RU2783382C1 - Signalling of inter-layer prediction in a video bitstream - Google Patents

Abstract

FIELD: video data processing.

SUBSTANCE: invention relates to video encoding tools. Parsing of at least one video parameter set (VPS) containing at least one syntax element indicating whether at least one level in the scalable bitstream is one of the dependent layer of the scalable bitstream and the independent layer of the scalable bitstream is performed. A picture is decoded at the dependent level by analysing and interpreting the list of inter-layer reference pictures (ILRP). Each of a picture at the independent layer and another picture at the dependent layer are performed without parsing and interpreting the ILRP list.

EFFECT: increased efficiency of video encoding.

20 cl, 14 dwg

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present invention claims priority of U.S. Provisional Application No. 62/903,647, filed September 20, 2019, and priority of U.S. Patent Application No. 17/019,567, filed September 14, 2020, the contents of which are incorporated herein in their entirety.

BACKGROUND OF THE INVENTION

1. Technical field

[0002] The disclosed invention relates to video coding and decoding, and more specifically to inter-layer prediction signaling in a video bitstream.

2. Description of the prior art

[0003] Video encoding and decoding using motion-compensated inter-picture prediction has been known for several decades. An uncompressed digital video may consist of a sequence of images, each of which has a spatial size of, for example, 1920×1080 luminance samples and their associated chrominance samples. An image sequence may have a fixed or variable image rate (informally also referred to as a "frame rate"), such as 60 images per second, or 60 Hz. Uncompressed video data has significant bit rate requirements. For example, 1080p60 4:2:0 video with 8 bits per sample (resolution of 1920x1080 luminance samples at 60Hz frame rate) requires about 1.5Gbps of bandwidth. An hour of such video requires more than 6000 GB of memory.

[0004] One goal of video encoding and decoding may be to reduce redundancy in the input video signal by compressing. Compression can help to alleviate the aforementioned bandwidth or storage requirements, in some cases by two orders of magnitude or more. For this, both lossless and lossy compression can be used. Lossless compression refers to techniques for reconstructing an exact copy of the original signal from the compressed original signal. When lossy compression is used, the reconstructed signal may not be identical to the original signal, but the discrepancy between the original and reconstructed signals is small enough that the reconstructed signal can be used for the intended application. Lossy compression is widely used for video. The amount of distortion allowed depends on the application; for example, users of some custom streaming applications can tolerate higher distortion than users of broadcast TV applications. The achievable compression ratio may reflect that a higher allowed/allowable distortion may result in a higher compression ratio.

[0005] The video encoder and decoder may use techniques from several broad categories including, for example, motion compensation, transformation, quantization, and entropy coding, some of which are presented below.

[0006] Historically, video encoders and video decoders were designed to work with a given image size, which in most cases for a coded video sequence (CVS, Coded Video Sequence), a group of pictures (GOP, Group of Pictures) or a similar multi-picture time frame was defined and remained constant. For example, with respect to MPEG-2, system designs are known to change the horizontal resolution (and hence image size) depending on factors such as scene activity, but only for I-pictures, which is typically the case with GOP. The resampling of reference pictures to use different resolutions within CVS is known, for example, from the ITU-T Rec. H.263 Annex P. However, in this case the image size is not changed, only the reference pictures are resampled, potentially using only parts of the image (in the case of downsampling) or only parts of the captured scene (in the case of upsampling). In addition, H.263 Annex Q allows single macroblock resampling by a factor of two (in each dimension), up or down. Again, the image is not resized. The macroblock size is fixed in H.263 and therefore does not need to be transmitted.

[0007] Image resizing in predicted images has become mainstream in current video coding techniques. For example. VP9 provides the ability to resample reference pictures (RPR, Reference Picture Resampling) and change the resolution for the entire image. Likewise, some solutions for VVC (including, for example, the solution by Hendry et al., "Adaptive Resolution Change (ARC) for VVC", Joint Video Team document JVET-M0135-vl, January 9-19, 2019. , incorporated herein in its entirety) provide the possibility of resampling entire reference pictures with a different, higher or lower resolution. This document proposes to encode the different resolutions in a sequence parameter set and refer to them using the syntax elements for each image in the image parameter set.

SUMMARY OF THE INVENTION

[0008] In order to solve one or more various technical problems, this invention describes new syntaxes and their uses for signaling scaling in a video bitstream. Thus, improved (de)coding efficiency can be achieved.

[0009] According to the present embodiments, when resampling the reference picture (RPR, Reference Picture Resampling) or when changing the adaptive resolution (ARC, Adaptive Resolution Change) using the modification of the high-level syntax (HLS, High-Level Syntax), additional resources to support scalability. In technical aspects, inter-layer prediction is used in a scalable system to improve the coding efficiency of the enhanced layers. In addition to the motion compensated spatial and temporal predictions that are available in the single layer codec, inter-layer prediction uses resampled video data of the reconstructed reference picture from the reference layer to predict the current enhancement layer. Then, the resampling process for inter-layer prediction is performed at the block level by modifying the existing interpolation process for motion compensation. This means that no additional resampling process is required to support scalability. The present invention discloses high level syntax elements to support spatial/quality scalability using RPR.

[0010] Included is a method and apparatus comprising a memory capable of storing computer program code and a processor or processors capable of accessing the computer program code and operating under the control of the computer program code. The computer program code includes parsing code configured such that at least one processor parses at least one Video Parameter Set (VPS) containing at least one syntax element indicating whether at least at least one layer in the scalable bitstream by one of the dependent scalable bitstream layer and the independent scalable bitstream layer, the first decoding code is configured such that at least one processor decodes a picture in the dependent layer by parsing and interpreting an Inter-layer Reference Picture List (ILRP, Inter-Layer Reference Picture), and the second decoding code is configured such that at least one processor decodes the picture in an independent layer without parsing and interpreting the ILRP list.

[0011] According to embodiments, the second decoding code is further configured such that at least one processor decodes a picture in an independent layer by parsing and interpreting a reference picture list that does not contain decoded pictures of another layer.

[0012] According to embodiments, the inter-layer reference picture list contains a decoded picture of another layer.

[0013] According to embodiments, the parsing code is further configured such that at least one processor parses at least one VPS by determining if another syntax element specifies a maximum number of levels.

[0014] According to embodiments, the parsing code is further configured such that at least one processor parses at least one VPS by determining whether the VPS contains a flag indicating that another layer in the scalable bitstream is a reference layer for at least one level.

[0015] According to embodiments, the parsing code is further configured such that at least one processor parses at least one VPS by determining whether a flag indicates another level as a reference level for at least one level by indicating an index of another level, and an index of at least one level.

[0016] According to embodiments, the parsing code is further configured such that at least one processor parses at least one VPS by determining if a flag indicates that another layer is not a reference layer for at least one layer by specifying an index of another level and an index of at least one level.

[0017] According to embodiments, the parsing code is further configured such that at least one processor parses at least one VPS by determining whether the VPS contains a flag indicating that a plurality of layers containing at least one layer should be decoded, by interpreting the ILRP list.

[0018] According to embodiments, the parsing code is further configured such that at least one processor parses at least one VPS by determining whether the VPS contains a flag indicating that a plurality of layers containing at least one layer should be decoded. , without interpreting the ILRP list.

[0019] According to embodiments, the parsing code is further configured such that at least one processor analyzes whether at least one VPS also determines whether the VPS contains a flag indicating that a plurality of layers is to be decoded containing at least one level, by interpreting the ILRP list.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Additional features, nature and various advantages of the disclosed invention will be apparent from the following detailed description and the accompanying drawings, in which:

[0021] FIG. 1 is a schematic representation of a simplified block diagram of a communication system according to an embodiment;

[0022] FIG. 2 is a schematic representation of a simplified block diagram of a communication system according to embodiments;

[0023] FIG. 3 is a schematic representation of a simplified block diagram of a decoder according to embodiments;

[0024] FIG. 4 is a schematic representation of a simplified block diagram of an encoder according to embodiments;

[0025] FIG. 5A is a schematic representation of prior art ARC/RPR parameter signaling options;

[0026] FIG. 5B is a schematic representation of prior art ARC/RPR parameter signaling options;

[0027] FIG. 5C is a schematic representation of ARC/RPR parameter signaling options according to embodiments;

[0028] FIG. 5D is a schematic representation of ARC/RPR parameter signaling options according to embodiments;

[0029] FIG. 5E is a schematic representation of ARC/RPR parameter signaling options according to embodiments;

[0030] FIG. 6 is a schematic representation of image resolution signaling according to embodiments;

[0031] FIG. 7 is a schematic representation of image size signaling and matching window in SPS according to embodiments;

[0032] FIG. 8 is a schematic representation of signaling the presence of inter-layer prediction in SPS according to embodiments;

[0033] FIG. 9 is a schematic representation of inter-layer prediction index signaling in a slice header according to embodiments;

[0034] FIG. 10 is a schematic representation of a computer system according to embodiments.

DETAILED DESCRIPTION

[0035] The proposed functions described below can be used alone or in combination with each other in any order. In addition, each of the embodiments may be implemented by a processing circuit (eg, one or more processors or one or more integrated circuits). In one example, one or more processors execute a program that is stored on a computer-readable medium.

[0036] Figure 1 shows a simplified block diagram of a communication system (100) according to an embodiment of the present invention. System (100) may include at least two terminals (110 and 120) connected to each other via network (150). In the case of unidirectional data transmission, the first terminal (110) may encode video data at the local location for transmission to another terminal (120) via the network (150). The second terminal device (120) may receive the encoded video data of another terminal device from the network (150), decode the encoded data, and display the reconstructed video data. One-way communication may be inherent in media service applications and the like.

[0037] FIG. 1 shows a second pair of terminals (130, 140) designed to support bi-directional transmission of coded video data, which may occur, for example, during a video conference. In the case of bi-directional data transmission, each terminal device (130, 140) may encode the video data captured at the local location for transmission to another terminal device via the network (150). Each terminal device (130, 140) may also receive the encoded video data transmitted by the other terminal device, may decode the encoded data, and may display the reconstructed video data on a local display device.

[0038] In FIG. 1, terminal devices (110, 120, 130, and 140) can be illustrated as servers, personal computers, and smartphones, but this does not limit the principles of the present invention. Embodiments of the present invention find application in laptop computers, tablet computers, media players and/or dedicated video conferencing equipment. Network (150) represents any number of networks that carry encoded video data between terminals (110, 120, 130, and 140), including, for example, wired and/or wireless networks. The communication network (150) allows data to be exchanged in a circuit-switched and/or packet-switched mode. Exemplary networks include telecommunications networks, local area networks, wide area networks, and/or the Internet. For the purposes of this discussion, the architecture and topology of the network (150) may not be relevant to the present invention unless specifically noted below.

[0039] Figure 2 shows, as an example of the application of the disclosed invention, the placement of a video encoder and a video decoder in a streaming environment. The disclosed invention may be equally applicable to other video processing applications, including, for example, video conferencing, digital television, storage of compressed video on digital media, including CD, DVD, memory card, etc., etc.

[0040] The streaming system may include a capture subsystem (213), which may include a video source (201), such as a digital camera, producing, for example, a stream (202) of uncompressed video samples. This stream (202) of samples, shown with a thick line to emphasize the large amount of data compared to the bitstreams of the encoded video, can be processed by the encoder (203) connected to the camera (201). The encoder (203) may include hardware, software, or a combination thereof for providing or implementing aspects of the disclosed invention, as described in more detail below. The encoded video bitstream (204), shown as a thin line to emphasize the smaller amount of data compared to the sample stream, may be stored on the streaming server (205) for future use. One or more streaming clients (206, 208) may access the streaming server (205) to retrieve copies (207, 209) of the encoded video bitstream (204). The client (206) may include a video decoder (210) that decodes an incoming copy of the encoded video bitstream (207) and produces an outgoing stream (211) of video samples that can be displayed on a display (212) or other rendering device (not shown). ). In some streaming systems, the video bitstreams (204, 207, 209) may be encoded according to one video coding/compression standard or another. Examples of these standards include ITU-T Recommendation H.265. A video coding standard is being developed, officially called Versatile Video Coding, or VVC. The disclosed invention may be used in the context of VVC.

[0041] FIG. 3 may be a functional block diagram of a video decoder (210) according to an embodiment of the present invention.

[0042] The receiver (310) may receive one or more codec video sequences for decoding by the decoder (210); in the same or another embodiment, one coded video sequence at a time, where the decoding of each coded video sequence is independent of other coded video sequences. The encoded video sequence may be received from a channel (312), which may be a hardware/software link to a storage device where the encoded video data is stored. The receiver (310) may receive encoded video data with other data, such as encoded audio data and/or auxiliary data streams, which may be relayed to their respective usable objects (not shown). The receiver (310) may separate the encoded video sequence from other data. To combat network jitter, a buffer memory (315) may be connected between the receiver (310) and the entropy decoder/analyzer (320) (hereinafter "analyzer"). If the receiver (310) receives data from a storage/forwarder with sufficient bandwidth and controllability, or from an isosynchronous network, the buffer (315) may not be used or may be small. For use in best effort packet networks, such as the Internet, a buffer memory (315) may be required, which may be relatively large and may have a predominantly adaptive size. [0043] The video decoder (210) may include an analyzer (320) for reconstructing symbols (321) from an entropy coded video sequence. The categories of these symbols include information used to control the operation of the video decoder (210) and possibly information to control a visualization device such as a display (212) that is not an integral part of the decoder but may be connected to it, as shown in FIG. .2. The control information for the rendering device(s) may be Supplementary Enhancement Information (SEI) messages or Video Usability Information (VUI) parameter set fragments (not shown). The analyzer (320) may analyze/entropy decode the received encoded video sequence. Encoding of the encoded video sequence may be performed according to a video coding method or standard, and may follow principles well known to one skilled in the art, including variable length coding, Huffman coding, context sensitive or context sensitive arithmetic coding, etc. The analyzer (320) can extract from the encoded video sequence a set of subgroup parameters for at least one of the subgroups of pixels in the video decoder based on at least one parameter corresponding to the group. Subgroups may include groups of pictures (GOP, Groups of Pictures), images, tiles, slices, macroblocks, coding units (CU, Coding Units), blocks, transformation units (TU, Transform Units), prediction units (PU, Prediction Units ) etc. The entropy decoder/analyzer can also extract information from the encoded video sequence, such as transform coefficients, quantizer parameter values, motion vectors, etc.

[0044] The analyzer (320) may perform an entropy decoding/analysis operation of the video sequence received from the buffer (315) to create symbols (321).

[0045] Several different modules may be used for symbol reconstruction (321) depending on the type of encoded video image or parts thereof (eg, inter- and intra-image, inter- and intra-block) and other factors. Which modules are used, and how, may be determined by the subgroup management information extracted from the encoded video sequence by the analyzer (320). The flow of such subgroup management information between the analyzer (320) and the multiple modules is not shown hereinafter for simplicity.

[0046] In addition to the previously mentioned functional blocks, the decoder (210) can be fundamentally divided into several functional modules, as described below. In a practical implementation operating under commercial constraints, many of these modules interact closely with one another and can, at least partially, be nested within one another. However, for the purposes of describing the disclosed invention, a fundamental subdivision into the following functional modules is appropriate.

[0047] The first module is the scaling/inverse transform module (351). The scaling/inverse transform module (351) receives the quantized transform coefficient as well as control information including the transform used, block size, quantization factor, quantization scaling matrices, etc. as character(s) (321) from the analyzer (320). This module can output blocks containing sample values that can be entered into the aggregator (355).

[0048] In some cases, the output samples of the scaling / inverse transform block (351) may refer to an intra-coded block; that is, a block that does not use predicted information from previously reconstructed images, but may use predicted information from previously reconstructed portions of the current image. Such predicted information may be provided by an intra-picture prediction module (352). In some cases, intra-image prediction module (352) generates a block of the same size and shape as the block to be reconstructed using previously reconstructed environment information extracted from the current (partially reconstructed) image (356). The aggregator (355) in some cases adds, for each sample, the prediction information generated by the intra prediction module (352) to the output sample information provided by the scaling/inverse transform module (351).

[0049] In other cases, the output samples of the scaling/inverse transform module (351) may refer to an intra-coded block, possibly with motion compensation. In such a case, the motion compensation prediction module (353) may access the reference picture memory (357) to retrieve samples used for prediction. After motion compensation has been applied to the extracted samples according to the symbols (321) associated with the block, these samples can be added by the aggregator (355) to the output signal of the scaler / inverse transform (in this case referred to as "residual samples" or "residual signal") to generate output sample information. The reference picture memory addresses from where the motion compensation prediction module retrieves the predicted samples may be governed by the motion vectors available to the motion compensation prediction module in the form of symbols (321), which may have X, Y and reference picture components, for example. Motion compensation may also include interpolation of sample values retrieved from reference picture memory when accurate subsample motion vectors, motion vector prediction mechanisms, and so on are used.

[0050] Various loop filtering techniques can be applied to the aggregator (355) output samples in the loop filter module (356). The video compression techniques may include deblocking filter techniques under the control of parameters included in the encoded video bitstream and become available to the loop filter module (356) as symbols (321) from the parser (320), but may also respond to metainformation received during decoding of the previous (in the order of decoding) parts of the encoded image or encoded video sequence, as well as to respond to previously reconstructed and contour filtered sample values.

[0051] The loop filter module (356) may provide a stream of samples that may be fed to the renderer (212) as well as stored in the reference picture memory (356) for use in future inter-picture prediction.

[0052] Some encoded pictures, when fully reconstructed, can be used as reference pictures for future prediction. When the encoded picture is completely reconstructed and the encoded picture is identified as a reference picture (e.g., by the analyzer (320)), the current picture buffer (356) may become part of the reference picture buffer (357), and a fresh current picture buffer may be re-allocated before reconstruction of the next picture begins. encoded image.

[0053] Video decoder 320 may perform decoding operations in accordance with a predefined video data compression method, which may be documented in a standard such as ITU-T recommendation H.265. The encoded video sequence may conform to the syntax specified by the video compression method or standard used, in the sense that it adheres to the syntax of the video compression method or standard specified in a video compression technology document or standard, and in particular in the related documents of those standards. It may also be necessary for consistency that the complexity of the encoded video sequence remain within the boundaries given by the level of video compression technology or standard. In some cases, the levels limit the maximum image size, the maximum frame rate, the maximum sampling rate for reconstruction (measured in megasamples per second, for example), the maximum reference image size, and so on. The limits set by the levels, in some cases, may be further limited by the specifications of the hypothetical reference decoder (HRD, Hypothetical Reference Decoder) and metadata for managing the HRD buffer signaled in the encoded video sequence.

[0054] According to embodiments, the receiver (310) may receive additional (redundant) data with encoded video. Additional data may be included as part of the encoded video sequence(s). The additional data may be used by the video decoder (320) to correctly decode the data and/or more accurately reconstruct the original video data. The additional data may be provided in the form of, for example, temporal, spatial, or enhanced SNR levels, redundant levels, redundant images, forward error correction codes, and so on.

[0055] FIG. 4 may be a functional block diagram of a video encoder (203) according to an embodiment of the present invention.

[0056] The encoder (203) may receive video samples from a video source (201) (which is not part of the encoder) that may capture the video image(s) to be encoded by the encoder (203).

[0057] The video source (201) may provide the source video sequence to be encoded by the encoder (203) in the form of a digital video sample stream of any suitable bit depth (e.g., 8 bits, 10 bits, 12 bits, etc.), any color space (eg, BT.601 Y CrCB, RGB, etc.), and any suitable sampling structure (eg, Y CrCb 4:2:0, Y CrCb 4:4:4). In a media service system, the video source (201) may be a storage device where previously prepared video is stored. In a videoconferencing system, the video source (203) may be a camera that captures local image information as a video sequence. The video data may be provided as a plurality of individual images that give a sense of movement when viewed in sequence. The images themselves can be organized as a spatial array of pixels, each of which may contain one or more samples, depending on the sampling structure, color space, etc. used. It is not difficult for a person skilled in the art to understand the relationship between pixels and samples. The following description is about readings.

[0058] According to an embodiment, the encoder (203) may encode and compress images of the source video sequence into the encoded video sequence (443) in real time or subject to any other time constraints imposed by the application. Setting the proper coding rate is one of the functions of the controller (450). The controller controls other function modules as described below and is operatively connected to these function modules. The connection is not shown for simplicity. The parameters set by the controller may include parameters related to frequency adjustment (picture skip, quantizer, lambda value applied in rate-distortion optimization, etc.), picture size, group of pictures scheme (GOP, Group Of Pictures), maximum motion vector search area, etc. A person skilled in the art can readily identify other functions of the controller (450) as they may relate to a video encoder (203) optimized for a particular system design.

[0059] Some video encoders operate in a mode known to those skilled in the art as "coding loop". As a very simplified description, an encoding loop may include an encoding component of an encoder (430) (hereinafter "source encoder") (responsible for creating symbols based on the input image to be encoded and the reference image(s)), and ( local) decoder (433) built into the encoder (203) that reconstructs the symbols to produce sample data that the (remote) decoder must also produce (because any compression between the symbols and the encoded video bitstream is lossless in the video compression technologies considered in the disclosed invention). This reconstructed sample stream enters the reference picture memory (434). Since decoding a stream of symbols produces bit-accurate results independent of the position of the decoder (local or remote), the contents of the reference picture buffer will also be the same bit-accuracy for the local encoder and the remote encoder. In other words, the predicted portion of the encoder "sees" as reference picture samples exactly the same sample values as the decoder would "see" if using prediction during decoding. This fundamental principle of reference picture synchronism (and eventually drift if synchronism cannot be maintained due to, for example, channel errors) is well known to those skilled in the art.

[0060] The "local" decoder (433) may operate in the same manner as the "remote" decoder (210) detailed above with reference to FIG. However, again with respect to FIG. 3, since the symbols are available and the encoding/decoding of the symbols in the encoded video sequence by the entropy encoder (445) and parser (320) can be lossless, the entropy decoding portions of the decoder (210) including the channel ( 312), receiver (310), buffer (315), and parser (320) may not be fully implemented in the local decoder (433).

[0061] In doing so, it can be concluded that any decoding technology present in a decoder, with the exception of analysis/entropy decoding, must also be present, in essentially identical functional form, in the corresponding encoder. For this reason, the disclosed invention is focused on the operation of the decoder. The description of the encoding technologies can be abbreviated as they are the inverse of the decoding technologies described in detail. Only in some areas a more detailed description is required, which is given below.

[0062] In operation, source encoder (430) may perform motion-compensated predictive coding in which an input frame is predictively encoded based on one or more previously encoded frames from the video sequence, referred to as "reference frames". Thus, the encoding engine (432) encodes the differences between the pixel blocks of the input frame and the pixel blocks of the reference frame(s) that can be selected as the predicted reference(s) to the input frame.

[0063] The local video decoder (433) may decode the encoded video data of the frames, which may be specified as reference frames, based on the symbols generated by the source encoder (430). The operations of the encoding engine (432) may be predominantly lossy processes. If the encoded video data is decoded in a video decoder (not shown in FIG. 4), then the reconstructed video sequence can typically be a copy of the original video sequence with some errors. The local video decoder (433) duplicates the decoding processes that may be performed by the video decoder on the reference frames and may cause the reconstructed reference frames to be stored in the reference picture cache (434). Thus, the encoder (203) can locally store copies of the reconstructed key frames having the same content as the reconstructed key frames that will be received by the video decoder at the receiver side (in the absence of transmission errors).

[0064] The predictor (435) may perform prediction searches for the encoding engine (432). Thus, for a new frame to be encoded, the predictor (435) can search the reference picture memory (434) for sample data (as candidates for the role of reference pixel blocks) or some metadata, for example, motion vectors of the reference picture, block shapes etc., which can serve as a proper reference for predicting new images. The predictor (435) may operate on a "sample-to-pixel-blocks" basis to find proper references for prediction. In some cases, according to the search results obtained by the predictor (435), the input picture may have prediction references extracted from the plurality of reference pictures stored in the reference picture memory (434).

[0065] The controller (450) may control the encoding operations of the video encoder (430), including, for example, setting parameters and subgroup parameters used to encode video data.

[0066] The output of all of the above functional modules may be entropy encoded in an entropy encoder (445). The entropy encoder translates symbols generated by various functional modules into an encoded video sequence by lossless symbol compression according to techniques known to one skilled in the art, such as Huffman coding, variable run length coding, arithmetic coding, and so on.

[0067] The transmitter (440) may buffer the encoded video sequence(s) created by the entropy encoder (445) in preparation for transmission over a communication channel (460), which may be a hardware/software link to a storage device where encoded video data. The transmitter (440) may combine the encoded video data from the video encoder (430) with other data to be transmitted, such as encoded audio data and/or auxiliary data streams (sources not shown).

[0068] The controller (450) may control the operation of the encoder (203). During encoding, the controller (450) may assign to each encoded picture one or another encoded picture type, which may determine the encoding methods applicable to the corresponding picture. For example, images can often be assigned the following frame types:

[0069] An intra-picture (I-picture) may be an image that can be encoded and decoded without using any other frame in the sequence as a prediction source. Some video codecs allow different types of intra-pictures, including, for example, pictures in the Independent Decoder Refresh (IDR) format. One skilled in the art will be aware of the 1-image varieties and their respective uses and features.

[0070] A predicted picture (P-picture) that can be encoded and decoded using intra prediction or inter prediction using at most one motion vector and a reference index to predict sample values of each block.

[0071] A bi-directionally predicted picture (B-picture) that can be encoded and decoded using intra prediction or inter prediction using no more than two motion vectors and reference indices to predict sample values of each block. Likewise, multi-predicted pictures may use more than two reference pictures and associated metadata to reconstruct a single block.

[0072] Source images typically allow for spatial division into multiple blocks of samples (eg, blocks of 4x4, 8x8, 4x8, or 16x16 samples each) and coding on a block-by-block basis. Blocks may be predictively encoded with reference to other (previously encoded) blocks determined by the coding assignment applied to the respective images of those blocks. For example, 1-picture blocks can be coded without prediction or predictively with reference to previously coded blocks of the same picture (spatial prediction or intra prediction). Blocks of pixels of P-pictures can be encoded without prediction, using spatial prediction or temporal prediction with reference to one pre-coded reference picture. Blocks of B-pictures may be encoded without prediction by spatial prediction or temporal prediction with reference to one or two previously encoded reference pictures.

[0073] The video encoder (203) may perform encoding operations according to a predetermined video coding technology or standard, such as ITU-T Rec. H.265. In operation, the video encoder (203) may perform various compression operations, including predictive encoding operations that exploit temporal and spatial redundancies in the input video sequence. Therefore, the encoded video data may conform to the syntax given by the video coding technology or standard being used.

[0074] According to an embodiment, transmitter (440) may transmit additional data with encoded video. Video encoder (430) may include such data as part of an encoded video sequence. Supplementary data may include temporal/spatial/SNR enhancement levels, other types of redundant data such as redundant images and slices, Supplementary Enhancement Information (SEI) messages, Visual Usability (VUI) parameter set fragments. Information), etc.

[0075] Before a more detailed description of certain aspects of the disclosed invention, it is necessary to introduce several terms that will be referred to in the remainder of this description.

[0076] Further, a sub-image refers, in some cases, to a rectangular arrangement of samples, blocks, macroblocks, coding units, or the like, which are semantically grouped and which can be independently encoded with a changed resolution. One or more sub-images may form an image. One or more encoded sub-images may form an encoded image. One or more sub-images may be assembled into an image, and one or more sub-images may be extracted from the image. In certain environments, one or more encoded sub-images may be assembled in the compressed domain without being re-coded to the sample level in the encoded image, and in the same or in certain other cases, one or more encoded sub-images may be extracted from the encoded image in the compressed domain.

[0077] Further, reference picture resampling (RPR, Reference Picture Resampling) or adaptive resolution change (ARC, Adaptive Resolution Change) refers to mechanisms that allow changing the resolution of a picture or sub-picture in a coded video sequence, for example, by resampling a reference picture. In the following, RPR/ARC parameters refer to control information required to perform adaptive resolution change, which may include, for example, filter parameters, scaling factors, output and/or reference picture resolutions, various control flags, and so on.

[0078] The description above is focused on encoding and decoding a single semantically independent encoded video image. Before describing the implementation of encoding/decoding of multiple sub-images with independent RPR/ARC parameters and the implied additional complication of the workflow, options for signaling the RPR/ARC parameters should be described.

[0079] Figure 5 shows several new RPR/ARC parameter signaling options. It should be noted that each of the options has certain advantages and disadvantages in terms of coding efficiency, complexity and architecture. In a video coding standard or technology, one or more of these options, or options known in the art, may be selected for RPR/ARC parameter signaling. The parameters may not be mutually exclusive and are expected to be interchanged depending on application requirements, standards used, or encoder selection.

[0080] RPR/ARC parameter classes may include:

- upsampling/downsampling coefficients, separate or combined in the X and Y dimensions;

- upsampling/downsampling coefficients with the addition of a temporal dimension indicating zooming in/out at a constant rate for a given number of images;

- any of the above two clauses may trigger the encoding of one or more supposedly short syntax elements that may point to a table containing coefficients);

- resolution, in the X or Y dimension, in units of samples, blocks, macroblocks, CUs, or any other suitable granularity of the input picture, output picture, reference picture, coded picture, merged or separate. (If there is more than one resolution (for example, one for the input image, and one for the reference image); in some cases, one set of values can be derived from another set of values. This can be controlled, for example, using flags. For a more detailed example, see . below.);

- "warp" coordinates like those used in Annex P of H.263, again with the appropriate granularity as described above (Annex P of H.263 defines one efficient way to encode such warp coordinates, but others may also be developed , potentially more efficient methods For example, according to embodiments, the reverse Huffman variable-length coding of warp coordinates according to Annex P is replaced by binary coding with an appropriate length, where the length of the binary codeword can be, for example, determined based on the maximum image size, possibly multiplied by by a certain factor and shifted by a certain amount to allow "warping" beyond the limits of the maximum image size), and/or

- upsampling or downsampling filter parameters (In the simplest case, only one upsampling and/or downsampling filter can be used. However, in some cases it may be preferable to allow more flexibility in filter design, this may require signaling filter parameters. Such parameters may be selected by an index in a list of possible filter designs, the filter may be fully specified (e.g., by a list of filter coefficients using suitable entropy coding techniques), the filter may be implicitly selected by upsampling/downsampling relationships according to which, in in turn, the signaling is performed in accordance with any of the mechanisms mentioned above, etc.).

[0081] The following description assumes encoding a finite set of upsampling/downsampling coefficients (the same coefficient to be used in both the X dimension and the Y dimension) indicated by a codeword. For this codeword, variable length encoding is advantageously used, such as using exponential Golomb code common to certain syntax elements in video coding specifications such as H.264 and H.265. One suitable mapping of values to upsampling/downsampling factors may, for example, correspond to the following Table. one:

[0082] Many similar mappings can be designed in accordance with the requirements of the application and the capabilities of the upsampling and downsampling mechanisms available in the video compression technology or standard. This table can contain more values. Values may also be represented by entropy encoding mechanisms other than Exponential Golomb codes, such as using binary encoding. This can have certain advantages when the resampling factors are of interest outside of the video processing engines themselves (primarily the encoder and decoder), such as with MANE. It should be noted that for the (presumably) most common case where no resolution change is required, a short exponential Golomb code can be chosen; in the table above it is only one bit. This may have an advantage in coding efficiency over using binary codes for the most common case.

[0083] The number of entries in the table, as well as their semantics, can be fully or partially configurable. For example, the basic table structure may be conveyed in a "high" level parameter set such as a sequence or a decoder parameter set. Alternatively or additionally, one or more such tables may be defined in a video coding technology method or standard and may be selected, for example, by a decoder or sequence parameter set.

[0084] The following describes how the upsampling/downsampling ratio (ARC information) encoded as described above can be included in the syntax of a video coding method or standard. Similar considerations may apply to one or more codewords driving the upsampling/downsampling filters. See below for a discussion of the case where a filter or other data structure requires relatively large amounts of data.

[0085] As shown in the example of FIG. 5A, illustration (500A) shows that H.263 Application P includes ARC information (502) in the form of four warp coordinates in the image header (501), specifically in the extension H.263 PLUSPTYPE header (503). This may be a reasonable design choice when a) there is an image header available and b) frequent changes to the ARC information are expected. However, the amount of data when using H.263-style signaling can be quite large, and the scaling factors may not be related to picture boundaries because the picture header may be temporary. In addition, as shown in the example of FIG. 5B, illustration (500B) shows that JVET-M0135 includes PPS information (504), ARC reference information (505), SPS information (507), and table information (506). target permission.

[0086] According to the exemplary embodiment, FIG. 5C shows an example (500C) showing tile group header information (508) and ARC information (509); 5D shows an example (500D) showing tile group header information (514), ARC reference information (513), SPS information (516), and ARC information (515), and FIG. 5E shows an example (500E) , which shows information (511) set(s) of adaptation parameters (APS) and information (512) ARC.

[0087] Figure 6 shows an example (600) of a table that uses adaptive resolution, in this example the output resolution is encoded in units of samples (613). The numeric value (613) refers to both the output_pic_width_in_luma_samples syntax element and the output_pic_height_in_luma_samples syntax element, which together can define the resolution of the output image. Elsewhere in a video coding method or standard, certain restrictions may be defined for any value. For example, the level definition may limit the number of total output samples that can be the product of the values of these two syntax elements. In addition, certain video coding methods or standards, or external methods or standards such as, for example, system standards, may restrict the numbering range (for example, one or both dimensions must be divisible by a power of 2) or image format (for example, width and height must have a ratio of 4:3 or 16:9). Such limitations may be introduced to facilitate hardware implementations, or for other reasons that will be clear to a person skilled in the art in terms of the disclosure of the present invention.

[0088] In some applications, it may be desirable for the encoder to instruct the decoder to use a particular reference picture size, rather than assuming that this size is the size of the output picture. In this example, the reference_pic_size_present_flag (614) syntax element disables the conditional presence of the reference picture sizes (615) (again, the numeric value refers to both width and height).

[0089] Certain video coding techniques or standards, such as VP9, support spatial scalability by implementing certain forms of reference picture resampling (implemented quite differently from the disclosed invention) in combination with temporal scalability to provide spatial scalability. In particular, some reference pictures may be upsampled using higher resolution ARC-style techniques to form the basis of the spatial enhancement layer. These upsampled images can be enhanced using conventional high resolution prediction engines to add detail.

[0090] The disclosed invention can be and is used in such an environment according to embodiments. In some cases, in the same or in a different embodiment, a value in the NAL unit header, such as a temporal identifier field, may be used to indicate not only the temporal but also the spatial level. This provides certain advantages for certain systems; for example, existing Selected Forwarding Units (SFUs) created and optimized for forwarding selected at the temporal level based on the NAL Header Temporal Identifier value can be used without modification for scalable environments. To make this possible, there may be a requirement for a match between the encoded picture size and the temporal level indicated by the temporal identifier field in the NAL unit header.

[0091] According to embodiments, inter-layer dependency information may be conveyed in the VPS (or in DPS, SPS, or SEI messages). The dependency information between layers may be used to identify which layer is used as a reference for decoding the current layer. The decoded picture picA in the forward layer with nuh_layer_id equal to m can be used as a reference picture for picture picB with nuh_layer_id equal to n when n is greater than m and the two pictures picA and picB belong to the same access unit.

[0092] According to the same or other embodiments, a list of inter-layer reference pictures (ILRP, Inter-Layer Reference Picture) can be explicitly transmitted with a list of reference pictures of internal prediction (IPRP, biter-Prediction Reference Picture) in the slice header (or in the parameter set ). Both ILRPs and IPRPs can be used to generate forward and backward prediction reference picture lists.

[0093] According to the same or other embodiments, the syntax elements in the VPS (or other parameter set) may indicate whether each layer is dependent or independent. In the example (700) shown in FIG. 7, the vps syntax element _ax_layers_minus1 (703) plus 1 may indicate the maximum number of layers allowed in one or more, potentially all, VPS-related CVSs (701). The syntax element vps_all_independent_layers_flag (704) equal to 1 may indicate that all layers in CVS are encoded independently, ie without using inter-layer prediction. The syntax element vps_all_independent_layers_flag (704) equal to 0 may indicate that one or more layers in CVS may use inter-layer prediction. When this syntax element is absent, the value of the vps_all_independent_layers_flag syntax element may be considered to be 1. When the value of the vps_all_independent_layers_flag syntax element is 1, the value of the vps_independent_layer_flag[i] (706) syntax element may be considered to be 1. When the value of the vps_all_independent_layers_flag syntax element is 0, the value of the syntax element vps_independent_layer_flag[0] may be considered to be 1. FIG. 7 shows that the syntax element vps_independent_layer_flag[i] (706) of 1 may indicate that inter-layer prediction is not used at the layer index i. The syntax element vps_independent_layer_flag[i] equal to 0 may indicate that inter-layer prediction can be used at the layer index i and vps_layer_dependency_flag[i] is present in the VPS. The syntax element vps_direct_dependency_flagf[i][j] (707) equal to 0 may indicate that the level at index j is not a direct reference level for the level at index i. The vps_direct_dependency_flag[i][j] syntax element equal to 1 may indicate that the level at index j is not a direct reference level for the level at index i. When vps_direct_dependency_flagf[i][j] is absent for i and j in the range 0 to vps_max_layers_minusl inclusive, it can be assumed to be 0. DirectDependentLayerIdx[i][j] variable indicating the j-th direct dependent layer of the i-th layer is defined as follows:

[0094] The variable GeneralLayerldx[i] indicating the index of the layer with nuh_layer_id equal to vps_layer_id[i] is defined as follows:

[0095] According to the same or other embodiments? 7 shows that when the value of the vps_max_layers_minusl syntax element is greater than zero and the value of the vps_all_independent_layers_flag syntax element is zero, the vps_output_layers_mode and vps_output_layer_flags [i] syntax elements can be transmitted. The syntax element vps_output_layers_mode (708) equal to 0 may indicate that only the highest layer is output. The syntax element vps_output_layer_mode equal to 1 may indicate that all levels may be output. The vps_output_layer_mode syntax element equal to 2 may indicate that levels are output with the vps_output_layer_flag [i] (709) syntax element equal to 1. The value of the vps_output_layers_mode syntax element must be in the range 0 to 2 inclusive. The value 3 of the vps_output_layer_mode syntax element may be reserved for future use. When this syntax element is absent, the value of the vps_output_layers_mode syntax element may be assumed to be 1. The vps_output_layer_flag[i] syntax element equal to 1 may indicate that the i-th layer is being output. The syntax element vps_output_layer_flag[i] equal to 0 may indicate that the i-th layer is not output. The list OutputLayerFlagf[i], for which a value of 1 can indicate that the i-th level is output, and a value of 0 indicates that the i-th level is not output, is defined as follows:

[0096] According to the same or other embodiments, the output of the current image can be defined as follows:

- If the value of the syntax element PictureOutputFlag is 1, and the value of the syntax element DpbOutputTimef[n] is equal to the value of the syntax element CpbRemovalTime[n], then the current image is output.

- Otherwise, if the value of the PictureOutputFlag syntax element is 0, then the current image is not output, but will be stored in the DPB as specified in below.

Otherwise (the value of the PictureOutputFlag syntax element is 1 and the value of the DpbOutputTimef[n] syntax element is greater than the value of the CpbRemovalTime[n] syntax element), the current image is output later and stored in the DPB (as specified below) and output at time DpbOutputTimef[n] , unless specified to be output by decoding or outputting the no_output_of_prior_pics_flag syntax element equal to 1 at a time prior to DpbOutputTimef[n].

On output, the image is cropped using the appropriate window

cropping specified in the PPS for the image.

[0097] According to the same or other embodiments, the PictureOutputFlag syntax element can be defined as follows:

- If one of the following conditions is true, then PictureOutputFlag is set to 0:

- The current image is a RASL image and the NoIncorrectPicOutputFlag value of the associated IRAP image is 1.

- gdr_enabled_flag is 1 and the current image is a GDR image with NohicorrecfPicOutputFlag equal to 1.

- gdr_enabled_flag is 1, the current image is linked to a GDR image with NomcorrectPicOutputFlag equal to 1, and

the PicOrderCntVal value of the current picture is less than the RpPicOrderCntVal value of the associated GDR picture.

- vps_output_layer_mode is 0 or 2 and OutputLayerFlag[GeneralLayerldx[nuh layer id]] is 0.

- Otherwise, PictureOutputFlag is set to pic_output_flag.

[0098] According to the same or other embodiments, the PictureOutputFlag syntax element can also be defined as follows:

If one of the following conditions is true, then PictureOutputFlag

set to 0:

- The current image is a RASL image and the NoIncorrectPicOutputFlag value of the associated IRAP image is 1.

- gdr_enab_led_flag is 1 and the current image is a GDR image with NoIncorrectPicOutputFlag set to 1.

- gdr_enabled_flag is 1, the current image is linked to a GDR image with NoIncorrectPicOutputFlag equal to 1, and

the PicOrderCntVal value of the current picture is less than the RpPicOrderCntVal value of the associated GDR picture.

The value of vps_output_layer_mode is 0 and the current accessor contains an image that has a PictureOutputFlag value of 1 and a nuh_layer_id nuhLid value greater than that of the current image that is related to the output layer (that is, the value of OutputLayerFlag[GeneralLayerIdx[nuhLid]] is 1) .

- vps_output_layer_mode is 2 and OutputLayerFlag[GeneralLayerldx[nuh layer id]] is 0.

- Otherwise, PictureOutputFlag is set to pic_output_flag.

[0099] According to the same or other embodiments, a flag in the VPS (or another set of parameters) may indicate whether ILRPs are being transmitted for the current slice (or picture). For example, in the example (800) shown in FIG. 8, the inter_layer_refjtics_jtresent flag syntax element equal to 0 may indicate that no ILRPs are used for intra-coded picture prediction in CVS. An inter_layer_ref_pics flag syntax element of 1 may indicate that ILRPs may be used for intra-prediction of one or more coded pictures in CVS.

[0100] According to the same or other embodiments, an Inter-Layer Reference Picture List (ILRP) for an image in the k-th layer may or may not be transmitted when the k-th layer is layer dependent. However, the ILRP list for a picture in the k-th layer should not be transmitted, and no ILRP should be entered in the reference picture list when the k-th layer is an independent layer.

inter_layer_ref_pics_present_flag may be set to 0 when sps_video_parameter_set_id is 0, when nuhlayerid is 0, or when vpsindependentlayer_flag[GeneralLayerIdx[nuh layer id]] is 1.

[0101] According to the same or other embodiments, example (900) in FIG. 9 shows that reference picture lists RefPicList[0] and RefPicListf[1] can be formed as follows:

[0102] The adaptive resolution parameter transmission techniques described above may be implemented in computer software using computer readable instructions and physically stored on one or more computer readable media. For example, FIG. 10 shows a computer system (1000) suitable for implementing some embodiments of the disclosed invention.

[0103] Computer software may be coded using any suitable machine code or programming language that can be assembled, compiled, linked, or similar mechanisms to form code containing instructions that can be directly executed or interpreted, executed as microinstructions, etc. .P. computer central processing units (CPU, Central Processing Unit), graphic processors (GPU, Graphics Processing Unit), etc.

[0104] Instructions may be executed on various types of computers or components thereof, including, for example, personal computers, tablet computers, servers, smartphones, gaming devices, IoT devices, and the like.

[0105] The components shown in FIG. 10 for the computer system (1000) are illustrative and are not intended to impose any limitation on the scope of application or functionality of the computer software implementing embodiments of the present invention. The configuration of the components should also not be interpreted as having any dependency or requirement in connection with any one or combination of the components shown in the illustrative embodiment of the computer system (1000).

[0106] The computer system (1000) may include some human interface input devices. Such an input device may be responsible for input by one or more users through, for example, tactile input (e.g., keystrokes, waving, glove movements), audio input (e.g., voice, claps), visual input (e.g., gestures), olfactory input (not shown). Human interface devices can also be used to capture certain media not necessarily directly related to conscious human input, such as sound (e.g. speech, music, external sound), images (e.g. scanned images, photographic images received from a still image camera). ), video (eg, 2D video, 3D video including stereoscopic video).

[0107] The input human interface of the device may include one or more of the following components (one of each depicted): keyboard (1001), mouse (1002), touch pad (1003), touch screen (1010), joystick (1005), microphone (1006), scanner (1007), camera (1008).

[0108] The computer system (1000) may also include some human interface output devices. Such output devices may stimulate the senses of one or more users through, for example, tactile output, sound, light, and smell/taste. Such output devices may include tactile output devices (e.g., tactile feedback via touch screen (1010) or joystick (1005), but may also be tactile feedback devices that do not serve as input devices), audio output devices (e.g., speakers (1009), headphones (not shown)), visual output devices (e.g., screens (1010), including CRT screens, LCD screens, plasma screens, OLED screens, each with or without touch screen input capabilities , each with or without haptic feedback capabilities, some of which are capable of 2D visual output or more than 3D output through, for example, stereographic output; virtual reality goggles (not shown), holographic displays, and smoke tanks (not shown)) and printers (not shown).

[0109] The computer system (1000) may also include human accessible storage devices and associated media, such as optical media including CD/DVD ROM/RW (1020) with CD/DVD media (1021), etc. .p., flash memory cards (1022), removable hard drive or solid state drive (1023), conventional magnetic media such as tape and floppy disk (not shown), dedicated ROM/ASIC/PLD based devices such as security hardware keys (not shown) and the like.

[0110] Those skilled in the art should also understand that the term "computer-readable media" as used in connection with the invention disclosed herein does not encompass transmission media, carrier waves, or other short-term signals.

[0111] The computer system (1000) may also include an interface to one or more communication networks. Networks can be, for example, wireless, wired, optical. Networks may additionally be local, wide area, metropolitan, transport and industrial, real-time, latency, etc. Examples of networks include local area networks such as Ethernet, wireless LANs, cellular networks including GSM, 3G, 4G, 5G, LTE, etc., digital wide area networks for wired or wireless television, including cable television, satellite TV and terrestrial TV, transport and industrial include CANBus, etc. Some networks typically require external network interface adapters that are connected to some general purpose data ports or peripheral buses (1049) (for example, computer system USB ports (1000)); others are typically built into the core of the computer system (1000) by connecting to a system bus as described below (eg, an Ethernet interface to a PC computer system or a cellular network interface to a smartphone computer system). Using any of these networks, the computer system (1000) can communicate with other entities. Such communications may be unidirectional with receive-only capability (eg, broadcast), unidirectional with transmit-only capability (eg, CANBus to some CANBus devices), or bidirectional, eg, to other computer systems using a local or wide area digital network. Several protocols and protocol stacks may be used on each of these networks and the network interfaces described above.

[0112] The aforementioned human interface devices, human accessible storage devices, and network interfaces can be connected to the core (1040) of the computer system (1000).

[0113] The core (1040) may include one or more central processing units (CPUs) (1041), graphics processing units (GPUs) (1042), specialized programmable processing modules in the form of Field Programmable Gate Arrays (FPGAs). ) (1043), hardware accelerators for some tasks (1044), etc. These devices, together with read-only memory (ROM) (1045), random access memory (1046), high capacity internal storage such as user-inaccessible internal hard drives, SSD, etc. (1047) can be connected via the system bus (1048). In some computer systems, the system bus (1048) may be available in the form of one or more physical connectors to allow for expansions with additional CPUs, GPUs, and the like. Peripherals can be connected either directly to the system bus (1048) of the kernel, or via a peripheral bus (1049). Peripheral bus architectures include PCI, USB, and the like.

[0114] CPUs (1041), GPUs (1042), FPGAs (1043), and accelerators (1044) may execute some instructions, which together may constitute the aforementioned computer code. This computer code may be stored in ROM (1045) or RAM (1046). Transient data may also be stored in RAM (1046), while persistent data may be stored, for example, in an internal mass storage (1047). Fast storage and retrieval from any storage device can be achieved through the use of cache memory, which can be closely associated with one or more CPU (1041), GPU (1042), mass storage (1047), ROM (1045), RAM (1046) etc.

[0115] Computer-readable media may store computer code for performing various computer-implemented operations. The media and computer code may be specially created for the purposes of the present invention or may be well known and available to those skilled in the art of computer software.

[0116] By way of example, and not limitation, a computer system having an architecture (1000), and in particular a core (1040), can provide functionality through execution by processor(s) (including(and) CPU, GPU, FPGAs, accelerators, etc.) software embodied in one or more tangible computer-readable media. Such computer-readable media can be media associated with the user-accessible mass storage described above, as well as some persistent storage (1040) such as internal mass storage (1047) or ROM (1045). Software implementing various embodiments of the present invention may be stored on such devices and executed by the core (1040). The computer-readable medium may include one or more memory devices or microcircuits, in accordance with specific requirements. The software may cause the core (1040) and, in particular, its processors (including CPU, GPU, FPGA, etc.) to execute specific processes or specific parts of the specific processes described here, including setting data structures stored in RAM (1046) , and modifying such data structures according to processes defined by the software. Additionally or alternatively, the computer system may provide functionality through logic hardwired or otherwise embodied in circuitry (e.g., an accelerator (1044)) that may operate in place of or in conjunction with software to perform specific processes or specific portions of the specific processes described herein. A reference to software may cover logic, and vice versa when appropriate. Reference to computer-readable media can encompass a circuit (eg, an integrated circuit (IC, Integrated Circuit)) where software is stored for execution, a circuit embodying logic for execution, or both, as appropriate. The present invention encompasses any suitable combination of hardware and software.

[0117] Although several illustrative embodiments are described here, variations, permutations, and various replacement equivalents are possible and are within the scope of the invention. Thus, those skilled in the art can provide numerous systems and methods that, although not explicitly shown or described herein, embody the principles of the invention and thus fall within its spirit and scope.

Claims (31)

1. A method for video decoding a scalable bitstream, comprising: parsing at least one video parameter set (VPS) comprising at least one syntax element indicating whether at least one layer in the scalable bitstream is one of a dependent scalable bitstream layer and an independent scalable bitstream layer; decoding the picture in the dependent layer by parsing and interpreting an inter-layer reference picture list (ILRP); and decoding each of the picture in the independent layer and the other picture in the dependent layer without parsing and interpreting the ILRP list. 2. The method of claim 1, wherein decoding an image in an independent layer includes parsing and interpreting a list of reference pictures that does not contain decoded images of another layer. 3. The method of claim 1, wherein the list of inter-layer reference pictures contains a decoded picture of another layer. 4. The method of claim 1, wherein parsing the at least one VPS also includes determining if another syntax element specifies a maximum number of levels. 5. The method of claim 1, wherein parsing the at least one VPS also includes determining if the VPS contains a flag indicating whether another layer in the scalable bitstream is a reference layer for the at least one layer. 6. The method of claim 5, wherein parsing at least one VPS also includes determining if said flag indicates another layer as a reference layer for said at least one layer by specifying an index of another layer and an index of said at least one level. 7. The method of claim 5, wherein parsing the at least one VPS also includes determining if said flag indicates that the other layer is not a reference layer for said at least one layer by specifying an index of another layer and an index of said at least one level. 8. The method of claim 1, wherein parsing the at least one VPS also includes determining if the VPS contains a flag indicating whether a plurality of layers containing said at least one layer should be decoded by interpreting the ILRP list. 9. The method of claim 1, wherein analyzing the at least one VPS also includes determining if the VPS contains a flag indicating whether a plurality of layers containing said at least one layer should be decoded without interpreting the ILRP list. 10. The method of claim 1, wherein the ILRP list is transmitted with the intra prediction reference picture (IPRP) list to the VPS. 11. A device for video decoding of a scalable bit stream, comprising: at least one memory configured to store computer program code; and at least one processor configured to access the computer program code and to operate under the control of the computer program code, the computer program code comprising: parsing code configured such that at least one processor parses at least one video parameter set (VPS) containing at least one syntax element indicating whether at least one layer in the scalable bitstream is one of the dependent a scalable bitstream layer and an independent scalable bitstream layer; a first decoding code configured such that at least one processor decodes a picture in a dependent layer by parsing and interpreting an inter-layer reference picture list (ILRP); and a second decoding code configured such that at least one processor decodes each of the picture in the independent layer and the other picture in the dependent layer without parsing and interpreting the ILRP list. 12. The apparatus of claim 11, wherein the second decoding code is further configured such that at least one processor decodes an independent layer picture by parsing and interpreting a reference picture list that does not contain other layer decoded pictures. 13. The apparatus of claim 11, wherein the list of inter-layer reference pictures contains a decoded picture of another layer. 14. The apparatus of claim 11, wherein the parsing code is further configured such that at least one processor parses at least one VPS by determining whether another syntax element specifies a maximum number of levels. 15. The apparatus of claim 11, wherein the parsing code is further configured such that at least one processor parses at least one VPS by determining whether the VPS contains a flag indicating whether another layer in the scalable bitstream is a reference layer. for said at least one level. 16. The apparatus of claim 15, wherein the parsing code is further configured such that at least one processor parses at least one VPS by determining if said flag indicates another layer as a reference layer for said at least one layer. by specifying an index of another level and an index of said at least one level. 17. The apparatus of claim 15, wherein the parsing code is further configured such that at least one processor parses at least one VPS by determining if said flag indicates that another layer is not a reference layer for said at least one level by specifying an index of another level and an index of said at least one level. 18. The apparatus of claim. 11, wherein the parsing code is further configured such that at least one processor parses at least one VPS by determining whether the VPS contains a flag indicating whether a plurality of layers should be decoded containing the at least one level, by interpreting the ILRP list. 19. The apparatus of claim. 11, wherein the parsing code is further configured such that at least one processor parses at least one VPS by determining whether the VPS contains a flag indicating whether a plurality of layers should be decoded containing the at least one level, without interpreting the ILRP list. 20. A computer-readable medium that stores a program configured to cause a computer to do: parsing at least one video parameter set (VPS) comprising at least one syntax element indicating whether at least one layer in the scalable bitstream is one of a dependent scalable bitstream layer and an independent scalable bitstream layer; decoding the picture in the dependent layer by parsing and interpreting an inter-layer reference picture list (ILRP); and decoding each of the picture in the independent layer and the other picture in the dependent layer without parsing and interpreting the ILRP list.

Images