Patent application number | Description | Published |
20080212677 | Efficient Video Block Mode Changes in Second Pass Video Coding - This disclosure describes techniques for second pass video coding in a multi-pass video coding scenario. The coding modes for some video blocks encoded during a second pass may be changed relative to the coding modes used for such video blocks in the first pass. However, motion information does not change for those video blocks that have the changed modes. In particular, mode changes can be made in the second coding pass relative to the modes used in the first coding pass without changing the manner in which motion information will be derived at the decoder, e.g., due to similarities between the original modes of the first pass and changed modes used in the second pass. The second pass coding techniques may also include quantization parameter adjustments, and the mode changes can cause such quantization parameter adjustments to have more profound refinements effects on the second pass coding. | 09-04-2008 |
20080273596 | DIGITAL MULTIMEDIA CHANNEL SWITCHING - The disclosure relates to techniques for coding a channel switch frame used for switching between channels of digital multimedia content. In particular, an encoding device may code channel switch frame to exclude one or more blocks of pixels that may be reconstructed at a desired fidelity at a decoding device using one or more spatial error concealment algorithms. Excluding the one or more blocks of pixels of the channel switch frame that can be reconstructed at a desirable fidelity reduces the amount of bandwidth necessary to code the portion of the channel switch frame, thus allowing more efficient utilization of available bandwidth. | 11-06-2008 |
20090109341 | DETECTING SCENE TRANSITIONS IN DIGITAL VIDEO SEQUENCES - This disclosure describes techniques for detecting scene transitions in a digital video sequence. An encoding device may, for example, analyze a distribution of pixel values over a plurality of frames to detect locations at which the scene transitions occur. In particular, the encoding device analyzes the distribution of pixel locations having values in a mid-range of possible pixel values to identify locations in the plurality of frames that experience a significant short-term increase in the number of pixel locations having mid-range pixel values. A significant short-term increase in the number of pixel locations with pixel values in the mid-range of possible pixel values is indicative of a soft transition. In this manner, occurrences of gradual scene transitions are detected by identifying locations within the plurality of frames that have significant short-term increases in the number of pixel locations having mid-range pixel values. | 04-30-2009 |
20090154816 | ADAPTIVE GROUP OF PICTURES (AGOP) STRUCTURE DETERMINATION - This disclosure is directed to techniques for determining a picture type for each of a plurality of frames included in a video sequence based on cross-correlations between the frames. The cross-correlations include first order cross-correlations between image information within pairs of frames included in the video sequence and second order cross-correlations between pairs of the first order cross-correlations. The first order cross-correlations may be analyzed to detect video transitional effects between the frames. The first and second order cross-correlations may be comparatively analyzed to determine temporal similarities between the frames. Therefore, the correlation-based determination techniques determine picture types for the frames based on the video transitional effects and the temporal similarities. The correlation-based determination techniques may calculate the first order cross-correlations between images within pairs of frames, or between sets of subimages within pairs of frames that are then averaged over the subimages for each of the pairs of frames. | 06-18-2009 |
20100076998 | METHOD AND SYSTEM FOR GENERATING A DYNAMIC HELP DOCUMENT - A method for generating a dynamic help document involves obtaining question-answer pairs associated with a client-server application, determining rankings of the question-answer pairs based on user feedback about the question-answer pairs, and determining a first preferred question-answer pair based on rankings of question-answer pairs. The method further involves generating the dynamic help document using the first preferred question-answer pair, updating rankings of the question-answer pairs based on additional user feedback about the question-answer pairs, determining a second preferred question-answer pair based on updated rankings of the question-answer pairs, and updating the dynamic help document by replacing the first preferred question-answer pair with the second preferred question-answer pair. | 03-25-2010 |
20100260262 | EFFICIENT TRANSCODING OF B-FRAMES TO P-FRAMES - This disclosure describes techniques for efficient transcoding from a first format that supports I-units, P-units and B-units to a second format that supports I-units and P-units but does not support the B-units. In particular, this disclosure provides techniques for converting B-frames or B-slices of the first format into P-frames or P-slices of the second format. The techniques avoid the need to decode and re-encode that frames or slices. Instead, residuals associated with the B-video blocks in the first format are augmented and made to be dependent upon only one of the two lists associated with the B-video blocks so that such B-video blocks in the first format can be redefined as P-video blocks in the second format. | 10-14-2010 |
20120294360 | CHANNEL SWITCH FRAME - Methods and apparatus to process multimedia data enabling faster channel acquisitions, improved error recovery and improved efficiency. An encoder device encodes a first portion of multimedia data using inter-coding to generate a first version, and encodes the first portion of multimedia data using intra-coding to generate a second version. A decoder device receives a first version of a first portion of multimedia data, wherein the first version is inter-coded, receives a second version of the first portion of multimedia data, wherein the second version is intra-coded, and selectively decodes the first and second received versions. | 11-22-2012 |
Patent application number | Description | Published |
20110138192 | Verifiable, Leak-Resistant Encryption and Decryption - This patent describes techniques usable by devices to encrypt and decrypt sensitive data to in a manner that provides security from external monitoring attacks. The encrypting device has access to a base secret cryptographic value (key) that is also known to the decrypting device. The sensitive data are decomposed into segments, and each segment is encrypted with a separate encryption key derived from the base key and a message identifier to create a set of encrypted segments. The encrypting device uses the base secret cryptographic value to create validators that prove that the encrypted segments for this message identifier were created by a device with access to the base key. The decrypting device, upon receiving an encrypted segments and validator(s), uses the validator to verify the message identifier and that the encrypted segment are unmodified, then uses a cryptographic key derived from the base key and message identifier to decrypt the segments. Derived keys and validators are produced using methods designed to preserve security even if cipher and hashing operations leak information. Embodiments for systems including SoCs, firmware loading, FPGAs and network communications are described. | 06-09-2011 |
20130173928 | CRYPTOGRAPHIC DEVICE WITH RESISTANCE TO DIFFERENTIAL POWER ANALYSIS AND OTHER EXTERNAL MONITORING ATTACKS - Techniques usable by devices to encrypt and decrypt sensitive data to in a manner that provides security from external monitoring attacks. The encrypting device has access to a base secret cryptographic value (key) that is also known to the decrypting device. The sensitive data are decomposed into segments, and each segment is encrypted with a separate encryption key derived from the base key and a message identifier to create a set of encrypted segments. The encrypting device uses the base secret cryptographic value to create validators that prove that the encrypted segments for this message identifier were created by a device with access to the base key. The decrypting device, upon receiving an encrypted segments and validator(s), uses the validator to verify the message identifier and that the encrypted segment are unmodified, then uses a cryptographic key derived from the base key and message identifier to decrypt the segments. | 07-04-2013 |
20140101753 | Risk Adaptive Information Flow Based Access Control - Systems and methods are provided to manage risk associated with access to information within a given organization. The overall risk tolerance for the organization is determined and allocated among a plurality of subjects within the organization. Allocation is accomplished using either a centralized, request/response or free market mechanism. As requested from subjects within the organization for access to objects, i.e. information and data, are received, the amount of risk or risk level associated with each requested is quantified. Risk quantification can be accomplished using, for example, fuzzy multi-level security. The quantified risk associated with the access request in combination with the identity of the object and the identity of the subject are used to determine whether or not the request should be granted, denied or granted with appropriated mitigation measures. | 04-10-2014 |
20140247944 | CRYPTOGRAPHIC DEVICE WITH RESISTANCE TO DIFFERENTIAL POWER ANALYSIS AND OTHER EXTERNAL MONITORING ATTACKS - Techniques usable by devices to encrypt and decrypt sensitive data to in a manner that provides security from external monitoring attacks. The encrypting device has access to a base secret cryptographic value (key) that is also known to the decrypting device. The sensitive data are decomposed into segments, and each segment is encrypted with a separate encryption key derived from the base key and a message identifier to create a set of encrypted segments. The encrypting device uses the base secret cryptographic value to create validators that prove that the encrypted segments for this message identifier were created by a device with access to the base key. The decrypting device, upon receiving an encrypted segments and validator(s), uses the validator to verify the message identifier and that the encrypted segment are unmodified, then uses a cryptographic key derived from the base key and message identifier to decrypt the segments. | 09-04-2014 |