Abstract: A method and apparatus for optimal signal encoding based on reference data relating encoded-signal characteristics to encoding parameters are disclosed. Reference vectors of encoding parameters and corresponding measurements of encoded-signal characteristics are used to establish a functional relationship between each characteristic and the encoding parameters. Candidate vectors of encoding parameters are identified based on user-defined boundaries of both the encoding parameters and acceptable encoded-signal characteristics. A figure of merit is determined for each candidate vector and the candidate vector of highest figure of merit is presented to an encoder.

Abstract: Methods and systems for encoding video data are provided. Evolving standards for video encoding such as High Efficiency Video Coding (HEVC) standard require a significant increase in computational complexity for both inter and intra encoding. The method includes calculating an approximate cost of each of a first set of prediction modes. Then selecting a second set of prediction modes from the first set of prediction modes based on probability distributions associated with each of the modes in the first set of prediction modes, the second set having substantially fewer prediction modes than the first. A number of candidate prediction modes prior to rate distortion optimization (RDO) is reduced. Experimental results show that the proposed method provides substantial time reduction and negligible quality loss as compared to the HEVC reference.

Abstract: Methods and systems for parallel rate-constrained motion estimation in a video encoder are provided. Embodiments of the present invention provide a solution for the problem of the reliance upon spatial dependencies when processing parallel RCME on a frame. In order to solve this problem, embodiments of the present invention determine a list of at least two Motion Vector Predictor Candidates (MVPC), determine, in parallel for at least two of said at least two MVPCs, corresponding Motion Vector Candidates (MVC) using Rate-Constrained Motion Estimation (RCME) and determine the optimal Motion Vector (MV) among the determined MVCs based on rate distortion optimization.

Abstract: A video encoder with rate-constrained search ordering feature for reducing computational cost of motion estimation in video coding has been provided. The video encoder has a motion estimation module for determining vector encoding costs for respective motion vectors corresponding to candidate blocks in a video frame, and assigning an order for evaluating a rate-constrained cost of each candidate block based on the determined vector encoding costs.

Abstract: System and method for optimizing a transcoding session between multiple terminals are disclosed. The method determines properties of the transcoding session, including a number of terminals participating in the transcoding session, media characteristics supported by each terminal, a measure of performance of the transcoding session to be optimized, and optionally a proportion of time involved in the transcoding session for each terminal. Then a cost function characterizing the measure of performance of the transcoding session and depending on the above properties of the transcoding session is built, followed by optimizing the cost function with respect to said measure of performance to determine an optimal measure of performance for the transcoding session and optimal values for the media characteristics for each terminal. In one embodiment, codecs used by multiple terminals and computational complexity of the transcoding session are optimized.

Abstract: Methods and systems for encoding video data are provided. Evolving standards for video encoding such as High Efficiency Video Coding (HEVC) standard require a significant increase in computational complexity for both inter and intra encoding. The method includes calculating an approximate cost of each of a first set of prediction modes. Then selecting a second set of prediction modes from the first set of prediction modes based on probability distributions associated with each of the modes in the first set of prediction modes, the second set having substantially fewer prediction modes than the first. A number of candidate prediction modes prior to rate distortion optimization (RDO) is reduced. Experimental results show that the proposed method provides substantial time reduction and negligible quality loss as compared to the HEVC reference.

Abstract: System and method for optimizing a transcoding session between multiple terminals are disclosed. The method determines properties of the transcoding session, including a number of terminals participating in the transcoding session, media characteristics supported by each terminal, a measure of performance of the transcoding session to be optimized, and optionally a proportion of time involved in the transcoding session for each terminal. Then a cost function characterizing the measure of performance of the transcoding session and depending on the above properties of the transcoding session is built, followed by optimizing the cost function with respect to said measure of performance to determine an optimal measure of performance for the transcoding session and optimal values for the media characteristics for each terminal. In one embodiment, codecs used by multiple terminals and computational complexity of the transcoding session are optimized.

Abstract: Methods and systems for parallel rate-constrained motion estimation in a video encoder are provided. Embodiments of the present invention provide a solution for the problem of the reliance upon spatial dependencies when processing parallel RCME on a frame. In order to solve this problem, embodiments of the present invention determine a list of at least two Motion Vector Predictor Candidates (MVPC), determine, in parallel for at least two of said at least two MVPCs, corresponding Motion Vector Candidates (MVC) using Rate-Constrained Motion Estimation (RCME) and determine the optimal Motion Vector (MV) among the determined MVCs based on rate distortion optimization.

Abstract: Method and system for transcoding a sequence of input images into a sequence of output images that can effectively handle one or more transcoding uses cases are presented. The embodiments of the invention exploit the incoming metadata retrieved from the decoding process to adapt the video content and to achieve a significant speed-up in comparison to the traditional cascaded approach while maintaining high quality for output images.

Abstract: A method and device for improving rate controlling in video coding of sequences including a series of Inter frames separated by Intra frames, when a decoding delay is considered, comprise for each Inter frame of the series: computing a target frame size, computing a maximum buffer level related to a position of each Inter frame relative to a previous Intra frame and an upcoming Intra frame, and optimizing a transmission buffer level in response to the computed target frame size and the computed maximum buffer level.

Abstract: A method and system for parallel encoding of frames in a video are described, exploiting parallel processing at both frame and slice levels. One or more slices are processed in a preceding frame by one or more cores in a multi-core processor, and a slice is processed in a succeeding frame provided at least one of said one or more cores in the multi-core processor is available for processing; and the processing of a slice from said one or more slices at same physical location in the preceding input frame has been completed, the processing of frames and slices in the preceding and succeeding frames being performed at least partially in parallel. A significant speedup in comparison to the sequential encoding approach is achieved while maintaining high visual quality for the output video. A corresponding system for parallel encoding of a video is also provided.

Abstract: An improved MPEG-4 to H.264 transcoding algorithm is provided, exploiting residual, coding mode and motion vector information from the MPEG-4 stream. The use of the relative sum of absolute residuals (RSAR) to classify macroblocks (MB) leads to small sets of coding modes (CM) to test, and significantly reduces the computational complexity. In addition, RSAR is used to conditionally refine motion vectors (MV); only those MVs most likely to lead to quality improvements are refined. The average RSAR statistics are obtained from the transcoding of the previous Inter frame to provide adaptive thresholds for coding mode selection as well as conditional MV refinement. A corresponding video transcoder system is also provided.

Abstract: A visual quality assessment method and system are based on deriving a quality metric by comparing sub-band approximations of a distorted image and an undistorted version of the same image, providing a good compromise between computational complexity and accuracy. The sub-band approximations are derived from Discrete Wavelet (Haar) transforms of small image blocks of each image. Due to inherent symmetries, the wavelet transform is “blind” to certain types of distortions. But the accuracy of the method is enhanced, and the blindness of the transform is overcome, by computing quality metrics for the distorted image as well as computing quality metrics for a shifted version of the distorted image and combining the results.

Abstract: An image registration method is disclosed for processing a distorted image into a registered image that is aligned with reference to an original image. Distortions from the original image may include scaling, rotation, and noise. The method is based on correlating Radon transforms of both images to determine the rotation angle, and the scaling factor is determined by dividing averages of the overall luminance of each image on the assumption that any added noise will cancel. The Fast Fourier Transform (FFT) is used to estimate global spatial shifts. In one embodiment, the distorted image is first scaled to the size of the original image before being rotated. In another embodiment, the original image is first scaled to the size of the distorted image before rotating the distorted image, and finally scaling it to match the original image. A corresponding system for image registration is also provided.

Abstract: A method (and corresponding equipment) by which a multimedia message is sent from a sending terminal (21) via a messaging server (22)—such as a MMS Proxy-Relay in MMS or a SIP proxy server in SIP IM—to a receiving terminal (25) having limited multimedia capabilities, with the sending terminal (21) adapted to include a user agent (21a) for inserting, into the message, media characteristics of the message sufficient in detail to enable the messaging server (22) to determine whether the message should be transcoded based on actual or assumed multimedia capabilities of the receiving terminal (25), and with the messaging server (22) configured to read the media characteristics and decide whether the message should be transcoded based only on the inserted media characteristics and on actual or assumed multimedia capabilities of the receiving terminal (25). The media characteristics are advantageously inserted into the header of the message.

Abstract: Method and system for transcoding a sequence of input images into a sequence of output images that can effectively handle one or more transcoding uses cases are presented. The embodiments of the invention exploit the incoming metadata retrieved from the decoding process to adapt the video content and to achieve a significant speed-up in comparison to the traditional cascaded approach while maintaining high quality for output images.

Abstract: Method and system for determining a measure of quality for images are presented. Multi-level decomposition of images in the wavelet domain using a variable number of levels of decomposition and aggregation of selected subbands is performed to obtain an accurate measure of quality. The processing time is reduced in comparison to that required by other methods for generating measures of quality.

Abstract: Method and system for determining a measure of quality for images by using multi-level decomposition are presented. Multi-level decomposition of images is performed in the wavelet domain producing subbands at each level of decomposition. Aggregation of subbands is performed across multiple levels to produce an accurate measure of image quality. By aggregating only selected subbands the computational complexity of the method is greatly reduced.

Abstract: Method and system for determining a measure of quality for images are presented. Multi-level decomposition of images in the wavelet domain using a variable number of levels of decomposition and aggregation of selected subbands is performed to obtain an accurate measure of quality. The processing time is reduced in comparison to that required by other methods for generating measures of quality.

Abstract: Method and system for determining a measure of quality for images by using multi-level decomposition are presented. Multi-level decomposition of images is performed in the wavelet domain producing subbands at each level of decomposition. Aggregation of subbands is performed across multiple levels to produce an accurate measure of image quality. By aggregating only selected subbands the computational complexity of the method is greatly reduced.