Patent application number | Description | Published |
20100246688 | BLIND NOISE ANALYSIS FOR VIDEO COMPRESSION - Example embodiments of the present invention provide a method or device for coding source video. The method or device may provide for a segment of video frames from the source video, computing a noise map for the segment of the source video where the noise map is computed from differences among pixels selected from spatially-distributed sampling patterns in the segment, computing control parameter adjustments based on the noise map, and coding the selected segment of source video according to control parameters generated from a default coding policy and the control parameter adjustments, where the default coding policy includes default control parameters of the encoder. | 09-30-2010 |
20100309975 | IMAGE ACQUISITION AND TRANSCODING SYSTEM - A method and system are provided to encode a video sequence into a compressed bitstream. An encoder receives a video sequence from an image-capture device, together with metadata associated with the video sequence, and codes the video sequence into a first compressed bitstream using the metadata to select or revise a coding parameter associated with a coding operation. Optionally, the video sequence may be conditioned for coding by a preprocessor, which also may use the metadata to select or revise a preprocessing parameter associated with a preprocessing operation. The encoder may itself generate metadata associated with the first compressed bitstream, which may be used together with any metadata received by the encoder, to transcode the first compressed bitstream into a second compressed bitstream. The compressed bitstreams may be decoded by a decoder to generate recovered video data, and the recovered video data may be conditioned for viewing by a postprocessor, which may use the metadata to select or revise a postprocessing parameter associated with a postprocessing operation. | 12-09-2010 |
20100309987 | IMAGE ACQUISITION AND ENCODING SYSTEM - A method and system are provided to encode a video sequence into a compressed bitstream. An encoder receives a video sequence from an image-capture device, together with metadata associated with the video sequence, and codes the video sequence into a first compressed bitstream using the metadata to select or revise a coding parameter associated with a coding operation. Optionally, the video sequence may be conditioned for coding by a preprocessor, which also may use the metadata to select or revise a preprocessing parameter associated with a preprocessing operation. The encoder may itself generate metadata associated with the first compressed bitstream, which may be used together with any metadata received by the encoder, to transcode the first compressed bitstream into a second compressed bitstream. The compressed bitstreams may be decoded by a decoder to generate recovered video data, and the recovered video data may be conditioned for viewing by a postprocessor, which may use the metadata to select or revise a postprocessing parameter associated with a postprocessing operation. | 12-09-2010 |
20110149087 | Joint Bandwidth Detection Algorithm For Real-Time Communication - A video coding system and method for increasing a transmitted output bit rate of a video encoding system by altering the content of the bit stream. A video encoder may receive a coding mode signal from a computer application for coding source video data, the coding mode signal indicating a target bit rate having a risk factor related to transmission error associated to the target bit rate. The coded bitstream may be modified based on the risk factor indicated in the coding mode signal. A modified coded bitstream may be outputted at the target bit rate and at a reduced coding efficiency, and the channel may be tested for transmission errors. Based on the test results, a revised coding mode signal indicating the same target bit rate, but a revised risk factor may be provided. The coded bitstream may be revised by removing the modifications previously made to the coded bitstream and a revised coded bitstream having greater coding efficiency may be output at the target bit rate. | 06-23-2011 |
20110235709 | FRAME DROPPING ALGORITHM FOR FAST ADAPTATION OF BUFFERED COMPRESSED VIDEO TO NETWORK CONDITION CHANGES - A video coding and transmission system may employ techniques for adapting buffered video to network condition changes. Video data may be coded as reference data and non-reference data. According to the embodiments, non-reference frame may be detected in buffered video while awaiting transmission to a network. When network degradation is detected, one or more of the buffered non-reference frames may be dropped when network degradation is detected. Information about the dropped frames may be passed to an encoder for updating buffer parameters for future encoding. In this manner, a video coding system may provide faster responses to changing network conditions than systems without such buffer management techniques. | 09-29-2011 |
20110249073 | Establishing a Video Conference During a Phone Call - Some embodiments provide a method for initiating a video conference using a first mobile device. The method presents, during an audio call through a wireless communication network with a second device, a selectable user-interface (UI) item on the first mobile device for switching from the audio call to the video conference. The method receives a selection of the selectable UI item. The method initiates the video conference without terminating the audio call. The method terminates the audio call before allowing the first and second devices to present audio and video data exchanged through the video conference. | 10-13-2011 |
20110249074 | In Conference Display Adjustments - Some embodiments provide a method for modifying a composite display of a first mobile device that is engaged in a video conference with a second device. The method presents, on the first device, the composite display having a first video captured by the first device and a second video captured by the second device. The method receives, at the first device, an input for modifying the composite display during the video conference. The method modifies the composite display based on the received input. | 10-13-2011 |
20110249075 | Remote Control Operations in a Video Conference - Some embodiments provide a method for allowing a first device that is in a video conference with a second mobile device to remotely control the second mobile device. The method sends images captured by a camera of the first device to the second device. The method receives images captured by a camera of the second device. The method sends a command through a communication channel of a real-time communication session to the second device. The command is for instructing the second device to perform an operation that modifies the images captured by the camera of the second device. | 10-13-2011 |
20110249076 | Different Rate Controller Configurations for Different Cameras of a Mobile Device - Some embodiments provide a method for encoding video pictures captured by a mobile device having at least first and second cameras. The method identifies a first rate controller parameter that is based on at least a first value that quantifies one characteristic of the first camera. The method uses the first rate controller parameter to configure a set of rate controllers to adjust a bit rate for encoding video pictures captured by the first camera. The method identifies a second rate controller parameter that is based on at least a second value that quantifies the same characteristic of the second camera. The first and second values are different, and the difference causes the first and second rate controller parameters to be different. The method uses the second rate controller parameter to configure the set of rate controllers to adjust a bit rate for encoding video pictures captured by the second camera. | 10-13-2011 |
20110249077 | Video Conference Network Management for a Mobile Device - Some embodiments provide a method for managing a video conference between a first device and a second device. The method identifies a first ceiling bit rate for transmitting video conference data to the second device through the communication channel. The method identifies a current bit rate that is less than the first ceiling bit rate. The method receives networking data regarding the communication channel from the second device. The method determines, from the received network data, that the communication channel will sustain an increase in the current bit rate. The method increments the current bit rate. The method iteratively performs the receiving, determining, and incrementing operations until a determination is made that the communication channel will not sustain the increase in the current bit rate. | 10-13-2011 |
20110249078 | Switching Cameras During a Video Conference of a Multi-Camera Mobile Device - Some embodiments provide a method for conducting a video conference between a first mobile device and a second device. The first mobile device includes first and second cameras. The method selects the first camera for capturing images. The method transmits images captured by the first camera to the second device. The method receives selections of the second camera for capturing images during the video conference. The method terminates the transmission of images captured by the first camera and transmits images captured by the second camera of the first mobile device to the second device during the video conference. | 10-13-2011 |
20110249133 | COMPRESSION-QUALITY DRIVEN IMAGE ACQUISITION AND PROCESSING SYSTEM - Embodiments of the present invention provide a video encoding system in which a video coding engine establishes coding quality metrics that govern its own operation as well as the operation of a camera and/or a pre-processor. An imaging system may include an image acquisition system, a pre-processor and a coding engine. The coding engine may output a quality indicator identifying, for each portion of a video sequence currently being coded, a relatively level of coding quality that is being achieved. The imaging system further may include an image acquisition controller and a pre-processor controller that impose respective operating parameters upon the image acquisition system and the pre-processor in response to these quality indicators. In this manner, overall performance of the imaging system may be improved. | 10-13-2011 |
20110249729 | ERROR RESILIENT HIERARCHICAL LONG TERM REFERENCE FRAMES - Embodiments of the present invention provide a video encoding system that codes video sequence into a multi-level hierarchy based on levels of long term reference (LTR) frames. According to the present invention, an encoder designates a reference frame as a long term reference (LTR) frame and transmits the LTR frame to a receiver. Upon receiving feedback from the receiver acknowledging receipt of the LTR frame, the encoder periodically codes subsequent frames as reference frames using the acknowledged LTR frame as a reference and designates subsequent reference frames as secondary LTR frames. A determined number of frames after each secondary LTR frame may be coded using a preceding secondary LTR frame as a reference. | 10-13-2011 |
20110249742 | COUPLED VIDEO PRE-PROCESSOR AND CODEC INCLUDING REFERENCE PICTURE FILTER THAT MINIMIZES CODING EXPENSE DURING PRE-PROCESSING MODE TRANSITIONS - A video coding system includes a coding engine operable to code source video according to motion compensated prediction techniques, a reference picture cache to store decoded picture data of previously-coded reference pictures, and a programmable filter to apply selected filtering operation(s) to picture data retrieved from the reference picture cache and provided to the coding engine. A video decoding system includes a decoding engine operable to decode coded video data, a reference picture cache to store decoded picture data of previously-decoded reference pictures, and a programmable filter to apply a filtering operation to picture data retrieved from the reference picture cache and provided to the decoding engine as determined by the coded video data. Video coding/decoding systems so configured may avoid coding costs that can be incurred when a pre-processing filter switches pre-processing modes within source data in a manner that causes divergence between stored reference pictures and video pictures input to the coding engine. | 10-13-2011 |
20110274167 | VIDEO CODING SYSTEM USING SUB-CHANNELS AND CONSTRAINED PREDICTION REFERENCES TO PROTECT AGAINST DATA TRANSMISSION ERRORS - A coding technique is disclosed in which frames of a video sequence are assigned to one of a plurality of sub-channels to be transmitted to a decoder. The frames are coded according to predictive coding techniques such that ordinarily prediction references of the frames in each sub-channel only reach the reference frames that occur within the same sub-channel. Thus, if transmission errors arise with respect to one sub-channel, decoding may occur for another sub-channel until the transmission error is detected and corrected. | 11-10-2011 |
20110298886 | Auto Exposure Techniques for Variable Lighting Conditions - Systems, methods, and a computer readable medium for performing auto exposure (AE) techniques that are beneficial in variable lighting conditions—and particularly applicable to handheld and/or mobile videoconferencing applications—are disclosed herein. Handheld and/or mobile videoconferencing applications—unlike their fixed camera counterparts—are often exposed to a wide variety of rapidly changing lighting and scene conditions, and thus face a difficult trade-off between adjusting exposure parameter values too frequently or not frequently enough. In personal electronic devices executing such handheld and/or mobile videoconferencing applications, it may be desirable to: use a small, centered, and center-weighted exposure metering region; set a relatively low brightness target value; and adjust the camera's exposure parameter values according to a distance-dependent convergence speed function. The use of such techniques, in conjunction with a relatively large stability region, may also improve the quality of a video encoder's temporal predictions—and thus video quality—in videoconferencing applications. | 12-08-2011 |
20110298965 | SCENE-AWARE AUTOMATIC-EXPOSURE CONTROL - A scene-aware auto-exposure control process stabilizes changes in a camera's auto-exposure settings so as to reduce lighting and color flicker during image capture operations. A metric, referred to as the Modified Adjusted Luminance (MAL) metric, is defined to remain relatively constant as long as the lighting of the scene being captured remains relatively constant. Thus, scene changes such as an object moving into, out of, or around in a scene do not significantly affect the MAL metric's value and do not, therefore, trigger an exposure adjustment. Once the MAL metric indicates a scene's lighting is stable, the camera's auto-exposure operation may be suppressed. As long as incoming frames indicate a stable lighting condition (based on the MAL metric), auto-exposure operation may remain suppressed. When incoming frames result in a substantially different MAL over a specified number of frames, auto-exposure operation may be restored. | 12-08-2011 |
20110299588 | RATE CONTROL IN VIDEO COMMUNICATION VIA VIRTUAL TRANSMISSION BUFFER - Embodiments of the present invention provide a video encoding system that may include a coding engine to code an input video signal according to a video compression process, compression of each portion of the input signal performed according to coding parameters assigned to the respective portion. The video encoding system may also include a rate controller to select coding parameters of each portion of the input signal, the rate controller estimating delay of delivery of coded video data by a delivery network according to a leaky bucket modeling process and selecting coding parameters of a portion to be coded based at least in part on the estimated delay. | 12-08-2011 |
20110299589 | RATE CONTROL IN VIDEO COMMUNICATION VIA VIRTUAL TRANSMISSION BUFFER - Embodiments of the present invention provide a video encoding system that may include a coding engine to code an input video signal according to a video compression process, compression of each portion of the input signal performed according to coding parameters assigned to the respective portion. The video encoding system may also include a rate controller to select coding parameters of each portion of the input signal, the rate controller estimating delay of delivery of coded video data by a delivery network according to a leaky bucket modeling process and selecting coding parameters of a portion to be coded based at least in part on the estimated delay. | 12-08-2011 |
20110299604 | METHOD AND APPARATUS FOR ADAPTIVE VIDEO SHARPENING - A video coding system and method to adjust the sharpening procedures performed during post-processing by analyzing statistics information collected during encoding and decoding. The statistics information collected may be directed to the source of the video data, the operations executed during pre-processing and encoding of the video data, the transmission of the video data from encoder to decoder, or the operations executed during decoding. The statistics information may comprise a collection of data values, calculated statistics, or instructions for the suggested post-processing adjustments. Accumulated supplemental information may be transmitted from the encoder to the decoder via an out-of-band channel, associated with the encoded video sequence transmitted on a communications channel. | 12-08-2011 |
20110299605 | METHOD AND APPARATUS FOR VIDEO RESOLUTION ADAPTATION - A system and method for gradually changing the resolution of a video signal to avoid a large spike in the video data transmitted between an encoder and a decoder. Upon detection of a change in the quality of source video, of the quality of the encoding process, or of the channel conditions, any of which may negatively impact the rate of frame transmission from encoder to decoder, or the quality of frames transmitted, a responsive change in the resolution of the video frame may be gradually implemented. To change the resolution by increasing the effective image size, each successive frame in a sequence of frames may contain additional pixel blocks in the expansion image area at the new resolution. In an embodiment, the decoder displays the video image at the original resolution until the resolution switch has been completed. | 12-08-2011 |
20110302473 | ERROR CORRECTION CODING - Coded video data may be transmitted between an encoder and a decoder using multiple FEC codes and/or packets for error detection and correction. Only a subset of the FEC packets need be transmitted between the encoder and decoder. The FEC packets of each FEC group may take, as inputs, data packets of a current FEC group and also an untransmitted FEC packet of a preceding FEC group. Due to relationships among the FEC packets, when transmission errors arise and data packets are lost, there remain opportunities for a decoder to recover lost data packets from earlier-received FEC groups when later-received FEC groups are decoded. This opportunity to recover data packets from earlier FEC groups may be useful in video coding and other systems, in which later-received data often cannot be decoded unless earlier-received data is decoded properly. | 12-08-2011 |
20120057073 | Scene-Aware Automatic-Exposure Control - A scene-aware auto-exposure control process stabilizes changes in a camera's auto-exposure settings so as to reduce lighting and color flicker during image capture operations. A metric, referred to as the Modified Adjusted Luminance (MAL) metric, is defined to remain relatively constant as long as the lighting of the scene being captured remains relatively constant. Thus, scene changes such as an object moving into, out of, or around in a scene do not significantly affect the MAL metric's value and do not, therefore, trigger an exposure adjustment. Once the MAL metric indicates a scene's lighting is stable, the camera's auto-exposure operation may be suppressed. As long as incoming frames indicate a stable lighting condition (based on the MAL metric), auto-exposure operation may remain suppressed. When incoming frames result in a substantially different MAL over a specified number of frames, auto-exposure operation may be restored. | 03-08-2012 |
20120092991 | ADAPTING TRANSMISSION TO IMPROVE QOS IN A MOBILE WIRELESS DEVICE - A method and apparatus for adapting transmission to improve quality of service in a mobile wireless device that includes an application processor and a transceiver. An application service connection is established between the mobile wireless device and a remote device. The transceiver in the mobile wireless device monitors real time properties of a radio frequency access link that transports packets for the application service between the mobile wireless device and a wireless communication network. The transceiver provides local feedback to the application processor of updated values of the monitored real time properties. The application processor adjusts packet data generation and transmission in response to the updated values to manage quality of service for the application service connection. Packet data transmission adjustment includes active management of queues in the transceiver by the application processor, selectively dropping packets based on packet classifications and the local feedback information provided to the application processor. | 04-19-2012 |
20120106632 | METHOD AND APPARATUS FOR ERROR RESILIENT LONG TERM REFERENCING BLOCK REFRESH - A system and method for coding video data wherein a pixel block may be coded for refresh with reference to an LTR frame that was successfully transmitted, or has a high probability of having been successfully transmitted from the encoder to the decoder. Not all pixel blocks in the frame may be refreshed at the same rate. Pixel blocks containing edge details, containing a significant object, or containing foreground image data may be refreshed more often than pixel blocks containing smooth, background, or relatively less significant image data. | 05-03-2012 |
20120170654 | VIDEO CODING SYSTEM USING IMPLIED REFERENCE FRAMES - A video coding/decoding system builds implied reference frames from a plurality of reference frames developed during coding. Coded data of reference pictures are decoded and stored in a reference picture cache. An implied reference frame may be derived from a plurality of reference frames and may be stored in the reference picture cache. Thereafter, coding of new input data may proceed using the implied reference frame as a source of prediction. The method may be used to identify visual elements such as background elements that may persist in video over a longer period that can be captured by the system under conventional reference frames assembly and eviction. Implied reference frames may be built at both an encoder and a decoder to serve as sources of prediction. | 07-05-2012 |
20120195364 | DYNAMIC MODE SEARCH ORDER CONTROL FOR A VIDEO ENCODER - A system and method for coding video data wherein a coding mode decision process may be dynamically adjusted according to any of a plurality of factors including video image content, image complexity, motion, channel conditions, the status of the video system components, or other relevant factor. Each of a plurality of potential coding modes may be assigned a weight reflecting an estimation of the likelihood that the coding mode will result in quality image data. The coding mode decision process may then be altered by changing the order of coding modes attempted according to the assigned weight. Code removal and early termination may further alter the coding mode decision process. | 08-02-2012 |
20120195372 | JOINT FRAME RATE AND RESOLUTION ADAPTATION - A video coder employs techniques for applying frame rate adaptation and variable resolution adaptation in response to environmental coding factors present at the coding terminal. According to such techniques, a coder may estimate a coding quality level to be applied based on the environmental coding factors. The coder may retrieve from a controller table, settings for resolution and frame rate based on the estimated quality level. Optionally, the coder further may retrieve settings identifying a range of quantization parameters that may be used during coding. Prior to coding, the coder may configure input video data to match the resolution and frame rate settings retrieved from the controller table. Thereafter, the coder may code the reconfigured input video data by motion-compensation prediction constrained, as applicable, by the retrieved quantization parameter range. | 08-02-2012 |
20120195376 | DISPLAY QUALITY IN A VARIABLE RESOLUTION VIDEO CODER/DECODER SYSTEM - In a video coder/decoder system using variable resolution adaptation, decoder techniques provide a mechanism to changing resolution of coded lower-resolution video to a higher resolution for rendering. Coded video data of a low resolution frame may be decoded. A motion estimation search may be performed between the decoded low resolution frame and a cache of previously-stored high resolution video frames. If the motion estimation search generates one or more matches, high resolution video data of the decoded frame may generated as a derivation of matching data from the cached video frames. | 08-02-2012 |
20120207212 | VISUALLY MASKED METRIC FOR PIXEL BLOCK SIMILARITY - Selecting a coding mode for coding video data by measuring a distortion sensitivity threshold for a pixel block, calculating a distortion threshold representative of the maximum distortion that may be effectively masked by the brightness and texture of the pixel block, estimating the distortion induced by coding the pixel block according to skip mode and coding the source pixel block with a predictive coding technique if the estimated distortion value exceeds the distortion threshold. The distortion sensitivity threshold may include, for example, a brightness value or a texture value. The contrast between the pixel block and the surrounding pixel blocks may also be considered such that if the contrast exceeds a contrast threshold calculated based on the measurement of brightness and texture, the source pixel block may be coded with a predictive coding technique even if the estimated distortion value does not exceed the distortion threshold. | 08-16-2012 |
20120207214 | WEIGHTED PREDICTION PARAMETER ESTIMATION - Video coding systems incorporate techniques for deriving scalars W and/or O for use in weighted prediction. W represents a scaling factor and O represents an offset value. Given a frame of input video to be coded, a prediction match may be established one or more reference frames. The input frame may be parsed into a plurality of regions. Thereafter the scaling factor W and/or offset value O may be derived by developing a system of equations relating a predicted pixel to the pixel in the frame by the scaling factor W and/or offset value O. Equations within the system may be prioritized according to priority among regions, and scaling factor W and/or offset value O may be solved for. The scaling factor W and/or offset value O may be used during weighted prediction of the input frame. | 08-16-2012 |
20120260145 | Per-Image Forward Error Correction - Some embodiments provide a method for encoding digital video. The method receives a digital video image. The method encodes the digital video image. The method generates error correction information for the encoded digital video image using only data from the encoded digital video image. The method transmits the generated error correction information with the encoded digital video image. In some embodiments, the method determines a level of error protection for the encoded digital video image based on an image type of the encoded digital video image. | 10-11-2012 |
20120281715 | ADAPTIVE BANDWIDTH ESTIMATION - Some embodiments provide a method of combining multiple streams of data packets into a single combined stream in a manner that facilitates accurate estimation of bandwidth of a connection over a network between two devices. When combining the streams into the combined stream, the method associates a set of packets from a first stream and a reference packet from a second stream to form a longer sequence of packets in the combined stream. The method sends the combined stream from a first device to a second device so that the second device can estimate the bandwidth of the connection between the first and second devices based on the inter-arrival times of the packets in the sequence of packets. | 11-08-2012 |
20120328018 | OPTIMIZED SEARCH FOR REFERENCE FRAMES IN PREDICTIVE VIDEO CODING SYSTEM - A system and method for efficiently performing motion estimation during temporal prediction for coding. When a new frame is presented for coding, an encoder may identify a limited number of pixel blocks within the input frame that are complex. The encoder may perform motion estimation searches to find reference frame(s) that are adequate prediction references for the complex pixel blocks. The encoder may search for prediction references for the remaining pixel blocks of the new frame, confining the search to the reference frame(s) that were selected as prediction references of the complex pixel blocks. | 12-27-2012 |
20130003845 | ADAPTIVE CONFIGURATION OF REFERENCE FRAME BUFFER BASED ON CAMERA AND BACKGROUND MOTION - In a video coding/decoding system, reference picture caches in a video coder and decoder may be partitioned dynamically based on camera and background motion can lead to improved coding efficiency and coding quality. When a camera is fixed and therefore exhibits low motion, a system may allocate larger portions of the reference picture cache to storage of long term reference frames. In this case, foreground elements of an image (for example, a person) may move in front of a relatively fixed background. Increasing the number of long term reference frames can increase the chances that, no matter where the foreground elements are within a frame currently being coded, the reference picture cache will contain at least one frame that provides an adequate prediction match to background elements within the new frame. Thus the background elements uncovered in the current frame can be coded at high quality with a low number of bits. When a camera exhibits high motion, the system may allocate larger portions of the reference picture cache to storage of short term reference frames. | 01-03-2013 |
20130003846 | FRAME ENCODING SELECTION BASED ON FRAME SIMILARITIES AND VISUAL QUALITY AND INTERESTS - A system an method for determining to select frames from a video sequence that have high visual appeal and can be coded at high quality when frame rates of coded video drop to such low levels that perceptual sensations of moving video are lost. A metric is derived from a candidate input frame, and such metric is used to determine whether to increase or decrease a weight accorded to the candidate input frame. In an embodiment, the metric may be the auto- exposure data associated with the candidate input frame. | 01-03-2013 |
20130027581 | ADAPTIVE AUTO EXPOSURE ADJUSTMENT - Techniques for adjusting exposure parameters of a camera such that video data captured by the camera may be coded efficiently. A camera with auto exposure control may capture and output frames of video. A pre-processor may estimate brightness of the frames of the video output from the camera. A controller may estimate a rate of brightness change among the frames, and when the rate of change is lower than a predetermined threshold, the controller may reduce sensitivity of the auto exposure control. A coding engine may predictively code the video. | 01-31-2013 |
20130034146 | SELECTION OF ENCODER AND DECODER FOR A VIDEO COMMUNICATIONS SESSION - For a first device participating in a video communications session with a second device, some embodiments provide a method that receives sets of encoding features supported by each of one or more decoders of the second device. The method selects an encoder for the video communication session from several encoders available to the first device. The method selects a set of encoding features of the selected encoder based on the sets of encoding features received from the second device. The method transmits an encoded video bitstream to the second device along with information identifying the selected features in order for the second device to select a decoder to decode the bitstream. | 02-07-2013 |
20130034151 | FLEXIBLE CODEC SWITCHING - A system and method for switching between multiple encoders or decoders may be implemented to quickly and seamlessly transfer coding operations between two encoders. Before switching from a first encoder to a second encoder, the second encoder is initialized and updated with a copy of the necessary information from the first encoder. Similarly when switching from a first decoder to a second decoder, the second decoder is initialized and the necessary information from the first decoder is passed to the second decoder. A controller may monitor the system to identify a condition that would trigger an encoder switch and identify the encoder that best suits the system conditions. According to an embodiment, a shared memory unit accessible by either encoder may store the initialization information. According to an embodiment, a shared decode unit accessible by either encoder may transmit decoded frames between encoders. | 02-07-2013 |
20130070151 | Auto Exposure Techniques for Variable Lighting Conditions - Systems, methods, and a computer readable medium for performing auto exposure (AE) techniques that are beneficial in variable lighting conditions—and particularly applicable to handheld and/or mobile videoconferencing applications—are disclosed herein. Handheld and/or mobile videoconferencing applications—unlike their fixed camera counterparts—are often exposed to a wide variety of rapidly changing lighting and scene conditions, and thus face a difficult trade-off between adjusting exposure parameter values too frequently or not frequently enough. In personal electronic devices executing such handheld and/or mobile videoconferencing applications, it may be desirable to: use a small, centered, and center-weighted exposure metering region; set a relatively low brightness target value; and adjust the camera's exposure parameter values according to a distance-dependent convergence speed function. The use of such techniques, in conjunction with a relatively large stability region, may also improve the quality of a video encoder's temporal predictions—and thus video quality—in videoconferencing applications. | 03-21-2013 |
20130195178 | OBJECT DETECTION INFORMED ENCODING - Embodiments of the present invention provide techniques for coding video data efficiently based on detection of objects within video sequences. A video coder may perform object detection on the frame and when an object is detected, develop statistics of an area of the frame in which the object is located. The video coder may compare pixels adjacent to the object location to the object's statistics and may define an object region to include pixel blocks corresponding to the object's location and pixel blocks corresponding to adjacent pixels having similar statistics as the detected object. The coder may code the video frame according to a block-based compression algorithm wherein pixel blocks of the object region are coded according to coding parameters generating relatively high quality coding and pixel blocks outside the object region are coded according to coding parameters generating relatively lower quality coding. | 08-01-2013 |
20130195183 | VIDEO CODING EFFICIENCY WITH CAMERA METADATA - A system and method for using camera capture settings and related metadata to estimate the parameters for encoding a frame of the captured video data and to modify reference frames to accommodate detected camera setting changes. According to an embodiment, global brightness and color changes in video capture may be modeled by performing a sequence of transform operations on the reference frames to further improve the coding efficiency of a video coding system. | 08-01-2013 |
20130222515 | SYSTEM AND METHOD FOR OPTIMIZING VIDEO CONFERENCING IN A WIRELESS DEVICE - A wireless device described herein can use information on data flow, in addition to indications from the physical network, to decide on suitable bandwidth usage for audio and video information. This data flow information is further used to determine an efficient network route to use for high-quality reception and transmission of audio and video data, as well as the appropriate time to switch between available network routes to improve bandwidth performance. | 08-29-2013 |
20130223525 | PIXEL PATCH COLLECTION FOR PREDICTION IN VIDEO CODING SYSTEM - In a video coding system, an encoder may include a coding engine to predictively code input video, a decoder to reconstruct reference pictures generated by the coding engine, a reference picture cache to store the reconstructed reference pictures, a patch cache to store prediction patches generated from other sources, and a prediction search unit to search among the reference picture cache and the patch cache to generate prediction references for use by the coding engine while coding input video. The prediction patches may be assembled from a variety of sources including: predefined image content, reference pictures being evicted from the reference picture cache, image content of prior coding sessions and image data stored by applications on a common terminal where the encoder resides. A decoder may store prediction patches in its own patch cache for synchronous decoding. | 08-29-2013 |
20130235928 | ADVANCED CODING TECHNIQUES - Embodiments of the present invention provide techniques for efficiently coding/decoding video data during circumstances when constraints are imposed on the video data. A frame from a video sequence may be marked as a delayed decoder refresh frame. Frames successive to the delayed decoder refresh frame in coding order may predictively coded without reference to frames preceding the delayed decoder refresh frame in coding order. The distance between the delayed decoder refresh frame and the successive frames may exceed a distance threshold. Frames successive to a current frame in decoding order may be decoded without reference to frames preceding the current frame in decoding order. The distance between the current frame and the successive frames may exceed a distance threshold. | 09-12-2013 |
20130254620 | IMPROVED ERROR CORRECTION CODING FOR RECOVERING MULTIPLE PACKETS IN A GROUP IN VIEW OF LIMITED BANDWIDTH - Coded video data may be transmitted between an encoder and a decoder using multiple FEC codes and/or packets for error detection and correction. Only a subset of the FEC packets need be transmitted between the encoder and decoder. The FEC packets of each FEC group may take, as inputs, data packets of a current FEC group and also an untransmitted FEC packet of a preceding FEC group. Due to relationships among the FEC packets, when transmission errors arise and data packets are lost, there remain opportunities for a decoder to recover lost data packets from earlier-received FEC groups when later-received FEC groups are decoded. This opportunity to recover data packets from earlier FEC groups may be useful in video coding and other systems, in which later-received data often cannot be decoded unless earlier-received data is decoded properly. | 09-26-2013 |
20130265378 | Switching Cameras During a Video Conference of a Multi-Camera Mobile Device - Some embodiments provide a method for conducting a video conference between a first mobile device and a second device. The first mobile device includes first and second cameras. The method selects the first camera for capturing images. The method transmits images captured by the first camera to the second device. The method receives selections of the second camera for capturing images during the video conference. The method terminates the transmission of images captured by the first camera and transmits images captured by the second camera of the first mobile device to the second device during the video conference. | 10-10-2013 |
20130328771 | Camera-Assisted Motion Estimation for Application Control - Embodiments of the present invention generate estimates of device motion from two data sources on a computing device—a motion sensor and a camera. The device may compare the estimates to each other to determine if they agree. If they agree, the device may confirm that device motion estimates based on the motion sensor are accurate and may output those estimates to an application within the device. If the device motion estimates disagree, the device may alter the motion estimates obtained from the motion sensor before outputting them to the application. | 12-12-2013 |
20130329064 | TEMPORAL ALIASING REDUCTION AND CODING OF UPSAMPLED VIDEO - Embodiments of the invention provide techniques for upsampling a video sequence for coding. According to the method, an estimate of camera motion may be obtained from motion sensor data. Video data may be analyzed to detect motion within frames output from a camera that is not induced by the camera motion. When non-camera motion falls within a predetermined operational limit, video upsampling processes may be engaged. In another embodiment, video upsampling may be performed by twice estimating image content for a hypothetical new a frame using two different sources as inputs. A determination may be made whether the two estimates of the frame match each other sufficiently well. If so, the two estimates may be merged to yield a final estimated frame and the new frame may be integrated into a stream of video data. | 12-12-2013 |
20130329798 | INFERRED KEY FRAMES FOR FAST INITIATION OF VIDEO CODING SESSIONS - A video coding system may initiate coding of a new coding session with reference to an “inferred key frame” that is known both to an encoder and a decoder before a coding session begins. The inferred key frame need not be transmitted between the encoder and decoder via the channel. Instead, the inferred key frame may be stored locally at the encoder and the decoder. Frames coded at the onset of a video coding session may be coded with reference to the inferred key frame, which increases the likelihood a decoder will receive a frame it can decode properly and accelerate the rate at which the decoder generates recovered video data. Inferred key frames may be used as prediction references to recover from transmission errors. | 12-12-2013 |
20130329799 | PREDICTIVE VIDEO CODER WITH LOW POWER REFERENCE PICTURE TRANSFORMATION - Video coders may perform perspective transformation of reference frames during coding in a manner that conserves processing resources. When a new input frame is available for coding, a camera position for the input frame may be estimated. A video coder may search for reference pictures having similar camera positions as the position of the input frame and, for each reference picture identified, the video coder may perform a prediction search to identify a reference picture that is the best prediction match for the input frame. Once the video coder identifies a reference picture to serve as a prediction source for the input frame, the video coder may derive a transform to match the reference frame data to the input frame data and may transform the reference picture accordingly. The video coder may code the input frame using the transformed reference picture as a prediction reference and may transmit coded frame data and the camera position of the input frame to a decoder. Thus, the video coder may perform derivation and execution of transforms on a limited basis which conserves system resources. | 12-12-2013 |
20140044194 | ENTROPY CODING TECHNIQUES AND PROTOCOL TO SUPPORT PARALLEL PROCESSING WITH LOW LATENCY - In a communication system, parallel encoding and decoding of serially-coded data occurs in a manner that supports low latency communication. A plurality of data items may be coded as serially-coded data sequences and a transmission sequence may be built from them. An index table may be built having a plurality of entries representing respective start points of the serially-coded data sequences within the transmission sequence. The transmission sequence may be transmitted to a channel and, thereafter, the index table may be transmitted. Latencies otherwise involved in inserting an index table into the beginning of a transmission sequence may be avoided. | 02-13-2014 |
20140064165 | RADIO POWER SAVING TECHNIQUES FOR VIDEO CONFERENCE APPLICATIONS - In video conferencing over a radio network, the radio equipment is a major power consumer especially in cellular networks such as LTE. In order to reduce the radio power consumption in video conferencing, it is important to introduce an enough radio inactive time. Several types of data buffering and bundling can be employed within a reasonable range of latency that doesn't significantly disrupt the real-time nature of video conferencing. In addition, the data transmission can be synchronized to the data reception in a controlled manner, which can result in an even longer radio inactive time and thus take advantage of radio power saving modes such as LTE C-DRX. | 03-06-2014 |
20140071309 | SIGNAL SHAPING FOR IMPROVED MOBILE VIDEO COMMUNICATION - In certain low-light or other poor image capture conditions, the camera capture settings may create noise fitting a known profile, including certain specific color ranges and signal frequencies, in the captured image. A pre-processor may identify frequency bands and DC offsets that may indicate noise in an image captured with known settings. Then the areas of the image containing the identified frequencies and offsets may be analyzed spatially and temporally to confirm that the identified regions are noise and not part of the scene and an appropriate filter defined. | 03-13-2014 |
20140072029 | ADAPTIVE SCALER SWITCHING - An adaptive scaler switching system may implement multiple scalers including both a software scaler and a hardware scaler, and a controller that may manage the switch between scalers by considering the real-time constraints of the system and the available system resources. Information about the availability of system resources may be received in real-time, for example the controller may receive information about the system thermal status, the timing requirements for processing the video data, the quality of the scaled data, and any other relevant system statistics that may affect the scaler switch decision. According to an embodiment, the system may maintain statistics in a table, and update the table information as necessary. | 03-13-2014 |
20140086315 | ERROR RESILIENT MANAGEMENT OF PICTURE ORDER COUNT IN PREDICTIVE CODING SYSTEMS - Coding techniques for input video may include assigning picture identifiers to input frames in either long-form or short-form formats. If a network error has occurred that results in loss of previously-coded video data, a new input frame may be assigned a picture identifier that is coded in a long-form coding format. If no network error has occurred, the input frame may be assigned a picture identifier that is coded in a short-form coding format. Long-form coding may mitigate against loss of synchronization between an encoder and a decoder by picture identifiers. | 03-27-2014 |
20140092987 | ENTROPY CODING TECHNIQUES AND PROTOCOL TO SUPPORT PARALLEL PROCESSING WITH LOW LATENCY - In a communication system, parallel encoding and decoding of serially-coded data occurs in a manner that supports low latency communication. A plurality of data items may be coded as serially-coded data sequences and a transmission sequence may be built from them. An index table may be built having a plurality of entries representing respective start points of the serially-coded data sequences within the transmission sequence. The transmission sequence may be transmitted to a channel and, thereafter, the index table may be transmitted. Latencies otherwise involved in inserting an index table into the beginning of a transmission sequence may be avoided. | 04-03-2014 |
20140092997 | ERROR RESILIENT TRANSMISSION OF RANDOM ACCESS FRAMES AND GLOBAL CODING PARAMETERS - Error mitigation techniques are provided for video coding system in which input frames are selected for coding either as a Random Access Pictures (“RAP frames”) or as a non-RAP frame. Coded RAP frames may include RAP identifiers that set an ID context for subsequent frames. Coded non-RAP frames may include RAP identifiers that match the RAP identifiers that were included in the coded RAP frames. Thus, in the absence of transmission errors, a coded non-RAP frame should include a RAP identifier that matches the identifier of the preceding RAP frame. If the identifier of a non-RAP frame does not match the identifier of the RAP frame that immediately preceded it, then it indicates that a RAP frame was lost during transmission. In this case, the decoder may engage error recovery processes. | 04-03-2014 |
20140269932 | CODEC TECHNIQUES FOR FAST SWITCHING - A video streaming method for transitioning between multiple sequences of coded video data may include receiving and decoding transmission units from a first sequence of coded video data. In response to a request to transition to a second sequence of coded video data, the method may determine whether a time to transition to the second sequence of coded video data can be reduced by transitioning to the second sequence of coded video data via an intermediate sequence of coded video data. If the time can be reduced, the method may include receiving at least one transmission unit from an intermediate sequence of coded video data that corresponds to the request to transition, decoding the transmission unit from the intermediate sequence, and transitioning from the first sequence to the second sequence via the decoded transmission unit from the intermediate sequence. | 09-18-2014 |
20140354759 | Establishing a Video Conference During a Phone Call - Some embodiments provide a method for initiating a video conference using a first mobile device. The method presents, during an audio call through a wireless communication network with a second device, a selectable user-interface (UI) item on the first mobile device for switching from the audio call to the video conference. The method receives a selection of the selectable UI item. The method initiates the video conference without terminating the audio call. The method terminates the audio call before allowing the first and second devices to present audio and video data exchanged through the video conference. | 12-04-2014 |
20140362159 | ADAPTIVE POST-PROCESSING FOR MOBILE VIDEO CALLING SYSTEM - A system may include a receiver, a decoder, a post-processor, and a controller. The receiver may receive encoded video data. The decoder may decode the encoded video data. The post-processor may perform post-processing on frames of decoded video sequence from the decoder. The controller may adjust post-processing of a current frame, based upon at least one condition parameters detected at the system. | 12-11-2014 |
20140362162 | RADIO POWER SAVING TECHNIQUES FOR VIDEO CONFERENCE APPLICATIONS - In video conferencing over a radio network, the radio equipment is a major power consumer especially in cellular networks such as LTE. In order to reduce the radio power consumption in video conferencing, it is important to introduce an enough radio inactive time. Several types of data buffering and bundling can be employed within a reasonable range of latency that doesn't significantly disrupt the real-time nature of video conferencing. In addition, the data transmission can be synchronized to the data reception in a controlled manner, which can result in an even longer radio inactive time and thus take advantage of radio power saving modes such as LTE C-DRX. | 12-11-2014 |
20140362919 | COHERENCE GROUPS: REGION DESCRIPTORS FOR LOW BIT RATE ENCODING - The invention is directed to an efficient way for encoding and decoding video. Embodiments include identifying different coding units that share a similar characteristic. The characteristic can be, for example: quantization values, modes, block sizes, color space, motion vectors, depth, facial and non-facial regions, and filter values. An encoder may then group the units together as a coherence group. An encoder may similarly create a table or other data structure of the coding units. An encoder may then extract the commonly repeating characteristic or attribute from the coding units. The encoder may transmit the coherence groups along with the data structure, and other coding units which were not part of a coherence group. The decoder may receive the data, and utilize the shared characteristic by storing locally in cache, for faster repeated decoding, and decode the coherence group together. | 12-11-2014 |
20140362927 | VIDEO CODEC FLASHING EFFECT REDUCTION - A system may include a detector, a controller, and an encoder. The detector may receive data from video input to detect a group of pixels in a video sequence, and may determine whether the group of pixels needs additional bits for encoding. The controller may determine the number of bits for the additional bits and may allocate the additional bits with the number of bits in a data stream. The encoder may by controlled by the controller to encode the group of pixels with the additional bits, and output to the encoded output. | 12-11-2014 |
20150016804 | TRICK PLAY IN DIGITAL VIDEO STREAMING - System and methods for improved playback of a video stream are presented. Video snippets are identified that include a number of consecutive frames for playback. Snippets may be evenly temporally spaced in the video stream or may be content adaptive. Then the first frame of a snippet may be selected as the first frame of a scene or other appropriate stopping point. Scene detection, object detection, motion detection, video metadata, or other information generated during encoding or decoding of the video stream may aid in appropriate snippet selection. | 01-15-2015 |