Abstract: Example methods and apparatus to detect transport faults in media presentation systems are disclosed. An example method comprises decoding a media stream to form audio data and pixel data, computing a first value representative of the media stream using pixel data associated with a first set of the video frames, computing a second value representative of the media stream using pixel data associated with a second set of the video frames, computing a third value representative of first speech in a first segment of the audio data, computing a fourth value representative of second speech in a second segment of the audio data, determining a fifth value representative of a likelihood that a transport failure has affected the media stream, the fifth value determined using the first, second, third and fourth values, and comparing the fifth value to a threshold to determine whether to generate a transport failure alert.

Abstract: A system, method and computer-readable media are introduced that relate to data coding and decoding. A computing device encodes received data such as video data into a base layer of compressed video and an enhancement layer of compressed video. The computing device controls drift introduced into the base layer of the compressed video. The computing device, such as a scalable video coder, allows drift by predicting the base layer from the enhancement layer information. The amount of drift is managed to improve overall compression efficiency.

Abstract: A method for detecting aliasing artifacts includes receiving a second image that has been converted from a first image and evaluating the second image using a computer to detect aliasing artifacts due to the conversion, where the evaluation is performed without reference to the first image. The second image is a different size than the first image The second image is evaluated by identifying patches in the image that are likely to contain strong directional energy with few distractions and to estimate a direction component for each of the identified patches. The total energy of each patch is partitioned into an estimated signal energy and an estimated aliasing energy. The estimated aliasing energy and the estimated signal energy of each of the identified patches are combined to obtain an estimate of the aliasing artifacts in the image.

Abstract: A system, method and computer-readable media are introduced that relate to data coding and decoding. A computing device encodes received data such as video data into a base layer of compressed video and an enhancement layer of compressed video. The computing device controls drift introduced into the base layer of the compressed video. The computing device, such as a scalable video coder, allows drift by predicting the base layer from the enhancement layer information. The amount of drift is managed to improve overall compression efficiency.

Abstract: Example methods and apparatus to detect transport faults in media presentation systems are disclosed. An example method comprises decoding a media stream to form audio data and pixel data, computing a first value representative of the media stream using pixel data associated with a first set of the video frames, computing a second value representative of the media stream using pixel data associated with a second set of the video frames, computing a third value representative of first speech in a first segment of the audio data, computing a fourth value representative of second speech in a second segment of the audio data, determining a fifth value representative of a likelihood that a transport failure has affected the media stream, the fifth value determined using the first, second, third and fourth values, and comparing the fifth value to a threshold to determine whether to generate a transport failure alert.

Abstract: A method and apparatus for managing video transport is disclosed. A system that incorporates teachings of the present disclosure may include, for example, a server having a controller to predict visibility to a viewer of packet loss impairment for communicated video content based at least in part on scene information for one or more packets of the video content. Other embodiments are disclosed.

Abstract: Scalable video coders have traditionally avoided using enhancement layer information to predict the base layer, so as to avoid so-called “drift”. As a result, they are less efficient than a one-layer coder. The present invention is directed to a scalable video coder that allows drift, by predicting the base layer from the enhancement layer information. Through careful management of the amount of drift introduced, the overall compression efficiency can be improved while only slighly degrading resilience for lower bit-rates.

Abstract: A method and apparatus are described for inserting a watermark in the compressed domain. The watermark inserted does not require a reference. An overall watermarking system incorporating the invention combines cleartext, bitstream, and integrated watermarking. In a perceptual coder, the data enters a filterbank, where it is processed into multiple separate coefficients. A rate/distortion control module uses noise threshold information from a perceptual coder, together with bit-count information from a noiseless coder, to compute scale factors. The coefficients are multiplied by the scale factors and quantized, then noiseless coded and then output for further processing/transmission. The invention supports three embodiments for inserting a mark into the bitstream imperceptibly. It is assumed that some set of scale factor bands have been selected, into which mark data will be inserted. In one embodiment, a set of multipliers {xi=2Ni: i&egr;M} is chosen.

Abstract: A method and system for maintaining the quality of video transported over wireless channels uses a transcoder to modify and maintain the optical resilience of an encoded bitstream. The transcoder increases the spatial resilience by reducing the number of blocks per slice, and increases the temporal resilience by increasing the proportion of I-blocks that are transmitted in each frame. Also, the transcoder maintains the same input bit rate by dropping less significant coefficients as it increases resilience. The transcoder of the present invention maintains the resilience at an optimal level to accommodate the prevailing channel conditions as measured by the BER of the wireless channel. Rate distortion theory is applied to determine the optimal allocation of bit rate among spatial resilience, temporal resilience and source rate, where it is has been found that the optimal allocation of the present invention (which occurs in near-real time) provides nearly the same result as doing an exhaustive search.

Abstract: A method and apparatus provide a smoothing and rate adaptation algorithm to facilitate the flow of video data, maintaining video quality while avoiding potentially harmful buffering delays. The invention uses a smoothing interval to determine a rate to request for allocation. The invention also adapts the encoding rate in relation to a target delay for a source buffer.

Abstract: The problems associated with slow timing recovery in an ATM receiver are overcome by detecting the transmission rate of a received bit stream and periodically detecting the transmitted Enc.sub.-- CR values, which are used to calculate additional estimated clock reference (Est.sub.-- CR) values between the actual transmitted Enc.sub.-- CR values. The Est.sub.-- CR values are then used along with the actually received Enc.sub.-- CR values to generate a phase locked loop (PLL) error signal (TC.sub.-- ERROR), wherein the PLL is caused to converge more rapidly. In one embodiment, the TC.sub.-- ERROR values are generated for each received cell or packet instead of only for each received Enc.sub.-- CR value and, consequently, timing recovery is significantly speeded up. Additionally, the Est.sub.-- CR values can be adjusted to minimize the effects of lost cells, as well as, drift in the transmission rate.