JP2019110376A - Decode error detection estimation device, video decoding device, and program for the devices - Google Patents

Abstract

To provide a decode error detection estimation device for efficiently detecting or estimating a decode error generated in decoding a coded video stream, a video decoding device for performing error concealment depending on the detection of the decode error, and a program for the devices.SOLUTION: A decode error detection estimation device 10 comprises: a the-number-of-clips detection unit 103 for detecting the number of clips in a decode error determination block preset for an input decode area; and a decode error determination unit 105 that compares the number of clips in a present block constituting the decode error determination block on which the detection is performed with the number of clips in a past block in a predetermined past frame of a comparison target or a specified value and, according to a predetermined determination criterion, determines whether or not the present block includes a decode error. A video decoding device 1 of the present invention comprises the decode error detection estimation device 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for detecting a decoding error at the time of decoding of a coded video, and more particularly to a decoding error detection / estimating device for detecting or estimating a decoding error that occurs when decoding a coded video stream, detection of the decoding error The present invention relates to a video decoding apparatus that performs error concealment in accordance with the above, and programs for these.

  In general, a video coding system defines a specific bit string called a start code. The start code is used to separate bitstreams. It is guaranteed that the start code does not appear except at the break position.

  In the present specification, portions other than the start code separated by the start code are referred to as a payload (the payload is referred to as an NAL unit in a video coding scheme according to H.264 or H.265 or the like). The payload is composed of a header portion indicating information such as a slice or a macroblock, and a data portion indicating orthogonal transform coefficients, motion vectors, and residual signals thereof. Generally, almost all the bits in the payload belong to the data part, except for extremely low bit rate streams. Also, a region of a video obtained by decoding the payload is referred to as a decoding region (that is, a region to be allocated to a frame image from which an image obtained by decoding the payload is restored) in the present specification. The decoding area is an entire screen (referred to as a frame image, a picture or the like) or a part of the screen (referred to as a slice, a tile or the like), and is designated by a stream header.

  In recent video coding methods such as H. 265 / MPEG-H HEVC and the like, in order to improve bit use efficiency, non-specific bit strings that are difficult to detect decoding errors appear in payloads (especially data) other than start codes. Do. Therefore, as a known method for detecting a decoding error that occurs when decoding a coded video stream, the start code may appear before the decoding of the decoding area is completed (lack of payload) or the decoding of the decoding area is completed. Despite this, it is detected by detecting whether the start code does not appear (payload surplus). In the known decoding error detection technique using this start code, the error position in the decoding area can not be grasped, and the entire decoding area must be subjected to the error concealment, so the processing efficiency is not good.

  A decoding error detection circuit is known which detects an error when data which can not be decoded occurs during decoding of variable-length data (see, for example, Patent Document 1). The variable-length data is data compressed by variable-length coding in which data typified by Huffman coding and a code word correspond one to one. Decode error detection is possible because only a specific combination of bits exists in a codeword used in variable-length coding.

  However, recent video coding schemes, such as H. 265 / MPEG-H HEVC, use arithmetic coding rather than variable length coding (especially in the data section) to improve bit usage efficiency. In arithmetic coding, since a predetermined code word does not exist, as described above, a non-specific bit string that is difficult to detect a decoding error appears in the payload (especially data) other than the start code. Can not perform decoding error detection.

  There is also known a technique for detecting a macroblock in which a decoding error has occurred at the time of video decoding (see, for example, Patent Document 2). Patent Document 2 discloses the following two examples as a decoding error detection technique.

  (1) As a result of decoding the macroblock information, there is no corresponding data. This is, for example, when the macro block information is decoded and then reproduced with reference to a reference frame, the reference frame is pointing to "list 10", and the reference frame list is "list 0" to "list For example, there were only 8 ".

  (2) The value resulting from decoding the macroblock information does not exist in the encoding correspondence table. This is, for example, the case where the decoded result has a value of "40" but only values from "0" to "30" are defined in the encoding correspondence table.

  However, since the technique disclosed in Patent Document 2 is a technique for detecting a decoding error of a macroblock involved in a header portion in which a reference frame list or a coding correspondence table is shown, most of the bit strings in the payload are generally data portions. Since it is (in particular, an orthogonal transformation coefficient or its residual signal), a high detection probability can not be expected.

  And, in recent video coding methods such as H. 265 / MPEG-H HEVC method, in order to maximize the bit use efficiency, values which are not present in the coding correspondence table are not decoded in the first place. It is difficult to perform decoding error detection by the technique disclosed in reference 2.

Unexamined-Japanese-Patent No. 5-95536 Patent No. 4309784

  As described above, recent video coding methods such as the H. 265 / MPEG-H HEVC method and the like improve the bit use efficiency, so it is difficult to detect decoding errors in payloads (especially data) other than the start code. A specific bit string appears. Therefore, as a known method for detecting a decoding error that occurs when decoding a coded video stream, the start code may appear before the decoding of the decoding area is completed (lack of payload) or the decoding of the decoding area is completed. Despite this, it is detected by detecting whether the start code does not appear (payload surplus). In the known decoding error detection technique using this start code, the error position in the decoding area can not be grasped, and the entire decoding area must be subjected to the error concealment, so the processing efficiency is not good.

  Further, with the technique of Patent Document 1 or 2, it is difficult to detect a decoding error that occurs when decoding a coded video stream according to a recent video coding method such as H. 265 / MPEG-H HEVC. .

  For this reason, H. Not only in H. 265 / MPEG-H HEVC format but also in recent video coding systems such as H. 265 / MPEG-H HEVC format or the like, decoding errors generated when decoding the encoded video stream are efficiently detected or not Techniques to estimate are desired.

  Therefore, in view of the above problems, the object of the present invention is as follows. Not only in H. 265 / MPEG-H HEVC format but also in recent video coding systems such as H. 265 / MPEG-H HEVC format or the like, decoding errors generated when decoding the encoded video stream are efficiently detected or not A decoding error detection / estimating device to estimate, a video decoding device that performs error concealment according to the detection of the decoding error, and a program thereof are provided.

  A decoding error detection and estimation apparatus according to a first aspect of the present invention is a decoding error detection and estimation apparatus for detecting or estimating a decoding error generated when decoding a coded video stream, and decoding the coded video stream The number of clips detecting means for inputting the obtained decoding area and detecting the number of clips in the decoding error judgment block of the block size preset to perform the decoding error judgment on the inputted decoding area, and the detected decoding error The number of clips of the current block constituting the judgment block is compared with the number of clips of the past block (block in the past frame) at the same block position as the current block in the predetermined comparison target past frame. Whether the current block has a decoding error according to Or it determines, characterized in that it comprises a and a decoding error determination section for generating a decoding error determination signal indicating the presence or absence of decoding error.

  Further, in the decoding error detection and estimation apparatus according to the first aspect of the present invention, the decoding error determination means determines that the number of clips of the current block is increased by a predetermined amount from the number of clips of the past block as the predetermined determination criterion. It is characterized in that when it is determined that there is a decoding error.

  Further, in the decoding error detection and estimation apparatus according to the first aspect of the present invention, the decoding error determination unit compares, as a comparison target past frame determined in advance, the previous frame decoded immediately before in the decoding order. It is characterized by

  Furthermore, a decoding error detection and estimation apparatus according to a second aspect of the present invention is a decoding error detection and estimation apparatus for detecting or estimating a decoding error generated when decoding a coded video stream, which decodes the coded video stream And the number-of-clips detecting means for detecting the number of clips in the decoding error determination block of the block size set in advance for performing the decoding error determination on the input decoding area, and the detection The number of clips of the current block constituting the decoding error determination block is compared with a predetermined value determined in advance, it is determined whether the current block has a decoding error according to a predetermined determination criterion, and the presence or absence of a decoding error is indicated. And a decode error determination unit that generates a decode error determination signal. It is characterized in.

  Further, in the decoding error detection and estimation apparatus according to the second aspect of the present invention, the decoding error judging means compares the specified value with the number of clips of the current block as the predetermined judgment standard, When it is determined that the number of clips in the group is larger than the predetermined value by a predetermined amount, it is determined that there is a decoding error.

  Further, in the decoding error detection and estimation apparatus according to the first and second aspects of the present invention, the decoding error determination means compares and determines the ratio of the number of clips to the number of pixels in the decoding error determination block. Do.

  Furthermore, the video decoding apparatus according to the present invention performs error concealment by complementing the corresponding decoding area based on the decoding error detection and estimation apparatus according to the present invention, and the decoding error determination signal obtained from the decoding error detection and estimation apparatus. And a complementing means for generating a video stream subjected to the texting.

  Furthermore, the program of the present invention configures a computer as a program for causing the computer to function as a decoding error detection and estimation device according to the present invention or a video decoding device according to the present invention.

  According to the present invention, since the number of clipped pixel values generated in the decoding process is used to detect or estimate the decoding error generated when decoding the encoded video stream, Efficiently detect or estimate a place where a decoding error has occurred not only in H. 265 / MPEG-H HEVC and other recent video coding methods, but also in H. 265 / MPEG-H HEVC and other video coding methods. Is possible.

It is a block diagram which illustrates schematic structure of a video decoding apparatus provided with the decoding error detection estimation apparatus of 1st Embodiment by this invention. It is explanatory drawing which shows an example of the block division regarding the decoding error determination block in the decoding error detection estimation apparatus of 1st Embodiment by this invention. It is explanatory drawing which shows the comparative example of the number of clips used for the decoding error determination in the decoding error detection estimation apparatus of 1st Embodiment by this invention. It is a block diagram which illustrates schematic structure of a video decoding apparatus provided with the decoding error detection estimation apparatus of 3rd Embodiment by this invention. It is explanatory drawing of the number of clips used for the decoding error determination in the decoding error detection estimation apparatus of 2nd Embodiment by this invention.

First Embodiment
(Video decoding device)
FIG. 1 is a block diagram illustrating a schematic configuration of a video decoding device 1 provided with a decoding error detection and estimation device 10 according to a first embodiment of the present invention. The decoding error detection and estimation apparatus 10 according to the present invention functions as an apparatus for detecting or estimating a decoding error that occurs when decoding a coded video stream.

  First, the video decoding device 1 includes a decoding error detection / estimation device 10, a decoding processing unit 11, and a complementing unit 12.

  The decoding processing unit 11 is a functional unit that receives an encoded video stream and performs decoding processing. When the decoding processing unit 11 receives the encoded video stream, the decoding processing unit 11 can divide the decoding region specified by the stream header at the time of decoding, and sequentially outputs the decoding region to the complementing unit 12.

  In general, H.1. In video decoding devices in recent video coding methods such as H. 265 / MPEG-H HEVC as well as video coding methods prior to H.264, when decoding (generation of a decoding area), within the allowable range And clipping the pixel values. That is, the clip is a process of replacing pixel values exceeding the allowable minimum value or maximum value with the allowable minimum value or maximum value, respectively. In general, in the video encoding method, performing clipping in the decoding process is defined (for example, in the H.265 / MPEG-H HEVC method, it is defined as a function such as Clip 3). Also, the allowable range (minimum value or maximum value) may not be fixed, but may be variable in the video stream. In this case, the clip is a process of clipping the pixel value within the range permitted by the block.

  First, the decode error detection / estimation device 10 according to the first embodiment receives a decode area designated as a determination target of a decode error in real time from the decode processing unit 11, and determines the decode error for the input decode area. In order to do this, the block is divided into decode error determination blocks of a block size set in advance. Subsequently, the decoding error detection / estimation device 10 detects the number of clips in the current block constituting the decoding error determination block, and detects the number of clips of the detected current block and a predetermined past frame to be compared (preferably, The current block in the immediately preceding decoded frame in decoding order and the number of clips of the past block at the same block position (the same block size) are compared. Then, when comparing the number of clips in the current block with the number of clips in the past block, the decoding error detection / estimation device 10 determines whether the current block has a decoding error according to a predetermined determination criterion. A decode error determination signal (including indicating that there is a decode error and indicating that there is no decode error) indicating a presence or absence of a decode error is generated and output to the complement unit 12 or to the outside.

  The complementing unit 12 temporarily stores the decoding area sequentially input from the decoding processing unit 11, and complements the corresponding decoding area based on the decoding error determination signal obtained from the decoding error detection and estimation device 10 Generate a video stream with concealment and output it to the outside. The technique relating to this complementation itself is not the spirit of the present invention, and can be a known technique by interpolation, extrapolation or the like.

  Although the example of incorporating the decoding error detection and estimation apparatus 10 of this embodiment shown in FIG. 1 into the video decoding apparatus 1 is shown, the decoding error detection and estimation apparatus 10 of this embodiment is outside the video decoding apparatus 1. You may provide. Further, the decoding error detection and estimation apparatus 10 of the present embodiment can be configured simply as an apparatus that outputs the decoding error determination signal for the decoding area to the outside. For example, the present invention can be used for applying a decoding error determination signal (including indicating that there is only a decoding error or indicating that there is no decoding error) to a decoding area in a moving image file to be stored.

(Decoding error detection and estimation device)
Hereinafter, the decoding error detection and estimation apparatus 10 of the present embodiment shown in FIG. 1 will be described in detail. As shown in FIG. 1, the decoding error detection and estimation apparatus 10 of the present embodiment includes a target decoding area extracting unit 101, a block dividing unit 102, a clip number detection unit 103, a clip memory 104, and a decoding error determination unit 105. The decode error determination unit 105 further includes a clip number comparison unit 105a.

  The target decoding area extraction unit 101 inputs a decoding area in real time from the decoding processing unit 11 or extracts and inputs a decoding area specified as a determination target of a decoding error, and the block division unit 102 receives the input decoding area. Output to

  The block division unit 102 divides the input decode area obtained from the target decode area extraction unit 101 into decode error judgment blocks of a block size set in advance for judging a decode error, and the respective decode error judgment blocks Is output to the clip number detection unit 103. Also, the block division unit 102 outputs, to the clip number detection unit 103 and the decode error determination unit 105, block division information indicating the frame number of the frame image including the decode area, the block size of each decode error determination block, and the block position. .

  The block size of each decoding error determination block that divides the decoding area can be an arbitrary size. FIG. 2 is an explanatory diagram showing an example of block division regarding a decoding error determination block in the decoding error detection and estimation apparatus 10 of the first embodiment according to the present invention. For example, as shown in FIG. 2, in the n-th frame image F (n) in the decoding order of the encoded video stream, it is assumed that the decoding region DI is configured by a part (slice, tile, etc.) The decoding area DI may be the entire frame, which is specified by the stream header). Decoding area DI is divided by the block size of the basic unit that performs encoding / decoding assuming that the k-th encoding / decoding block is bk # k, but the m-th decoding error determination block is BK # m. Then, the block size can be made larger than the block size of this encoding / decoding block bk # k.

  As the block size of the decoding error determination block BK # m is larger, false detection and omission of detection can be prevented, and the processing speed is improved, while identification of the position in the frame image F (n) where a block error has occurred is rough become. From this point of view, as the block size of the decoding error determination block BK # m, the coding / decoding block which is a basic unit for coding / decoding is set to the block size of bk # k (for example, in H.265 / MPEG-H HEVC) It is preferable to use the same size as CTU).

  The clip number detection unit 103 accumulates and detects the number of clips of each decoding error determination block based on the block division information obtained from the block division unit 102 and each decoding error determination block, and the number of clips of each decoding error determination block Are output to the decoding error determination unit 105 as the number of clips of the current block. Also, the clip number detection unit 103 outputs the clip number of the current block detected based on the block division information to the clip memory 104. Here, instead of the block division unit 102 outputting the block division information to the decode error determination unit 105, the clip number detection unit 103 outputs the block division information acquired from the block division unit 102 to the decode error determination unit 105. Can also be configured.

  The clip memory 104 temporarily stores the number of clips of the current block obtained from the number-of-clips detector 103, the frame number of the frame image including the decoding area, the block size of each decoding error determination block, and the block position. accumulate. The clip memory 104 updates and holds the number of clips of each decoding error determination block for a predetermined number of frames. In this example, the number of decoding error determination blocks in the previous frame decoded immediately before in the decoding order Keep updated the number of clips. In the initial state, the clip memory 104 holds no clip (the number of clips is zero). Instead of the frame number, the clip memory 104 may hold information that can specify the current frame, for example, a relative value from the beginning of a GOP (Group Of Pictures) or an index in a predetermined coding order.

  The decoding error determination unit 105 specifies in advance a past frame specified in advance based on the block division information obtained from the block division unit 102 or the clip number detection unit 103 and the clip number of the current block obtained from the clip number detection unit 103 (this example Then, the number of clips in the past block at the same block position (same block size) as the current block in the immediately preceding decoded frame in the decoding order is acquired from the clip memory 104.

  Then, the decode error determination unit 105 compares the number of clips of the current block with the number of clips of the past block according to a predetermined determination criterion by the clip number comparison unit 105a, and the current block has a decode error. It generates a decode error determination signal (including indicating that there is only a decode error or indicating that there is no decode error) that indicates the presence or absence of a decode error according to the result of the clip number comparison unit 105a. Output to the complement unit 12 or to the outside.

  FIG. 3 is an explanatory view showing a comparative example of the number of clips used for decoding error determination in the decoding error detection and estimation apparatus 10 of the first embodiment of the present invention. As shown in FIG. 3, the clip number comparison unit 105a designates in advance the number of clips in the current block BK # m to be subjected to decoding error determination in the nth frame image F (n) in decoding order in the encoded video stream. The number of clips of the past block BK # m 'at the same block position (same block size) as the current block in the past frame (in this example, the past frame F (n-1) decoded immediately before in decoding order) By comparing in accordance with a predetermined determination criterion, it is determined whether or not there is a decoding error.

  Here, as an example of the predetermined determination criterion, the clip number comparison unit 105a compares the clip number of the past block with the clip number of the current block, and the clip number of the current block is more than the clip number of the past block. If it is determined that there is a fixed amount increase, it is determined that there is a decoding error. Preferably, the ratio is determined by comparing the ratio of the number of clips to the number of pixels in the decoding error determination block.

For example, as an example of the predetermined determination reference, when the predetermined number of clips is increased, the number of clips in the past block is P, the number of clips in the current block is C, and the number of pixels in the decoding error determination block is S. , And can be configured as the following three examples.
(1) When (C + 1) / (P + 1)> k is satisfied, it is determined that there is a decoding error.
(2) When C / S-P / S> n is satisfied, it is determined that there is a decoding error.
(3) When C / S-P * k / S> n is satisfied, it is determined that there is a decoding error.

  Note that k and n in the above equation are parameters to be set in advance. k is a value of 1.0 or more, and n is a value of 0 or more. As the values of k and n are smaller, the omission of detection of the decoding error decreases but the false detection increases. Conversely, as the values of k and n increase, false detection of decoding errors decreases, but detection leaks increase. For example, when using the determination criterion of (2) above, it is preferable to set the value of n to about 0.01 to 0.03.

  According to the decoding error detection and estimation apparatus 10 of the first embodiment and the video decoding apparatus 1 including the same, it occurs in the decoding process in order to detect or estimate the decoding error generated when decoding the encoded video stream In order to use the number of clipped pixel values, In a recent video coding method with high bit use efficiency such as H. 265 / MPEG-H HEVC method as well as the H. 265 or earlier video coding method, it is possible to efficiently detect or estimate a place where a decoding error occurs. It becomes possible.

Second Embodiment
(Video decoding device)
FIG. 4 is a block diagram illustrating a schematic configuration of a video decoding device 1 provided with the decoding error detection and estimation device 10 according to the second embodiment of the present invention. The same reference numerals as in the first embodiment shown in FIG. 1 denote the same constituent elements. The video decoding device 1 according to the second embodiment is the same as the first embodiment except that the configuration of the decoding error detection / estimation device 10 is different, and the decoding processing unit 11 and the complementing unit 12 The description is omitted. Further, the decoding error detection and estimation apparatus 10 of the second embodiment is different from the first embodiment in that the decoding error is determined without holding the number of clips of the past block in the clip memory 104.

  Although the decoding error detection and estimation apparatus 10 of this embodiment shown in FIG. 4 shows an example incorporated in the video decoding apparatus 1, the decoding error detection and estimation apparatus 10 of this embodiment is the same as the first embodiment. May be provided outside the video decoding device 1. Further, the decoding error detection and estimation apparatus 10 of the present embodiment can be configured simply as an apparatus that outputs the decoding error determination signal for the decoding area to the outside. For example, the present invention can be used for applying a decoding error determination signal (including indicating that there is only a decoding error or indicating that there is no decoding error) to a decoding area in a moving image file to be stored.

(Decoding error detection and estimation device)
The decode error detection and estimation apparatus 10 of the present embodiment shown in FIG. 4 will be described in detail below. As shown in FIG. 4, the decoding error detection and estimation apparatus 10 of the present embodiment includes a target decoding area extracting unit 101, a block dividing unit 102, a clip number detection unit 103, and a decoding error determination unit 105. The decode error determination unit 105 further includes a clip number comparison unit 105 b.

  As in the first embodiment, the target decoding area extracting unit 101 inputs a decoding area in real time from the decoding processing unit 11 or extracts and inputs a decoding area designated as a judgment target of a decoding error, and the input The decoded area is output to the block division unit 102.

  As in the first embodiment, the block division unit 102 makes a block to a decode error determination block of a block size set in advance for performing a decode error determination on the input decode region obtained from the target decode region extraction unit 101. The division is performed, and each decoding error determination block is output to the clip number detection unit 103. Also, the block division unit 102 outputs, to the clip number detection unit 103 and the decode error determination unit 105, block division information indicating the frame number of the frame image including the decode area, the block size of each decode error determination block, and the block position. .

  Also in this embodiment, as described with reference to FIG. 2 in the first embodiment described above, the block size of each decoding error determination block that divides the decoding area can be an arbitrary size.

  Similarly to the first embodiment, the number-of-clips detection unit 103 accumulates and detects the number of clips of each decoding error determination block based on the block division information obtained from the block division unit 102 and each decoding error determination block, The number of clips of each decoding error determination block is output to the decoding error determination unit 105 as the number of clips of the current block. Here, instead of the block division unit 102 outputting the block division information to the decode error determination unit 105, the clip number detection unit 103 outputs the block division information acquired from the block division unit 102 to the decode error determination unit 105. Can also be configured.

  The decoding error determination unit 105 is determined by the clip number comparison unit 105 b based on the block division information obtained from the block division unit 102 or the clip number detection unit 103 and the clip number of the current block obtained from the clip number detection unit 103. The number of clips of the current block is compared with a predetermined value determined in advance according to the determination criteria of (1), it is determined whether the current block has a decoding error, and according to the result of the clip number comparison unit 105b, A decode error determination signal (including indicating that there is a decode error and indicating that there is no decode error) indicating the presence or absence of a decode error is generated and output to the complement unit 12 or to the outside.

  FIG. 5 is an explanatory view showing a comparative example of the number of clips used for decoding error determination in the decoding error detection and estimation apparatus 10 of the second embodiment according to the present invention. As shown in FIG. 5, the number-of-clips comparison unit 105b determines, in advance, the number of clips in the current block BK # m to be subjected to decoding error determination in the nth frame image F (n) in decoding order in the encoded video stream. The specified value is compared according to a predetermined judgment standard to determine the presence or absence of a decoding error.

  Here, as an example of the predetermined determination criterion, the clip number comparison unit 105b compares the specified value (for example, the number of clips determined in advance) with the number of clips of the current block, and the number of clips of the current block is the specified If it is determined that there is a predetermined amount increase from the value, it is determined that there is a decoding error. Preferably, the ratio is determined by comparing the ratio of the number of clips to the number of pixels in the decoding error determination block.

For example, as an example of the predetermined determination reference, when the number of clips in the current block is C and the number of pixels in the decoding error determination block is S, the increase of the predetermined number of clips is as in the following two examples. It can be configured.
(4) When C> n is satisfied, it is determined that there is a decoding error.
(5) When C / S> n is satisfied, it is determined that there is a decoding error.

  Here, n in the above equation is a preset parameter. The smaller the value of n, the less the detection error of the decoding error but the more false detection. Conversely, as the value of n increases, false detection of decoding errors decreases, but detection leaks increase. For example, when using the determination criteria of (5) above, it is preferable to set the value of n to about 0.01 to 0.03.

  Also in the second embodiment, since the number of clips of pixel values generated in the decoding process is used to detect or estimate the decoding error generated when decoding the encoded video stream, In a recent video coding method with high bit use efficiency such as H. 265 / MPEG-H HEVC method as well as the H. 265 or earlier video coding method, it is possible to efficiently detect or estimate a place where a decoding error occurs. It becomes possible.

  Further, in the second embodiment, since only the number of clips of the current block needs to be detected, the processing load can be reduced compared to the first embodiment.

  The decoding error detection / estimation device 10 or the video decoding device 1 in each of the above embodiments can be configured by a computer, and a program for causing each processing unit of the decoding error detection / estimation device 10 or the video decoding device 1 to function Can be suitably used. Specifically, a control unit for controlling each processing unit of the decoding error detection and estimation apparatus 10 or the video decoding apparatus 1 can be configured by a central processing unit (CPU) in a computer, and each processing unit is operated. A storage unit for appropriately storing a program necessary for causing the program can be configured by at least one memory. That is, by causing such a computer to execute the program by the CPU, the functions possessed by the processing units of the decoding error detection / estimation device 10 or the video decoding device 1 can be realized. Furthermore, a program for realizing the function of each processing unit of the decoding error detection / estimation device 10 or the video decoding device 1 can be stored in a predetermined area of the storage unit (memory) described above. Such a storage unit can be configured by a RAM or ROM inside the device, or can also be configured by an external storage device (for example, a hard disk). Also, such a program can be configured as part of software (stored in a ROM or an external storage device) on an OS used by a computer. Furthermore, a program for causing such a computer to function as each processing unit of the decoding error detection / estimation device 10 or the video decoding device 1 can be recorded on a computer readable recording medium. Also, each processing unit of the decoding error detection / estimation device 10 or the video decoding device 1 can be configured as a part of hardware or software, and can be realized in combination.

  Although the present invention has been described above by taking the example of the specific embodiment, the present invention is not limited to the example of the above embodiment, and various modifications can be made without departing from the technical concept thereof. For example, in the example of the embodiment described above, although a specific determination criterion is illustrated and described, various modified examples are conceivable, such as using a root mean square. Accordingly, the transmission device and the reception device according to the present invention are not limited to the examples of the embodiments described above, but are limited only by the claims.

  According to the present invention, a decoding error generated when decoding a coded video stream can be efficiently detected or estimated, which is useful for applications of a video coding method that requires error concealment.

DESCRIPTION OF SYMBOLS 1 video decoding apparatus 10 decoding error detection / estimation apparatus 11 decoding processing unit 12 complementing unit 101 target decoding area extracting unit 102 block dividing unit 103 clip number detecting unit 104 clip memory 105 decoding error judging unit 105a, 105b clip number comparing unit

Claims (8)

A decoding error detection and estimation apparatus that detects or estimates a decoding error that occurs when decoding a coded video stream, comprising:
The number of clips for detecting the number of clips in the decoding error judgment block of the block size which is previously set in order to input the decoding area obtained by decoding the encoded video stream and to make a decoding error judgment on the input decoding area Detection means;
The number of clips of the current block constituting the detected decoding error determination block is compared with the number of clips of the past block at the same block position as the current block in the predetermined comparison target past frame, according to a predetermined determination criterion Decoding error judgment means for judging whether the current block has a decoding error and generating a decoding error judgment signal indicating presence or absence of a decoding error;
A decoding error detection and estimation apparatus comprising:   The decoding error judging means judges that there is a decoding error when it is judged that the number of clips of the current block is increased by a predetermined amount from the number of clips of the past block as the predetermined judgment standard. The decoding error detection estimation apparatus according to claim 1.   3. The decode error detection method according to claim 1, wherein the decode error determination unit sets, as a comparison target, a past frame that has been decoded immediately before in the decoding order as the predetermined comparison target past frame. Estimator. A decoding error detection and estimation apparatus that detects or estimates a decoding error that occurs when decoding a coded video stream, comprising:
The number of clips for detecting the number of clips in the decoding error judgment block of the block size which is previously set in order to input the decoding area obtained by decoding the encoded video stream and to make a decoding error judgment on the input decoding area Detection means;
The number of clips in the current block making up the detected decoding error determination block is compared with a predetermined value determined in advance, and it is determined whether the current block has a decoding error according to a predetermined determination criterion. Decoding error judging means for generating a decoding error judgment signal indicating presence or absence;
A decoding error detection and estimation apparatus comprising:   The decoding error determination means compares the specified value with the number of clips of the current block as the predetermined determination reference, and determines that the number of clips of the current block is increased by a predetermined amount from the specified value. 5. The decoding error detection and estimation apparatus according to claim 4, wherein it is determined that there is a decoding error, in the case where it is detected.   The decoding error detection estimation according to any one of claims 1 to 5, wherein the decoding error judgment means compares and judges the ratio of the number of clips to the number of pixels in the decoding error judgment block. apparatus. A decoding error detection and estimation apparatus according to any one of claims 1 to 6,
Complementing means for generating a video stream subjected to error concealment by complementing the corresponding decoding area based on the decoding error determination signal obtained from the decoding error detection and estimation device;
A video decoding apparatus comprising:   A program for causing a computer to function as the decoding error detection and estimation device according to any one of claims 1 to 6 or the video decoding device according to claim 7.