JP2007067842A - Apparatus and method for editing moving image coding data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extract coding data with intra-picture other than the IDR picture defined as the editing point. <P>SOLUTION: The coding data are inputted from an HDD101 to a coding data extracting unit 102 and a reordering information generating unit 104; and the coding data extracting unit 102 extracts the coding data after the editing point from the coding data, and outputs the same data to a header information changing unit 103 in accordance with designation by external users or the like. The header information changing unit 103 changes the header information of the leading picture of the coding data thereof to that indicating that the information is the IDR picture, and also changes and outputs the header information between the editing point and the next IDR picture. A reordering information generating unit 104 generates the reordering information on the basis of the maximum storing quantity of the reference pictures of the coding data, and a reordering information inserting unit 105 outputs the reordering information by inserting the same information into the header changing and coding data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a moving image encoded data editing apparatus and a moving image encoded data editing method for extracting encoded data obtained by encoding a moving image signal in units of pictures.

  In recent years, MPEG2 and MPEG4 systems have been used as high-efficiency encoding methods for moving images. In these encoding methods, first, digital image data corresponding to one screen is divided into blocks made up of several pixels, a motion vector indicating motion between images is detected for each block, and a predicted image called motion compensation is generated. And encoding is performed on the difference value between the obtained predicted image and the encoded reference picture.

  Pictures are divided into several types according to the method of generating a predicted image. A picture that does not have a reference picture and uses only prediction within the screen is called an I picture, and a picture that performs inter-picture prediction coding using one reference picture is called a P picture, and uses two reference pictures. A picture that performs inter-screen predictive coding is called a B picture.

  18A and 18B are diagrams for explaining an encoding method in the conventional MPEG-2 encoding. FIG. 18A shows the arrangement of frames at the time of display, and FIG. 18B shows the arrangement of frames at the time of encoding. FIG. In FIG. 18, an I picture I2 is encoded without using a reference image. Since the P picture is predicted using the immediately preceding I picture or P picture, for example, the P picture P5 is encoded using the immediately preceding I picture I2. The B picture is predicted using the immediately preceding I picture or P picture and the immediately following I picture or P picture. For example, the B picture B3 includes the immediately preceding I picture I2 and the immediately following P picture. It is encoded using the picture P5.

  In encoding using inter-picture predictive encoding, since reference image data needs to be encoded first, encoding is performed after rearranging pictures. That is, as shown in FIG. 18B, for example, the B picture B3 is subjected to predictive coding using the immediately following P picture P5, so the P picture P5 is coded before the B picture B3.

  Also, in MPEG-2 encoding, a hierarchy called a group of pictures (GOP) in which a plurality of pictures are grouped is defined, and this is used as a basic unit of encoding processing to implement editing and random access of encoded data. Yes. For example, in the case of the GOP shown in FIG. 18A, the GOP structure starts with a B picture. However, since the first B picture is also predicted from the P picture of the previous GOP, it is cut out in units of GOPs. I can't. Therefore, a configuration in which the prediction from the previous GOP is excluded can be adopted. This is called a closed GOP.

  FIGS. 19A and 19B illustrate an encoding method in the case of a closed GOP. FIG. 19A shows the arrangement of frames at the time of display, and FIG. 19B shows the arrangement of frames at the time of encoding. For example, as shown in FIG. 19A, the I-picture is arranged at the head of the GOP in the frame arrangement at the time of display, and the prediction is completed in units of GOP as shown in FIG. The GOP pictures are not used for prediction.

  On the other hand, in H.264 currently being standardized by the ITU, a reference picture can be selected from a plurality of candidates called a reference picture list and used, so it is possible to refer to a picture that is arbitrarily distant. ing.

  20 is a diagram for explaining an encoding method in H.264.

  For example, the P picture P6 can refer to an I picture IDR (instantaneous Decorder Refresh) 0 that is farther away than the immediately preceding P picture P3. Also, the B picture can refer to the P picture P6 which is a picture separated in time like B1, and two pictures (P3, P6) located later in time like the B picture B2 ) Or a B picture such as a B picture B5 can be used as a reference image. Note that an IDR (instantaneous decorder refresh) picture is a special I picture that indicates that subsequent pictures can be correctly decoded without using information of pictures (slices) before that picture. The previous picture cannot be referenced across pictures. Therefore, in FIG. 20, it is not possible to refer to pictures before IDR0.

  As described above, in H.264, it is possible to refer to an arbitrarily distant picture, so that the decoded image is managed in a buffer called a decoded picture buffer (DPB).

  FIG. 21 is a conceptual diagram illustrating DPB management in H.264.

  The DPB stores the decoded output waiting picture and the referenced picture. Each picture is assigned a number representing a display order called a picture order count (POC). Also, a number called a frame number (FN) is assigned to the referenced picture. FN is a number that increases by 1 in the coding order, that is, in the order of referenced pictures.

  A picture stored in the DPB is marked as either “used as reference” (hereinafter referred to as “used”) or “unused as a reference image” (hereinafter referred to as “unused”). The Further, it is marked as either “waiting for output” (hereinafter referred to as “needed”) or “not needed to output” (hereinafter referred to as “not needed”).

  When the current picture to be decoded (current picture) is P6 in the encoding order shown in FIG. 20B, the first and second recording areas of the DPB have POC as shown in FIG. IDR0 in which “FN”, “used” or “unused”, “needed” or “not needed” is set, and P3 are stored, and the third recording area is empty.

  FIG. 22 is a diagram illustrating POC and FN given to a picture.

  When a picture that is not referred to by other pictures, such as a B picture, is entered, for example, in the arrangement of P, B, B, P, FN becomes N, N + 1, N + 1, N + 1. The FN is 0, 1, 2, 3, 3, 3, 4, 4, 5, 5.

Next, DPB processing after decoding will be described with reference to FIG. Here, it is assumed that the upper limit (MaxDPB) of the number of DPB frames is 3, and the maximum number of stored reference pictures (no_of_ref) is 3. FIG. 23A shows the state of DPB after decoding P6 in FIG. Since IDR0, P3, and P6 stored in the DPB are all referenced pictures, they are marked as used. Further, since P3 and P6 are waiting for output, they are marked as needed, but since IDR0 has already been output, it is marked as not needed. Next, B1 is decoded. Since B1 is not a referenced picture, it is marked as unused.

  Next, the POC of the picture stored in the DPB is compared with the POC of the picture B1, and since the POC of B1 is minimum, the picture B1 is output. In this case, the picture B1 does not need to be stored in the DPB. The same applies to B2. Therefore, the state of the DPB after decoding B2 remains as shown in FIG.

  Next, B4 is decoded. B4 is a B picture, but is marked as unsed because it is a referenced picture. Here, since the number of reference pictures marked as used is four and exceeds no_of_ref, the picture with the smallest FN is set to unused. That is, IDR0 is marked as unused. As a result, unused and not needed pictures are unnecessary in the subsequent decoding process, and are therefore deleted from the DPB. That is, IDR0 is deleted from the DPB, and B4 is stored in the DPB.

  FIG. 23B shows the state of the DPB after B4 decoding.

  Next to B4, B5 is decoded. Since B5 is not a referenced picture, it is marked as unused. Next, the POC of the picture stored in the DPB is compared with the POC of the picture B5. Since the POC of the B5 is not minimum, it is marked as need and stored in the DPB. However, since the DPB is already full, the picture with the smallest POC is output and is not needed. That is, P3 is output as not needed, but P3 is marked as used and cannot be deleted from the DPB. Therefore, a picture with the smallest POC is output. In this case, B4 is applicable, but B4 is also used and cannot be deleted. Therefore, B5 is further output and set as not needed. As a result, B5 becomes unused and not needed, and is deleted without being stored in the DPB.

  FIG. 23 (c) shows the state of the DPB after coding at B5.

  In H.264, regarding the above-described used or unused mark processing, by adding information called a memory management control operation (MMCO) command, a picture marked as used in the DPB can be changed. It can also be unused.

  When an IDR picture that is a special intra picture is decoded, all the images in the DPB are marked as unused, and all the images are output and deleted in the POC order (the output of the image is determined by the information in the encoded data). It is also possible not to do this). Therefore, it is not possible to refer to the previous image across IDR pictures. In the IDR picture, POC and FN are reset to zero. In H.264, the first picture of the encoded data must be an IDR picture.

  Also, when a specific command is added using the MMCO command, all the images in the DPB are unused, and all the images in the DPB are output in the POC order and are all deleted.

  Next, the reference picture list will be described. The reference picture list is a list in which the pictures marked as used among the pictures stored in the DPB are arranged in order. A reference picture is designated by adding information indicating what number of picture in the list to each macroblock (MB) or sub-MB.

  In the P picture, DPB pictures are arranged in ascending order of picture number (PN). Here, PN is a field picture based on FN, and is equivalent to FN in a frame picture. For example, in FIG. 22, the DPB state when decoding P9 is the state shown in FIG. 23C, so the reference picture list is “P3, P6, B4”.

  In the B picture, two reference picture lists are used. One is a picture in which the POC is smaller than the picture to be decoded in order of increasing POC, and the picture in which the POC is larger than the picture to be decoded is arranged in order of increasing POC. The other is a picture in which the POC larger than the picture to be decoded is arranged in the order of increasing POC, and the picture having a smaller POC than the picture to be decoded is arranged in the order of increasing POC. For example, when B5 is decoded in FIG. 22, the DPB is in the state shown in FIG. 23B, so that the first list is “B4, P3, P6” and the second list is “P6, B4, P3 ".

  As described above, in the MPEG-2 encoding method, in a GOP that is not a closed GOP, the first B picture is predicted from the P picture of the previous GOP, and therefore cannot be cut out in GOP units. Similarly, also in H.264, in an intra picture that is not an IDR picture, a subsequent image can refer to a previous image across the intra picture, and thus encoded data cannot be cut out.

  Therefore, in order to solve this problem, for example, in Patent Document 1, when encoded data that is not a closed GOP is connected in the MPEG-2 encoding method, the first B picture of the GOP is deleted.

  Also, Patent Document 2 discloses a method of re-encoding by replacing the first B picture of a GOP with the immediately preceding picture when encoded data that is not a closed GOP is connected in the MPEG-2 encoding system. .

Further, in Patent Document 3, in the H.264 encoding method, when a POC discontinuity occurs due to editing with a picture other than an IDR picture, a flag indicating this is stored as additional information, and from the flag during reproduction, A technique for specifying an edit point and managing the DPB so that inconsistency does not occur is disclosed.
Japanese Patent Laid-Open No. 10-66085 JP 2000-295567 A JP 2004-274732 A

  However, in the conventional method, the first B picture of the GOP is deleted. However, in the H.264 encoding method, since the B picture can also be a referenced image, if the B picture is deleted, the subsequent encoding is inconsistent. There is a problem that may occur.

  In the method of re-encoding by replacing the previous picture, the encoded data editing apparatus needs to have a re-encoding circuit. However, in the H.264 method, the encoding method is complicated and the circuit is increased. There is also a problem that it may lead to a significant increase.

  Further, in the technique disclosed in Patent Document 3 described above, a flag indicating inconsistency caused by editing is used, but it is necessary to perform a specific operation using the flag at the time of decoding, and it is said that it lacks versatility. There is also a problem.

  Therefore, the present invention has been made paying attention to the above points, and provides a moving image encoded data editing apparatus and a moving image encoded data editing method capable of cutting out encoded data at an arbitrary editing point. With the goal.

  In order to achieve the above object, an image encoded data editing apparatus according to the present invention is a moving image encoded data editing apparatus that extracts encoded data obtained by encoding a moving image signal in units of pictures at arbitrary editing points. An encoded data extraction unit for extracting encoded data after the edit point from the encoded data, and header information for changing the header information of the encoded data after the edit point to the content starting from the edit point And a changing unit.

  In the image encoded data editing apparatus of the present invention, the encoded data after the editing point is extracted from the encoded data, and the header information of the encoded data after the editing point is changed to the content starting from the editing point. The encoded data can be cut out at the edit point.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1

  FIG. 1 is a block diagram showing Embodiment 1 of the encoded data editing apparatus of the present invention. The operation of the encoded data editing apparatus according to the first embodiment, that is, the encoded data editing processing method will be described below with reference to FIG.

  In FIG. 1, the encoded data editing apparatus according to the first embodiment includes an HDD 101, an encoded data extraction unit 102, a header information change unit 103, a reordering information creation unit 104, and a reordering information insertion unit 105. .

  Next, an outline of the operation will be described.

  The encoded data stored in the HDD 101 is, for example, ITU-T H.264. It is encoded by the H.264 encoding method, and is input to the encoded data extraction unit 102 and the reordering information creation unit 104. Here, it is assumed that the encoded data is stored in the HDD 101, but other media may be used.

  The encoded data extraction unit 102 extracts encoded data after the edit point from the encoded data extracted from the HDD 101 according to the edit point (cutout point) and cutout length specified by an external user or the like, The extracted encoded data is output to the header information changing unit 103. Note that edit points (cutout points) designated by the user or the like from the outside are input not only to the encoded data extraction unit 102 but also to the header information change unit 103, the reordering information creation unit 104, and the reordering information insertion unit 105. is doing. The same applies to other embodiments described later.

  Then, the header information changing unit 103 changes the header of the leading intra picture of the extracted encoded data input from the encoded data extracting unit 102 to indicate that it is an IDR picture, as will be described later. The header information POC information and FN information from the editing point to the next IDR picture are changed and output as header change encoded data.

  The reordering information creation unit 104 creates reordering information based on the maximum number of reference pictures stored in the encoded data input from the HDD 101. The maximum number of stored reference pictures of encoded data is described in a sequence parameter set (SPS) that is added to or transmitted in advance at the beginning of the encoded data of the entire sequence, and for each slice unit of the encoded data. Is selected as an adaptive parameter set.

  The reordering information insertion unit 105 adds the reordering information to the header change encoded data input from the header information change unit 103, and outputs it as edited encoded data.

  Next, details of the operation will be described.

  FIG. 2 is an example of encoded data input to the encoded data editing apparatus according to the first embodiment.

  FIG. 2 shows a part of the encoded data, and it is assumed that the encoded data exists before and after this. The same applies to other embodiments described later. Also, the POC of the encoded data shown in FIG. 2 is as shown in FIG. 2, and the editing point is the intra picture I6. In FIG. 2, arrows indicate the relationship of pictures to be predicted.

  The encoded data extraction unit 103 extracts encoded data after the edit point from the encoded data from the HDD 101 in accordance with an edit point (cutout point) designated from the outside and a cutout length. In addition, information related to the entire encoded data such as a sequence, a parameter set, and the like is simultaneously extracted from the encoded data before the editing point. Here, the edit point and the length are designated from the outside. Of course, the encoded data editing apparatus itself may be provided with a device that can designate the edit point, and the designation may be performed using the device.

  FIG. 3 is a diagram illustrating an example of encoded data extracted by the encoded data extraction unit 102.

  Note that the encoded data shown in FIG. 3 shows only the head portion of the extracted encoded data, and does not describe a sequence parameter set or the like. Of course, the encoded data may continue after this. This also applies to other embodiments described later.

  The header information changing unit 103 changes the header information of the encoded data as shown in FIG. 3 extracted by the encoded data extracting unit 102.

  FIG. 4 is a flowchart showing the flow of the header information changing process in the header information changing unit 103.

  First, in S401, the header information changing unit 103 changes information indicating whether or not the picture is an IDR picture in the header information to information indicating that the picture is an IDR picture.

  Next, the header information changing unit 103 adds information added only to the IDR picture, such as an ID assigned to the IDR picture, in S402.

  Next, the header information changing unit 103 calculates a difference value from the POC and FN of the extracted encoded stream in S403. Note that the POC and FN of the extracted encoded stream extracted by the encoded data extraction unit 102 are as shown in FIG.

  Then, in S404, the header information changing unit 103 sets the first picture of the encoded stream after editing to the IDR picture, so that the FN and POC of the first picture are reset to 0 and other extracted encodings following the first picture The POC and FN of the data picture are changed. At this time, since the values of POC and FN of the first picture become a difference value, the change is made by subtracting the values of POC and FN of the first picture from the values of POC and FN of the pictures of other extracted encoded data. Do. This change is repeated from the first picture of the extracted encoded data to the picture before the next IDR picture.

  FIG. 5 shows the picture type and POC and FN of the header change encoded data in which the header information is changed in this way.

  As apparent from comparing the POC and FN of the encoded data after the header information change shown in FIG. 5 with the POC and FN of the encoded data before the header information change shown in FIG. 3, the picture type of the I picture I6 at the editing point Is changed to an IDR picture type of IDR0, the FN and POC are reset to 0, and the POC and FN of the picture following IDR0 are relatively changed in response to the reset of the FN and POC of the I picture I6, that is, I The POC value 6 and the FN value 3 of the picture I6 are respectively subtracted.

  Next, reordering information creation processing in the reordering information creation unit 104 will be described.

  FIG. 6 is a diagram showing the state of the DPB after decoding the first picture IDR0 of the header change encoded data shown in FIG.

  Here, it is assumed that the upper limit (MAX DPB) of the number of DPB frames (pictures) is, for example, 2 frames (pictures), and the maximum number of reference pictures stored (no_of_ref) is, for example, 2 frames (pictures). Thus, immediately after the decoding of the IDR0 picture, only the IDR0 picture is stored in the DPB. Therefore, even if the above-described reference picture list is created, there is only one picture in the reference picture list.

  FIG. 7 shows an example of the reference picture list MP used when decoding B5 which is the next picture of IDR0. In this case, as shown in FIG. 6, since only the IDR0 picture is stored in the DPB, in the reference picture list MP, idx0 is set to IDR0 and idx1 is set to NONE (none). Note that, when decoding a B picture, two reference picture lists MP are used, but only one of them will be described here.

  The reference picture list can be rearranged by sending reordering information in the slice header added for each slice. If reordering information is used, it is possible to include a plurality of the same pictures in the reference picture list.

  On the other hand, in the encoded data before clipping shown in FIG. 2, the DPB state after decoding the I6 picture is as shown in FIG.

  FIG. 8 is a diagram showing that P4 and I6 are stored in the DPB, and both are marked as used and needed.

  Thus, in the state of the DPB before being cut out as shown in FIG. 2, there are two pictures marked as used as shown in FIG. 8, so that the reference picture list MP used when decoding B5 is included in the reference picture list MP. As shown in FIG. 9, there are two pictures I6 and P4 as idx0 and idx1, respectively.

  Therefore, there is a possibility that the second picture in the reference picture list may be designated as the reference picture. However, if the DPB is in the state shown in FIG. 6 and the reference picture list as shown in FIG. In the encoded data, since only one picture exists in the reference picture list, inconsistency occurs.

  Therefore, the reordering information creation unit 104 according to the first embodiment encodes the code so that the number of pictures in the reference picture list of the encoded data after the editing point is the same as the maximum number of stored reference pictures (no_of_ref). The reordering information is created so that the picture temporally closest to the picture B5 to be converted is inserted into a free space in the reference picture list. At that time, the reordering information creation unit 104 may of course create the reordering information so as to insert the intra picture that is the editing point, or it is included in the reference picture list. Of course, the reordering information may be created so that the picture is copied and inserted into the reference picture list.

  FIG. 10 shows a reference picture list at the time of decoding when such reordering information is received.

  In this case, since the picture temporally closest to the picture B5 to be encoded is IDR0, as shown in FIG. 7, by cutting out at an arbitrary reference point of the encoded data, NONE ( If no) is set, the reordering information creation unit 104 of the first embodiment sets IDR0 as idx1.

  Therefore, the reordering information creation unit 104 according to the first embodiment encodes NONE (None) even if NONE (None) is set in the reference picture list by clipping the encoded data at an arbitrary reference point. By creating reordering information in which the temporally closest picture is added to the power picture B5, even when the second picture in the reference picture list is designated as the reference picture during decoding, the number of reference pictures is insufficient. It is possible to prevent the occurrence of inconsistencies.

  Since the DPB is reset when the next IDR picture comes, the reordering information creation unit 104 checks the state of the DPB from the editing point to the next IDR picture, and refers to the referenced picture in the DPB. Similarly, reordering information is added to a picture whose number is less than the maximum number of stored reference pictures (no_of_ref).

  The reordering information created by the reordering information creation unit 104 is output to the ordering information insertion unit 105, and the reordering information insertion unit 105 encodes the edit points after the editing point where the header information is changed by the header information change unit 103. Insert reordering information into the data.

  FIG. 11 shows an example of edited encoded data output from the reordering information insertion unit 105 according to the first embodiment.

  The reordering information insertion unit 105 according to the first embodiment inserts reordering information in the slice header of slice data in each picture of encoded data after the editing point whose header information has been changed by the header information change unit 103. To do.

  As described above, according to the encoded data editing apparatus of the first embodiment, the encoded data after the edit point to be edited such as extraction of the encoded data is extracted, and the header information of the encoded data after the edit point is extracted. Is changed to the content having the edit point as the head, so that the encoded data can be cut out at an arbitrary edit point.

  In particular, in the first embodiment, H.264 is used. The number of referenced images stored in the DPB after editing the encoded data encoded by the H.264 encoding method is compared with the maximum number of stored reference pictures (no_of_ref). If the number is small, reordering information is inserted to instruct that the intra picture as the editing point is added to the reference picture list until the maximum number of pictures in the reference picture list is stored. Since the header information of the picture is rewritten to that of the IDR picture, it is possible to compensate for the missing reference picture in the DPB even when the encoded data cut out with any intra picture other than the IDR picture is decoded. Intra-pictures other than IDR pictures while preventing quality degradation of the decoded image due to missing reference pictures It is possible to cut out the encoded data catcher as an editing point.

  In the first embodiment, the description has been given without providing an encoded data connection unit that connects the edited encoded data in which the reordering information is inserted by the reordering information insertion unit 105 to other encoded data. Similar to the encoded data connection unit 207 of the second embodiment (see FIG. 11) described below, the encoded data connection unit 207 converts the edited encoded data into which the reordering information has been inserted into other encoded data. Of course, it may be made to connect to.

Embodiment 2. FIG.
FIG. 12 is a block diagram showing a configuration example of Embodiment 2 of the encoded data editing apparatus of the present invention. Note that in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 12, the encoded data editing apparatus according to the second embodiment includes an HDD 101, an encoded data extraction unit 102, a header information change unit 203, a reordering information creation unit 104, a reordering information insertion unit 105, and an MMCO information insertion unit 206. The encoded data connection unit 207 is configured.

  Next, an outline of the operation will be described.

  The encoded data stored in the HDD 101 is input to the encoded data extraction unit 102, the reordering information creation unit 104, and the MMCO information insertion unit 206. Here, it is assumed that the encoded data is stored in the HDD 101, but other media may be used. In the second embodiment, since a plurality of encoded data are connected, a plurality of encoded data are input from the HDD 101. Here, the encoded data for cutting out the encoded data is referred to as connection encoded data, and the encoded data connecting the encoded data is referred to as connected encoded data. Note that the encoded data input to the encoded data editing apparatus according to the second embodiment is an encoded bit stream as shown in FIG. 2 as described in the first embodiment.

  The encoded data extraction unit 102 extracts the encoded data after the edit point from the connection encoded data according to the edit point (cutout point) designated from the outside and the cutout length, as in the first embodiment. And output to the header information changing unit 203 as extracted encoded data. Note that edit points (cutout points) designated by the user or the like from the outside or the inside are not only the encoded data extraction unit 102 but also the header information change unit 203 and the reordering information creation unit 104 as in the first embodiment. On the other hand, in the case of the second embodiment, the encoded data connecting unit 207 is connected to the connection partner of the encoded data cut out at the edit point. The reordering information inserting unit 105 and the MMCO information inserting unit 206 The information specifying the connected encoded data is specified by the user or the like from the outside or the inside. In addition, information related to the entire encoded data such as a sequence, a parameter set, and the like is simultaneously extracted from the encoded data before the editing point. Here, the edit point and length are designated from the outside. Of course, it is also possible to provide a device that can designate an edit point in the encoded data editing device, and use that to designate the edit point. In the second embodiment, it is assumed that the editing point is an intra picture I6. Note that the encoded data extraction unit 103 according to the second embodiment also extracts encoded data as shown in FIG. 3 as in the first embodiment.

  The header information changing unit 203 changes the POC information and FN information of the header information from the editing point of the input extracted encoded data to the next IDR picture as described later, and re-records the header changed encoded data as header changed encoded data. Output to the ordering information creation unit 104.

  Similar to the first embodiment, the reordering information creation unit 104 creates reordering information based on the maximum number of reference pictures stored at the editing point of the encoded data input from the HDD 101. The reordering information insertion unit 105 adds the reordering information to the encoded data after the header information change input from the header information change unit 203 and outputs it to the MMCO information insertion unit 206.

  The MMCO information insertion unit 206 inserts MMCO information (hereinafter referred to as a reset MMCO command) instructing DPB resetting into the header portion of the picture at the editing point to which the reordering information insertion unit 105 has added the reordering information. , Output to the encoded data connection unit 207 as MMCO insertion data.

  The encoded data connection unit 207 displays the connection encoded data after the edit point in which the MMCO information is inserted in the header part of the picture connection of the edit point after the connected data specified by an external or internal instruction. Connected and output as edited encoded data to a decoding device or a recording device such as the HDD 101 again.

  Next, main operations in the encoded data editing apparatus according to the second embodiment will be described in detail.

  FIG. 13 is a flowchart showing the flow of the header information changing process by the header information changing unit 203 of the second embodiment.

  First, the header information changing unit 203 calculates the difference value from the POC and FN of the extracted encoded stream extracted by the encoded data extracting unit 102 in S401. The POC and FN of the extracted encoded stream are as shown in FIG. 3, and the encoded data after editing has an MMCO reset command added to the header portion of the picture at the editing point. The FN and POC of the picture, that is, the first picture of the connection encoded data are reset to zero. That is, the POC and FN of the first picture of the extracted encoded data are the difference values.

  Next, the header information changing unit 203 changes the FN and POC using this difference value in S402. This change is repeated from the first picture of the extracted encoded data to the picture before the next IDR picture.

  FIG. 14 is a diagram showing the picture type, POC, and FN of the header change encoded data according to the second embodiment.

  As apparent from comparison with the encoded data POC and FN before the header information shown in FIG. 3 is changed, the FN and POC of the I picture I6 are reset to 0, respectively, and the POC and FN of the picture following the I picture I6 are reset. Also, the I picture I6 is relatively changed according to the reset of the FN and POC. That is, the difference between the header information according to Embodiment 1 shown in FIG. 5 and the encoded data after change is that the picture I6 is not changed to the picture IDR0.

  FIG. 15 is a diagram showing the state of the DPB after decoding the first picture I6 of the header change encoded data shown in FIG.

  Here, it is assumed that the upper limit (MaxDPB) of the number of DPB frames is 2, and the maximum number of stored reference pictures (no_of_ref) is 2. In this way, immediately after decoding the next picture after the picture to which the MMCO reset command is added, only the picture is stored in the DPB. Therefore, even if the above-described reference picture list is created, there is only one picture in the DPB. 6 is different from FIG. 6 in that the picture I6 is not changed to the picture IDR0.

  Then, also in the second embodiment, the reference picture list used when decoding B5, which is the next picture of picture I6, is as shown in FIG. 7, as in the first embodiment.

  On the other hand, in the encoded data before clipping shown in FIG. 2, the state of DPB after decoding picture I6 is as shown in FIG. 8, as in the first embodiment.

  FIG. 8 is a diagram showing that P4 and I6 are stored in the DPB, and both are marked as used and needed. As shown in FIG. 8, in the state of the DPB before being cut out, there are two pictures marked as used. Therefore, the reference picture list used when decoding B5 has two pictures as shown in FIG. There are pictures. Therefore, there is a possibility that the second picture in the reference picture list is designated as the reference picture. However, as described above, in the header change encoded data, only one picture exists in the reference picture list. Will occur.

  Therefore, as in the first embodiment, the reordering information creation unit 104 makes the number of pictures in the reference picture list of the encoded data after the editing point equal to the maximum number of stored reference pictures (no_of_ref). Then, reordering information is created so that the picture temporally closest to the picture B5 to be encoded is inserted into the empty space in the reference picture list, and output to the reordering information insertion unit 105. At that time, the reordering information creation unit 104 may create the reordering information so as to insert an intra picture as an edit point, as in the first embodiment, or may be posted in the reference picture list. For example, the reordering information may of course be created so that the first picture is copied and inserted into the empty reference picture list.

  The reordering information insertion unit 105 uses the reordering information created by the reordering information creation unit 104 as the first picture of the encoded data after the editing point whose header information has been changed by the header information change unit 203 as described above, That is, it is inserted into the header information of the picture at the edit point and output to the MMCO information insertion unit 206.

  Accordingly, also in the second embodiment, the reference picture list at the time of decoding when such reordering information is received is as shown in FIG. 10 as in the first embodiment, and thus reordering is performed in this way. By adding information, it is possible to prevent the occurrence of inconsistency that the number of pictures in the reference picture list becomes insufficient even when the second picture of the reference picture is designated as the reference picture.

  Therefore, since the DPB is reset when the next IDR picture comes, the reordering information creation unit 104 checks the state of the DPB from the editing point to the next IDR picture, and the referenced picture in the DPB. Similarly, reordering information is added to a picture whose number is less than the maximum number of stored reference pictures (no_of_ref).

  On the other hand, the MMCO information insertion unit 206 sends MMCO information (hereinafter referred to as a reset MMCO command) instructing DPB resetting to the header portion of the picture at the edit point where the reordering information is inserted by the reordering information insertion unit 105. The data is inserted and output to the encoded data connection unit 207 as MMCO insertion data.

  The encoded data connecting unit 207 connects the encoded data after the editing point in which the MMCO command is inserted by the MMCO information inserting unit 206 into the header part of the picture of the connected editing point, and is connected to the encoded data designated from inside or outside. Connected after the last picture of the data, it is output as edited encoded data to a decoding device (not shown), the HDD 101 or the like. As a result, in a decoding apparatus (not shown) or the like, after decoding the picture B18, when decoding the MMCO command in the header part of the picture at the editing point, all the pictures in the DPB are marked as unused and then deleted. (Reset), and then the encoded data after the editing point is decoded.

  FIG. 16 is a diagram illustrating an example of connected encoded data.

  The example of the connected encoded data shown in FIG. 16 shows only the last part of the connected encoded data, and the connected encoded data exists before this. In this case, the connection encoded data after the editing point is connected to the last picture B18 of the connected encoded data by the encoded data connection unit 207.

  FIG. 17 shows an example of edited encoded data output from the encoded data editing apparatus according to the second embodiment.

  That is, in the second embodiment, the reordering information insertion unit 105 performs reordering information in the slice header of the slice data in each picture of the encoded data after the editing point whose header information has been changed by the header information change unit 103. The reordering information created by the creation unit 104 and the MMCO information inserted by the MMCO information insertion unit 106 are inserted.

  As described above, according to the encoded data editing apparatus of the second embodiment, the encoded data after the editing point for performing editing such as extraction of the encoded data is extracted, and the header information of the encoded data after the editing point is extracted. Is changed to the content starting from the edit point, so that the encoded data can be cut out at an arbitrary edit point.

  In particular, in the second embodiment, H.264 is used. The number of referenced images stored in the DPB after editing the encoded data encoded by the H.264 encoding method is compared with the maximum number of stored reference pictures (no_of_ref). If the number is small, reordering information is inserted to instruct that the intra picture as the editing point is added to the reference picture list until the number of pictures in the reference picture list reaches the maximum number of stored pictures. Since the MMCO command information for instructing resetting of the DPB that outputs all the images in the DPB as being unreferenceable is added to the last picture of the encoded data, as in the first embodiment, any other than the IDR picture Even when encoded data cut out with an intra picture is decoded, it is possible to compensate for the missing reference picture in the DPB. , While achieving prevention of quality deterioration of the decoded image due to lack of a reference picture is cut out encoded data an intra-picture other than the IDR picture as an editing point, it is possible to connect to other coded data.

  In the second embodiment, the encoded data connection unit 207 is provided. However, the present invention is not limited to this, and the encoded data connection unit 207 is not provided as in the first embodiment. Of course, it is only necessary to cut out and output the encoded data at an arbitrary editing point.

  Further, in the second embodiment, the MMCO information insertion unit 26 inserts MMCO information into the header portion of the picture at the editing point where the reordering information insertion unit 105 has inserted the reordering information, and encodes the data as MMCO insertion data. Although the output to the data connection unit 207 has been described, the present invention is not limited to this. For example, the reordering information and the insertion timing of the MMCO insertion data are reversed. Of course, the reordering information insertion unit 105 may insert the reordering information from the reordering information creation unit 104 after inserting the MMCO information.

  In the first and second embodiments, the ITU-T H. The encoded data encoded by the H.264 encoding method has been described as the object of editing (cutting out), but the present invention is not limited to this, and the encoded data encoded by another encoding method is the target. Of course.

It is a block diagram which shows Embodiment 1 of the encoded data editing apparatus of this invention. 4 is an example of encoded data input to the encoded data editing apparatus according to Embodiment 1. It is a figure which shows the example of the encoding data extracted by the encoding data extraction part. It is a flowchart which shows the flow of the header information change process in a header information change part. It is a figure which shows the picture type and POC and FN of the header change coding data in which header information was changed. FIG. 6 is a diagram showing a state of a DPB after decoding the first picture IDR0 of the header change encoded data shown in FIG. It is a figure which shows an example of the reference picture list MP used when decoding B5 which is the next picture of IDR0. It is a figure which shows that P4 and I6 are stored in DPB, and both are marked used and needed. It is a figure which shows an example of the reference picture list MP used when decoding B5. It is a figure which shows an example of the reference picture list at the time of decoding when the reordering information by this Embodiment 1 is received. It is a figure which shows an example of the edited encoded data output from the reordering information insertion part 105 of this Embodiment 1. FIG. It is a block diagram which shows the structural example of Embodiment 2 of the encoded data editing apparatus of this invention. It is a flowchart which shows the flow of the header information change process by the header information change part of this Embodiment 2. It is a figure which shows the picture type and POC and FN of header change coding data by this Embodiment 2. FIG. It is a figure which shows the state of DPB after decoding the head picture I6 of the header change coding data shown in FIG. It is a figure which shows an example of to-be-connected encoded data. It is a figure which shows an example of the edited encoded data output from the encoded data editing apparatus of this Embodiment 2. It is a figure explaining the encoding method in the conventional MPEG-2 encoding, (a) is a sequence of the frame at the time of a display, (b) is a figure which shows the sequence of the frame at the time of an encoding. An encoding method in the case of a closed GOP will be described. (A) shows the arrangement of frames at the time of display, and (b) shows the arrangement of frames at the time of encoding. It is a figure explaining the encoding method in H.264. It is a conceptual diagram explaining management of DPB in H.264. It is a figure explaining POC and FN given to a picture. (A) is a diagram showing the state of DPB after decoding P6 in FIG. 22, (b) is a diagram showing the state of DPB after B4 decoding, and (c) is the state of DPB after coding at B5 FIG.

Explanation of symbols

101 HDD
102 Encoded data extraction unit 103, 203 Header information change unit 104 Reordering information creation unit 105 Reordering information insertion unit 206 MMCO information insertion unit 207 Encoded data connection unit

Claims (10)

A moving image encoded data editing apparatus that cuts out encoded data obtained by encoding a moving image signal in units of pictures at an arbitrary editing point,
An encoded data extraction unit for extracting encoded data after the editing point from the encoded data;
A header information change unit that changes the header information of the encoded data after the edit point to the content starting from the edit point;
A moving image encoded data editing apparatus. The arbitrary editing point is an intra picture between two IDR (Instantaneous Decoding Refresh) pictures.
The moving image encoded data editing apparatus according to claim 1, wherein: further,
A reordering information creating unit that creates reference picture reordering information according to the maximum number of reference pictures of the encoded data;
A reordering information insertion unit for inserting the reordering information into encoded data after the editing point in which the content of the header information is changed;
The moving image encoded data editing apparatus according to claim 1 or 2, further comprising: The header information change unit, when changing the header information of the encoded data after the edit point to the content starting from the edit point, information indicating the picture type in the header information of the picture at the edit point is an IDR picture Change to type,
The moving image encoded data editing apparatus according to claim 2 or 3, wherein Further, an MMCO information insertion unit for inserting MMCO information for instructing resetting of a decoding picture buffer into a picture at an edit point into which the reordering information has been inserted by the reordering information insertion unit,
4. The moving image encoded data editing apparatus according to claim 3, further comprising: The reordering information creation unit creates reordering information so that the number of reference pictures of encoded data after the editing point is the same as the maximum number of reference pictures recorded in the encoded data.
4. The moving image encoded data editing apparatus according to claim 3, wherein The reordering information creation unit sets a time for a picture to be encoded so that the number of reference pictures of encoded data after the editing point is the same as the maximum number of reference pictures stored in the encoded data. Create reordering information that adds the closest picture as a reference image,
7. The moving image encoded data editing apparatus according to claim 6, wherein The reordering information creation unit generates an intra picture at an edit point so that the number of reference pictures of encoded data after the edit point is the same as the maximum number of reference pictures stored in the encoded data. Create reordering information to be added as a reference image,
7. The moving image encoded data editing apparatus according to claim 6, wherein The reordering information creation unit is listed in the reference picture list so that the number of reference pictures of the encoded data after the editing point is the same as the maximum number of reference pictures recorded in the encoded data. Create reordering information to add the current picture as a reference image,
7. The moving image encoded data editing apparatus according to claim 6, wherein A moving image encoded data editing method for cutting out encoded data obtained by encoding a moving image signal in units of pictures at an arbitrary editing point,
Extracting encoded data after the edit point from the encoded data,
A moving image encoded data editing method, wherein header information of encoded data after the edit point is changed to contents starting from the edit point.

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