WO2010031352A1 - Video coding/decoding method and apparatus - Google Patents

Abstract

A method and an apparatus for video coding/decoding are provided. At the coding end, selecting intra-prediction mode for the current coding block is performed according to prediction modes of adjacent blocks, then the current coding block is coded by using the selected intra-prediction mode. When the limited DC prediction mode is selected as the intra-prediction mode, the availability of every adjacent block is determined according to the position relation between the current coding block and every adjacent block as well as including the inter-predicted block or not in every adjacent block. At the decoding end, the current decoding block is decoded based on the current intra-prediction mode acquired by analysis.

Description

 The invention relates to a Chinese patent application filed on September 19, 2008, and the application number is 200810222649. 2. The Chinese patent application titled "A Method and Apparatus for Video Codec" Priority is hereby incorporated by reference in its entirety.

The present invention relates to the field of communications technologies, and in particular, to a video codec technology.

BACKGROUND OF THE INVENTION In a video communication system, error or packet loss of video data is generally unavoidable. Therefore, corresponding measures are needed to improve the error resistance of video data, so that video information can be recovered from errors as soon as possible. Provide users with a better subjective experience.

 At present, an implementation scheme for providing error resilience is an intra-frame refresh method, and corresponding error recovery can be achieved to a certain extent by corresponding intra-frame refresh. As shown in FIG. 1 , the P frame is encoded by using the inter mode, and the corresponding IR frame is a refresh frame, and some or all of the macro blocks in the IR frame are encoded by using an intra coding mode, that is, in an IR frame. An intra-coded macroblock (refresh macroblock) is encoded using only the intra-coding mode by referring only to adjacent macroblocks of the frame.

 Specifically, the intra-coded macroblock in the refresh frame may refer to a corresponding adjacent macroblock, where the adjacent macroblock is in the same strip as the intra-coded macroblock in the refresh frame, then the adjacent macroblock Both the intra-coded macroblock and the inter-coded macroblock in the block can be used as reference macroblocks for intra-coded macroblocks in the refresh frame.

 In the process of implementing the present invention, the inventors have found that at least the following problems exist in the prior art:

 In the above intra refresh method, if a neighboring macroblock of a refresh macroblock is an inter prediction macroblock (δΡΡ macroblock), since the P macroblock may refer to the previous P frame, the P macroblock will have It is possible to accumulate the corresponding transmission error from the previous reference P frame, and pass the error to the refresh macroblock (ie, the I macroblock in the IR frame), so that the refresh macroblock may also be affected by the transmission error, thereby reducing The error recovery capability of the intra refresh method.

SUMMARY OF THE INVENTION Embodiments of the present invention provide a video encoding and decoding method and apparatus, which can ensure error recovery performance and improve codec performance.

 A method of video encoding, including:

 Selecting an intra prediction mode of the current coding block according to a prediction mode of the neighboring block;

Encoding operation of the current coding block by using the selected intra prediction mode, wherein the DC prediction in the selection is limited When the mode is used as the intra prediction mode, Bay IJ:

 Each adjacent block is available only when the current coded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one of the adjacent blocks that have been encoded is an inter prediction block, each adjacent block is unavailable; or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current encoding block. A video encoding device includes:

 An intra prediction mode selecting unit, configured to select, according to a prediction mode of the neighboring block, an intra prediction mode of the current coding block;

 a first encoding operation unit, configured to perform an encoding operation on the current encoding block by using an intra prediction mode selected by the intra prediction mode selecting unit, wherein if the limited DC prediction mode is selected as the intra prediction mode, the shell IJ:

 Each adjacent block is available only when the current coded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 At least one of the adjacent blocks that have been encoded is an inter prediction block, and each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current encoding block. A method of video decoding, comprising:

 Parsing the code stream to be decoded, and obtaining an intra prediction mode used by the current decoding block;

 The decoding operation is performed according to the intra prediction mode adopted by the currently decoded block obtained by the parsing, wherein if the intra prediction mode used is the limited DC prediction mode, the Bay IJ:

 Each adjacent block is available only when the current decoded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one of the adjacent blocks that have been decoded is an inter prediction block, each adjacent block is unavailable; or,

Each adjacent block is unavailable; The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current decoding block. A video decoding device includes:

 An intra prediction mode determining unit, configured to parse the received encoded code stream, and obtain an intra prediction mode used by the current decoding block;

 a first decoding operation unit, configured to perform a decoding operation according to an intra prediction mode adopted by the current decoding block obtained by the intra prediction mode determining unit, where, if the adopted intra prediction mode is a limited DC prediction mode, :

 Each adjacent block is available only when the current decoded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one of the adjacent blocks that have been decoded is an inter prediction block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current decoding block. A method of video encoding, including:

 Determine the availability of neighboring blocks of the current coded block, including:

 Each adjacent block is available only when the current decoded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current coding block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current decoded block; and an encoding operation is performed according to availability of the left neighboring block and the upper neighboring block.

 A video encoding device includes:

 a first neighboring block availability identifying unit, configured to determine availability of a neighboring block of the current coded block, including: each neighboring block is available only when the current coded block is in the same macroblock as each neighboring block, otherwise, Each adjacent block is unavailable;

or, If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current coding block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current encoding block, and a second encoding operation unit, configured to determine, according to the first neighboring block availability identifying unit, the left The availability of the neighboring block and the upper neighboring block encodes the current coded block.

 A method of video decoding, comprising:

 Parsing the code stream to determine the availability of neighboring blocks, including:

 Each adjacent block is available only when the current decoded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current decoded block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current decoding block; and performing a decoding operation according to availability of the left neighboring block and the upper neighboring block.

 A video decoding device includes:

 a second neighboring block availability identifying unit, configured to parse the received coded stream, and determine the availability of the neighboring block, including:

 Each adjacent block is available only when the current coded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current decoded block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current encoding block, and a second decoding operation unit, configured to determine, according to the second neighboring block availability identifying unit, the left Adjacent block and upper The availability of neighboring blocks performs a decoding operation on the currently decoded block.

 It can be seen from the technical solutions provided by the foregoing embodiments of the present invention that the embodiment of the present invention adopts a limited DC prediction mode, or determines the availability of neighboring blocks by using a new determining method of neighboring block availability, thereby enabling The error recovery performance is guaranteed, and the coding efficiency of the intra refresh macroblock can be effectively improved, and the codec performance is improved. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some of the present invention. For the embodiments, those skilled in the art can obtain other drawings according to the drawings without any creative labor.

 1 is a schematic diagram of a refresh frame in the prior art;

 2 is a schematic structural diagram 1 of an encoding apparatus according to an embodiment of the present invention;

 3 is a schematic structural diagram 1 of a decoding apparatus according to an embodiment of the present invention;

 4 is a schematic structural diagram 2 of an encoding apparatus according to an embodiment of the present invention;

 FIG. 5 is a schematic structural diagram 2 of a decoding apparatus according to an embodiment of the present invention.

The embodiments of the present invention will be described clearly and completely in conjunction with the drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of them. An embodiment. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

 The implementation provided by the embodiment of the present invention may implement flexible selection of the reference block at the sub-block level, and may specifically be an intra-coded block for the adjacent block in the process of selecting the prediction mode of the current intra-coded sub-block. The prediction of the intra prediction mode coded neighboring block or the interframe coding block (the adjacent block coded by the inter prediction mode) determines whether the current subblock is limited in the DC prediction mode for the encoding operation. At the decoding end, it can be determined whether the encoding end uses the corresponding limited DC prediction mode for encoding, and performs corresponding intra prediction decoding operation. Alternatively, it may also be agreed that the availability rule of the neighboring block is that each adjacent block is available only when the current decoded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable, and according to the corresponding The availability of adjacent blocks is coded.

 The codec mode provided by the embodiment of the present invention can improve the coding efficiency, that is, the compression capability of the intra refresh macroblock, while ensuring the corresponding error recovery performance.

In the embodiment of the present invention, the encoding end may specifically perform the selection of the intra prediction mode of the current coding block according to the prediction mode of the neighboring block, and perform coding operation on the current coding block by using the selected intra prediction mode, where When the restricted DC prediction mode is selected as the intra prediction mode, then during the encoding process:

 Each neighboring block is available only when the current coded block is in the same macroblock as each neighboring block. Otherwise, each neighboring block is unavailable. For example, it may be considered only when the current coded block is the last luma block. Each neighboring block is available, and when the current coded block is another block, each neighboring block is unavailable;

 Or,

 If at least one of the adjacent blocks that have been encoded is an inter prediction block, each adjacent block is unavailable; or,

 Each adjacent block is unavailable;

 Each neighboring block may include at least one of a left neighboring block or an upper neighboring block of the current encoding block. Optionally, in order to facilitate the decoding end to identify whether the restricted DC prediction mode is adopted, the encoding end may further write, in the encoded code stream, whether to use the flag of the limited DC prediction mode; further, the flag of the limited DC prediction mode may be Written in the sequence header, header, slice header, macroblock or subblock of the stream. Alternatively, if the corresponding limited DC prediction mode is adopted by default, it is not necessary to write the flag of the DC prediction mode in the code stream to the code stream.

 In the embodiment of the present invention, at the encoding end, the availability of the neighboring block of the current coding block may also be determined first, which may be:

 Each neighboring block is available only when the current coded block is in the same macroblock as each neighboring block. Otherwise, each neighboring block is unavailable. For example, it may be considered only when the current coded block is the last luma block. Each neighboring block is available, and when the current coded block is another block, each neighboring block is unavailable;

 Or,

 If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current coding block, each adjacent block is not available;

 Or,

 Each adjacent block is unavailable;

 The neighboring block may include at least one of a left neighboring block or an upper neighboring block of the current encoding block; and then, according to the availability of the left neighboring block and the upper neighboring block of the current encoding block, corresponding Encoding operation.

 In the foregoing process, the method may further include: if there is no inter prediction block in the left neighboring block or the upper neighboring block of the current coding block, the left neighboring block or the upper neighboring block of the current coding block is available.

In the above processing, an indication flag may also be written in the encoded code stream for indicating that the encoding operation is performed according to the availability of the left neighboring block and the upper neighboring block determined according to the above manner. Optionally, the indicator may be specifically, but not limited to, written in a sequence header, an image header, a slice header, a macroblock or a subblock of the encoded code stream.

 In the embodiment of the present invention, after decoding the code stream to be decoded at the decoding end and obtaining the intra prediction mode used by the current decoding block, the decoding operation may be performed according to the intra prediction mode adopted by the currently decoded block obtained by the parsing, where Corresponding to the encoding end, if the intra prediction mode used is the limited DC prediction mode, then during the decoding process:

 Each neighboring block is available only when the current decoded block is in the same macroblock as each neighboring block. Otherwise, each neighboring block is unavailable. For example, only when the current coded block is the last luma block, each phase The neighboring block is available, and when the current encoding block is another block, the corresponding neighboring blocks are unavailable;

 Or,

 If at least one of the adjacent blocks that have been decoded is an inter prediction block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 Each neighboring block may include at least one of a left neighboring block or an upper neighboring block of the current decoded block. Optionally, when the decoding end obtains the flag of the DC prediction mode that is limited, if the intra prediction mode used by the current decoding block is the DC prediction mode, determining that the current decoding block adopts the limited DC prediction mode, Thereby, the decoding operation can be performed according to the limited DC prediction mode; wherein the flag of the restricted DC prediction mode can be obtained by parsing in a sequence header, an image header, a slice header, a macroblock or a subblock of the code stream. Alternatively, the decoder can also use the corresponding limited DC prediction mode by default.

 In the embodiment of the present invention, the decoding end may directly parse the received coded stream and determine the availability of the neighboring block, which may be:

 Each neighboring block is available only when the current decoded block is in the same macroblock as each neighboring block. Otherwise, each neighboring block is unavailable. For example, only when the current coded block is the last luma block, each phase The neighboring block is available, and when the current encoding block is another block, the corresponding neighboring blocks are unavailable;

 Or,

 If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current decoded block, each adjacent block is not available;

 Or,

 Each adjacent block is unavailable;

The neighboring block may include at least one of a left neighboring block or an upper neighboring block of the current decoding block; afterwards, the current decoded block may be corresponding according to the availability of the left neighboring block and the upper neighboring block. Decoding operation Work.

 In the foregoing process, the method may further include: if there is no inter prediction block in the left neighboring block or the upper neighboring block of the current decoding block, the left neighboring block or the upper neighboring block of the current decoding block is available.

 In the above processing, the encoded code stream may also be parsed to obtain an indication flag, and according to the indication, it is determined that a corresponding decoding operation needs to be performed according to the availability of the left neighboring block and the upper neighboring block determined according to the above manner.

 The embodiments of the present invention may be specifically, but not limited to, applied to a real-time video monitoring system.

 Specifically, in the embodiment of the present invention, the processing procedure used at the encoding end and the decoding end may be, but is not limited to, including the following steps:

 (1) Encoding end

 At the encoding end, the specific encoding process can include:

 (1) determining whether the current inter-coded frame needs to be intra-frame refreshed;

 For example, whether the frame needs to be refreshed may be determined by a frame interval of a certain period, or the frame may be manually specified by a network command or the like.

 (2) If it is determined that the current frame needs to perform intra-frame refresh, then the current macroblock in the current frame that needs to be intra-coded, also referred to as a refresh macroblock, according to the availability of neighboring blocks of the refresh macroblock (ie, adjacent Whether the macroblock can be used as a reference macroblock of the current macroblock) determining an encoding mode of each subblock of the macroblock, that is, selecting an intra prediction mode of the current coding subblock;

 The availability of the neighboring block means: the neighboring block is already encoded, and is in the same stripe as the current block. At this time, if at least one of the upper neighboring block or the left neighboring block is interframe predicting, Block, then, for the DC prediction mode in the intra prediction mode, it is determined that the neighboring blocks are unavailable, or only when the current coding block is the last luma block, each neighboring block is available, and the current coding block is other blocks. In time, the corresponding neighboring blocks are unavailable, or each neighboring block of the DC mode coded block in the frame is unavailable; the DC prediction mode at this time may be referred to as a limited DC prediction mode.

 (3) selecting, from the candidate intra prediction mode obtained in step (2), an intra prediction mode of the current coding subblock;

 (4) performing encoding operation on the current coding sub-block by using the selected intra prediction mode, and writing the syntax value corresponding to the selected intra prediction mode into the code stream, wherein if the limited DC prediction mode is selected, the coding operation is performed. , it is also possible to write a flag using the restricted DC prediction mode in the code stream.

 (2) Decoding end

 At the decoding end, the corresponding decoding processing steps may include:

(1) Acquiring a code stream, parsing an image header of an inter prediction frame or other parts in a code stream to obtain whether the frame is made a flag with a limited DC prediction mode;

 (2) if the intra prediction mode of the current sub-block (ie, the current decoding block) is the DC prediction mode, performing intra prediction of the sub-block using the limited DC prediction mode;

 The corresponding limited DC prediction mode refers to: the DC prediction mode of the current sub-block uses only 128 (or other integer) for intra prediction decoding operation; or, only when the current sub-code block is the last luminance block, each adjacent The block is available, and when the current decoding block is another sub-block, the corresponding neighboring blocks are unavailable (that is, only when the current decoding block is another sub-block, the DC prediction mode of the current sub-block uses only 128 or other Integer performs intra prediction decoding operation); or, each neighboring block of the coding block in all DC prediction modes in the frame is unavailable, and the DC prediction mode of the current coding block is only used by 128 (or other integer) prediction. In order to facilitate the understanding of the embodiments of the present invention, the specific application process of the present invention will be described in detail below with reference to specific application examples.

 (1) Encoding end

 In the embodiment of the present invention, for a sub-block (ie, a current coding block) that needs to perform intra prediction coding, when there is at least one inter prediction block in the left neighboring block or the upper neighboring block, the corresponding encoding processing step The method may include: (1) selecting an intra prediction mode from a set of intra prediction modes including a restricted DC prediction mode, where the corresponding restricted DC prediction mode means that the prediction mode cannot refer to neighboring blocks, and other intra predictions The mode can refer to the intra prediction block in the neighboring block or the inter prediction block in the adjacent block. The process of selecting an intra prediction mode can be selected by using the RD0 (rate distortion optimization) mode. The method selects a corresponding intra prediction mode according to any one or more of a mode selection method of a neighboring block availability, a SAD (absolute value difference) mode selection method, or a fast algorithm mode selection method.

 (2) encoding the current sub-block to be encoded using the selected intra prediction mode;

 (3) in the generated coded stream, using the flag of the restricted DC prediction mode to mark the current sub-block to be encoded using the restricted DC prediction mode;

 The flag of the restricted DC prediction mode may be specifically represented by a separate symbol in the sequence header, picture header, slice header, macroblock, sub-block or other part of the code stream, and may also be combined with other syntax units.

 (2) Decoding end

In the embodiment of the present invention, assuming that AVS (Digital Audio Video Codec Standard) is taken as an example, the syntax semantic modification in the PB picture header that can be performed is as shown in bold in the following table: Pb_picture_header() { descriptor pb_picture— start— code f(32) bbv delay u(16) picture— coding— type u(2)

If (picture coding type == ⁶ 01' || picture coding type == '11,)

 limitedDC_prediction flag (l) picture— distance u(8) next— start— code()

 }

 In the above table, the restricted DC prediction mode flag: limitedDC_prediction_flag, which can be a 1-bit unsigned integer. For example, when it is "1", it means that when the coding mode of the luminance or chrominance block of the frame is the intra-frame DC prediction mode, except for the last luminance sub-block, the other sub-blocks are predicted by using "128". When it is "0", it indicates that the normal DC prediction mode is used; or, the reverse is also possible.

 Let the image sample matrix to which the current block belongs be I, I can represent the luminance or chrominance matrix, and the current image is the forward predictive coded frame and the limited DC_prediction_flag is ' 1, 1, [J:

 If the current intra prediction block is a luma block and the IntraLumaPredMode is equal to '2, the image samples of the left adjacent block and the upper adjacent block of the 0th, 1st, and 2nd sub-blocks are 'unavailable', and the third sub-block The image samples of the left adjacent block and the upper adjacent block are all "available";

 If the current intra prediction block is a chroma block and IntraChromaPredMode is equal to '0', the image samples of the left adjacent block and the upper adjacent block of the current block are all "unavailable".

 In this embodiment, the specific decoding step may include the following process:

 (1) parsing an image header of the video frame to obtain an indicator symbol (ie, whether to use a restricted DC prediction mode flag), the indicator symbol is specifically used to indicate whether the DC prediction mode of the frame uses a limited DC prediction mode; In the step, if the frame uses the limited DC prediction mode, a sequence of frames may be indicated in the sequence header, or the image header may indicate whether the frame uses the limited DC prediction mode, or whether the limit is used by default. DC prediction mode (in this case, if the limited DC prediction mode is adopted by default, the corresponding indicator can be omitted);

(2) decoding to obtain an intra prediction mode of one sub-block;

 (3) If the intra prediction mode of the sub-block is the DC prediction mode, and the indication symbol obtained in the step (1) is the DC prediction mode indicating the frame usage limitation, the Bay IJ:

If at least one of the left or upper neighboring blocks of the current block is an inter prediction block, then for the current block is a luma block, the left adjacent block and the upper adjacent block of the 0th, 1st, and 2nd sub-blocks are both ' Not available, and the left neighboring block and the upper neighboring block of the third sub-block are both 'available'; for the current intra-predicted block to be a chroma block, the left neighboring block of the current block and the upper adjacent block Are 'not available';

 Or,

 If at least one of the left or upper neighboring blocks of the current block is an inter prediction block, the left or upper neighboring block of the current block is 'unavailable', if the left neighboring block or the upper neighboring block of the current block If there is no inter prediction block, then the left adjacent block or the upper adjacent block of the current block is 'available';

 (4) performing a corresponding intra prediction decoding operation, and the specific prediction manner may include:

 If the top left adjacent block is 'available', then the predicted value in DC prediction mode:

 predMatrix [x, y] = ( (r [x] +2xr [x+l] +r [x+2] +2) »2+ (c [y] +2xc [y+l] +c [y+ 2] +2) » 2) »1;

 If the upper neighboring block is 'available', then the predicted value in DC prediction mode:

 predMatrix [x, y] = (r [x] +2xr [x+1] +r [x+2] +2) »2;

 If the left neighboring block is 'available', then the predicted value in DC prediction mode:

 predMatrix [x, y] = (c [y] +2xc [y+1] +c [y+2] +2) »2;

 If the left and upper neighboring blocks are not available, the predicted value in DC prediction mode:

 predMatrix [x,y] = 128 (x, y=0~7). Of course, the "128" can also be replaced by other values. The embodiment of the present invention further provides a video encoding device, as shown in FIG. 2, which may specifically include:

 The intra prediction mode selection unit 201 is configured to perform, according to the prediction mode of the neighboring block, the selection of the intra prediction mode of the current coding block;

 The first encoding operation unit 202 is configured to perform an encoding operation on the current encoding block by using the intra prediction mode selected by the intra prediction mode selecting unit 201, wherein if the limited DC prediction mode is selected as the intra prediction mode, :

 Each neighboring block is available only when the current coded block is in the same macroblock as each neighboring block. Otherwise, each neighboring block is unavailable, for example, only when the current coded block is the last block of brightness, Adjacent blocks are available;

 Or,

 At least one of the neighboring blocks that have been decoded is an inter prediction block, and each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 Each neighboring block may include at least one of a left neighboring block or an upper neighboring block of the current encoding block. Optionally, the apparatus may further include a restricted DC prediction mode flag writing unit 203, configured to write, in the encoded code stream obtained by the first encoding operation unit 202, whether the flag of the restricted DC prediction mode is used.

The embodiment of the invention further provides a video decoding device, as shown in FIG. 3, which may specifically include: The intra prediction mode determining unit 301 is configured to parse the received encoded code stream, and obtain an intra prediction mode adopted by the current decoding block. Optionally, the intra prediction mode determining unit 301 obtains the DC with the limitation in the parsing. When the flag of the prediction mode is predicted, if the intra prediction mode adopted by the current decoding block is the DC prediction mode, it is determined that the current decoding block adopts the limited DC prediction mode.

 The first decoding operation unit 302 is configured to perform a decoding operation according to the intra prediction mode adopted by the current decoding block obtained by the intra prediction mode determining unit 301, where the intra prediction mode is a limited DC prediction mode. , then - only when the current decoded block is in the same macro block as each neighboring block, each neighboring block is available; otherwise, each neighboring block is unavailable, for example, only the current decoded block is the last luma block When adjacent blocks are available;

 Or,

 If at least one of the adjacent blocks that have been decoded is an inter prediction block, each adjacent block is unavailable; or,

 Each adjacent block is unavailable;

 Each neighboring block may include at least one of a left neighboring block or an upper neighboring block of the current decoded block. Another embodiment of the present invention further provides a video encoding apparatus. As shown in FIG. 4, the specific implementation structure may include:

 The first neighboring block availability identifying unit 401 is configured to determine the availability of the neighboring block of the current coded block, including: each neighboring block is available only when the current coded block is in the same macro block as each adjacent block, otherwise , each neighboring block is unavailable, for example, each neighboring block may be available only when the current coded block is the last luma block;

 Or,

 If there is at least one inter prediction block in the left adjacent or upper neighboring block of the current coding block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 Each of the neighboring blocks may include at least one of a left neighboring block or an upper neighboring block of the current coded block. Optionally, the first neighboring block availability identifying unit 401 may further include: if the current coded block is If there is no inter prediction block in the left neighboring block or the upper neighboring block, the left neighboring block or the upper neighboring block of the current coded block is available;

 The second encoding operation unit 402 is configured to perform an encoding operation on the current encoding block according to the availability of the left neighboring block and the upper neighboring block determined by the first neighboring block availability identifying unit 401.

Another embodiment of the present invention further provides a video decoding apparatus. As shown in FIG. 5, the specific implementation structure may include Includes:

 The second neighboring block availability identifying unit 501 is configured to parse the received coded stream and determine the availability of the neighboring block, including:

 Each neighboring block is available only when the current decoded block is in the same macroblock as each neighboring block. Otherwise, each neighboring block is unavailable, for example, only when the current decoded block is the last luma block, Adjacent blocks are available;

 Or,

 If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current decoded block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 Each of the neighboring blocks may include at least one of a left neighboring block or an upper neighboring block of the current decoded block. Optionally, the second neighboring block availability identifying unit 501 may further include: if the currently decoded block is If there is no inter prediction block in the left neighboring block or the upper neighboring block, the left neighboring block or the upper neighboring block of the current decoding block is available;

 The second decoding operation unit 402 is configured to perform a decoding operation on the current decoded block according to the availability of the left neighboring block and the upper neighboring block determined by the second neighboring block availability identifying unit 501.

 A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium, the program In execution, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM). In summary, the embodiment of the present invention can reduce the code rate by using inter-frame prediction in a still area, and the intra prediction coding that limits the motion area ensures the error-proof spreading function of the frame, thereby improving the video after being compressed and transmitted. The subjective and objective quality of the video displayed at the decoder.

 The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed by the present invention. Alternatives are intended to be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

Rights request

A video encoding method, comprising:

 Selecting an intra prediction mode of the current coding block according to a prediction mode of the neighboring block;

 Encoding operation of the current coding block by using the selected intra prediction mode, wherein when the limited DC prediction mode is selected as the intra prediction mode,

 Each adjacent block is available only when the current coded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one of the adjacent blocks that have been encoded is an inter prediction block, each adjacent block is unavailable; or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current encoding block.

2. The method according to claim 1, further comprising:

 Writing a flag in the encoded code stream whether or not to use the restricted DC prediction mode;

 Or,

 The default DC prediction mode is adopted by default.

 The method according to claim 2, wherein the flag of the restricted DC prediction mode is written in a sequence header, an image header, a slice header, a macroblock or a subblock of the coded code stream.

 4. A video encoding apparatus, comprising:

 An intra prediction mode selecting unit, configured to select, according to a prediction mode of the neighboring block, an intra prediction mode of the current coding block;

 a first encoding operation unit, configured to perform an encoding operation on the current encoding block by using an intra prediction mode selected by the intra prediction mode selecting unit, wherein if the limited DC prediction mode is selected as the intra prediction mode, the shell IJ: only When the current coding block is in the same macro block as each adjacent block, each adjacent block is available; otherwise, each adjacent block is unavailable;

 Or,

 At least one of the adjacent blocks that have been encoded is an inter prediction block, and each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current encoding block.

5. The device according to claim 4, wherein the device further comprises:

 The restricted DC prediction mode flag writing unit is configured to write in the coded code stream whether or not the flag of the limited DC prediction mode is used.

 6. A method of video decoding, comprising:

 Parsing the code stream to be decoded, and obtaining an intra prediction mode used by the current decoding block;

 The decoding operation is performed according to the intra prediction mode adopted by the currently decoded block obtained by the parsing, wherein if the intra prediction mode used is the limited DC prediction mode, the Bay IJ:

 Each adjacent block is available only when the current decoded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one of the adjacent blocks that have been decoded is an inter prediction block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current decoding block.

The method according to claim 6, wherein the obtaining the intra prediction mode adopted by the current decoding block comprises: parsing a frame used by the current decoding block when parsing the flag of the DC prediction mode using the limitation The intra prediction mode is a DC prediction mode, and the current decoding block adopts a limited DC prediction mode;

 Or,

 By default, the current decoded block uses a limited DC prediction mode.

 8. The method according to claim 7, wherein the parsing process of obtaining a flag using the restricted DC prediction mode comprises:

 A sequence header, an image header, a slice header, a macroblock, or a subblock in the parsing stream is used to obtain a flag of the restricted DC prediction mode.

 9. A video decoding device, comprising:

 An intra prediction mode determining unit, configured to parse the received encoded code stream, and obtain an intra prediction mode used by the current decoding block;

a first decoding operation unit, configured to perform a decoding operation according to an intra prediction mode adopted by the current decoding block obtained by the intra prediction mode determining unit, where the adopted intra prediction mode is a limited DC prediction mode, IJ: Each adjacent block is available only when the current decoded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one of the adjacent blocks that have been decoded is an inter prediction block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current decoding block.

The device according to claim 9, wherein the intra prediction mode determining unit, when parsing the flag that adopts the restricted DC prediction mode, if the intra prediction mode adopted by the current decoding block is the DC prediction mode The pre-before decoding block uses a limited DC prediction mode.

 11. A method of video encoding, comprising:

 Determine the availability of neighboring blocks of the current coded block, including:

 Each adjacent block is available only when the current decoded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current coding block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current decoding block; and an encoding operation is performed according to availability of the left neighboring block and the upper neighboring block.

 The method according to claim 11, wherein the method further comprises:

 An indication flag is written in the encoded code stream for indicating that the encoding operation is performed according to the availability of the left neighboring block and the upper neighboring block.

 The method according to claim 12, wherein the indication flag is written in a sequence header, an image header, a slice header, a macroblock or a subblock of the encoded code stream.

 14. A video encoding apparatus, comprising:

a first neighboring block availability identifying unit, configured to determine availability of a neighboring block of the current coded block, including: each neighboring block is available only when the current coded block is in the same macroblock as each neighboring block, otherwise, Each adjacent block is unavailable; or,

 If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current coding block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current encoding block, and a second encoding operation unit, configured to determine, according to the first neighboring block availability identifying unit, the left The availability of the neighboring block and the upper neighboring block encodes the current coded block.

 15. A method of video decoding, comprising:

 Parsing the code stream to determine the availability of neighboring blocks, including:

 Each adjacent block is available only when the current decoded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

 If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current decoded block, each adjacent block is unavailable;

 Or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current decoding block; and performing a decoding operation according to availability of the left neighboring block and the upper neighboring block.

 The method according to claim 15, wherein the method further comprises:

 The code stream is parsed, an indication flag is obtained, and according to the indication, it is determined that a decoding operation needs to be performed according to the availability of the left neighboring block and the upper neighboring block.

 17. A video decoding apparatus, comprising:

 a second neighboring block availability identifying unit, configured to parse the received coded stream, and determine the availability of the neighboring block, including:

 Each adjacent block is available only when the current coded block is in the same macro block as each adjacent block; otherwise, each adjacent block is unavailable;

 Or,

If at least one inter prediction block exists in the left adjacent or upper neighboring block of the current decoding block, each adjacent block is unavailable; or,

 Each adjacent block is unavailable;

 The neighboring block includes at least one of a left neighboring block or an upper neighboring block of the current encoding block, and a second decoding operation unit, configured to determine, according to the second neighboring block availability identifying unit, the left The availability of the neighboring block and the upper neighboring block performs a decoding operation on the currently decoded block.

 18. A method of video decoding, comprising:

 Parsing the code stream to be decoded, and obtaining an intra prediction mode used by the current decoding block;

 The decoding operation is performed according to the intra prediction mode adopted by the currently decoded block obtained by the parsing, wherein if the intra prediction mode used is the limited DC prediction mode, the Bay IJ:

 If the current intra prediction block is a luma block and is in a DC mode, the image samples of the left adjacent block and the upper adjacent block of the 0th, 1st, and 2nd sub-blocks are both 'unavailable', and the left side of the third sub-block The image samples of the adjacent block and the upper adjacent block are all "available";

 If the current intra prediction block is a chroma block and is in DC mode, the image samples of the left adjacent block and the upper adjacent block of the current block are "unavailable".

 The method according to claim 18, wherein the obtaining the intra prediction mode adopted by the current decoding block comprises:

 If the intra prediction mode adopted by the current decoding block is the DC prediction mode, the current decoding block adopts the limited DC prediction mode.

 Or,

 By default, the current decoded block uses a limited DC prediction mode.

 The method according to claim 18, wherein the parsing the process of obtaining the flag of the restricted DC prediction mode comprises:

 A sequence header, an image header, a slice header, a macroblock, or a subblock in the parsing stream is used to obtain a flag of the restricted DC prediction mode.

 New claim 2:

 21. A method of video decoding, comprising:

 Parsing the code stream to be decoded, and obtaining an intra prediction mode used by the current decoding block;

 The decoding operation is performed according to the intra prediction mode adopted by the currently decoded block obtained by the parsing, wherein if the intra prediction mode used is the limited DC prediction mode, the Bay IJ:

Only when the current decoded block is in the same macro block as the left adjacent block and the upper adjacent block, the left adjacent block and the upper adjacent block may be Use, otherwise, the left adjacent block and the upper adjacent block are unavailable;

 Or,

 If at least one of the left adjacent block and the upper adjacent block that has been decoded is an inter prediction block, the left adjacent block and the upper adjacent block are unavailable;

 Or,

 Both the left adjacent block and the upper adjacent block are unavailable.

 The method according to claim 21, wherein the obtaining the intra prediction mode adopted by the current decoding block comprises:

 When the flag of the DC prediction mode with the limitation is obtained, if the intra prediction mode used by the current decoding block is the DC prediction mode, the current decoding block of the block lj uses the limited DC prediction mode;

 Or,

 By default, the current decoded block uses a limited DC prediction mode.

 The method according to claim 22, wherein the parsing process of obtaining a flag using the restricted DC prediction mode comprises:

 A sequence header, an image header, a slice header, a macroblock, or a subblock in the parsing stream is used to obtain a flag of the restricted DC prediction mode.