Patent classifications
H04N19/198
Method and an apparatus for encoding/decoding residual coefficient
The encoding/decoding method and apparatus according to the present invention derives a residual coefficient of a residual block, calculates a quantization parameter for a residual block, performs dequantization on a residual coefficient using a quantization parameter, and performs inverse transform on a dequantized residual coefficient to reconstruct a residual sample of a residual block.
METHOD FOR GENERATING PREDICTION BLOCK IN AMVP MODE
A transmission method for data comprising a bitstream for an image, the method including obtaining the bitstream for the image; and transmitting the data comprising the bitstream, wherein the bitstream is decoded by a decoding device, wherein the image decoding device is configured to derive, by a motion compensation predictor, motion information using effective spatial and temporal merge candidates of a current prediction unit; generate, by the motion compensation predictor, a prediction block of the current prediction unit using the motion information; entropy decode, by an entropy decoder, a bit stream to generate a quantized coefficient sequence, inversely scan, by an inverse quantizer/inverse transformer, the quantized coefficient sequence to generate a quantized block, inversely quantize, by the inverse quantizer/inverse transformer, the quantized block to generate a transformed block using a quantization parameter, and inversely transform, by the inverse quantizer/inverse transformer, the transformed block to generate a residual block; and generate, by an adder, a reconstructed block using the prediction block and the residual block, wherein a motion vector of the temporal merge candidate is a motion vector of a temporal merge candidate block within a temporal merge candidate picture, and the quantization parameter is derived using an average of two effective quantization parameters among a left quantization parameter, an upper quantization parameter and a previous quantization parameter of a current coding unit, wherein when the quantized block is larger than a predetermined size, the quantized block is generated with plurality of subblocks, and a scan pattern of inversely scanning for the plurality of subblocks is the same as a scan pattern of inversely scanning for quantized coefficients of each subblock, and wherein a scanning scheme for inversely scanning the quantized coefficients is determined according to an intra-prediction mode and a size of a transform unit.
METHOD FOR GENERATING PREDICTION BLOCK IN AMVP MODE
A method of decoding video data, the method including via a motion compensation predictor generating a prediction block of a current prediction unit using a reference index and a motion vector of the current prediction unit; via an entropy decoder, entropy decoding a bitstream to generate a quantized coefficient sequence; via an inverse quantizer/inverse transformer, generating a quantized block using the quantized coefficient sequence and inversely quantizing the quantized block to generate a transformed block using a quantization parameter, and inversely transforming the transformed block to generate a residual block, wherein the inverse quantizer/inverse transformer generates the quantization block by selecting two effective quantization parameters that are available and exist among left, upper, and previous quantization parameters according to an order of priority levels set for the left, upper, and previous quantization parameters and using an average of the two effective quantization parameters; and via an adder, generating a reconstructed block using the prediction block and the residual block, wherein the motion vector is derived using a motion vector predictor which is set equal to one of an effective spatial motion vector candidate and an effective temporal motion vector candidate.
Multimedia distribution system
A multimedia file and methods of generating, distributing and using the multimedia file are described. Multimedia files in accordance with embodiments of the present invention can contain multiple video tracks, multiple audio tracks, multiple subtitle tracks, a complete index that can be used to locate each data chunk in each of these tracks and an abridged index that can enable the location of a subset of the data chunks in each track, data that can be used to generate a menu interface to access the contents of the file and ‘meta data’ concerning the contents of the file. Multimedia files in accordance with several embodiments of the present invention also include references to video tracks, audio tracks, subtitle tracks and ‘meta data’ external to the file. One embodiment of a multimedia file in accordance with the present invention includes a series of encoded video frames, a first index that includes information indicative of the location within the file and characteristics of each encoded video frame and a separate second index that includes information indicative of the location within the file of a subset of the encoded video frames.
Scalable Video Coding Using Inter-Layer Prediction of Spatial Intra Prediction Parameters
The coding efficiency of scalable video coding is increased by substituting missing spatial intra prediction parameter candidates in a spatial neighborhood of a current block of the enhancement layer by use of intra prediction parameters of a co-located block of the base layer signal. By this measure, the coding efficiency for coding the spatial intra prediction parameters is increased due to the improved prediction quality of the set of intra prediction parameters of the enhancement layer, or, more precisely stated, the increased likelihood, that appropriate predictors for the intra prediction parameters for an intra predicted block of the enhancement layer are available thereby increasing the likelihood that the signaling of the intra prediction parameter of the respective enhancement layer block may be performed, on average, with less bits.
Signaling of Number of Merge Candidates
Aspects of the disclosure provide a method and an apparatus including processing circuitry for video encoding. The processing circuitry determines a maximum number of geometric merge mode merge candidates, and generates maximum number of geometric merge mode candidates information based on a relation between the maximum number of geometric merge mode merge candidates and a maximum number of merge candidates. The processing circuitry generates a coded video bitstream including coding information. The coding information indicates that a geometric merge mode is enabled for a coding level higher than a picture level of a current picture and the maximum number of merge candidates satisfies a condition. The maximum number of geometric merge mode merge candidates is equal to the maximum number of merge candidates minus a value indicated by the maximum number of geometric merge mode candidates information.
METHOD AND APPARATUS FOR ADAPTIVELY PROCESSING VIDEO SAMPLES IN A VIDEO SIGNAL FRAME
A method and apparatus for adaptively processing video samples in a video signal frame, the video samples being arranged in a Largest Coding Unit. The method comprises extracting a plurality of video samples from the Largest Coding Unit, calculating a correction offset for a first video sample of the extracted plurality of video samples upon the basis of a first value of the first video sample and a second value of a second video sample of the extracted plurality of video samples, and weighting the first video sample with the correction offset.
INTRA PREDICTION MODE MAPPING METHOD AND DEVICE USING THE METHOD
The present invention relates to an intra prediction mode mapping method and a device using the method. The intra prediction mode includes: decoding flag information providing information regarding whether an intra prediction mode of a plurality of candidate intra prediction modes for the current block is the same as the intra prediction mode for the current block, and decoding a syntax component including information regarding the intra prediction mode for the current block in order to induce the intra prediction mode for the current block if the intra prediction mode from among the plurality of candidate intra prediction modes for the current block is not the same as the intra prediction mode for the current block. Thus, it is possible to increase the efficiency with which are images are decoded.
METHODS AND APPARATUS FOR DETERMINING QUANTIZATION PARAMETER PREDICTORS FROM A PLURALITY OF NEIGHBORING QUANTIZATION PARAMETERS
Methods and apparatus are provided for determining quantization parameter predictors from a plurality of neighboring quantization parameters. An apparatus includes an encoder for encoding image data for at least a portion of a picture using a quantization parameter predictor for a current quantization parameter to be applied to the image data. The quantization parameter predictor is determined using multiple quantization parameters from previously coded neighboring portions. A difference between the current quantization parameter and the quantization parameter predictor is encoded for signaling to a corresponding decoder.
Transmission bit-rate control in a video encoder
A video encoder receives a minimum number of bits (MIN) and a maximum number of bits (MAX) to be used to encode a segment of a sequence of image frames, the segment including a set of pictures contained in the sequence of image frames. The video encoder encodes the set of pictures using a total number of bits greater than the minimum number of bits (MIN), and not exceeding the maximum number of bits (MAX). Thus, the transmission bit-rate of the video encoder can be constrained to lie within a maximum and minimum rate. In an embodiment, the constraints are enforced over relatively short time intervals.