receiving, from a decoder, a feedback message indicative of having received the first slice of the first picture; and in response to receiving the feedback message indicative of having received the first slice of the first picture, setting the first slice of the first picture as a reference slice for encoding a second picture of the video stream, wherein the second picture is encoded after receiving the feedback message.

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Shanghai, China

Zesen Zhuang