TWI392368B - Method, apparatus and computer-readable medium for decoding a video signal - Google Patents

Description

Video signal decoding method, decoding device and computer readable medium thereof

The invention relates to a coding scheme of a video signal.

In general, compression coding refers to a series of signal processing techniques that transmit digital information through a communication circuit or store digital information in a format suitable for the storage medium. Compressed encoded targets include audio, video, characters, and more. In particular, the scheme of completing video compression coding is called video sequence compression. Typically, image sequences are characterized by spatial redundancy and temporal redundancy.

In particular, the bitstream of the adjustable video coding can be partially and selectively decoded. For example, a low complexity decoder can decode the base layer, and a low data rate bit stream is captured for transmission over a limited capacity network. In order to gradually produce high-resolution images, it is necessary to gradually enhance the quality of the images.

Accordingly, the present invention provides a coding scheme for video signals that substantially obviates one or more of the problems of the limitations and disadvantages of the prior art.

It is an object of the present invention to provide a method for enhancing the coding efficiency of encoded video signals.

Another object of the present invention is to provide a method for minimizing the transmission of associated information of inter-layer prediction when the area in the enhancement layer does not correspond to the reference layer.

Another object of the present invention is to provide a method for confirming adjustable video editing Configuration information on the code bit stream to minimize the transmission of associated information for inter-layer prediction.

Another object of the present invention is to provide a method for minimizing the transmission of associated information of inter-layer prediction by confirming information indicating whether or not inter-layer prediction is performed.

It is an object of the present invention to provide a method for minimizing the transmission of associated information for inter-layer prediction by confirming quality identification information.

Another object of the present invention is to provide a method for enhancing the coding efficiency of a video signal by defining information for indicating the processing of a segment boundary.

It is still another object of the present invention to provide a method for improving coding efficiency in accordance with configuration information identifying a tunable video encoded bit stream at an appropriate location.

Accordingly, the present invention provides the following effects or advantages.

First, it is checked whether the current block in the enhancement layer can be predicted using inter-layer prediction. If the current block in the enhancement layer is not predicted using inter-layer prediction, there is no need to transmit coded information for inter-layer prediction. Therefore, the present invention improves the coding efficiency. Second, by identifying the configuration information of the tunable video coding at the appropriate location, the transmission information associated with the inter-layer prediction can be minimized. For example, by identifying information and/or quality identification information indicating whether inter-layer prediction is performed, the inter-layer predicted association transmission information can be minimized. The present invention enables parallel processing by defining information for indicating the processing of the segment boundaries. Therefore, the encoding efficiency of the video signal can be greatly increased by using the various methods explained above.

Other advantages and features of the present invention will be partially explained in the following description, and other advantages, objects and features of the present invention are common to the art. The invention may be partially understood by the following description of the invention or may be derived from the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the <RTIgt;

In order to obtain the object and other features of the present invention, the present invention is embodied and described in detail. The decoding method of the video signal of the present invention includes the following steps: decoding the bit stream of the first layer; obtaining the first flag information. For indicating whether the inter-layer prediction is completed on the current block of the second layer; obtaining information for controlling the characteristics of the deblocking filter according to the first flag information; and using the filter for controlling the deblocking filter The information of the feature performs deblocking filtering.

Preferably, the second layer is different from the first layer in terms of screen ratio or spatial resolution, and the first layer is the same video signal from the second layer.

Preferably, the information used to control the characteristics of the deblocking filter includes information indicating the method of operation of the deblocking filter and the offset information required to resolve the block filtering.

In a more preferred case, the offset information required for the deblocking filtering is obtained from the information indicating the operational scheme of the deblocking filtering.

Preferably, the method further comprises obtaining quality identification information for identifying the quality of the current block of the second layer. The information used to control the characteristics of the deblocking filter is obtained based on the first flag information and the quality identification information.

It will be understood that the general description of the invention as described above and the subsequent The detailed description of the present invention is intended to be illustrative and illustrative of the invention.

Preferred embodiments of the present invention will now be described in detail in conjunction with the drawings.

First, the compression coding of video signal data needs to consider spatial redundancy, time redundancy, adjustable redundancy, and redundancy between views. A compression coding scheme that considers tunable redundancy is an embodiment of the present invention. The technical idea of the present invention can be applied to time redundancy, spatial redundancy, inter-view redundancy, and the like. In the disclosure of the present invention, the encoding includes two concepts of encoding and decoding. The coding can be flexibly interpreted to correspond to the technical idea and scope of protection of the present invention.

In the bit sequence configuration of the video signal, there is a separate layer structure between the video coding layer (VCL) and the underlying system, which is called a network abstraction layer (NAL). The video encoding layer itself processes the encoding process of the moving image, and the underlying system is used to transmit and store the encoded information. The output generated by the encoding process is the video encoding layer data and is mapped through the network abstraction layer unit before being transmitted or stored. Each network abstraction layer unit includes compressed video data or raw byte sequence payload (RBSP) (original byte sequence load: result data of motion image compression), wherein the original byte sequence load It is the data corresponding to the header information.

The network abstraction layer unit mainly consists of two parts, which are the network abstraction layer header and the original byte sequence load. The network abstraction layer header contains flag information (nal_ref_idc) And information (nal_unit_type). The flag information (nal_ref_idc) is used to indicate whether a segment of the reference image that becomes the network abstraction layer unit is included, and the information (nal_unit_type) indicates the type of the network abstraction layer unit. The compressed initial data is stored in the original byte sequence load. The tail element of the original byte sequence load is added to the end of the original byte sequence load to represent the length of the original byte sequence load for 8-bit multiplication. The types of the network abstraction layer unit include an instant decoding refresh (IDR) image, a sequence parameter set (SPS), a picture parameter set (PPS), and a supplementary enhancement information (supplemental enhancement information). SEI) and so on.

Therefore, if the information (nal_unit_type) for indicating the network abstraction layer unit type indicates a tunable video coding segment, the coding performance can be improved by adding various configuration information related to the tunable coding. For example, the flag information, the dependency identification information, the quality identification information, the flag information (no_inter_layer_pred_flag), the priority identification information, and the like may be added, wherein the flag information indicates whether the current access unit is an immediate decoding update access unit, and the identification information is dependent. Used to indicate spatial adjustability, flag information (no_inter_layer_pred_flag) is used to indicate whether inter-layer prediction is used. In order to manage the decoded image buffer more efficiently, various configuration information on the adjustable code can be used. The following will be explained in detail with reference to "Fig. 2".

In standardization, various types and levels need to be set to achieve the target product at an appropriate cost. In this example, the decoder should satisfy the corresponding type and etc. Level and judgment requirements. Thus, two concepts, 〞 and 〞 levels, are defined to indicate a function or parameter that is used to indicate the extent to which the decoder can handle the range of compressed sequences. The type identifier (profile_idc) identifies that the bit stream is based on the specified type. The type identifier is represented as a flag indicating the type that is the basis of the bit stream. For example, in H.264/AVC, if the type identifier is 66, it means that the basis of the bit stream is the baseline profile. If the type identifier is 77, it means that the bit stream is based on the main profile. If the type identifier is 88, it means that the basis of the bit stream is an extended profile. In addition, the type identifier can be included in the sequence parameter set.

Therefore, in order to process the adjustability sequence, it is necessary to identify whether the type of the input bit stream is of the type used for the adjustability sequence. If the input bit stream is identified as being of a type for the adjustability sequence, then the grammar needs to be added such that at least one additional information for the tunable sequence is transmitted. In this example, the type used for the tunable sequence is an additional scheme of H.264/AVC indicating the type pattern used to handle the tunable video. Because Scalable Video Coding (SVC) is an add-on solution to the conventional advanced video coding, adding grammar to the tunable video coding mode as additional information is more effective than adding non-practical grammar. For example, when the type identifier of the advanced video coding indicates the type of the tunable code, if the information on the tunable sequence is increased, the coding efficiency can be improved.

Several embodiments of an efficient video signal decoding method are explained below.

Figure 1 is a block diagram of the tunable video coding system of the present invention.

In order to provide an effective sequence for various communication environments and various terminals, the sequence provided to the terminal should also be diversified. If the sequence optimized for each terminal is provided to the corresponding terminal, it means that a sequence source is prepared for the combined values of the various parameters, wherein these parameters include the number of frames transmitted per second, the resolution, and each pixel. The number of bits and so on. Therefore, the burden of providing an optimized sequence is imposed on the content provider. Therefore, the content provider encodes the initial sequence to make it a high bit rate compressed sequence data. Upon receiving the sequence request made by the terminal, the content provider decodes the initial sequence, encodes it into sequence data suitable for the sequence processing capability of the terminal, and then provides the encoded data to the terminal. Since this transcoding is accompanied by an encoding-decoding-encoding program, the time delay generated when the sequence is provided cannot be avoided. Therefore, complex hardware devices and algorithms are additionally required.

Adjustable video coding, on the other hand, is a coding scheme suitable for encoding video signals having the best image quality such that a partial sequence of the generated image sequences is represented as a decoded sequence. In this example, a partial sequence represents a sequence containing boxes that are intermittently selected from the entire sequence. For image sequences encoded by tunable video coding, spatial tunability at low bit rates reduces sequence size. The use of quality adjustability also reduces the image quality of the sequence. In this example, a sequence of images containing a small size screen and/or a reduced number of frames per second may be referred to as a base layer, and a sequence containing a relatively large size screen and/or a relatively large number of frames per second may be referred to as an enhancement layer. .

Encoded by the above adjustable scheme by merely receiving and processing partial sequences The image sequence enables a low image quality sequence representation. However, if the bit rate is lowered, the image quality is correspondingly degraded. In order to solve the problem of degradation of image quality, a separate auxiliary image sequence with a low bit rate can be provided, such as an image sequence containing a small size screen and/or a lower number of frames per second. Such an auxiliary sequence may be referred to as a base layer, and a main image sequence may be referred to as an enhancement layer.

In describing the various embodiments of inter-layer prediction, the concepts used in the present disclosure include a first layer and a second layer. For example, the second layer can include a different spatial resolution or screen ratio than the first layer. Also, the second layer may comprise a different image quality than the first layer. In more detail, the first layer can be a base layer and the second layer can be a reinforcement layer. When inter-layer prediction is completed, the layer based layer can be the reference layer and the second layer can be the current layer. The basic layers and enhancement layers explained in the following description are merely examples and are not intended to limit the explanation of the present invention.

The tunable video coding system is explained in detail below. First, the tunable coding system includes an encoder 102 and a decoder 110. The encoder 102 includes a base layer encoding unit 104, an enhancement layer encoding unit 106, and a multiplex unit 108. The decoder 110 may include a demultiplexing unit 112, a base layer decoding unit 114, and an enhancement layer decoding unit 116. By compressing the input sequence signal X(n), the base layer encoding unit 104 is capable of generating a basic bit stream. Using the input sequence signal X(n) and the information generated by base layer encoding unit 104, enhancement layer encoding unit 106 can generate an enhancement layer bitstream. Using the base layer bit stream and the enhancement layer bit stream, the multiplex unit 108 can generate an adjustable bit stream.

The resulting adjustable bit stream is transmitted to decoder 110 through a particular channel. Through the demultiplexing unit 112 of the decoder 110, the transmitted adjustable bit stream can be separated into increments. Strong layer bit stream and base layer bit stream. The base layer decoding unit 114 receives the base layer bit stream, and then decodes the base layer bit stream into a sequence signal of the internal macro block and residual and motion information between the blocks. In this example, the corresponding decoding can be done based on a single loop decoding method.

The enhancement layer decoding unit 116 receives the enhancement layer bit stream and decodes the output sequence signal Xe(n) with reference to the base layer bit stream re-established by the base layer decoding unit 114. In this example, the output sequence signal Xb(n) is a sequence signal having a lower image quality or resolution than the subsequent output sequence signal Xe(n).

The enhancement layer decoding unit 116 includes a first header information acquisition unit, a second header information acquisition unit, a deblocking filter unit, and an increase sampling unit. The first header information obtaining unit may obtain configuration information of the bit stream from the header of the network abstraction layer. For example, the first header information obtaining unit may obtain quality identification information, information for indicating whether or not the inter-layer prediction is used, and the like. The second header information obtaining unit can obtain the configuration information of the bit stream from the segment header. For example, the second header information obtaining unit may obtain information for indicating processing of the segment boundary in the sampling program, association information of the operation of the deblocking filter, information on the phase shift of the color difference signal, and indication of the position between the images. Information on the deviation of the difference, whether to perform information on adaptive prediction, etc. The deblocking filter unit can perform deblocking filtering using the associated information of the operation of the deblocking filter. The addition sampling unit may use the deviation information indicating the position difference between the images used for inter-layer prediction to increase the sampling of the first layer. Therefore, inter-layer prediction can be accomplished using information on the first layer of the increased sampling.

Therefore, each enhancement layer encoding unit 106 and enhancement layer decoding unit 116 complete encoding using inter-layer prediction. Inter-layer prediction means predicting the enhancement layer's sequence signal using the base layer's motion information and/or texture information. In this example, the material information means the image data or pixel value belonging to the macro block. For example, in the inter-layer prediction method, there is an internal basic prediction mode or a residual prediction mode. The internal basic prediction mode means a mode based on the corresponding region in the base layer to predict the block of the enhancement layer. In this example, the corresponding area in the base layer means the area encoded in the internal mode. Meanwhile, the residual prediction mode may use a corresponding region in the base layer containing residual data, where the residual data is the image difference value. In both cases, the corresponding area in the base layer can be increased or decreased by sampling. Sampling means that the image resolution is changed. Sampling can include resampling, downsampling, and upsampling. For example, internal sampling can be resampled to complete inter-layer prediction. Use the downsampling filter to reduce image resolution by regenerating pixel data. This can be referred to as downsampling. In addition, the use of an additional sampling filter can generate several additional pixel data to enhance image resolution. This can be referred to as increasing sampling. Resampling can include two concepts of reducing sampling and increasing sampling. In the present disclosure, the term "sample" can be appropriately interpreted in accordance with the technical concept and scope of protection of the corresponding embodiments of the present invention.

Meanwhile, the base layer and the enhancement layer are generated for different usages or purposes for the same sequence content, and are different from each other in terms of spatial resolution, frame rate, bit rate, and the like. When encoding video signals through inter-layer prediction, in the case of non-dyadic Case), that is, the ratio of the enhancement layer to the base layer in terms of spatial resolution is not an integer of 2, and may be referred to as extended spatial scalability (ESS). For example, when the enhancement layer is encoded through inter-layer prediction for a video signal having a ratio of 16:9 (horizontal: vertical), then an example occurs in which the base layer is encoded to include an image having a ratio of 4:3. In this example, since the base layer is encoded in a cropping state in which the initial video signal is partially cropped, even if the base layer is expanded for inter-layer prediction, the entire area of the enhancement layer cannot be covered. Therefore, because a partial region of the enhancement layer cannot contain a corresponding region in the increased sampling base layer, the partial region does not use an increased sampling base layer for inter-layer prediction. That is, this means that inter-layer prediction cannot be applied to a partial area. In this example, the encoded information for inter-layer prediction is not transmitted. Reference will be made to the "5th drawing", "6th drawing", "7th drawing", "8th drawing", "9th drawing", "10th drawing" and "11th drawing" in the examples. explain in detail.

FIG. 2 and FIG. 3 are respectively schematic structural diagrams of configuration information that can be added to the adjustable sequence of the adjustable video coded bit stream and an image for describing the configuration information according to an embodiment of the present invention.

"Fig. 2" shows a configuration example of the network abstraction layer unit on which the configuration information on the adjustable sequence is added. First, the network abstraction layer unit may mainly include a network abstraction layer unit header and an original byte sequence load. The network abstraction layer unit header may include identification information (nal_ref_idc) and information ((nal_unit_type). The identification information (nal_ref_idc) is used to indicate whether the network abstraction layer unit contains a fragment of the reference image, and the information ((nal_unit_type) indicates the network Extract the type of layer unit. The extended area of the road abstraction layer unit header can be limitedly included. For example, if the information used to indicate the network abstraction layer unit type is associated with the tunable video coding or indicates a network abstraction layer unit, the network abstraction layer unit may include an extended area of the network abstraction layer unit header. In particular, if nal_unit_type = 20 or 14, the network abstraction layer unit may include an extended area of the network abstraction layer unit header. The configuration information of the adjustable sequence can be added to the extended area of the header of the network abstraction layer unit according to the flag information (svc_mvc_flag) capable of identifying whether it is a tunable video encoded bit stream.

In another example, if the information used to indicate the type of network abstraction layer unit is information indicating a subset sequence parameter set, the original byte sequence load may include information on the subset sequence parameter set. In particular, if nal_unit_type = 15, the original byte sequence load may include information on the subset sequence parameter set, information on the slice layer, and the like. In this example, depending on the type information, the subset sequence parameter set may include an extended region of the sequence parameter set. For example, if the type information (profile_idc) is of a type related to tunable video coding, the subset sequence parameter set may include an extended region of the sequence parameter set. Alternatively, according to the type information, the sequence parameter set may include an extended area of the sequence parameter set. The extended region of the sequence parameter set may include information for controlling the characteristics of the deblocking filter in the inter-layer prediction, parameters for increasing the information association of the sampling process, and the like. The various configuration information on the tunable sequence is explained in detail below, such as the extended area of the network abstraction layer unit header, the extended area of the sequence parameter set, and the configuration information contained in the fragment layer.

First, it is possible to obtain the flag information from the extended region of the sequence parameter set. (inter_layer_deblocking_filter_control_present_flag), used to indicate whether there is information in the inter-layer prediction for controlling the characteristics of the deblocking filter. It is possible to obtain information (extended_spatial_scalability) from the extended region of the sequence parameter set for indicating the location of the parameter associated with the information of the sampling program. In particular, for example, if extended_spatial_scalability = 0, it may mean that there are no parameters for increasing the sampling procedure in the sequence parameter set or fragment header. If extended_spatial_scalability=1, it can mean that there are parameters in the sequence parameter set for increasing the sampling procedure. If extended_spatial_scalability=2, it can mean that there are parameters in the fragment header for increasing the sampling procedure. The parameters for increasing the sampling procedure will be explained in detail later with reference to "Fig. 9".

The information 4 for indicating whether or not inter-layer prediction is used means flag information indicating whether or not inter-layer prediction is used when decoding a coded segment. Flag information can be obtained from the extended area of the network abstraction layer header. For example, if the flag information is set to 1, it means that the inter-layer prediction is not used. If the flag information is set to 0, the inter-layer prediction may or may not be used in accordance with the coding scheme in the macroblock. This is because inter-layer prediction in macroblock units can be used or not used.

The quality identification information 3 indicates information identifying the quality of the network abstraction layer unit. When describing the configuration information, please refer to "Figure 3." For example, a single image can be encoded as a layer that is qualitatively different from each other. In "Picture 3", layers in Spa_Layer0 and Spa_Layer1 can be encoded as layers that are qualitatively different from each other. In particular, assume that the information used to identify the quality of the network abstraction layer unit is named quality_id, layer B1, B2, ..., B10 can be set to quality_id=0. Layers Q1, Q2, ..., Q10 can be set to quality_id=1. That is, layers B1, B2, ..., B10 mean layers containing the lowest image quality. These are called basic images. Layers Q1, Q2, ..., Q10 correspond to layers comprising layers B1, B2, ..., B10 and contain images of better quality than layers B1, B2, ..., B10. Quality identification information can be defined in a number of ways. For example, quality identification information can be represented as 16 levels.

The identification information indicating the spatial adjustability means that information identifying the dependencies on the network abstraction layer unit is identified. When describing the configuration information, please refer to "Figure 3." For example, dependency information changes according to spatial resolution. In Figure 3, the layers in Spa_Layer0 and Spa_Layer1 can contain the same resolution. The layer in Spa_Layer0 may contain images obtained by downsampling on the layer in Spa_Layer1. In particular, for example, it is assumed that the information identifying the dependency on the network abstraction layer unit is represented as dependency_id, and the layer in Spa_Layer0 contains the relationship of dependency_id=0. The layer in Spa_Layer1 contains the relationship of dependency_id=1. Dependency identification information can be defined in a number of ways. Therefore, the network abstraction layer unit containing the same value as the information identifying the dependency can be expressed as a dependency representation.

At the same time, a single layer can be defined in accordance with the information and quality identification information used to identify dependencies. In this case, the network abstraction layer unit including the same value as the identification dependency information and the quality identification information can be expressed as a layer representation.

The identification information used to indicate the time adjustability is expressed as information for identifying the time level of the network abstraction layer unit. The time level can be described in the hierarchical B image structure Said. For example, the layer of Spa_Layer0 (B1, Q1) and the layer (B3, Q3) may contain the same time level Tem_Layer0. If the layer (B5, Q5) is the reference layer (B1, Q1) and the layer (B3, Q3), the layer (B5, Q5) may include the time level Tem_Layer0 of the layer (B1, Q1) and the layer (B3, Q3). Higher time level Tem_Layer1. Similarly, if layers (B7, Q7) are reference layers (B1, Q1) and layers (B5, Q5), then layers (B7, Q7) may contain a higher time level than the time level Tem_Layer1 of layers (B5, Q5). Tem_Layer2. All network abstraction layer units within a single access unit may contain the same time level value. In the example of instant decoding update access unit, the time level value becomes zero.

The flag information is used to indicate whether the reference basic image is used as a reference image, and the flag information indicates whether the reference basic image is used as a reference image in the inter-layer prediction program or whether the decoded image is used as a reference image in the inter-layer prediction program. The flag information may include the same value of the network abstraction layer unit in the same layer, where the network abstraction layer unit of the same layer is the network abstraction layer unit that contains the same information of the identification dependency.

The priority identification information represents information for identifying the priority of the network abstraction layer unit. Use priority recognition information to provide inter-layer ductility or inter-image scalability. For example, using priority identification information can provide the user with a sequence of multiple time and space levels. Thus, the user can see a sequence of special time and space or just a sequence of different constraints. Priority information can be formed in a variety of ways according to its reference conditions. Priority information can be randomly formed without special reference. And, the priority information can be determined by the decoder.

The configuration information in the extended area of the network abstraction layer unit header may include flag information, which is used to indicate whether the current access unit is an immediate decoding update access unit.

Various information about inter-layer prediction can be included in the slice layer. For example, it may include information for increasing the processing of the segment boundary in the sampling program, information related to the operation of the deblocking filter, information about the phase shift of the chroma signal, and information between the indicator layers. The deviation of the positional difference information 8, as well as the information indicating the occurrence or non-occurrence of the implementation of the adaptive prediction, etc. The above information can be obtained from the fragment header.

As for the example of the information 6 associated with the operation of the deblocking filter, it may be information indicating the operation method of the deblocking filter (disable_deblocking_filter_idc), deviation information (inter_layer_slice_alpha_c0_offset_div2, inter_layer_slice_beta_offset_div2) required to perform deblocking filtering, and the like.

As for the information 7 example on the phase shift of the color signal, it may be information on the horizontal and vertical phase offsets of the image color components used for inter-layer prediction (scaled_ref_layer_left_offset, scaled_ref_layer_right_offset, scaled_ref_layer_right_offset, scaled_ref_layer_bottom_offset).

As an example of the offset information 8 indicating the difference in position between the layers, it may be a deviation information (scaled_ref_layer_left_offset, which is used to indicate the difference between the upper and lower left and right positions between the sampled image and the current image used for inter-layer prediction. Scaled_ref_layer_top_offset, scaled_ref_layer_right_offset, scaled_ref_layer_bottom_offset).

As an example of information 5 indicating that the base layer increases the processing of macroblocks on the segment boundary in the sampling process, it may be information (constrained_intra_resampling_flag) if there is more than at least two corresponding internal coding blocks of the first layer in the second layer. The fragment indicates that the current macroblock cannot be predicted by using the corresponding inner coding block in the first layer.

The information 9 indicating the presence or absence of the implementation of the adaptive prediction can indicate that the predicted associated information appears or does not appear within the segment header and macroblock layers. Based on the information indicating the presence or absence of the implementation of the adaptive prediction, it can be determined which adaptive prediction method will be used. This will be explained in detail below with reference to "Figure 11".

Figure 4 shows a schematic diagram of the relationship between the sample base layer and the enhancement layer.

When tunable video encoding, it is possible to check if the current block of the enhancement layer can use inter-layer prediction. For example, it may be checked whether an area corresponding to all pixels in the current block exists in the base layer. As for the result of the check procedure, if the current block of the enhancement layer is not used for inter-layer prediction, there is no need to transmit coded information for inter-layer prediction. Therefore, the coding efficiency can be improved.

Therefore, a function can be defined that can check that the current block of the enhancement layer can use inter-layer prediction. For example, the function 'in_crop_window()' can be defined as a function for checking whether the area corresponding to all pixels in the current block exists in the base layer. in. Assuming that the macroblock index in the horizontal direction on the enhancement layer is set to 'mbIdxX', the macroblock index in the vertical direction is set to 'mbIdxY', and the function in_crop_window() can return the value 'TRUE (or ' if the following conditions are satisfied). 1')'.

mbIdxX (ScaledBaseLeftOffset+15)/16 mbIdxX (ScaledBaseLeftOffset+ScaledBaseWidth-1)/16 mbIdxY (ScaledBaseTopOffset+15)/16 mbIdxY (ScaledBaseTopOffset+ScaledBaseHeight-1)/16

'mbIdxX' can be derived using the horizontal macroblock address and the number of macroblocks. ‘mbIdxY’ can be derived from different methods depending on whether the application of the macroblock adaptive box field is applied. For example, if a macroblock adaptive box field is applied, it can be obtained by considering a macro block pair. When considering a macroblock pair, it is assumed that the index of the upper macroblock is set to 'mbIdxY0', and the index of the lower macroblock is set to 'mbIdxY1'. 'mbIdxY0' can be obtained from the deviation information indicating the upper position difference between the increased sample image and the current image used for the inter-layer prediction and the macro block number information in the horizontal direction. In this example, the value of the horizontal macro block number information may be different depending on whether the current image is a frame image or a domain image. 'mbIdxY1' can be obtained from the deviation information indicating the difference in the upper position difference between the increased sample image and the current image used for the inter-layer prediction and the macro block number information in the vertical direction. Meanwhile, if the macroblock adaptive frame field is not applied, 'mbIdxY0' and 'mbIdxY1' can be set to the same value.

‘ScaledBaseLeftOffset’ indicates deviation information indicating the left positional deviation between the increased sampled image and the current image used for inter-layer prediction. ‘ScaledBaseTopOffset’ indicates deviation information indicating the upper positional deviation between the increased sampled image and the current image used for inter-layer prediction. ‘ScaledBaseWidth’ means to increase the horizontal width of the sampled image. ‘ScaledBaseHeight’ indicates an increase in the vertical height of the sampled image.

If any of the above conditions is not satisfied, the function in_crop_window() may return the value 'FALSE (or '0')'.

If the pixel corresponding to at least one pixel in the current block (CurrMbAddr) is not in the increased sampling base layer, that is, if the function in_crop_window(CurrMbAddr) returns the value 'FALSE', the association information of the inter-layer prediction is not used in the current region. Block, this information is not transmitted. Therefore, according to the embodiment of the present invention, if the corresponding base layer area does not exist by in_crop_window (CurrMbAddr), the transmission of the association information of the inter-layer prediction of the current block may be omitted.

An example of completing encoding using the function in_crop_window() is explained below in accordance with an embodiment of the present invention.

First, if it is recognized by ‘in_crop_window(CurrMbAddr)' that the area corresponding to the current block exists in the base layer, the enhancement layer encoding unit 106 performs inter-layer prediction using the material and/or motion information of the base layer. In this example, the motion information may include reference index information, motion vector information, segmentation information, and the like.

If the material and/or motion information of the current block is set to the material and/or motion information of the corresponding block, or the material and/or motion information of the current block is obtained from the material and/or motion information of the corresponding block. Then, the enhancement layer coding unit 106 increases The information stream indicating the complete command information or the obtained information is added to the enhancement layer, and then the decoder 110 is notified of the additional information. However, if it is recognized by ‘in_crop_window(CurrMbAddr)' that the region corresponding to the current block does not exist in the base layer, the enhancement layer encoding unit 106 may generate the enhancement layer without completing the inter-layer prediction. Meanwhile, if the decoder 110 confirms that the area corresponding to the current block does not exist in the base layer through ‘in_crop_window(CurrMbAddr)', the decoder 110 determines that the command information is not transmitted.

The "figure 5" and "figure 6" diagrams are respectively related to the syntax of the inter-layer prediction macroblock and the sub-macroblock prediction according to the embodiment of the present invention.

When the inter-layer prediction is completed, the information associated with the inter-layer prediction in the segment data of the current network abstraction layer is transmitted to the decoder. For example, in the case of motion vector prediction of the current block of the enhancement layer, a flag (motion_prediction_flag_lx) indicating whether or not to use the motion vector of the base layer can be obtained from the macroblock layer. In accordance with an embodiment of the present invention, in accordance with the manner of checking 'in_crop_window(CurrMbAddr)', the decoder can know whether the information related to the inter-layer prediction is transmitted by the encoder [510, 610]. For example, according to ‘in_crop_window(CurrMbAddr)', if the area corresponding to the current block does not exist in the base layer, the flag 'motion_prediction_flag_10/11' is not transmitted on the bit stream [520/530, 620/630].

The flag 'adaptive_motion_prediction_flag' indicates whether information associated with motion vector prediction occurring within the macroblock layer can be obtained from the segment data of the current network abstraction layer. According to an embodiment of the invention, in accordance with the inspection ‘adaptive_motion_prediction_flag’ and ‘in_crop_window(CurrMbAddr)’, the information associated with inter-layer prediction is not transmitted by the encoder [510]. For example, according to 'in_crop_window(CurrMbAddr)', if the area corresponding to the current block does not exist in the base layer, or according to 'adaptive_motion_prediction_flag', if the information associated with the motion vector prediction does not exist within the macro block, the flag 'motion_prediction_flag_10/ 11' was not transmitted [520/530, 620/630]. The above technical concept can also be applied to the sub-macroblock prediction shown in "FIG. 6".

Therefore, after the two kinds of information are recognized, only two conditions are satisfied, and the information associated with the layer is transmitted. Therefore, the coding efficiency can be improved.

FIG. 7 is a schematic diagram showing the syntax of residual prediction through inter-layer prediction according to an embodiment of the present invention.

When the inter-layer prediction is completed, the information associated with the inter-layer prediction in the segment data of the current network abstraction layer is transmitted to the decoder. For example, when predicting the residual signal of the current block, the flag 'residual_prediction_flag' for indicating whether to use the residual signal of the base layer can be obtained from the macroblock layer [740]. In this example, the layer is used to represent the information to know the base layer. According to an embodiment of the present invention, the information associated with the inner layer prediction is not transmitted by the encoder by confirming the manner of 'in_crop_window(CurrMbAddr)'.

For example, according to the information ‘adaptive_residual_prediction_flag’ and the segment type of the current block, ‘residual_prediction_flag’ can be obtained, where the information ‘adaptive_residual_prediction_flag’ indicates the occurrence of associated information for the prediction of residual signals within the macroblock [710]. The 'residual_prediction_flag' can also be obtained in accordance with ‘base_mode_flag’. 'base_mode_flag' indicates whether the type (mb_type) of the current macroblock is derived from the corresponding area of the base layer [720]. The 'residual_prediction_flag' can also be obtained according to the type of the current macroblock and the function in_crop_window(CurrMbAddr). For example, when the type of macro block and sub-macro block is not internal mode [MbPartPredType(mb_type,0)! =Intra_16x16(8x8 and 4x4)], and the value of in_crop_window(CurrMbAddr) is 'true', meaning that the corresponding region of the current macroblock exists in the base layer, and ‘residual_prediction_flag’ [730] is obtained. If the type of the current macroblock is not the internal mode, or the corresponding region of the current macroblock does not exist in the base layer [in_crop_window(CurrMbAddr)=0], the residual prediction is not completed. Encoder 102 generates an enhancement layer but does not include 'residual_prediction_flag'.

If 'residual_prediction_flag' is set to '1', the residual signal of the current block is predicted from the residual signal of the base layer. If 'residual_prediction_flag' is set to '0', the residual signal is encoded without inter-layer prediction. If "residual_prediction_flag" does not exist in the macroblock layer, it is obtained as follows. For example, 'residual_prediction_flag' is derived as a preset value (default_residual_prediction_flag) only if the following conditions are completely satisfied. First, 'base_mode_flag' should be set to '1', or the type of the current macroblock should not be the internal mode. Second, ‘in_crop_window(CurrMbAddr)’ should be set to '1'. Third, the flag 'no_inter_layer_pred_flag' indicating whether the inter-layer prediction is used should be set to '0'. Fourth, the fragment type should not be an EI fragment (ie, an I fragment or an SI (Switching I) fragment). Otherwise it can be drawn as '0'.

When the corresponding region of the current sequence block does not exist in the base layer by 'in_crop_window(CurrMbAddr)', the enhancement layer decoding unit 116 determines that the motion prediction flag (motion_prediction_flag) information does not exist in the macroblock or the sub-macroblock, And the data bit stream using only the enhancement layer re-establishes the video signal without inter-layer prediction. If the syntax element of the residual prediction is not included in the bitstream of the enhancement layer, the enhancement layer decoding unit 116 may obtain the residual prediction flag 'residual_prediction_flag'. At this time, whether or not the corresponding region of the current block exists in the base layer can be considered by ‘in_crop_window(CurrMbAddr)'. If 'in_crop_window(CurrMbAddr)' is set to '0', the enhancement layer decoding unit 116 can confirm that the corresponding region of the current sequence block does not exist in the base layer. In this example, 'residual_prediction_flag' is derived as '0', and then the video signal can be re-established using only the data of the enhancement layer without using the residual prediction of the residual signal of the base layer.

The "Fig. 8" is a grammatical structure diagram for performing deblocking filtering in accordance with the occurrence or non-occurrence of inter-layer prediction execution according to an embodiment of the present invention.

First, in accordance with an embodiment of the present invention, the encoder does not transmit the associated information of the inter-layer prediction by confirming the configuration information of the tunable video encoded bit stream. The configuration information of the tunable video encoded bit stream can be obtained from the extended area of the network abstraction layer header. E.g, The association information for deblocking filtering is obtained according to the information 'no_inter_layer_pred_flag' indicating the use of inter-layer prediction or the quality identification information (quality_id) [810]. As for the example of the associated information of the deblocking filter operation, there may be information (disable_deblocking_filter_idc) for indicating the operation method of the deblocking filter, and deviation information (slice_alpha_c0_offset_div2, slice_beta_offset_div2) required for deblocking filtering.

First, based on the information for controlling the characteristics of the deblocking filter, operational information for indicating the deblocking filter can be obtained. In this example, as shown in "Figure 2", information for controlling the characteristics of the deblocking filter can be obtained from the sequence parameter set. For example, as for information for controlling the characteristics of the deblocking filter, there may be flag information (inter_layer_deblocking_filter_control_present_flag) indicating whether there is information for controlling the characteristics of the deblocking filter for inter-layer prediction (820). Thus, information for indicating the method of operation of the deblocking filter can be obtained in accordance with the flag information (830).

In particular, if disable_deblocking_filter_idc=0, filtering can be done over the entire block edge of the luminance and color difference signals of the current image. If disable_deblocking_filter_idc=1, the filtering is not completed over the entire block edge of the current image. If disable_deblocking_filter_idc=2, filtering can be done over all block edges except for overlapping segment boundaries. If disable_deblocking_filter_idc=3, the filtering can be done over the edge of the block containing the unoverlapping segment boundaries, and then the filtering is done in the region containing the overlapping segment boundaries. Above the block boundary. If disable_deblocking_filter_idc=4, the filtering is only done above the block boundary of the luminance signal and not above the block boundary of the color signal. If disable_deblocking_filter_idc=5, the filtering is done over the edge of the block in the luminance signal except for the block edge of the block edge containing the overlapping segment boundaries, which is not completed above the edge of the block of the color signal. If disable_deblocking_filter_idc=6, the filtering is not completed above the edge of the block of the color signal, but only over the edge of the block of the luminance signal. After filtering is completed over the block boundary of the luminance signal containing the unoverlapping segment boundaries, filtering can be done over the block boundary of the luminance signal containing the overlapping segment boundaries.

Based on the information used to indicate the method of operation of the deblocking filter, the offset information required to deblock the block filter can be obtained. For example, if disable_deblocking_filter_idc=1, the deblocking filtering is not completed above the edge of all blocks. Therefore, the deviation information required to deblock the block filter can be obtained only when the value of 'disable_deblocking_filter_idc' is not set to 1. For example, 'inter_layer_slice_alpha_c0_offset_div2' and 'inter_layer_slice_beta_offset_div2' indicate the offset information used by the deblocking filter table in the access macroblock in inter-layer prediction (850). Therefore, the deblocking filtering can be done using the obtained deviation information.

FIG. 9 shows a syntax structure for obtaining deviation information indicating a position difference between an enhanced sampled reference image and a current image in accordance with an occurrence or non-occurrence of inter-layer prediction execution according to an embodiment of the present invention.

First, in accordance with an embodiment of the present invention, the encoder does not transmit the inter-layer prediction value associated information by checking the adjustable video coding bit stream value configuration information. The configuration information of the tunable video encoded bit stream can be obtained from the extended area of the network abstraction layer header. For example, in accordance with information (no_inter_layer_pred_flag) and quality identification information (quality_id) for whether or not the upper inter-layer prediction is used, parameter related information for increasing the sampling procedure can be obtained (910). As an example of the parameter related information for increasing the sampling procedure, there may be information on the phase shift of the color signal (930), deviation information indicating the position difference between the images (940), and the like. Parameter related information for increasing the sampling procedure can be obtained from the extended region of the sequence parameter set and the segment header.

As for the information (930) example on the phase shift of the color signal, there may be information on the horizontal phase shift of the color component of the image used for inter-layer prediction (ref_layer_chroma_phase_x_plus1), and information on the vertical phase change (ref_layer_chroma_phase_y_plus1). As an example of the deviation information (940) indicating the positional difference between images, there is deviation information (scaled_ref_layer_left_offset, scaled_ref_layer_right_offset, scaled_ref_layer_right_offset, scaled_ref_layer_right_offset) for indicating the up-and-down left-right positional deviation between the increased sample image and the current image used for the inter-layer prediction.

According to the information indicating the position of the parameter related information for increasing the sampling procedure (extended_spatial_scalability), the parameter related information for increasing the sampling procedure can be obtained. For example, if extended_spatial_scalability is set to 0, it means The parameter related information for increasing the sampling procedure is neither present in the sequence parameter set nor in the segment header. If extended_spatial_scalability is set to 1, it means that the parameter related information for increasing the sampling procedure does not exist in the segment header but exists in the sequence parameter set. If extended_spatial_scalability is set to 2, it means that the parameter related information for increasing the sampling procedure does not exist in the sequence parameter set but exists in the fragment header. Therefore, if extended_spatial_scalability is set to 2, parameter related information for increasing the sampling procedure within the fragment header can be controlled (920). In addition, if the extended_spatial_scalability is set to 1, the sequence parameter set can be controlled to increase the parameter related information of the sampling program.

The information on the phase shift of the color signal (930) and the deviation information (940) indicating the difference in position between the images can also be used to increase the sampling procedure.

FIG. 10 shows a syntax structure diagram for obtaining flag information for indicating whether to restrict the use of internal blocks in the base layer in accordance with the occurrence or non-occurrence of inter-layer prediction execution according to an embodiment of the present invention.

First, in accordance with an embodiment of the present invention, the encoder does not transmit the associated information of the inter-layer prediction by checking the configuration information of the tunable video encoded bit stream. The configuration information of the tunable video encoded bit stream can be obtained from the extended area of the network abstraction layer header. For example, according to the information (no_inter_layer_pred_flag) and the quality identification information (quality_id) indicating whether or not the inter-layer prediction is used, information for increasing the processing of the segment boundary in the sampling program can be obtained (1010). As for the information instance for indicating the processing of the segment boundary, the presence information (constrained_intra_resampling_flag) is used to indicate whether The use of internal blocks in the first layer of the current layer for the current block is restricted (1020). The decoding speed at the time of performing parallel processing can be improved by defining information for indicating whether to limit the use of internal blocks. Information used to indicate whether to limit the use of internal blocks is available from the fragment header.

Since the information for indicating whether to restrict the use of the internal block can be obtained from the slice header, even if the value is set to 1, it is necessary to check whether the reference block in the first layer corresponding to the current block is included in the first In a specific segment of the layer. Therefore, it can be confirmed whether or not the reference block in the first layer corresponding to the current block is included in the specific slice of the first layer when the constrained_intra_resampling_flag is set to 1. For example, if the reference block in the first layer overlaps at least two segments in the first layer, the current block is marked as an unused internal block in the first layer. In particular, the current block cannot be encoded using the internal base prediction mode. The internal basic prediction mode represents a mode of predicting the current block of the enhancement layer according to the corresponding sample of the base layer. In this example, the corresponding area of the base layer represents the block coded in the internal mode. If the corresponding region in the first layer is included in a particular segment of the first layer, the current block may be decoded using the inner block of the first layer. In this example, the current block can be marked to use the internal base prediction mode.

If the constrained_intra_resampling_flag is set to 1, the information (disable_deblocking_filter_idc) of the operation method of the deblocking filter described in conjunction with "Fig. 8" is limited. For example, disable_deblocking_filter_idc can only be set to 1, 2 or 4.

If constrained_intra_resampling_flag is set to 0, even if the corresponding block in the first layer overlaps at least two segments in the first layer, the current block of the second layer can be used to decode the current block of the second layer.

The above embodiments can be applied to a chrominance signal and a luminance signal in the same manner.

FIG. 11 is a grammatical structure diagram for obtaining adaptive prediction information according to the presence or absence of inter-layer prediction according to an embodiment of the present invention.

According to the embodiment of the present invention, by confirming the configuration information of the tunable video encoded bit stream, the association information of the inter-layer prediction is not transmitted from the encoder. The configuration information of the tunable video encoded bit stream can be obtained from the extended area of the network abstraction layer header. For example, based on the information 'no_inter_layer_pred_flag' indicating whether or not inter-layer prediction is used, usability prediction information [1110] can be obtained. The adaptive prediction information may indicate whether the predicted associated grammar exists in the corresponding location. For example, there is information 'adaptive_prediction_flag' indicating whether the predicted associated syntax exists in the slice header and the macroblock layer, and information 'adaptive_motion_prediction_flag' indicating whether the motion prediction related information exists in the macroblock layer, The information 'adaptive_residual_prediction_flag' or the like indicating whether or not residual prediction information exists in the macroblock layer.

If the inter-layer prediction is completed in accordance with whether or not the inter-layer prediction is used, the flag information 'slice_skip_flag' indicating the presence or absence of the fragment data may be first obtained [1120]. By confirming the information used to indicate the presence of the clip data, it can be judged Determine whether to get information in the macro block to complete the inter-layer prediction. According to the information for indicating the occurrence of the clip data, if the clip data exists in the clip [1130], the adaptive prediction flag 'adaptive_prediction_flag' [1140] can be obtained. Information 'adaptive_residual_prediction_flag' is also available to indicate whether the associated syntax of the residual prediction exists in the macroblock layer [1180]. According to the adaptive prediction flag, the information 'default_base_mode_flag' can be obtained to indicate how to obtain information indicating whether to predict motion information or the like from the corresponding block of the base layer [1150]. If the motion information or the like is not predicted from the corresponding block of the base layer [1155], the information 'adaptive_motion_prediction_flag' can be obtained for indicating whether or not the associated information of the motion prediction exists in the macroblock layer [1160]. If the associated information of the motion prediction is present in the macroblock layer [1165], the information 'default_motion_prediction_flag' can be obtained for indicating how to infer the motion prediction flag information [1170].

The information 'adaptive_motion_prediction_flag' and the information 'adaptive_residual_prediction_flag' are used in the macroblock layer, where the information 'adaptive_motion_prediction_flag' is used to indicate whether the associated syntax of the motion prediction exists in the macroblock layer, and the information 'adaptive_residual_prediction_flag' is used to indicate the association of the residual prediction. Whether the syntax exists in the macro block layer. For example, a flag 'motion_predection_flag_lx' can be obtained according to 'adaptive_motion_prediction_flag' for indicating whether or not to adapt to the motion vector of the base layer. According to ‘adaptive_residual_prediction_flag’, a flag 'residual_prediction_flag' can be obtained for indicating whether or not the residual signal of the base layer is adapted.

As described above, the decoder/encoder to which the present invention is applicable is provided to a broadcast transmitter/receiver of a multimedia broadcast for decoding a video signal, a data signal, etc., and an example of the multimedia broadcast may be a digital multimedia broadcast (digital multimedia Broadcasting; DMB). The transmitter/receiver of the multimedia broadcast may include a mobile communication terminal.

The decoding/encoding method applied by the present invention is configured with a computer-executed program and then stored in a computer-readable recording medium. The multimedia material containing the data structure of the present invention can be stored in a computer readable recording medium. The computer readable recording medium contains various storage devices for storing data that can be read by the computer system. The computer readable recording medium includes read only memory, random access memory, optical disk read only memory, magnetic tape, floppy disk, optical data storage device, etc., and also includes carrier waves (for example, transmission via the Internet) ) implemented device. The bit stream generated by this encoding method is stored in a computer readable recording medium or transmitted through a fixed line/wireless communication network.

While the invention has been described above in terms of the preferred embodiments thereof, it is not intended to limit the invention. It will be appreciated by those skilled in the art that modifications and modifications may be made without departing from the spirit and scope of the invention as disclosed in the appended claims. Please refer to the attached patent application for the scope of protection defined by the present invention.

102‧‧‧Encoder

104‧‧‧Basic layer coding unit

106‧‧‧Enhancement layer coding unit

108‧‧‧Multiple units

110‧‧‧Decoder

112‧‧ ‧ multiplex unit

114‧‧‧Basic layer decoding unit

116‧‧‧Enhancement layer decoding unit

1 is a block diagram of a tunable video coding system of the present invention; FIG. 2 and FIG. 3 are respectively a structural diagram of the configuration information that can be added to the adjustable video coding bit stream and the image for describing the configuration information according to an embodiment of the present invention; FIG. 4 is a sampled Schematic diagram of the relationship between the base layer and the enhancement layer; FIG. 5 and FIG. 6 are respectively schematic diagrams showing the syntax of the macroblock and sub-macroblock prediction through inter-layer prediction according to an embodiment of the present invention; FIG. 8 is a schematic diagram showing the syntax of residual prediction based on inter-layer prediction according to an embodiment of the present invention; FIG. 8 is a schematic diagram showing the syntax structure of performing deblocking filtering according to the presence or absence of inter-layer prediction execution according to an embodiment of the present invention; The figure shows a syntax structure diagram for obtaining deviation information indicating a position difference between an enhanced sample image and a current image according to an occurrence or non-occurrence of inter-layer prediction execution according to an embodiment of the present invention; FIG. 10 is a view showing an embodiment of the present invention; A syntax structure diagram for indicating whether to limit the use of internal blocks in the reference layer according to the presence or absence of inter-layer prediction execution; and FIG. 11 In accordance with the inter-layer prediction execution of occurrence or absence of the syntax structure of FIG obtained in Example adaptive prediction information of the next embodiment.

Claims (9)

A method for decoding a video signal includes: decoding a bit stream of a first layer; and obtaining a first flag information for indicating that inter-layer prediction is completed on a current block of a second layer, wherein the layer is Predicting the current block by using the information of the first layer; obtaining quality identification information for identifying one of the current blocks of the second layer; obtaining a second flag information for indicating Controlling the presence or absence of the information of one of the characteristics of a deblocking filter; obtaining the information according to the first flag information, the quality identification information, and the second flag information, the information being used to control the solution area The characteristic of the block filter; and performing the deblocking filtering using the information for controlling the characteristic of the deblocking filter. The method for decoding a video signal according to claim 1, wherein the information for controlling the characteristic of the deblocking filter comprises: information indicating one of the operation methods of the deblocking filter and the Deviation information required for deblocking filtering. The method for decoding a video signal as described in claim 2, wherein the deviation information required for performing one of the deblocking filters is based on a value of the information indicating the operation scheme of the deblocking filter. And get it. The method for decoding a video signal according to claim 1, wherein the second layer is different from the first layer in a screen ratio or a spatial resolution, and the first layer is from the second layer. The same video signal. The method for decoding a video signal as described in claim 1, wherein the information of the first layer includes motion information and material information of the first layer. A decoding device for video signals, comprising: a base layer decoding unit, configured to decode a bit stream of a first layer; and a first header information obtaining unit, configured to obtain a first flag information and a quality identification Information, wherein the first flag information indicates whether the inter-layer prediction is completed in a current block of a second layer, the quality identification information identifying a quality of the current block of the second layer, the inter-layer prediction by using the Information of the first layer to predict the current block; a second header information obtaining unit, wherein the second flag information indicates that one of the characteristics of a deblocking filter is present or not exists; The second header information acquiring unit obtains the information for controlling the characteristic of the deblocking filter according to the first flag information, the quality identification information, and the second flag information; and a deblocking filtering The unit, using the information that controls the characteristic of the deblocking filter, performs deblocking filtering. The method for decoding a video signal as described in claim 1, wherein the video signal is received as a broadcast signal. The method for decoding a video signal as described in claim 1, wherein the video signal is received through a digital medium. A computer readable medium for recording a program for decoding a video signal as described in claim 1 of the patent application.