Patent Application
20190306516
This disclosure relates to video coding and more particularly to techniques for intra prediction coding.
Digital video capabilities can be incorporated into a wide range of devices, including digital televisions, laptop or desktop computers, tablet computers, digital recording devices, digital media players, video gaming devices, cellular telephones, including so-called smartphones, medical imaging devices, and the like. Digital video may be coded according to a video coding standard. Video coding standards may incorporate video compression techniques. Examples of video coding standards include ISO/IEC MPEG-4 Visual and ITU-T H.264 (also known as ISO/IEC MPEG-4 AVC) and High-Efficiency Video Coding (HEVC). HEVC is described in High Efficiency Video Coding (HEVC), Rec. ITU-T H.265 April 2015, which is incorporated by reference, and referred to herein as ITU-T H.265. Extensions and improvements for ITU-T H.265 are currently being considered for development of next generation video coding standards. For example, the ITU-T Video Coding Experts Group (VCEG) and ISO/IEC (Moving Picture Experts Group (MPEG) (collectively referred to as the Joint Video Exploration Team (JVET)) are studying the potential need for standardization of future video coding technology with a compression capability that significantly exceeds that of the current HEVC standard. The Joint Exploration Model 2 (JEM 2), Algorithm Description of Joint Exploration Test Model 2 (JEM 2), ISO/IEC JTC1/SC29/WG11/N16066, February 2016, San Diego, Calif., US, which is incorporated by reference herein, describes the coding features that are under coordinated test model study by the JVET as potentially enhancing video coding technology beyond the capabilities of ITU-T H.265. It should be noted that the coding features of JEM 2 are implemented in JEM reference software maintained by the Fraunhofer research organization. Currently, the updated JEM reference software version 2 (JEM 2.0) is available. As used herein, the term JEM is used to collectively refer to algorithm descriptions of JEM 2 and implementations of JEM reference software.
Video compression techniques enable data requirements for storing and transmitting video data to be reduced. Video compression techniques may reduce data requirements by exploiting the inherent redundancies in a video sequence. Video compression techniques may sub-divide a video sequence into successively smaller portions (i.e., groups of frames within a video sequence, a frame within a group of frames, slices within a frame, coding tree units (e.g., macroblocks) within a slice, coding blocks within a coding tree unit, etc.). Intra prediction coding techniques (e.g., intra-picture (spatial)) and inter prediction techniques (i.e., inter-picture (temporal)) may be used to generate difference values between a unit of video data to be coded and a reference unit of video data. The difference values may be referred to as residual data. Residual data may be coded as quantized transform coefficients. Syntax elements may relate residual data and a reference coding unit (e.g., intra-prediction mode indices, motion vectors, and block vectors). Residual data and syntax elements may be entropy coded. Entropy encoded residual data and syntax elements may be included in a compliant bitstream.
In general, this disclosure describes various techniques for coding video data. In particular, this disclosure describes techniques for intra prediction video coding. The techniques described herein may be used for deriving cross-component prediction parameters. It should be noted that although techniques of this disclosure are described with respect to ITU-T H.264, ITU-T H.265, and JEM, the techniques of this disclosure are generally applicable to video coding. For example, intra prediction video coding techniques that are described herein with respect to ITU-T H.265 may be generally applicable to video coding. For example, the coding techniques described herein may be incorporated into video coding systems, (including future video coding standards) including block structures, intra prediction techniques, inter prediction techniques, transform techniques, filtering techniques, and/or entropy coding techniques other than those included in ITU-T H.265. Thus, reference to ITU-T H.264, ITU-T H.265, and/or JEM is for descriptive purposes and should not be construed to limit the scope to of the techniques described herein. Further, it should be noted that incorporation by reference of documents herein is for descriptive purposes and should not be construed to limit or create ambiguity with respect to terms used herein. For example, in the case where an incorporated reference provides a different definition of a term than another incorporated reference and/or as the term is used herein, the term should be interpreted in a manner that broadly includes each respective definition and/or in a manner that includes each of the particular definitions in the alternative.
An aspect of the invention is a method of decoding video data, the method comprising: receiving reconstructed samples of video data; determining an intra prediction parameter for luma component; and reconstructing one or more samples of a chroma component according to a cross-correlation prediction based on the determined intra prediction for the luma component.
Video content typically includes video sequences comprised of a series of frames. A series of frames may also be referred to as a group of pictures (GOP). Each video frame or picture may include a plurality of slices or tiles, where a slice or tile includes a plurality of video blocks. A video block may be defined an array of pixel values (also referred to as samples) that may be predictively coded. Video blocks may be ordered according to a scan pattern (e.g., a raster scan). A video encoder performs predictive encoding on video blocks and sub-divisions thereof. ITU-T H.264 specifies a macroblock including 16×16 luma samples. ITU-T H.265 specifies an analogous Coding Tree Unit (CTU) structure where a picture may be split into CTUs of equal size and each CTU may include Coding Tree Blocks (CTB) having 16×16, 32×32, or 64×64 luma samples. In ITU-T H.265, the CTBs of a CTU may be partitioned into Coding Blocks (CB) according to a corresponding quadtree block structure. According to ITU-T H.265, one luma CB together with two corresponding chroma CBs (e.g., Cr and Cb chroma components) and associated syntax elements are referred to as a coding unit (CU). A CU is associated with a prediction unit (PU) structure defining one or more prediction units (PU) for the CU, where a PU is associated with corresponding reference samples. That is, in ITU-T H.265 the decision to code a picture area using intra prediction or inter prediction is made at the CU level. In ITU-T H.265, a PU may include luma and chroma prediction blocks (PBs), where square PBs are supported for intra prediction and rectangular PBs are supported for inter prediction. Intra prediction data (e.g., intra prediction mode syntax elements) or inter prediction data (e.g., motion data syntax elements) may associate PUs with corresponding reference samples.
A video sampling format, which may also be referred to as a chroma format, may define the number of chroma samples included in a CU with respect to the number of luma samples included in a CU. For example, for the 4:2:0 format, the sampling rate for the luma component is twice that of the chroma components for both the horizontal and vertical directions. As a result, for a CU formatted according to the 4:2:0 format, the width and height of an array of samples for the luma component are twice that of each array of samples for the chroma components.
The difference between sample values included in a PU, CB, or another type of picture area structure and associated reference samples may be referred to as residual data. Residual data may include respective arrays of difference values corresponding to each component of video data (e.g., luma (Y) and chroma (Cb and Cr). Residual data may be in the pixel domain. A transform, such as, a discrete cosine transform (DCT), a discrete sine transform (DST), an integer transform, a wavelet transform, or a conceptually similar transform, may be applied to pixel difference values to generate transform coefficients. It should be noted that in ITU-T H.265, PUs may be further sub-divided into Transform Units (TUs). That is, an array of pixel difference values may be sub-divided for purposes of generating transform coefficients (e.g., four 8×8 transforms may be applied to a 16×16 array of residual values), such sub-divisions may be referred to as Transform Blocks (TBs). In JEM, residual values corresponding to a CB may be used to generate transform coefficients. Further, in JEM, a core transform and a subsequent secondary transforms may be applied (in the encoder) to generate transform coefficients. For the decoder the order of transforms is reversed. Further, whether a secondary transform is applied to generate transform coefficients may be dependent on a prediction mode.
Transform coefficients may be quantized according to a quantization parameter (QP). Quantized transform coefficients may be entropy coded according to an entropy encoding technique (e.g., content adaptive variable length coding (CAVLC), context adaptive binary arithmetic coding (CABAC), probability interval partitioning entropy coding (PIPE), etc.). Further, syntax elements, such as, a syntax element indicating a prediction mode, may also be entropy coded. Entropy encoded quantized transform coefficients and corresponding entropy encoded syntax elements may form a compliant bitstream that can be used to reproduce video data. A binarization process may be performed on syntax elements as part of an entropy coding process. Binarization refers to the process of converting a syntax value into a series of one or more bits. These bits may be referred to as “bins.”
As described above, intra prediction data or inter prediction data may associate an area of a picture (e.g., a PU or a CB) with corresponding reference samples. For intra prediction coding, an intra prediction mode may specify the location of reference samples within a picture. In ITU-T H.265, defined possible intra prediction modes include a planar (i.e., surface fitting) prediction mode (predMode: 0), a DC (i.e., flat overall averaging) prediction mode (predMode: 1), and 33 angular prediction modes (predMode: 2-34). For angular prediction modes, a row of neighboring samples above a PU or CB, a column of neighboring samples to the left of a PU or CB, and an upper-left neighboring sample may be defined. For example, in ITU-T H.265 a row of neighboring samples may include twice as many samples as a row of a PU (e.g., for a 8×8 PU, a row of neighboring samples includes 16 samples) that may be used for generating predictions. In ITU-T H.265, angular prediction modes enable a reference sample to be derived for each sample included in a PU or CB by pointing to samples in the adjacent row of neighboring samples, the adjacent column of neighboring samples, and/or the adjacent upper-left neighboring sample. In JEM, defined possible intra-prediction modes include a planar prediction mode (predMode: 0), a DC prediction mode (predMode: 1), and 65 angular prediction modes (predMode: 2-66). It should be noted that planar and DC prediction modes may be referred to as non-directional prediction modes and that angular prediction modes may be referred to as directional prediction modes. It should be noted that the techniques described herein may be generally applicable regardless of the number of defined possible prediction modes. For example, possible intra prediction modes may include any number of non-directional prediction modes (e.g., two or more fitting or averaging modes) and any number of directional prediction modes (e.g., 35 or more angular prediction modes). In an example, for intra prediction, a block of samples coded in the past within the same frame, may be used as reference to generate a prediction. The location of the reference block of samples may be explicitly signaled or may be derived based on a distortion metric obtained by comparing the neighborhood of samples to be predicted and the block being used for reference.
In current video coding systems implemented based on ITU-T H.265 and/or JEM, for angular prediction modes, the angular prediction mode used for generating predictive samples for a current video block may be selected based on a rate-distortion analysis (i.e., bit-rate vs. quality of video). In current video coding systems an analysis may include analyzing one or more angular prediction modes and the quality of resulting predictive samples generated from the set neighboring samples defined for the current video block, where the set of neighboring samples is limited to immediately adjacent samples. In order to increase the compression capability of ITU-T H.265 and/or JEM, so-call multiple line intra prediction techniques have been proposed. For example, Li et al., “Multiple line-based intra prediction,” Document: JVET-C0071 Joint Video Exploration Team (JVET) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11 3rd Meeting: Geneva, CH, 26 May-1 Jun. 2016, (hereinafter “JVET-C0071”), and Chang et al., “Arbitrary reference tier for intra directional modes,” Document: JVET-C0043 Joint Video Exploration Team (JVET) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11 3rd Meeting: Geneva, CH, 26 May-1 Jun. 2016, (hereinafter “JVET-C0043”), each of which are incorporated by reference herein, describe multiple line intra-prediction techniques.
In general, multiple line intra prediction techniques, define one or more respective reference lines that may be used as a set neighboring samples for generating intra prediction samples for a current video block.
In addition to generating reference samples according to the non-directional and/or the angular prediction modes described above, intra prediction coding may include so-called cross component correlation techniques. In general, intra prediction coding techniques including so-called cross component correlation techniques are based on an assumption that for most video codecs chroma sample prediction is performed after the luma sample reconstruction and as such, in these cases, information inferred from reconstructed luma samples can be used for chroma sample prediction. An example of a cross component correlation technique includes the Color Component correlation based prediction (CCCP) technique described in McCann et al., “Samsung's Response to the Call for Proposals on Video Compression Technology,” Document: JCTVC-A124 Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11 1st Meeting: Dresden DE, 15-23 Apr. 2010, (hereinafter “JCTVC-A124”), which is incorporated by reference herein. Further, JEM provides a cross component prediction technique, which may be referred to as a cross-component Linear Model (LM), for generating predictions for chroma based on reconstructed luma samples. The cross-component prediction technique in JEM is defined according to Equations (1) and (2):
predC(i,j)=α·recL(i,j)+β (1)
pred*Cr(i,j)=predCr(i,j)+α·resiCb′(i,j) (2)
where predC(i,j) represents the prediction of chroma samples in a block at location (i,j) and recL(i,j) represents the downsampled reconstructed luma samples of the same block at location (i,j) and where parameters alpha(α) and beta(β) are derived by minimizing regression error between the neighboring reconstructed luma and chroma samples around the current block.
Referring to Equation (2) above, in JEM, the cross-component prediction technique is extended to the prediction between two chroma components. That is, Cr component is predicted from Cb component. Further, as illustrated in Equation (2) instead of using the reconstructed sample signal, the cross component prediction for the Cr component is applied in residual domain, which is implemented by adding a weighted reconstructed Cb residual to the original Cr intra prediction to form the final Cr prediction.
B. Bross, W.-J. Han, G. J. Sullivan, J.-R. Ohm and T. Wiegand, “High Efficiency Video Coding (HEVC) text specification draft 7”, Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11, Doc. JCTVC-I1003, 9th Meeting, Geneva, CH, May. 2012 (hereinafter “JCTVC-I1003”), which is incorporated by reference herein describes example techniques for deriving parameters alpha and beta. JCTVC-I1003 defines formulas for various intermediate variables (e.g., L, C, LL, LC, al, etc.) that may be used to derive parameters alpha and beta. For the sake of brevity, a complete description of deriving parameters alpha and beta is not reproduced herein, however, reference is made to relevant sections of JCTVC-I1003. Further, it should be noted that other variations on the techniques described in JCTVC-I1003 for deriving parameters have been described (i.e., changing scaling values in equations for intermediate variables). However, it should be noted that current techniques for deriving parameters alpha and beta are limited to using an immediately adjacent row or column of neighboring chroma values and corresponding down-sampled luma values. It should be noted that parameters alpha and beta and variations thereof may be referred to and/or be examples of cross-component prediction parameters. As such, the term cross-component prediction parameters as used herein may refer to additional cross-component prediction parameters, intermediate variables used to derive parameters alpha and beta, and/or variations of parameters alpha and beta. Further, it should be noted that derivation of cross-component prediction parameters may occur at a video encoder for generating reconstructed reference samples and/or at video decoder for reconstructing video data from a compliant bitstream. Current techniques for deriving cross-component prediction parameters may be less than ideal.
As described above, intra prediction data or inter prediction data may associate an area of a picture (e.g., a PB or a CB) with corresponding reference samples. For inter prediction coding, a motion vector (MV) identifies reference samples in a picture other than the picture of a video block to be coded and thereby exploits temporal redundancy in video. For example, a current video block may be predicted from a reference block located in a previously coded frame and a motion vector may be used to indicate the location of the reference block. A motion vector and associated data may describe, for example, a horizontal component of the motion vector, a vertical component of the motion vector, a resolution for the motion vector (e.g., one-quarter pixel precision), a prediction direction and/or a reference picture index value. Further, a coding standard, such as, for example ITU-T H.265, may support motion vector prediction. Motion vector prediction enables a motion vector to be specified using motion vectors of neighboring blocks. Examples of motion vector prediction include advanced motion vector prediction (AMVP), temporal motion vector prediction (TMVP), so-called “merge” mode, and “skip” and “direct” motion inference. Further, JEM supports advanced temporal motion vector prediction (ATMVP) and Spatial-temporal motion vector prediction (STMVP).
As described above, syntax elements may be entropy coded according to an entropy encoding technique. As described above, a binarization process may be performed on syntax elements as part of an entropy coding process. Binarization is a lossless process and may include one or a combination of the following coding techniques: fixed length coding, unary coding, truncated unary coding, truncated Rice coding, Golomb coding, k-th order exponential Golomb coding, and Golomb-Rice coding. As used herein each of the terms fixed length coding, unary coding, truncated unary coding, truncated Rice coding, Golomb coding, k-th order exponential Golomb coding, and Golomb-Rice coding may refer to general implementations of these techniques and/or more specific implementations of these coding techniques. For example, a Golomb-Rice coding implementation may be specifically defined according to a video coding standard, for example, ITU-T H.265. After binarization, a CABAC entropy encoder may select a context model. For a particular bin, a context model may be selected from a set of available context models associated with the bin. In some examples, a context model may be selected based on a previous bin and/or values of previous syntax elements. For example, a context model may be selected based on the value of a neighboring intra prediction mode. A context model may identify the probability of a bin being a particular value. For instance, a context model may indicate a 0.7 probability of coding a 0-valued bin and a 0.3 probability of coding a 1-valued bin. After selecting an available context model, a CABAC entropy encoder may arithmetically code a bin based on the identified context model. It should be noted that some syntax elements may be entropy encoded using arithmetic encoding without the usage of an explicitly assigned context model, such coding may be referred to as bypass coding.
Communications medium 110 may include any combination of wireless and wired communication media, and/or storage devices. Communications medium 110 may include coaxial cables, fiber optic cables, twisted pair cables, wireless transmitters and receivers, routers, switches, repeaters, base stations, or any other equipment that may be useful to facilitate communications between various devices and sites. Communications medium 110 may include one or more networks. For example, communications medium 110 may include a network configured to enable access to the World Wide Web, for example, the Internet. A network may operate according to a combination of one or more telecommunication protocols. Telecommunications protocols may include proprietary aspects and/or may include standardized telecommunication protocols. Examples of standardized telecommunications protocols include Digital Video Broadcasting (DVB) standards, Advanced Television Systems Committee (ATSC) standards, Integrated Services Digital Broadcasting (ISDB) standards, Data Over Cable Service Interface Specification (DOCSIS) standards, Global System Mobile Communications (GSM) standards, code division multiple access (CDMA) standards, 3rd Generation Partnership Project (3GPP) standards, European Telecommunications Standards Institute (ETSI) standards, Internet Protocol (IP) standards, Wireless Application Protocol (WAP) standards, and Institute of Electrical and Electronics Engineers (IEEE) standards.
Storage devices may include any type of device or storage medium capable of storing data. A storage medium may include a tangible or non-transitory computer-readable media. A computer readable medium may include optical discs, flash memory, magnetic memory, or any other suitable digital storage media. In some examples, a memory device or portions thereof may be described as non-volatile memory and in other examples portions of memory devices may be described as volatile memory. Examples of volatile memories may include random access memories (RAM), dynamic random access memories (DRAM), and static random access memories (SRAM). Examples of non-volatile memories may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. Storage device(s) may include memory cards (e.g., a Secure Digital (SD) memory card), internal/external hard disk drives, and/or internal/external solid state drives. Data may be stored on a storage device according to a defined file format.
Referring again to
Referring again to
In the example illustrated in
As described above, a video block may be coded using an intra prediction. Intra prediction processing unit 212 may be configured to select an intra prediction mode for a video block to be coded. Intra prediction processing unit 212 may be configured to evaluate a frame and/or an area thereof and determine an intra prediction mode to use to encode a current block. As illustrated in
In one example, according to the techniques described herein, intra prediction processing unit 212 may be configured to generate a set of reference lines used for possible multiple line intra predictions. In one example, a set of reference lines used for possible multiple line intra predictions may include a set of reference lines other than a set including immediately adjacent lines (e.g., other than the nearest neighboring four lines). In one example, a set of reference lines may be defined as including every i-th line, where i equal 2, 3, 4 . . . 64, etc. (e.g., every other neighboring line, or every 4, 8, or 16 neighboring line, etc.). Further, in one example, a set of reference lines may be determined based on sample values included in neighboring lines. For example, if two possible reference lines include similar sample values, one of the lines may be replaced with another line in a set of neighboring reference lines (e.g., neighboring line 3 may be replaced by neighboring line 7, if it is similar to neighboring line 2). That is, according to the techniques described herein, a pruning process may be used to generate a set of reference lines for multiple line intra predictions.
In one example, according to the techniques described herein, intra prediction processing unit 212 may be configured to use a multiple line intra prediction technique for a luma component and use a cross-correlation prediction (e.g., a cross correlation prediction described above) for chroma components. In one example, according to the techniques described herein, intra prediction processing unit 212 may be configured to derive cross-component prediction parameters for both or each respective chroma component based on available reconstructed luma samples, including neighboring reconstructed luma samples, and available reconstructed chroma samples, including neighboring samples that are not limited to immediately adjacent neighboring samples, and/or one or more luma component prediction properties (e.g., luma prediction modes and/or reference lines used for luma prediction modes). Further, it should be noted that in the case of the 4:2:0 sampling format, intra prediction processing unit 212 may be configured to be generate down-sampled luma values corresponding to chroma sample values using additional filtering techniques, (e.g., Gaussian filters, etc.), where filtering techniques may be based on luma component prediction properties. It should be noted that although the techniques described herein are described with respect to examples using the 4:2:0 sampling format, the techniques described herein may be generally applicable to the 4:2:2 and 4:4:4 sampling formats described above and other sampling formats. Further, it should be noted that although the examples described herein are describe with respect to square CUs, the techniques described herein may be generally applicable to cases where predictions are based on rectangular partitions. Further, it should be noted that the techniques described herein may be generally applicable to cases where partitioning of samples in luma and chroma components may be independent of each other. Further, it should be noted that the techniques described herein may be generally applicable to cases where partitioning of samples in each component may be independent of the other component.
As described above, current techniques for deriving cross-component prediction parameters may be less than ideal. As further described above, the derivation of cross-component prediction parameters may occur at a video encoder for generating reconstructed reference samples and/or at video decoder for reconstructing video data from a compliant bitstream. Referring to
In an example, with respect to video encoding, neighboring reconstructed luma and/or chroma samples, a reconstructed luma component for the current CU, dimensions of the chroma block, chroma format and multiple line prediction parameters may be available for encoding the chroma components, in one example, a video decoder may derive cross-correlation parameters for decoding the chroma components in the current CU from neighboring reconstructed luma and/or chroma samples, a reconstructed luma component for the current CU, dimensions of the chroma block, chroma format and multiple line prediction parameters.
Referring again to
Referring again to
As illustrated in
Referring again to
Intra prediction processing unit 708 may be configured to receive intra prediction syntax elements and retrieve a predictive video block from reference buffer 716. Reference buffer 716 may include a memory device configured to store one or more frames of video data. Intra prediction syntax elements may identify an intra prediction mode, such as the intra prediction modes described above. In one example, intra prediction processing unit 708 may reconstruct a video block using according to one or more of the intra prediction coding techniques describe herein. Referring to
In one example, intra prediction processing unit 708 may be configured to derive cross-correlation parameters based on a reference line selected for the luma component intra prediction. For example, an array of neighboring samples and/or subsets thereof used to derive cross-correlation parameters may be based on a selected reference line used for the intra prediction of luma. Referring to
Further, in one example, intra prediction processing unit 708 may be configured to derive cross-correlation parameters based on the following logical conditions:
Further, in one example, intra prediction processing unit 708 may be configured to derive cross-correlation parameters based on the following logical conditions:
Further, in one example, intra prediction processing unit 708 may be configured to derive cross-correlation parameters based on the following logical conditions:
Further, in one example, intra prediction processing unit 708 may be configured to derive cross-correlation parameters based on the following logical conditions:
Further, in some examples, intra prediction processing unit 708 may be configured to derive cross-correlation parameters based on a subset of sample values included in one or more lines of neighboring samples.
In one example, intra prediction processing unit 708 may be configured to derive cross-correlation parameters based on sub-sets of samples based on the following logical conditions:
where, each of subsets 0-3 may include any and all combinations of samples included in reference lines and/or in available reconstructed samples.
In one example, intra prediction processing unit 708 may be configured to derive down-sampled reconstructed luma samples, and reconstructed chroma samples. The dimensions of the non-square chroma prediction unit may then be used to further subsample the down-sampled reconstructed luma samples, and reconstructed chroma samples. These sub-sampled samples may then be used to derive the cross-correlation parameters. In one example, the sub-sampling would be done for the longer edge, the step size would be dimension of longer edge divided by the dimension of shorter edge. It should be noted that reconstructed samples may include filtered reconstructed samples.
Referring again to
In one or more examples, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include computer-readable storage media, which corresponds to a tangible medium such as data storage media, or communication media including any medium that facilitates transfer of a computer program from one place to another, e.g., according to a communication protocol. In this manner, computer-readable media generally may correspond to (1) tangible computer-readable storage media which is non-transitory or (2) a communication medium such as a signal or carrier wave. Data storage media may be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, code and/or data structures for implementation of the techniques described in this disclosure. A computer program product may include a computer-readable medium.
By way of example, and not limitation, such computer-readable storage media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if instructions are transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. It should be understood, however, that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transitory media, but are instead directed to non-transitory, tangible storage media. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.
Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor,” as used herein may refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described herein. In addition, in some aspects, the functionality described herein may be provided within dedicated hardware and/or software modules configured for encoding and decoding, or incorporated in a combined codec. Also, the techniques could be fully implemented in one or more circuits or logic elements.
The techniques of this disclosure may be implemented in a wide variety of devices or apparatuses, including a wireless handset, an integrated circuit (IC) or a set of ICs (e.g., a chip set). Various components, modules, or units are described in this disclosure to emphasize functional aspects of devices configured to perform the disclosed techniques, but do not necessarily require realization by different hardware units. Rather, as described above, various units may be combined in a codec hardware unit or provided by a collection of interoperative hardware units, including one or more processors as described above, in conjunction with suitable software and/or firmware.
Moreover, each functional block or various features of the base station device and the terminal device used in each of the aforementioned embodiments may be implemented or executed by a circuitry, which is typically an integrated circuit or a plurality of integrated circuits. The circuitry designed to execute the functions described in the present specification may comprise a general-purpose processor, a digital signal processor (DSP), an application specific or general application integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic, or a discrete hardware component, or a combination thereof. The general-purpose processor may be a microprocessor, or alternatively, the processor may be a conventional processor, a controller, a microcontroller or a state machine. The general-purpose processor or each circuit described above may be configured by a digital circuit or may be configured by an analogue circuit. Further, when a technology of making into an integrated circuit superseding integrated circuits at the present time appears due to advancement of a semiconductor technology, the integrated circuit by this technology is also able to be used.
Various examples have been described. These and other examples are within the scope of the following claims.
<Overview>
In one example, a method of coding video data, comprises receiving reconstructed samples of video data, determining an intra prediction parameter for a luma component, reconstructing one or more samples of a chroma component according to a cross-correlation prediction based on the determined intra prediction for the luma component.
In one example, a device for video coding comprises one or more processors configured to receive reconstructed samples of video data, determine an intra prediction parameter for a luma component, reconstruct one or more samples of a chroma component according to a cross-correlation prediction based on the determined intra prediction for the luma component.
In one example, a non-transitory computer-readable storage medium comprises instructions stored thereon that, when executed, cause one or more processors of a device to receive reconstructed samples of video data, determine an intra prediction parameter for a luma component, reconstruct one or more samples of a chroma component according to a cross-correlation prediction based on the determined intra prediction for the luma component.
In one example, an apparatus comprises means for receiving reconstructed samples of video data, means for determining an intra prediction parameter for a luma component, means for reconstructing one or more samples of a chroma component according to a cross-correlation prediction based on the determined intra prediction for the luma component.
The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.
This Nonprovisional application claims priority under 35 U.S.C. § 119 on provisional Application No. 62/341,039 on May 24, 2016, the entire contents of which are hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2017/015163 | 4/13/2017 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62341039 | May 2016 | US |
