Thomson Licensing

Interdigital Ce Patent Holdings

Thomson Licensing Dtv

Interdigital Madison Patent Holdings

Ning Liao

Zhibo Chen

Jian Chen

Kai Xie

Jun Xu

Yun Tao Shi

Xiao Ming Ma

Fan Zhang

Xianlei Wang

Jun Li

Zhi Chen

Jianfeng Chen

Xian Wang

Xiaojun Ma

Xiao Dong Gu

Xiaodong Gu

Renlei Chen

Yuntao Shi

To estimate content complexity of a video, energy of prediction residuals is calculated. The prediction residuals are usually smaller when the video is less complex and more predictable. Scales of prediction residuals also depend on encoding configurations, for example, I pictures usually have larger prediction residuals than P and B pictures even when the contents are very similar and thus have similar perceived content complexity. To more closely reflect the content complexity, alignment scaling factors are estimated for different encoding configurations. Based on the energy of prediction residuals and alignment scaling factors, an overall content unpredictability parameter can be estimated to compute a compression distortion factor for the video. The compression distortion factor, combined with slicing and freezing distortion factors, can be used to estimate a video quality metric for the video.

Method and apparatus for video quality assessment based on content complexity

Methods and systems for scheduling wake/sleep cycles by a central device in a wireless network that have at least one mobile device include determining a system reference cycle as a minimum value of a delay constraint on a real-time service for each mobile device of the at least one mobile device that has a real-time service. A wake/sleep cycle length is attributed to each mobile device. The wake/sleep cycle length is an integer multiple of the system reference cycle such that a wake/sleep cycle length of a first mobile device is different from that of a second mobile device. A sleep period and a wake period are assigned within the wake/sleep cycle of each mobile device. The wake/sleep cycle of each mobile device is arranged to avoid collision of the wake period with those of other mobile devices.

Method for scheduling wake/sleep cycles by a central device in a wireless network

A particular implementation receives a bitstream and derives parameters from the bitstream. The parameters include quantization parameters, content unpredictability parameters, ratios of lost blocks, ratios of propagated blocks, error concealment distances, motion vectors, durations of freezing, and frame rates. Using these parameters, a compression distortion factor, a slicing distortion factor, and a freezing distortion factor are estimated respectively for distortions resulting from video compression, a slicing mode error concealment, and a freezing slicing mode error concealment. The distortion factors are then mapped to a composite video quality score. For applications with limited computational power, the estimation of distortion factors can be simplified. In particular, the compression distortion factor, the slicing distortion factor, and the freezing distortion factor can be predicted from quantization parameters, ratios of lost blocks, and durations of freezing, respectively.

Video quality measurement

Accuracy and efficiency of video quality measurement are major problems to be solved. According to the invention, a method for accurately predicting video quality uses a rational function of the quantization parameter QP, which is corrected by a correction function that depends on content unpredictability CU. Exemplarily, the correction function is a power function of the CU. Both QP and CU can be computed from the video elementary stream, without full decoding the video. This ensures high efficiency.

Method and apparatus for video quality measurement

The present invention provides a QoE (Quality of Experience) management solution, wherein QoE feedback is used to optimize the usage of QoS provisioning techniques, thus improving the utilization efficiency of network resources. According to one aspect of the invention, a method for QoE management for a network service provided to a user device, the method comprising: displaying a user interface on the user device for a user to input an expected QoE value of the network service; receiving the expected QoE value of the network service from the user; evaluating an objective QoE value of the network service as a function of network QoS parameters; and adjusting the QoS parameters of the network service if the objective QoE value is less than the expected QoE value.

Method and apparatus for quality of experience management for network services

A macroblock in a video sequence may be undecodable because the corresponding compressed data is lost or the syntax is out of synchronization. An undecodable macroblock may be concealed using error concealment technique. The level of initial visible artifacts caused by undecodable macroblocks may be estimated as a function of motion magnitude, error concealment distance, and/or residual energy. The initial visible artifacts may propagate spatially or temporally to other macroblocks through prediction. Considering both initial visible artifacts and propagated artifacts, levels of overall artifacts may be estimated for individual macroblocks. The visual quality for the video sequence can then be estimated by pooling the macroblock level artifact levels.

Video quality assessment at a bitstream level

Because neighboring frames may affect how a current frame is perceived, we examine different neighborhoods of the current frame and select a neighborhood that impacts the perceived temporal distortion (i.e., when frames are viewed continuously) of the current frame most significantly. Based on spatial distortion (i.e., when a frame is viewed independently of other frames in a video sequence) of frames in the selected neighborhood, we can estimate initial temporal distortion. To refine the initial temporal distortion, we also consider the distribution of distortion in the selected neighborhood, for example, the distance between the current frame and a closest frame with large distortion, or whether distortion occurs in consecutive frames.

Method and apparatus for context-based video quality assessment

The invention provides a method and apparatus for detecting a gradual transition picture in a bitstream. The method comprises: accessing a bitstream including encoded pictures; and determining a gradual transition picture in the bitstream using information from the bitstream without decoding the bitstream to derive pixel information.

Method and apparatus for detecting gradual transition picture in video bitstream

Spatial distortion (i.e., when a frame is viewed independently of other frames in a video sequence) may be quite different from temporal distortion (i.e., when frames are viewed continuously). To estimate temporal distortion, a sliding window approach is used. Specifically, multiple sliding windows around a current frame are considered. Within each sliding window, a large distortion density is calculated and a sliding window with the highest large distortion density is selected. A distance between the current frame and the closest frame with large distortion in the selected window is calculated. Subsequently, the temporal distortion is estimated as a function of the highest large distortion ratio, the spatial distortion for the current frame, and the distance. In another embodiment, a median of spatial distortion values is calculated for each sliding window and the maximum of median spatial distortion values is used to estimate the temporal distortion.

A method for estimating video quality on bit-stream level, wherein the video quality refers to a video after error concealment and the method is performed on bit-stream level before said error concealment, comprises extracting and/or calculating a plurality of global condition features from a video bit-stream, extracting and/or calculating a plurality of local effectiveness features at least for a lost MB, calculating a numeric error concealment effectiveness level for each (or at least for each lost) MB by emulating an error concealment method that is used in said error concealment, and providing the calculated error concealment effectiveness level as an estimated visible artifacts level of video quality.

Method and device for estimating video quality on bitstream level

A method for scheduling wake/sleep cycles by a central device in a wireless network is provided. The wireless network comprises at least one mobile device. The method comprises: attributing a wake/sleep cycle length to each mobile device, wherein the wake/sleep cycle length is an integer multiple of a system schedule cycle; assigning a sleep period and a wake period within the wake/sleep cycle of each mobile device; and arranging the wake/sleep cycle of each mobile device to avoid collision of the wake period with those of other mobile devices. The present invention can keep the maximum sleep cycle period of each MS to guarantee the QoS requirement and to efficiently utilize the system bandwidth.

A method and an apparatus for managing content distribution over multiple terminal devices in collaborative media system are provided. In the collaborative media system, a first media data is transmitted over a first channel path to a first media terminal and a second media data relevant to the first media data is transmitted over a second channel to a second media terminal. The method comprises: detecting a quality of the first media data on the first channel path and that of the second media data on the second channel path; upon detection the quality of the first media data being lower than a first predetermined value and that of the second media data being greater than a second predetermined value, transmitting the second media data over the second channel path, instead of the first media data over the first channel path, to the first media terminal (S).

Method and apparatus for managing content distribution over multiple terminal devices in collaborative media system

Objective video quality assessment models at media-layer or at packet-layer are known for estimating audio/video quality of experience. Existing models are not able to provide stable performance. A method for enabling quality assessment of a stream of frames of video data comprises receiving a sequence of packets, generating a set of parameters and inserting said generated set of parameters as side information into said stream of frames, wherein at least one parameter refers to a video slice level. A method for assessing the quality of a stream of frames of video data comprises receiving a sequence of packets, extracting a set of parameters from said sequence of packets and generating an estimated mean opinion score, wherein the video data comprise a slice level and wherein the extracted set of parameters comprises at least one parameter that refers to a video slice level.

Method and apparatus for assessing quality of video stream

When capturing packets at the application level for the purpose of QoS monitoring, a QoS monitor needs to be bound to the same IP address and port as those of a media player. However, due to the unicast duplicate binding problem, a unicast packet captured by the QoS monitor will not be received by the media player, which means the QoS monitor have affected the operation of the media player. The present invention provides a solution to make the QoS monitor, upon the receipt of a unicast packet, forward the packet to the socket of the media player. In order to guarantee that the forwarded packet can be received by the socket of the media player, the QoS monitor needs to keep the port unchanged and replace the destination IP address with the local host address (127.0.0.1). According to the invention, the QoS monitor can sniff the media player without interference to the normal operation of the media player.

Method and apparatus for monitoring quality of service of network

A method of a mobile station receiving data packets from a serving base station via a multicast or broadcast connection in a wireless network is provided for performing a handover from the serving base station to a target base station. The method comprises, at the level of the mobile station, the steps of: upon the detection of the quantity of buffered data packets in the mobile station being lower than a first threshold value, establishing a unicast connection with the serving base station to receive data packets from the serving base station; and upon detection of the level of buffered data packets reaching the predetermined threshold level, performing a handover from the serving base station to the target base station. According to the invention, a seamless handover of a mobile station in a wireless network providing Multicast and Broadcast Service (MBS service) can be achieved to prevent the MBS service interruption during the handover.

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Beijing, China

Ning Liao