WO2012014458A1 - Image encoding method and image decoding method - Google Patents

Abstract

Disclosed is an image encoding method which is capable of improving the encoding efficiency of inter-prediction encoding and which uses at least one reference image to perform prediction encoding. When a picture type is included in first header information added to a bit stream for every first processing unit and the picture type indicates inter-encoding, the maximum number of reference picture lists, which manage reference images used in inter-prediction in the first processing unit, is included in the first header information as a first maximum number of reference picture lists.

Description

Image encoding method and image decoding method

The present invention relates to an image encoding device, an image decoding device, an image encoding method, an image decoding method, a program for causing a computer to execute these methods, and the like that perform predictive encoding of a moving image using a plurality of reference images. .

FIG. 1 is a block diagram showing an example of a conventional encoding device. 1, the inter prediction control unit controls the inter prediction unit according to the picture type determined by the picture type determination unit (for example, H.264 slice type), and performs inter prediction coding. Specifically, picture types such as I picture (for example, H.264 I slice or IDR slice), P picture (for example, H.264 P slice), B picture (for example, H.264 B slice), etc. Accordingly, the maximum number of reference picture lists (for example, H.264 reference picture list) for managing reference images used for inter coding of each prediction unit block is 0 (no inter coding), 1 ( For example, H.264 reference picture list 0 and 2 (for example, H.264 reference picture list 0 and 1) were switched. The picture type is the first header information (for example, H.264 slice header) added to the bit stream for each first processing unit (for example, H.264 slice), from the encoding device to the decoding device. Be notified. The reference picture list includes at least one index (for example, H.264 reference index) corresponding to a reference image to be referred to by inter prediction, and is referred to by inter prediction using the reference picture list and the index for each block. Specify the picture to be used.

FIG. 2A, FIG. 2B, FIG. 3A, and FIG. FIG. 2A and FIG. 3A each show a typical prediction reference relationship of an image sequence in display order and inter prediction, and FIG. 2B and FIG. 3B each are encoded using two reference picture lists. The concept of the prediction reference relationship between a target block and a reference block is shown. The prediction reference using the reference picture list 0 (1) in FIG. 2B and FIG. H.264 list 0 (list 1) prediction.

FIG. 4 is a block diagram showing an example of a decoding apparatus corresponding to the conventional encoding apparatus of FIG. In the decoding apparatus of FIG. 4, the inter prediction control unit controls the inter prediction unit according to the picture type added to the bitstream, and performs inter prediction decoding.

In the conventional coding apparatus and decoding apparatus, the maximum number of reference picture lists for managing reference pictures used for inter coding of each prediction unit block is set to 0 according to the picture type such as I picture, P picture, and B picture, respectively. Since the main (no inter-coding) has been switched to one, two, there is a problem that inter prediction coding cannot be performed using three or more reference picture lists. As a result, there is a problem that the prediction unit block cannot be appropriately predicted and encoded and decoded, and the encoding efficiency is lowered.

Therefore, the present invention has been made in view of such problems, and an object thereof is to provide an image encoding method and an image decoding method that can improve encoding efficiency.

In order to achieve the above object, an image encoding method according to the present invention is an image encoding method that performs predictive encoding using at least one reference image, and includes a bitstream for each first processing unit. When the first header information to be added includes a picture type and the picture type indicates inter coding, the maximum number of reference picture lists for managing reference pictures used for inter prediction in the first processing unit is set as follows: The first header information is included in the first header information as the first maximum reference picture list number.

With this configuration, it is possible to perform inter prediction encoding using three or more reference picture lists, and it is possible to improve the encoding efficiency of inter prediction encoding.

In order to achieve the above object, an image decoding method according to the present invention is an image decoding method for decoding a bitstream that has been predictively encoded using at least one reference image, the first processing unit When the picture type included in the first header information added to the bitstream every time indicates inter coding, the maximum number of reference picture lists for managing reference pictures used for inter prediction in the first processing unit The bit stream is decoded according to the number of first maximum reference picture lists included in the first header information.

With this configuration, it is possible to perform inter prediction using three or more reference picture lists, and it is possible to improve the coding efficiency of inter prediction coding on the image coding device side.

The present invention can be realized not only as such an image encoding method or image decoding method, but also according to an image encoding device, an image decoding device or an integrated circuit that performs processing according to the method, and the method. It can also be realized as a program for causing a computer to execute the processing, or as a recording medium for storing the program.

The image encoding method and image decoding method of the present invention can improve the encoding efficiency of inter prediction encoding.

FIG. 1 is a block diagram illustrating an example of a conventional encoding device. FIG. 2A is a conceptual diagram illustrating an example of inter prediction encoding by a conventional encoding device and decoding device. FIG. 2B is a conceptual diagram illustrating an example of inter prediction encoding by a conventional encoding device and decoding device. FIG. 3A is a conceptual diagram illustrating another example of inter-prediction encoding by a conventional encoding device and decoding device. FIG. 3B is a conceptual diagram illustrating another example of inter prediction encoding by a conventional encoding device and decoding device. FIG. 4 is a block diagram showing an example of a conventional decoding device. FIG. 5 is a block diagram showing an example of the image coding apparatus according to Embodiment 1 of the present invention. FIG. 6A is a conceptual diagram showing an example of inter prediction encoding in Embodiment 1 of the present invention. FIG. 6B is a conceptual diagram showing an example of inter prediction coding in Embodiment 1 of the present invention. FIG. 7A is a flowchart showing an example of inter prediction control in the image coding device according to Embodiment 1 of the present invention. FIG. 7B is a flowchart showing an example of inter prediction control in the image coding device according to Embodiment 1 of the present invention. FIG. 8 is a block diagram showing an example of the image decoding apparatus according to Embodiment 1 of the present invention. FIG. 9A is a flowchart showing an example of inter prediction control in the image decoding apparatus according to Embodiment 1 of the present invention. FIG. 9B is a flowchart showing an example of inter prediction control in the image decoding apparatus according to Embodiment 1 of the present invention. FIG. 10 is an overall configuration diagram of a content supply system that realizes a content distribution service. FIG. 11 is an overall configuration diagram of a digital broadcasting system. FIG. 12 is a block diagram illustrating a configuration example of a television. FIG. 13 is a block diagram illustrating a configuration example of an information reproducing / recording unit that reads and writes information from and on a recording medium that is an optical disk. FIG. 14 is a diagram illustrating a structure example of a recording medium that is an optical disk. FIG. 15A is a diagram illustrating an example of a mobile phone. FIG. 15B is a block diagram illustrating a configuration example of a mobile phone. FIG. 16 is a diagram showing a structure of multiplexed data. FIG. 17 is a diagram schematically showing how each stream is multiplexed in the multiplexed data. FIG. 18 is a diagram showing in more detail how the video stream is stored in the PES packet sequence. FIG. 19 is a diagram illustrating the structure of TS packets and source packets in multiplexed data. FIG. 20 is a diagram illustrating a data structure of the PMT. FIG. 21 is a diagram showing an internal configuration of multiplexed data information. FIG. 22 shows the internal structure of stream attribute information. FIG. 23 is a diagram illustrating steps for identifying video data. FIG. 24 is a block diagram illustrating a configuration example of an integrated circuit that realizes the moving picture encoding method and the moving picture decoding method according to each embodiment. FIG. 25 is a diagram illustrating a configuration for switching the driving frequency. FIG. 26 is a diagram illustrating steps for identifying video data and switching between driving frequencies. FIG. 27 is a diagram illustrating an example of a lookup table in which video data standards are associated with drive frequencies. FIG. 28A is a diagram illustrating an example of a configuration for sharing a module of a signal processing unit. FIG. 28B is a diagram illustrating another example of a configuration for sharing a module of a signal processing unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 5 is a block diagram showing an example of the image coding apparatus according to Embodiment 1 of the present invention. 1 differs from the conventional coding apparatus shown in FIG. 1 in that it includes a maximum reference picture list number determination unit 101 and a configuration that adds the first and second maximum reference picture list numbers to a bitstream.

5 notifies the image decoding apparatus of the first maximum reference picture list number in the header (for example, H.264 slice header) assigned to each picture, and a plurality of pictures. The image decoding apparatus is notified of the second maximum reference picture list number in a header (for example, H.264 sequence parameter set) provided for each unit. Note that the first maximum reference picture list number does not necessarily need to be notified by a header added for each picture, and header information that can be used in common by a plurality of pictures (for example, H.264 picture parameter set). It is good also as a structure notified by.

The second maximum reference picture list number is determined by the maximum reference picture list number determination unit 101 to one or more according to the constraint conditions defined in the application standards and image codec standards using the present invention. The

6A and 6B show an example of inter prediction encoding that can be realized by the configuration of the image encoding device 100 of FIG. Specifically, the number of the first and second maximum reference picture lists can be notified from the image encoding device 100 to the image decoding device, so that, for example, as shown in FIG. 6A and FIG. Inter prediction using the reference picture lists 0 to 3 is possible.

7A and 7B are flowcharts showing an example of inter prediction control in the image encoding device 100 of FIG.

FIG. 7A uses three picture types: intra-coded pictures (eg, I pictures), forward inter-predictive coded pictures (eg, P pictures), and bi-directional inter-predictive coded pictures (eg, B pictures). An example is shown. In this flow, first, the second maximum reference picture list number is determined, and the second maximum reference picture list number is set in a header given each time a plurality of pictures are configured. Next, according to the second maximum reference picture list number, a memory area of a reference picture list management memory necessary for managing a reference picture list used for inter prediction is secured. Thereafter, the first maximum reference picture list number that is the maximum number of reference picture lists used for inter prediction of each picture is determined according to the picture type. In the case of forward inter-predictive coded pictures, the first maximum reference picture list number is set to one half of the second maximum reference picture list number. The first maximum picture list number is set to the same value as the second maximum reference picture list number. In the case of an intra-coded picture, the first maximum reference picture list number is set to zero. After the first maximum reference picture list number is determined, reference picture list management information (reference picture list management memory) is stored in a predetermined initialization method (for example, H.264) according to the first maximum reference picture list number. Initialization (initialization process for reference picture list)) (initialization order of the index corresponding to the reference image is determined in the reference picture list). Then, the picture is encoded using the reference picture list, and the first maximum reference picture list number is set in the header given to each picture.

In FIG. 7A, the number of first maximum reference picture lists is set to be half of the number of second maximum reference picture lists in the case of forward inter-predictive coded pictures, but the present invention is not limited to this example. For example, it is conceivable to set the first maximum reference picture list number to an arbitrary value smaller than the second maximum reference picture list number. FIG. 7A shows an example in which three types of picture types are used, but it is also possible to use four or more types of picture types. For example, a T-picture (triple-predictive picture) that refers to three or more pictures as a second bidirectional inter-predictive coded picture, and a Q that is a third bidirectional inter-predictive coded picture that refers to four or more pictures. It is conceivable to use a picture (Quad-predictive picture). Also, a new picture type that can distinguish the reference direction is defined for inter prediction coded pictures (B picture, T picture, and Q picture) that refer to two or more pictures, and a picture based on the new picture type is used. It is good as well. The reference direction is distinguished as follows: (1) Whether the reference direction is only a single direction (whether it is only forward or only backward) (2) Whether it is bidirectional (Whether forward reference and backward reference are mixed). In any case, when four or more picture types are used, the first maximum reference picture list number of the picture type picture that refers to the most pictures is the second maximum reference picture list number. It is conceivable that the first maximum picture list number of pictures of other picture types is set to an arbitrary value smaller than the second maximum reference picture list number.

FIG. 7B is an example in which two types of pictures, an intra-coded picture and an inter-predictive coded picture, are used. FIG. 7A is a method for determining the first maximum reference picture list number according to the picture type. Different. Specifically, in the case of an inter prediction coded picture, the first maximum reference picture list number is set to the same value as the second maximum reference picture list number, and in the case of an intra coded picture, The maximum reference picture list number of 1 is set to 0.

6A and 6B, in the flow of FIG. 7A, the second maximum reference picture list number is 4, the first maximum reference picture list number is 2 for the B picture, and the Q picture (Quad− Predictive picture) can be realized by setting it to 4. 2A and 2B can be realized by setting the second maximum reference picture list number to 2, the first maximum reference picture list number to 2 for B pictures, and 1 for P pictures. 3A and 3B can be realized by setting the second maximum reference picture list number to 2 and the first maximum reference picture list number to 2 for B pictures.

H. In the H.264 initialization process for reference picture list, only the reference picture list 0 and 1 are specified, but for the reference picture list (2n) (n is an integer of 1 or more), the sequence of the reference picture list 0 should be copied. Thus, for the reference picture list (2n + 1) (n is an integer greater than or equal to 1), it is possible to initialize all management information of the reference picture list necessary for inter prediction by copying the sequence of the reference picture list 1 is there.

In the image coding apparatus 100, the first maximum reference picture list number is set to a header given for each picture or header information that can be used in common for a plurality of pictures. When the number of picture lists is set to the same value as the second maximum reference picture list number, it may not be set in the header or header information. When the first maximum reference picture list number is not set in the header or the header information, the image decoding apparatus uses the second maximum reference picture list number instead of the first maximum reference picture list number. It can be decoded by determining that it is used. In this way, by not setting information on the number of some first maximum reference picture lists, the compression rate can be improved.

FIG. 8 is a block diagram illustrating an example of an image decoding device 200 corresponding to the image encoding device 100 of FIG. 4 differs from the conventional decoding apparatus of FIG. 4 in that the first and second maximum reference picture list numbers are read from the bitstream and used for the processing of the inter prediction control unit 201.

FIGS. 9A and 9B are flowcharts showing an example of inter prediction control in the image decoding apparatus 200 of FIG. 9A and 9B are flowcharts corresponding to FIGS. 7A and 7B, respectively, illustrating a flow of inter prediction control on the image encoding device 100 side.

9A and 9B, first, according to the second maximum reference picture list number, a memory area of the reference picture management memory necessary for managing the reference picture list used in the inter prediction is secured. Thereafter, if the first maximum reference picture list number is larger than the second maximum reference picture list number by comparing the first maximum reference picture list number and the second maximum reference picture list number, it is determined as an error. Then, predetermined error processing is performed. When it is determined to be normal, the first maximum reference picture list number is set as the third maximum reference picture list number, and reference picture list management information (reference picture management memory) is set according to the third maximum reference picture list number. ) Is initialized by the same initialization method as that on the image encoding apparatus 100 side.

Note that the predetermined error processing may be any error processing as long as it is a means for avoiding a fatal situation such as deadlock or hang-up of the system including the image decoding device 200. As an example of specific error processing, the system notifies the system that a fatal error has occurred in decoding processing, re-allocates the reference picture list management memory according to the number of first maximum reference picture lists, and performs decoding. There is a method of continuing processing. In this example, the system displays a message on the screen indicating that an error has occurred in the decryption process, so that the user (viewer) is informed of the abnormal state, and the user action such as stop playback or restart of the decryption process is performed. You can also encourage them. Further, when information on the first maximum reference picture list number is not obtained, an error can be avoided by setting the second maximum reference picture list number to the third maximum reference picture list number. Is possible.

In FIG. 6A, a Q picture is used as a picture corresponding to a conventional B picture. However, by adding a new picture type that uses a predetermined number of reference picture lists to I, P, and B pictures, Even if the notification of the first and second maximum reference picture list numbers from the image coding apparatus 100 to the image decoding apparatus 200 is omitted, prediction using three or more reference picture lists is possible. The same applies to the case where the number of reference pictures is identified as a new picture type (T picture, Q picture, etc.) and the picture type that distinguishes the aforementioned reference direction is used. However, in order to express an arbitrary number, it is necessary to newly define many picture types, and the image encoding device 100 notifies the image decoding device 200 of the first and second maximum reference picture list numbers. It goes without saying that higher flexibility can be secured.

For distinguishing the reference direction, the image coding apparatus 100 does not use a new picture type, but the image coding apparatus 100 performs every predetermined unit (second processing unit, first processing unit, slice unit, etc.) of the coded sequence. It is also possible to insert a value for distinguishing the reference direction (only forward reference, etc.) for a predetermined picture type (B picture, etc.) into the prepared field. In this case, the image decoding apparatus 200 receives a notification of the number of reference picture lists for each first processing unit or each second processing unit, and obtains a reference direction of a processing unit such as a plurality of pictures included in the predetermined unit. Can do.

(Embodiment 2)
By recording a program for realizing the configuration of the moving picture encoding method or the moving picture decoding method shown in each of the above embodiments on a storage medium, the computer system in which the processing shown in each of the above embodiments is independent It becomes possible to carry out easily. The storage medium may be any medium that can record a program, such as a magnetic disk, an optical disk, a magneto-optical disk, an IC card, and a semiconductor memory.

Further, application examples of the moving picture encoding method and the moving picture decoding method shown in the above embodiments and a system using the same will be described.

FIG. 10 is a diagram showing an overall configuration of a content supply system ex100 that realizes a content distribution service. A communication service providing area is divided into desired sizes, and base stations ex106, ex107, ex108, ex109, and ex110, which are fixed wireless stations, are installed in each cell.

This content supply system ex100 includes a computer ex111, a PDA (Personal Digital Assistant) ex112, a camera ex113, a mobile phone ex114, a game machine ex115 via the Internet ex101, the Internet service provider ex102, the telephone network ex104, and the base stations ex106 to ex110. Etc. are connected.

However, the content supply system ex100 is not limited to the configuration shown in FIG. 10 and may be connected by combining any of the elements. In addition, each device may be directly connected to the telephone network ex104 without going from the base station ex106, which is a fixed wireless station, to ex110. In addition, the devices may be directly connected to each other via short-range wireless or the like.

The camera ex113 is a device that can shoot moving images such as a digital video camera, and the camera ex116 is a device that can shoot still images and movies such as a digital camera. In addition, the mobile phone ex114 is a GSM (Global System for Mobile Communications) system, a CDMA (Code Division Multiple Access) system, a W-CDMA (Wideband-Code Division Multiple Access) system, an LTE (Long Terminal Evolution) system, an HSPA ( High-speed-Packet-Access) mobile phone or PHS (Personal-Handyphone System), etc.

In the content supply system ex100, the camera ex113 and the like are connected to the streaming server ex103 through the base station ex109 and the telephone network ex104, thereby enabling live distribution and the like. In live distribution, the content (for example, music live video) captured by the user using the camera ex113 is encoded as described in the above embodiments, and transmitted to the streaming server ex103. On the other hand, the streaming server ex103 stream-distributes the content data transmitted to the requested client. Examples of the client include a computer ex111, a PDA ex112, a camera ex113, a mobile phone ex114, and a game machine ex115 that can decode the encoded data. Each device that receives the distributed data decodes the received data and reproduces it.

Note that the captured data may be encoded by the camera ex113, the streaming server ex103 that performs data transmission processing, or may be shared with each other. Similarly, the decryption processing of the distributed data may be performed by the client, the streaming server ex103, or may be performed in common with each other. In addition to the camera ex113, still images and / or moving image data captured by the camera ex116 may be transmitted to the streaming server ex103 via the computer ex111. The encoding process in this case may be performed by any of the camera ex116, the computer ex111, and the streaming server ex103, or may be performed in a shared manner.

Further, these encoding / decoding processes are generally performed in the computer ex111 and the LSI ex500 included in each device. The LSI ex500 may be configured as a single chip or a plurality of chips. It should be noted that moving image encoding / decoding software is incorporated into some recording medium (CD-ROM, flexible disk, hard disk, etc.) that can be read by the computer ex111, etc., and encoding / decoding processing is performed using the software. May be. Furthermore, when the mobile phone ex114 is equipped with a camera, moving image data acquired by the camera may be transmitted. The moving image data at this time is data encoded by the LSI ex500 included in the mobile phone ex114.

Further, the streaming server ex103 may be a plurality of servers or a plurality of computers, and may process, record, and distribute data in a distributed manner.

As described above, in the content supply system ex100, the encoded data can be received and reproduced by the client. Thus, in the content supply system ex100, the information transmitted by the user can be received, decrypted and reproduced by the client in real time, and personal broadcasting can be realized even for a user who does not have special rights or facilities.

In addition to the example of the content supply system ex100, as shown in FIG. 11, at least one of the video encoding device and the video decoding device of each of the above embodiments is incorporated in the digital broadcasting system ex200. be able to. Specifically, in the broadcast station ex201, multiplexed data obtained by multiplexing music data and the like on video data is transmitted to a communication or satellite ex202 via radio waves. This video data is data encoded by the moving image encoding method described in the above embodiments. Receiving this, the broadcasting satellite ex202 transmits a radio wave for broadcasting, and this radio wave is received by a home antenna ex204 capable of receiving satellite broadcasting. The received multiplexed data is decoded and reproduced by a device such as the television (receiver) ex300 or the set top box (STB) ex217.

Also, a reader / recorder ex218 that reads and decodes multiplexed data recorded on a recording medium ex215 such as a DVD or a BD, or encodes a video signal on the recording medium ex215 and, in some cases, multiplexes and writes it with a music signal. It is possible to mount the moving picture decoding apparatus or moving picture encoding apparatus described in the above embodiments. In this case, the reproduced video signal is displayed on the monitor ex219, and the video signal can be reproduced in another device or system using the recording medium ex215 on which the multiplexed data is recorded. Alternatively, a moving picture decoding apparatus may be mounted in a set-top box ex217 connected to a cable ex203 for cable television or an antenna ex204 for satellite / terrestrial broadcasting and displayed on the monitor ex219 of the television. At this time, the moving picture decoding apparatus may be incorporated in the television instead of the set top box.

FIG. 12 is a diagram showing a television (receiver) ex300 that uses the moving picture decoding method and the moving picture encoding method described in the above embodiments. The television ex300 obtains or outputs multiplexed data in which audio data is multiplexed with video data via the antenna ex204 or the cable ex203 that receives the broadcast, and demodulates the received multiplexed data. Alternatively, the modulation / demodulation unit ex302 that modulates multiplexed data to be transmitted to the outside, and the demodulated multiplexed data is separated into video data and audio data, or the video data and audio data encoded by the signal processing unit ex306 Is provided with a multiplexing / demultiplexing unit ex303.

Further, the television ex300 decodes the audio data and the video data, or encodes each information, the audio signal processing unit ex304, the signal processing unit ex306 including the video signal processing unit ex305, and the decoded audio signal. A speaker ex307 for outputting, and an output unit ex309 having a display unit ex308 such as a display for displaying the decoded video signal. Furthermore, the television ex300 includes an interface unit ex317 including an operation input unit ex312 that receives an input of a user operation. Furthermore, the television ex300 includes a control unit ex310 that performs overall control of each unit, and a power supply circuit unit ex311 that supplies power to each unit. In addition to the operation input unit ex312, the interface unit ex317 includes a bridge unit ex313 connected to an external device such as a reader / recorder ex218, a recording unit ex216 such as an SD card, and an external recording unit such as a hard disk. A driver ex315 for connecting to a medium, a modem ex316 for connecting to a telephone network, and the like may be included. Note that the recording medium ex216 is capable of electrically recording information by using a nonvolatile / volatile semiconductor memory element to be stored. Each part of the television ex300 is connected to each other via a synchronous bus.

First, a configuration in which the television ex300 decodes and reproduces multiplexed data acquired from the outside by the antenna ex204 and the like will be described. The television ex300 receives a user operation from the remote controller ex220 or the like, and demultiplexes the multiplexed data demodulated by the modulation / demodulation unit ex302 by the multiplexing / demultiplexing unit ex303 based on the control of the control unit ex310 having a CPU or the like. Furthermore, in the television ex300, the separated audio data is decoded by the audio signal processing unit ex304, and the separated video data is decoded by the video signal processing unit ex305 using the decoding method described in each of the above embodiments. The decoded audio signal and video signal are output from the output unit ex309 to the outside. At the time of output, these signals may be temporarily stored in the buffers ex318, ex319, etc. so that the audio signal and the video signal are reproduced in synchronization. Also, the television ex300 may read multiplexed data from recording media ex215 and ex216 such as a magnetic / optical disk and an SD card, not from broadcasting. Next, a configuration in which the television ex300 encodes an audio signal or a video signal and transmits the signal to the outside or to a recording medium will be described. The television ex300 receives a user operation from the remote controller ex220 and the like, encodes an audio signal with the audio signal processing unit ex304, and converts the video signal with the video signal processing unit ex305 based on the control of the control unit ex310. Encoding is performed using the encoding method described in (1). The encoded audio signal and video signal are multiplexed by the multiplexing / demultiplexing unit ex303 and output to the outside. When multiplexing, these signals may be temporarily stored in the buffers ex320, ex321, etc. so that the audio signal and the video signal are synchronized. Note that a plurality of buffers ex318, ex319, ex320, and ex321 may be provided as illustrated, or one or more buffers may be shared. Further, in addition to the illustrated example, data may be stored in the buffer as a buffer material that prevents system overflow and underflow, for example, between the modulation / demodulation unit ex302 and the multiplexing / demultiplexing unit ex303.

In addition to acquiring audio data and video data from broadcasts, recording media, and the like, the television ex300 has a configuration for receiving AV input of a microphone and a camera, and performs encoding processing on the data acquired from them. Also good. Here, the television ex300 has been described as a configuration capable of the above-described encoding processing, multiplexing, and external output, but these processing cannot be performed, and only the above-described reception, decoding processing, and external output are possible. It may be a configuration.

In addition, when reading or writing multiplexed data from a recording medium by the reader / recorder ex218, the decoding process or the encoding process may be performed by either the television ex300 or the reader / recorder ex218, The reader / recorder ex218 may share with each other.

As an example, FIG. 13 shows a configuration of the information reproducing / recording unit ex400 when data is read from or written to an optical disk. The information reproducing / recording unit ex400 includes elements ex401, ex402, ex403, ex404, ex405, ex406, and ex407 described below. The optical head ex401 irradiates a laser spot on the recording surface of the recording medium ex215 that is an optical disk to write information, and detects reflected light from the recording surface of the recording medium ex215 to read the information. The modulation recording unit ex402 electrically drives a semiconductor laser built in the optical head ex401 and modulates the laser beam according to the recording data. The reproduction demodulator ex403 amplifies the reproduction signal obtained by electrically detecting the reflected light from the recording surface by the photodetector built in the optical head ex401, separates and demodulates the signal component recorded on the recording medium ex215, and is necessary To play back information. The buffer ex404 temporarily holds information to be recorded on the recording medium ex215 and information reproduced from the recording medium ex215. The disk motor ex405 rotates the recording medium ex215. The servo controller ex406 moves the optical head ex401 to a predetermined information track while controlling the rotational drive of the disk motor ex405, and performs a laser spot tracking process. The system control unit ex407 controls the entire information reproduction / recording unit ex400. In the reading and writing processes described above, the system control unit ex407 uses various kinds of information held in the buffer ex404, and generates and adds new information as necessary, and the modulation recording unit ex402, the reproduction demodulation unit This is realized by recording / reproducing information through the optical head ex401 while operating the ex403 and the servo control unit ex406 in a coordinated manner. The system control unit ex407 is composed of, for example, a microprocessor, and executes these processes by executing a read / write program.

In the above, the optical head ex401 has been described as irradiating a laser spot. However, a configuration in which higher-density recording is performed using near-field light may be used.

FIG. 14 shows a schematic diagram of a recording medium ex215 that is an optical disk. Guide grooves (grooves) are formed in a spiral shape on the recording surface of the recording medium ex215, and address information indicating the absolute position on the disc is recorded in advance on the information track ex230 by changing the shape of the groove. This address information includes information for specifying the position of the recording block ex231 that is a unit for recording data, and the recording block is specified by reproducing the information track ex230 and reading the address information in a recording or reproducing apparatus. Can do. Further, the recording medium ex215 includes a data recording area ex233, an inner peripheral area ex232, and an outer peripheral area ex234. The area used for recording user data is the data recording area ex233, and the inner circumference area ex232 and the outer circumference area ex234 arranged on the inner or outer circumference of the data recording area ex233 are used for specific purposes other than user data recording. Used. The information reproducing / recording unit ex400 reads / writes encoded audio data, video data, or multiplexed data obtained by multiplexing these data with respect to the data recording area ex233 of the recording medium ex215.

In the above description, an optical disk such as a single-layer DVD or BD has been described as an example. However, the present invention is not limited to these, and an optical disk having a multilayer structure and capable of recording other than the surface may be used. Also, an optical disc with a multi-dimensional recording / reproducing structure, such as recording information using light of different wavelengths in the same place on the disc, or recording different layers of information from various angles. It may be.

Also, in the digital broadcasting system ex200, the car ex210 having the antenna ex205 can receive data from the satellite ex202 and the like, and the moving image can be reproduced on a display device such as the car navigation ex211 that the car ex210 has. Note that the configuration of the car navigation ex211 may be, for example, a configuration in which a GPS receiver is added in the configuration illustrated in FIG.

FIG. 15A is a diagram showing the mobile phone ex114 using the video decoding method and the video encoding method described in the above embodiment. The mobile phone ex114 includes an antenna ex350 for transmitting and receiving radio waves to and from the base station ex110, a camera unit ex365 capable of capturing video and still images, a video captured by the camera unit ex365, a video received by the antenna ex350, and the like Is provided with a display unit ex358 such as a liquid crystal display for displaying the decrypted data. The mobile phone ex114 further includes a main body unit having an operation key unit ex366, an audio output unit ex357 such as a speaker for outputting audio, an audio input unit ex356 such as a microphone for inputting audio, a captured video, In the memory unit ex367 for storing encoded data or decoded data such as still images, recorded audio, received video, still images, mails, or the like, or an interface unit with a recording medium for storing data A slot ex364 is provided.

Furthermore, a configuration example of the mobile phone ex114 will be described with reference to FIG. 15B. The mobile phone ex114 has a power supply circuit part ex361, an operation input control part ex362, and a video signal processing part ex355 with respect to a main control part ex360 that comprehensively controls each part of the main body including the display part ex358 and the operation key part ex366. , A camera interface unit ex363, an LCD (Liquid Crystal Display) control unit ex359, a modulation / demodulation unit ex352, a multiplexing / demultiplexing unit ex353, an audio signal processing unit ex354, a slot unit ex364, and a memory unit ex367 are connected to each other via a bus ex370. ing.

When the end of call and the power key are turned on by a user operation, the power supply circuit unit ex361 starts up the mobile phone ex114 in an operable state by supplying power from the battery pack to each unit.

The cellular phone ex114 converts the audio signal collected by the audio input unit ex356 in the voice call mode into a digital audio signal by the audio signal processing unit ex354 based on the control of the main control unit ex360 having a CPU, a ROM, a RAM, and the like. Then, this is subjected to spectrum spread processing by the modulation / demodulation unit ex352, digital-analog conversion processing and frequency conversion processing are performed by the transmission / reception unit ex351, and then transmitted via the antenna ex350. The mobile phone ex114 also amplifies the received data received via the antenna ex350 in the voice call mode, performs frequency conversion processing and analog-digital conversion processing, performs spectrum despreading processing by the modulation / demodulation unit ex352, and performs voice signal processing unit After being converted into an analog audio signal by ex354, this is output from the audio output unit ex357.

Further, when an e-mail is transmitted in the data communication mode, the text data of the e-mail input by operating the operation key unit ex366 of the main unit is sent to the main control unit ex360 via the operation input control unit ex362. The main control unit ex360 performs spread spectrum processing on the text data in the modulation / demodulation unit ex352, performs digital analog conversion processing and frequency conversion processing in the transmission / reception unit ex351, and then transmits the text data to the base station ex110 via the antenna ex350. . In the case of receiving an e-mail, almost the reverse process is performed on the received data and output to the display unit ex358.

When transmitting video, still images, or video and audio in the data communication mode, the video signal processing unit ex355 compresses the video signal supplied from the camera unit ex365 by the moving image encoding method described in the above embodiments. The encoded video data is sent to the multiplexing / separating unit ex353. The audio signal processing unit ex354 encodes the audio signal picked up by the audio input unit ex356 while the camera unit ex365 images a video, a still image, etc., and sends the encoded audio data to the multiplexing / separating unit ex353. To do.

The multiplexing / demultiplexing unit ex353 multiplexes the encoded video data supplied from the video signal processing unit ex355 and the encoded audio data supplied from the audio signal processing unit ex354 by a predetermined method, and is obtained as a result. The multiplexed data is subjected to spread spectrum processing by the modulation / demodulation unit (modulation / demodulation circuit unit) ex352, digital-analog conversion processing and frequency conversion processing by the transmission / reception unit ex351, and then transmitted via the antenna ex350.

Decode multiplexed data received via antenna ex350 when receiving video file data linked to a homepage, etc. in data communication mode, or when receiving e-mail with video and / or audio attached Therefore, the multiplexing / separating unit ex353 separates the multiplexed data into a video data bit stream and an audio data bit stream, and performs video signal processing on the video data encoded via the synchronization bus ex370. The encoded audio data is supplied to the audio signal processing unit ex354 while being supplied to the unit ex355. The video signal processing unit ex355 decodes the video signal by decoding using the video decoding method corresponding to the video encoding method described in each of the above embodiments, and the display unit ex358 via the LCD control unit ex359. From, for example, video and still images included in a moving image file linked to a home page are displayed. The audio signal processing unit ex354 decodes the audio signal, and the audio is output from the audio output unit ex357.

In addition to the transmission / reception type terminal having both the encoder and the decoder, the terminal such as the mobile phone ex114 is referred to as a transmission terminal having only an encoder and a receiving terminal having only a decoder. There are three possible mounting formats. Furthermore, in the digital broadcasting system ex200, it has been described that multiplexed data in which music data is multiplexed with video data is received and transmitted. However, in addition to audio data, character data related to video is multiplexed. It may be converted data, or may be video data itself instead of multiplexed data.

As described above, the moving picture encoding method or the moving picture decoding method shown in each of the above embodiments can be used in any of the above-described devices / systems. The described effect can be obtained.

Further, the present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the scope of the present invention.

(Embodiment 3)
The moving picture coding method or apparatus shown in each of the above embodiments and the moving picture coding method or apparatus compliant with different standards such as MPEG-2, MPEG4-AVC, and VC-1 are appropriately switched as necessary. Thus, it is also possible to generate video data.

Here, when a plurality of pieces of video data conforming to different standards are generated, it is necessary to select a decoding method corresponding to each standard when decoding. However, since it is impossible to identify which standard the video data to be decoded complies with, there arises a problem that an appropriate decoding method cannot be selected.

In order to solve this problem, multiplexed data obtained by multiplexing audio data or the like with video data is configured to include identification information indicating which standard the video data conforms to. A specific configuration of multiplexed data including video data generated by the moving picture encoding method or apparatus shown in the above embodiments will be described below. The multiplexed data is a digital stream in the MPEG-2 transport stream format.

FIG. 16 is a diagram showing a structure of multiplexed data. As shown in FIG. 16, multiplexed data is obtained by multiplexing one or more of a video stream, an audio stream, a presentation graphics stream (PG), and an interactive graphics stream. The video stream indicates the main video and sub-video of the movie, the audio stream (IG) indicates the main audio portion of the movie and the sub-audio mixed with the main audio, and the presentation graphics stream indicates the subtitles of the movie. Here, the main video indicates a normal video displayed on the screen, and the sub-video is a video displayed on a small screen in the main video. The interactive graphics stream indicates an interactive screen created by arranging GUI components on the screen. The video stream is encoded by the moving image encoding method or apparatus shown in the above embodiments, or the moving image encoding method or apparatus conforming to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1. ing. The audio stream is encoded by a method such as Dolby AC-3, Dolby Digital Plus, MLP, DTS, DTS-HD, or linear PCM.

Each stream included in the multiplexed data is identified by PID. For example, 0x1011 for video streams used for movie images, 0x1100 to 0x111F for audio streams, 0x1200 to 0x121F for presentation graphics, 0x1400 to 0x141F for interactive graphics streams, 0x1B00 to 0x1B1F are assigned to video streams used for sub-pictures, and 0x1A00 to 0x1A1F are assigned to audio streams used for sub-audio mixed with the main audio.

FIG. 17 is a diagram schematically showing how multiplexed data is multiplexed. First, a video stream ex235 composed of a plurality of video frames and an audio stream ex238 composed of a plurality of audio frames are converted into PES packet sequences ex236 and ex239, respectively, and converted into TS packets ex237 and ex240. Similarly, the data of the presentation graphics stream ex241 and interactive graphics ex244 are converted into PES packet sequences ex242 and ex245, respectively, and further converted into TS packets ex243 and ex246. The multiplexed data ex247 is configured by multiplexing these TS packets into one stream.

FIG. 18 shows in more detail how the video stream is stored in the PES packet sequence. The first row in FIG. 18 shows a video frame sequence of the video stream. The second level shows a PES packet sequence. As shown by arrows yy1, yy2, yy3, yy4 in FIG. 18, a plurality of Video Presentation Units in the video stream are divided into pictures, B pictures, and P pictures, and are stored in the payload of the PES packet. . Each PES packet has a PES header, and a PTS (Presentation Time-Stamp) that is a display time of a picture and a DTS (Decoding Time-Stamp) that is a decoding time of a picture are stored in the PES header.

FIG. 19 shows the format of TS packets that are finally written in the multiplexed data. The TS packet is a 188-byte fixed-length packet composed of a 4-byte TS header having information such as a PID for identifying a stream and a 184-byte TS payload for storing data. The PES packet is divided and stored in the TS payload. The In the case of a BD-ROM, a 4-byte TP_Extra_Header is added to a TS packet, forms a 192-byte source packet, and is written in multiplexed data. In TP_Extra_Header, information such as ATS (Arrival_Time_Stamp) is described. ATS indicates the transfer start time of the TS packet to the PID filter of the decoder. Source packets are arranged in the multiplexed data as shown in the lower part of FIG. 19, and the number incremented from the head of the multiplexed data is called SPN (source packet number).

In addition, TS packets included in the multiplexed data include PAT (Program Association Table), PMT (Program Map Table), PCR (Program Clock Reference), and the like in addition to each stream such as video / audio / caption. PAT indicates what the PID of the PMT used in the multiplexed data is, and the PID of the PAT itself is registered as 0. The PMT has the PID of each stream such as video / audio / subtitles included in the multiplexed data and the attribute information of the stream corresponding to each PID, and has various descriptors related to the multiplexed data. The descriptor includes copy control information for instructing permission / non-permission of copying of multiplexed data. In order to synchronize the ATC (Arrival Time Clock), which is the ATS time axis, and the STC (System Time Clock), which is the PTS / DTS time axis, the PCR corresponds to the ATS in which the PCR packet is transferred to the decoder. Contains STC time information.

FIG. 20 is a diagram for explaining the data structure of the PMT in detail. A PMT header describing the length of data included in the PMT is arranged at the head of the PMT. After that, a plurality of descriptors related to multiplexed data are arranged. The copy control information and the like are described as descriptors. After the descriptor, a plurality of pieces of stream information regarding each stream included in the multiplexed data are arranged. The stream information includes a stream descriptor in which a stream type, a stream PID, and stream attribute information (frame rate, aspect ratio, etc.) are described to identify a compression codec of the stream. There are as many stream descriptors as the number of streams existing in the multiplexed data.

When recording on a recording medium or the like, the multiplexed data is recorded together with the multiplexed data information file.

As shown in FIG. 21, the multiplexed data information file is management information of multiplexed data, has one-to-one correspondence with the multiplexed data, and includes multiplexed data information, stream attribute information, and an entry map.

The multiplexed data information includes a system rate, a reproduction start time, and a reproduction end time as shown in FIG. The system rate indicates a maximum transfer rate of multiplexed data to a PID filter of a system target decoder described later. The ATS interval included in the multiplexed data is set to be equal to or less than the system rate. The playback start time is the PTS of the first video frame of the multiplexed data, and the playback end time is set by adding the playback interval for one frame to the PTS of the video frame at the end of the multiplexed data.

In the stream attribute information, as shown in FIG. 22, attribute information about each stream included in the multiplexed data is registered for each PID. The attribute information has different information for each video stream, audio stream, presentation graphics stream, and interactive graphics stream. The video stream attribute information includes the compression codec used to compress the video stream, the resolution of the individual picture data constituting the video stream, the aspect ratio, and the frame rate. It has information such as how much it is. The audio stream attribute information includes the compression codec used to compress the audio stream, the number of channels included in the audio stream, the language supported, and the sampling frequency. With information. These pieces of information are used for initialization of the decoder before the player reproduces it.

In this embodiment, among the multiplexed data, the stream type included in the PMT is used. Also, when multiplexed data is recorded on the recording medium, video stream attribute information included in the multiplexed data information is used. Specifically, in the video encoding method or apparatus shown in each of the above embodiments, the video encoding shown in each of the above embodiments for the stream type or video stream attribute information included in the PMT. There is provided a step or means for setting unique information indicating that the video data is generated by the method or apparatus. With this configuration, it is possible to discriminate between video data generated by the moving picture encoding method or apparatus described in the above embodiments and video data compliant with other standards.

FIG. 23 shows steps of the moving picture decoding method according to the present embodiment. In step exS100, the stream type included in the PMT or the video stream attribute information included in the multiplexed data information is acquired from the multiplexed data. Next, in step exS101, it is determined whether or not the stream type or the video stream attribute information indicates multiplexed data generated by the moving picture encoding method or apparatus described in the above embodiments. To do. When it is determined that the stream type or the video stream attribute information is generated by the moving image encoding method or apparatus described in the above embodiments, in step exS102, the above embodiments are performed. Decoding is performed by the moving picture decoding method shown in the form. If the stream type or video stream attribute information indicates that it conforms to a standard such as conventional MPEG-2, MPEG4-AVC, or VC-1, in step exS103, the conventional information Decoding is performed by a moving image decoding method compliant with the standard.

In this way, by setting a new unique value in the stream type or video stream attribute information, whether or not decoding is possible with the moving picture decoding method or apparatus described in each of the above embodiments is performed. Judgment can be made. Therefore, even when multiplexed data conforming to different standards is input, an appropriate decoding method or apparatus can be selected, and therefore decoding can be performed without causing an error. In addition, the moving picture encoding method or apparatus or the moving picture decoding method or apparatus described in this embodiment can be used in any of the above-described devices and systems.

(Embodiment 4)
The moving picture encoding method and apparatus and moving picture decoding method and apparatus described in the above embodiments are typically realized by an LSI that is an integrated circuit. As an example, FIG. 24 shows a configuration of an LSI ex500 that is made into one chip. The LSI ex500 includes elements ex501, ex502, ex503, ex504, ex505, ex506, ex507, ex508, and ex509 described below, and each element is connected via a bus ex510. The power supply circuit unit ex505 is activated to an operable state by supplying power to each unit when the power supply is on.

For example, when performing the encoding process, the LSI ex500 performs the microphone ex117 and the camera ex113 by the AV I / O ex509 based on the control of the control unit ex501 including the CPU ex502, the memory controller ex503, the stream controller ex504, the drive frequency control unit ex512, and the like. The AV signal is input from the above. The input AV signal is temporarily stored in an external memory ex511 such as SDRAM. Based on the control of the control unit ex501, the accumulated data is divided into a plurality of times as appropriate according to the processing amount and the processing speed and sent to the signal processing unit ex507, and the signal processing unit ex507 encodes an audio signal and / or video. Signal encoding is performed. Here, the encoding process of the video signal is the encoding process described in the above embodiments. The signal processing unit ex507 further performs processing such as multiplexing the encoded audio data and the encoded video data according to circumstances, and outputs the result from the stream I / Oex 506 to the outside. The output multiplexed data is transmitted to the base station ex107 or written to the recording medium ex215. It should be noted that data should be temporarily stored in the buffer ex508 so as to be synchronized when multiplexing.

In the above description, the memory ex511 is described as an external configuration of the LSI ex500. However, a configuration included in the LSI ex500 may be used. The number of buffers ex508 is not limited to one, and a plurality of buffers may be provided. The LSI ex500 may be made into one chip or a plurality of chips.

In the above description, the control unit ex501 includes the CPU ex502, the memory controller ex503, the stream controller ex504, the drive frequency control unit ex512, and the like, but the configuration of the control unit ex501 is not limited to this configuration. For example, the signal processing unit ex507 may further include a CPU. By providing a CPU also in the signal processing unit ex507, the processing speed can be further improved. As another example, the CPU ex502 may be configured to include a signal processing unit ex507 or, for example, an audio signal processing unit that is a part of the signal processing unit ex507. In such a case, the control unit ex501 is configured to include a signal processing unit ex507 or a CPU ex502 having a part thereof.

In addition, although it was set as LSI here, it may be called IC, system LSI, super LSI, and ultra LSI depending on the degree of integration.

Further, the method of circuit integration is not limited to LSI, and implementation with a dedicated circuit or a general-purpose processor is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

Furthermore, if integrated circuit technology that replaces LSI emerges as a result of progress in semiconductor technology or other derived technology, it is naturally possible to integrate functional blocks using this technology. Biotechnology can be applied.

(Embodiment 5)
When decoding video data generated by the moving picture encoding method or apparatus described in each of the above embodiments, the video data conforming to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1 is decoded. It is conceivable that the amount of processing increases compared to the case. Therefore, in LSI ex500, it is necessary to set a driving frequency higher than the driving frequency of CPU ex502 when decoding video data compliant with the conventional standard. However, when the drive frequency is increased, there is a problem that power consumption increases.

In order to solve this problem, moving picture decoding devices such as the television ex300 and LSI ex500 are configured to identify which standard the video data conforms to and switch the driving frequency in accordance with the standard. FIG. 25 shows a configuration ex800 in the present embodiment. The drive frequency switching unit ex803 sets the drive frequency high when the video data is generated by the moving image encoding method or apparatus described in the above embodiments. Then, the decoding processing unit ex801 that executes the moving picture decoding method described in each of the above embodiments is instructed to decode the video data. On the other hand, when the video data is video data compliant with the conventional standard, compared to the case where the video data is generated by the moving picture encoding method or apparatus shown in the above embodiments, Set the drive frequency low. Then, it instructs the decoding processing unit ex802 compliant with the conventional standard to decode the video data.

More specifically, the drive frequency switching unit ex803 includes the CPU ex502 and the drive frequency control unit ex512 in FIG. Also, the decoding processing unit ex801 that executes the moving picture decoding method shown in each of the above embodiments and the decoding processing unit ex802 that complies with the conventional standard correspond to the signal processing unit ex507 in FIG. The CPU ex502 identifies which standard the video data conforms to. Then, based on the signal from the CPU ex502, the drive frequency control unit ex512 sets the drive frequency. Further, based on the signal from the CPU ex502, the signal processing unit ex507 decodes the video data. Here, for the identification of the video data, for example, it is conceivable to use the identification information described in the third embodiment. The identification information is not limited to that described in Embodiment 3, and any information that can identify which standard the video data conforms to may be used. For example, it is possible to identify which standard the video data conforms to based on an external signal that identifies whether the video data is used for a television or a disk. In some cases, identification may be performed based on such an external signal. In addition, the selection of the driving frequency in the CPU ex502 may be performed based on, for example, a look-up table in which video data standards and driving frequencies are associated with each other as shown in FIG. The look-up table is stored in the buffer ex508 or the internal memory of the LSI, and the CPU ex502 can select the drive frequency by referring to the look-up table.

FIG. 26 shows steps for executing the method of the present embodiment. First, in step exS200, the signal processing unit ex507 acquires identification information from the multiplexed data. Next, in step exS201, the CPU ex502 identifies whether the video data is generated by the encoding method or apparatus described in each of the above embodiments based on the identification information. When the video data is generated by the encoding method or apparatus shown in the above embodiments, in step exS202, the CPU ex502 sends a signal for setting the drive frequency high to the drive frequency control unit ex512. Then, the drive frequency control unit ex512 sets a high drive frequency. On the other hand, if it indicates that the video data conforms to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1, in step exS203, the CPU ex502 drives the signal for setting the drive frequency low. This is sent to the frequency control unit ex512. Then, in the drive frequency control unit ex512, the drive frequency is set to be lower than that in the case where the video data is generated by the encoding method or apparatus described in the above embodiments.

Furthermore, the power saving effect can be further enhanced by changing the voltage applied to the LSI ex500 or the device including the LSI ex500 in conjunction with the switching of the driving frequency. For example, when the drive frequency is set low, it is conceivable that the voltage applied to the LSI ex500 or the device including the LSI ex500 is set low as compared with the case where the drive frequency is set high.

In addition, the setting method of the driving frequency may be set to a high driving frequency when the processing amount at the time of decoding is large, and to a low driving frequency when the processing amount at the time of decoding is small. It is not limited to the method. For example, the amount of processing for decoding video data compliant with the MPEG4-AVC standard is larger than the amount of processing for decoding video data generated by the moving picture encoding method or apparatus described in the above embodiments. It is conceivable that the setting of the driving frequency is reversed to that in the case described above.

Furthermore, the method for setting the drive frequency is not limited to the configuration in which the drive frequency is lowered. For example, when the identification information indicates that the video data is generated by the moving image encoding method or apparatus described in the above embodiments, the voltage applied to the LSIex500 or the apparatus including the LSIex500 is set high. However, when it is shown that the video data conforms to the conventional standards such as MPEG-2, MPEG4-AVC, VC-1, etc., it is also possible to set the voltage applied to the LSIex500 or the device including the LSIex500 low. It is done. As another example, when the identification information indicates that the video data is generated by the moving image encoding method or apparatus described in the above embodiments, the driving of the CPU ex502 is stopped. If the video data conforms to the standards such as MPEG-2, MPEG4-AVC, VC-1, etc., the CPU ex502 is temporarily stopped because there is room in processing. Is also possible. Even when the identification information indicates that the video data is generated by the moving image encoding method or apparatus described in each of the above embodiments, if there is a margin for processing, the CPU ex502 is temporarily driven. It can also be stopped. In this case, it is conceivable to set the stop time shorter than in the case where the video data conforms to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1.

Thus, it is possible to save power by switching the drive frequency according to the standard to which the video data conforms. In addition, when the battery is used to drive the LSI ex500 or the device including the LSI ex500, it is possible to extend the life of the battery with power saving.

(Embodiment 6)
A plurality of video data that conforms to different standards may be input to the above-described devices and systems such as a television and a mobile phone. As described above, the signal processing unit ex507 of the LSI ex500 needs to support a plurality of standards in order to be able to decode even when a plurality of video data complying with different standards is input. However, when the signal processing unit ex507 corresponding to each standard is used individually, there is a problem that the circuit scale of the LSI ex500 increases and the cost increases.

In order to solve this problem, a decoding processing unit for executing the moving picture decoding method shown in each of the above embodiments and a decoding conforming to a standard such as MPEG-2, MPEG4-AVC, or VC-1 The processing unit is partly shared. An example of this configuration is shown as ex900 in FIG. 28A. For example, the moving picture decoding method shown in each of the above embodiments and the moving picture decoding method compliant with the MPEG4-AVC standard are processed in processes such as entropy coding, inverse quantization, deblocking filter, and motion compensation. Some contents are common. For the common processing contents, the decoding processing unit ex902 corresponding to the MPEG4-AVC standard is shared, and for other processing contents specific to the present invention not corresponding to the MPEG4-AVC standard, the dedicated decoding processing unit ex901 is used. Configuration is conceivable. In particular, since the present invention is characterized by inverse quantization, for example, a dedicated decoding processing unit ex901 is used for inverse quantization, and other entropy coding, deblocking filter, motion compensation, and the like are used. For any or all of the processes, it is conceivable to share the decoding processing unit. For sharing of the decoding processing unit, for processing contents in common, to share the decoding processing unit for executing a moving picture decoding method described in each of embodiments, specific to the MPEG4-AVC standard processing content As for, a configuration using a dedicated decoding processing unit may be used.

Further, ex1000 in FIG. 28A shows another example in which processing is partially shared. In this example, a dedicated decoding processing unit ex1001 corresponding to processing content unique to the present invention, a dedicated decoding processing unit ex1002 corresponding to processing content specific to other conventional standards, and a moving picture decoding method of the present invention A common decoding processing unit ex1003 corresponding to processing contents common to other conventional video decoding methods is used. Here, the dedicated decoding processing units ex1001 and ex1002 are not necessarily specialized in the processing content specific to the present invention or other conventional standards, and may be capable of executing other general-purpose processing. Also, the configuration of the present embodiment can be implemented by LSI ex500.

Thus, the moving picture decoding method of the present invention, the processing contents to be shared by the moving picture decoding method of the conventional standard, by sharing the decoding processing unit, to reduce the circuit scale of LSI, and cost It is possible to reduce.

INDUSTRIAL APPLICABILITY The image encoding method and the image decoding method according to the present invention have the effect that the encoding efficiency can be improved. It can be applied to devices and the like.

DESCRIPTION OF SYMBOLS 100 Image coding apparatus 101 Maximum reference picture list number determination part 200 Image decoding apparatus 201 Inter prediction control part

Claims (6)

1. An image encoding method for performing predictive encoding using at least one reference image,
   When the first header information added to the bitstream for each first processing unit includes a picture type and the picture type indicates inter coding, a reference image used for inter prediction in the first processing unit is selected. The image encoding method, wherein the maximum number of reference picture lists to be managed is included in the first header information as a first maximum reference picture list number.
2. For each second processing unit including at least one of the first processing units, the second header information given to the bitstream or notified by an alternative means different from the bitstream, 2. The image encoding method according to claim 1, wherein the maximum number of the first maximum reference picture lists in the second processing unit is included as the second maximum reference picture list number.
3. An image decoding method for decoding a bitstream that has been predictively encoded using at least one reference image,
   When the picture type included in the first header information added to the bitstream for each first processing unit indicates inter coding, a reference for managing a reference image used for inter prediction in the first processing unit The image decoding method, wherein the bitstream is decoded according to a first maximum reference picture list number included in the first header information, which is a maximum number of picture lists.
4. Added to the bitstream for each second processing unit including one or more of the first processing units, or included in the second header information notified by alternative means different from the bitstream, The reference picture list management memory is secured according to a second maximum reference picture list number that is the maximum number of the first maximum reference picture lists in a second processing unit. Image decoding method.
5. The area that needs to be initialized in the reference picture list management memory is initialized by a predetermined initialization method for each of the first processing units according to the first maximum reference picture list number. Item 5. The image decoding method according to Item 4.
6. 5. The image decoding according to claim 4, wherein when the first maximum reference picture list number is larger than the second maximum reference picture list number, an error is determined and predetermined error processing is performed. Method
   

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