Abstract: This disclosure describes rules that may be applied during block-based video coding to ensure that quantization parameter selections for luma blocks will not adversely affect the quality of chroma blocks. In accordance with this disclosure, rate-controlled video encoding occurs in which quantization parameter changes in luma blocks are pre-evaluated to determine whether such quantization parameter changes in luma blocks will also cause quantization changes for chroma blocks. If quantization parameter changes in the luma blocks will also cause quantization changes for chroma blocks, then that quantization parameter change for luma blocks may be skipped and not evaluated. In this way, secondary effects of quantization parameter changes in the luma blocks (with respect to the chroma blocks) can be avoided.

Abstract: Techniques for improving the accuracy of prediction in intra-frame coding. A prediction mode can specify a pixel along a direction independently of other pixels along the same direction. In an embodiment, an encoder selects a prediction mode to best represent the image block. In an alternative embodiment, a decoder reconstructs each pixel in the image block by weighting neighboring pixels according to a weight matrix specified by the prediction mode.

Abstract: A video stream (for example, H.264 video) includes intra-encoded portions. Decoding an intra-encoded portion utilizes the result of decoding one or more other portions (called predecessors) in the frame. Frame reconstruction involves identifying a portion that has no predecessor portions that have not been decoded and then initiating decoding of the identified portion(s). When the decoding of a portion is substantially complete, then the remaining portions to be decoded are examined to identify portions that have no predecessors that have not been decoded. By carrying out this method, multiple portions may be decoded simultaneously. Each can be decoded on a different work entity, thereby increasing the rate of decoding of the overall frame. Because deblock filtering a predecessor destroys information needed in the intra-decoding of other portions, prefiltered predecessor information is stored in a buffer for subsequent use during intra-decoding, thereby facilitating simultaneous decoding of multiple portions.

Abstract: The disclosure is directed to techniques for region-of-interest (ROI) processing for video telephone (VT) applications. According to the disclosed techniques, a recipient device defines ROI information for video information transmitted by a sender device, i.e., far-end video information. The recipient device transmits the ROI information to the sender device. Using the ROI information transmitted by the recipient device, the sender device applies preferential encoding to an ROI within a video scene. In this manner, the recipient device is able to remotely control ROI encoding of far-end video information by the sender device.

Abstract: A reconstruction method for reconstructing a first signal from a set of sampled values generated by sampling a second signal at a sub-Nyquist rate and at uniform intervals, the method includes retrieving from the set of sampled values a set of shifts and weights with which the first signal can be reconstructed.

Abstract: A technique for recording information in a battery operated device is provided such that quality level of the recorded information may be changed “on the fly.” In one embodiment, while persistently recording information at a first quality level, the battery operated device may, in response to an input a desire or need to change recording quality level, thereafter persistently record the information at a second quality level different from the first quality level, without interrupting the continuity of the recording session. In a presently preferred embodiment, the information being recorded may comprise video information or audio information. Subsequent inputs indicating the need to change recording quality level yet again may also be received thereby causing the battery operated device to persistently record the information at yet another quality level, which quality level may be the same as the first quality level.