Qualcomm Incorporated

Yi Liang

Khaled Helmi El-Maleh

Sharath Manjunath

Haohong Wang

Suhail Jalil

Stephen A Molloy

King-Chung Lai

Scott Howard King

The disclosure is directed to techniques for content-adaptive background skipping for region-of-interest (ROI) video coding. The techniques may be useful in video telephony (VT) applications such as video streaming and videoconferencing, and especially useful in low bit-rate wireless communication applications, such as mobile VT. The disclosed techniques analyze content information of a video frame to dynamically determine whether to skip a non-ROI area within the frame. For example, the skipping determination may be based on content activity, such as ROI shape deformation, ROI motion, non-ROI motion, non-ROI texture complexity, and accumulated distortion due to non-ROI skipping. The skip determination may operate in conjunction with either frame-level or macroblock-level bit allocation.

Content-adaptive background skipping for region-of-interest video coding

This disclosure describes adaptive spatial variant interpolation (SVI) techniques for image upscaling. In various embodiments, the interpolation techniques described in this disclosure may support low complexity upscaling of image while promoting high image quality, including enhanced sharpness, higher contrast and more accurate interpolation. The interpolation techniques may be applied using generalized finite impulse response (FIR) filters. In some embodiments, the interpolation techniques may be content-adaptive to provide more accurate interpolation while suppressing significant artifacts associated with sharp edges. In addition, the interpolation techniques may be readily applicable to upscaling of color imagery and video, e.g., in both YCbCr (luminance, blue chrominance, red chrominance) and RGB (red, green, blue) formats.

Adaptive spatial variant interpolation for image upscaling

An adaptive Intra-refresh (IR) technique for digital video encoding adjusts IR rate based on video content, or a combination of video content and channel condition. The IR rate may be applied at the frame level or macroblock (MB) level. At the frame level, the IR rate specifies the percentage of MBs to be Intra-coded within the frame. At the MB level, the IR rate defines a statistical probability that a particular MB is to be Intra-coded. The IR rate is adjusted in proportion to a combined metric that weighs estimated channel loss probability, frame-to-frame variation, and texture information. The IR rate can be determined using a close-form solution that requires relatively low implementation complexity. For example, such a close-form does not require iteration or an exhaustive search. In addition, the IR rate can be determined from parameters that are available before motion estimation and compensation are performed.

Adaptive intra-refresh for digital video encoding

The disclosure is directed to adaptive frame skipping techniques for rate controlled video encoding of a video sequence. According to the disclosed techniques, an encoder performs frame skipping in an intelligent manner that can improve video quality of the encoded sequence relative to encoding using conventional frame skipping. In particular, the disclosed frame skipping scheme is adaptive and considers motion activity of the video frames in order to identify certain frames that can be skipped without sacrificing significant video quality. The described frame skipping techniques may take into account the tradeoff between spatial and temporal quality of different video frames. In this manner, the techniques can allocate limited resources between the spatial and temporal quality in a way that can improve the visual appearance of a video sequence.

Adaptive frame skipping techniques for rate controlled video encoding

This disclosure describes deblock filtering techniques in which an in-loop deblock filter of a first codec is used as a post deblock filter of a second codec. A number of techniques are also described to facilitate input parameter adjustments and allow for the effective use of the filter with both codecs. The techniques can simplify the architecture of a device that includes multiple codecs operating according to different coding standards. Specifically, the different codecs can use the same deblocking filter regardless of whether the coding standard calls for in-loop filtering or whether post filtering is used. For example, a filter designed as an in-loop deblocking filter for a codec that complies with the ITU-T H.264 coding standard can be used as a post deblocking filter for MPEG-4 video.

Deblock filtering techniques for video coding according to multiple video standards

Image processing techniques are described that reduce the amount of bandwidth required to read an image from memory for display. According to the techniques, a processor stores low change rate display layers in a memory such that a processor can read the display layers from the memory using a reduced amount of processing resources. An overlay module blends low change rate display layers into a combined overlay layer. A processor reads the overlay layer from the memory and selectively processes the overlay layer based on processing information for the overlay layer recorded in memory. The processor then blends the overlay layer and a high change rate video display layer to update a single image for display according to a high change rate. In addition, the overlay module updates the overlay layer based on the low change rate display layers according to a low change rate.

Blending multiple display layers

Methods and apparatus are presented for reducing the computational complexity of coding mode decisions by exploiting the correlations across spatially and/or temporally close coding mode decisions. A mode decision for a current macroblock is based on the mode decisions of spatially and/or temporarily close macroblocks.

Methods and apparatus for performing fast mode decisions in video codecs

In one embodiment, this disclosure provides an encoding device comprising a mode selection engine that performs mode selection for intra-prediction encoding regardless of whether the encoding device is programmed to comply with first encoding standard or a second encoding standard. The device also includes a first encoder to perform the intra-prediction encoding according to the selected mode in compliance with the first encoding standard when the encoding device is programmed to comply with the first encoding standard, and a second encoder to perform the intra-prediction encoding according to the selected mode in compliance with the second encoding standard when the encoding device is programmed to comply with the second encoding standard. The techniques can simplify mode selection in support of multiple different intra-prediction encoding standards.

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San Diego, CA, United States of America

Yi Liang