CN1595989A - Image decoder, image coder, image communication system, and coded bit stream converter - Google Patents

Abstract

The invention is an image decoding device which can decode even if the coding modes are not the same. It has: coding mode judging part for judging code mode according to code mode identification information in coding bit stream; according to the caption information of the first coding mode, sets the settings device of the caption information of the second coding mode; and decoding device for the image coding data of the first coding mode according to the caption information of the second coding mode.

Description

Image decoder, picture coding device, image communication system and coded bit stream converter

The application is that application number is the dividing an application for the application of " image decoder, picture coding device, image communication system and coded bit stream converter " that " 97182488.6 ", the applying date be on October 23rd, 1997, denomination of invention.

Technical field

The present invention relates to handle image decoder, picture coding device, image communication system and the coded bit stream converter of the coding stream of different coded systems.

Background technology

Now, in ISO/IEC JTC11/SC29/WG11, MPEG-4 in the standardized work (Moving Picture Experts Group Phase-4) mode and advise that with ITU-T H.263 standard is in the mode of foundation is attached to as the heading message in the coding stream of transmission signals (information signal of decoding usefulness) inequality.

Fig. 1 (a) is that expression is the figure of structure of the H.263 coding stream 201 of foundation with standard H.263, heading message 211 and with coded system H.263 encode as the macro block data 225 of image coded data by multiplexed.Fig. 1 (b) is the figure of the structure of expression MPEG-4 coding stream 202, heading message 212 and with the MPEG-4 coded system encode as the macro block data 239 of image coded data by multiplexed.As shown in the figure, the structure difference of coding stream, video object), VOL (Video Object Layer: the video object layer), VOP (Video Object Plane: relevant heading message such as video object plane) particularly in H.263, do not comprise (the Video Object: of needed VO when deciphering with MPEG-4.Therefore in order to carry out Image Communication, need independent image decoder and picture coding device respectively according to dual mode.

H.263 indication code 237, the often insertion of synchronizing information 238 more synchronously again of the GOB opening code 223 of coding stream 201, GOB heading message 224 and MPEG-4 coding stream 202 in addition, but just insert as required.

Like this since existing coding stream as above constitute, so there is such problem: for example in the image decoder of MPEG-4 correspondence, can not be to serving as the problem of deciphering according to the H.263 coding stream 201 that generates with H.263 standard.

In addition, for to corresponding with MPEG-4 and be that both coding stream of foundation is deciphered with H.263 standard, image decoder need have the decoding circuit of dual mode, has the problem of device complexity.

The present invention finishes in order to solve above-mentioned problem, its purpose is by means of simple structure, the image decoder that acquisition can be deciphered coding stream 201 H.263, generate the coding stream that can decipher with this image decoder picture coding device, H.263 coding stream is transformed into image communication system and the coded bit stream converter that communicates behind the MPEG-4 coding stream.

Summary of the invention

Image decoder of the present invention be to first heading message and with the first coded system image encoded coded data by the first multiplexed coding stream or to second heading message and the device deciphered by the second multiplexed coding stream with the second coded system image encoded coded data, this image decoder has: according to above-mentioned first heading message or above-mentioned second heading message, judge whether the coding stream that is received is the coded system judgment means of above-mentioned first coding stream or above-mentioned second coding stream; Receive above-mentioned second coding stream, the code translator that the image coding information of above-mentioned second coded system that comprises in above-mentioned second heading message is deciphered; And receive above-mentioned first coding stream, according to the above-mentioned first coded system image coding information that comprises in above-mentioned first heading message, set the setting device of the image coding information of above-mentioned second coded system, according to by the image coding information of above-mentioned setting device setting or the image coding information of deciphering by above-mentioned code translator, the image coded data that comprises in above-mentioned first coding stream or above-mentioned second coding stream is deciphered.

Therefore, has such effect: even the different coding stream of coded system also can be deciphered.

Image decoder of the present invention is a kind of like this device: the coded system judgment means is judged according to the coded system identifying information of first or second coded system that comprises in identification first heading message or second heading message.

Therefore, has such effect: even the different coding stream of coded system, also the recognition coding mode row decoding of going forward side by side easily.

Image decoder of the present invention is a kind of like this device: the coded system judgment means is judged according to the opening code that comprises in first heading message or second heading message.

Therefore, has such effect: even the different coding stream of coded system, also the recognition coding mode row decoding of going forward side by side easily.

Image decoder of the present invention is a kind of like this device: the coded system judgment means is judged according to the VOL that comprises in the H.263 opening code that comprises in first heading message or second heading message (Video Object Layer) opening code.

Therefore, have such effect: even coded system different H.263 with MPEG-4 coding stream, also the recognition coding mode row decoding of going forward side by side easily.

Image decoder of the present invention is a kind of like this device: the coded system judgment means is judged according to the VO that comprises in the image opening code that comprises in first heading message or second heading message (Video Object) opening code.

Therefore, have such effect: even coded system different H.263 with MPEG-4 coding stream, additional new heading message, also the recognition coding mode row decoding of going forward side by side easily.

Picture coding device of the present invention has: with first coded system picture signal is encoded, generate the code device of first coding stream; And make and guarantee heading message multiplexed heading message multiplex machine that sends in above-mentioned first coding stream of using with the interchangeability of second coding stream that adopts second coded system coding.

Therefore, have such effect: the code translator that second coding stream is deciphered generates first coding stream that can decipher.

Picture coding device of the present invention is a kind of like this device: it is that the coded system identifying information of first coded system is multiplexed that the heading message multiplex machine makes the opening code of second coded system and expression, as the heading message of guaranteeing that interchangeability is used.

Therefore, have such effect: the code translator that second coding stream is deciphered is the recognition coding mode easily, and generates first coding stream that can decipher.

Image communication system of the present invention has: with first coded system picture signal is encoded, generate the code device of first coding stream; To the code translator of deciphering with second coding stream of second coded system coding; And make from what above-mentioned code translator received and guarantee that the heading message that interchangeability uses is multiplexed above-mentioned first coding stream that receives from above-mentioned code device, send to the coded bit stream converter of above-mentioned code translator.

Therefore, have such effect: the code translator that second coding stream is deciphered generates first coding stream that can decipher.

Coded bit stream converter of the present invention has: input is with first coding stream of first coded system generation, the parser device that first heading message of above-mentioned first coded system is separated with image coded data; The code translator that separated above-mentioned first heading message is deciphered; According to first heading message, set second heading message of second coded system and the heading message setting device of encoding by above-mentioned code translator decoding; And make above-mentioned second heading message of above-mentioned image coded data that above-mentioned parser device separates and above-mentioned heading message setting device coding multiplexed, generate the multiplex machine of second coding stream.

Therefore, has such effect: can easily first coding stream be transformed into second coding stream.

Image decoder of the present invention be to first heading message and with the first coded system image encoded coded data by first coding stream of demultiplexing or device to being deciphered by second coding stream of multiplexedization with the second coded system image encoded coded data and second heading message, this image decoder has: according to above-mentioned first heading message or above-mentioned second heading message, judge whether the coding stream that is received is the coded system judgment means of above-mentioned first coding stream or above-mentioned second coding stream; Receive above-mentioned first coding stream, first code translator that above-mentioned first coding stream is deciphered; And receive above-mentioned second coding stream, second code translator that the image coding information of above-mentioned second coded system that comprises in above-mentioned second heading message is deciphered, at the coding stream that receives is under the situation of first coding stream, according to first heading message by above-mentioned first code translator decoding, the image coded data that comprises in first coding stream is deciphered, at the coding stream that receives is under the situation of second coding stream, according to image coding information, the image coded data that comprises in second coding stream is deciphered by above-mentioned second code translator decoding.

Therefore, have such effect: even the different coding stream of coded system, even and additional new heading message, also recognition coding mode easily even first coding stream is not set the image coding information of second coded system, also can be deciphered.

Description of drawings

Fig. 1 is the structure chart of existing H.263 coding stream of expression and MPEG-4 coding stream.

Fig. 2 is the structure chart of the coding stream that receives of the image decoder of expression example 1 of the present invention.

Fig. 3 is the structured flowchart of the image decoder of expression example 1 of the present invention.

Fig. 4 is the structured flowchart of the syntactic analysis variable-length decoding part of expression example 1 of the present invention.

Fig. 5 is the structured flowchart of the heading message analysis portion of expression example 1 of the present invention.

Fig. 6 is the structured flowchart of the H.263 visual heading message analysis portion of expression example 1 of the present invention.

Fig. 7 is the structured flowchart of the H.263 visual heading message decoding part of expression example 1 of the present invention.

Fig. 8 is the structured flowchart of the H.263GOB heading message analysis portion of expression example 1 of the present invention.

Fig. 9 is the key diagram of GOB.

Figure 10 is the structured flowchart of the GOB heading message decoding part of expression example 1 of the present invention.

Figure 11 represents the H.263 figure of the layer structure of macro block data.

Figure 12 is the structured flowchart of the macroblock layer syntactic analysis portion of expression example 1 of the present invention.

Figure 13 is the structured flowchart of the data block decoding part of expression example 1 of the present invention.

Figure 14 is the key diagram that calculates predictive vector.

Figure 15 is the structured flowchart of the structure decoding part of expression example 1 of the present invention.

Figure 16 is the structured flowchart of the re-quantization portion of expression example 1 of the present invention.

Figure 17 is the structured flowchart of the picture coding device of expression example 2 of the present invention and 4.

Figure 18 is the H.263 code device of explanation example 2 of the present invention and 4 and the related figure of MPEG-4 code translator.

Figure 19 is that the MPEG-4 of expression example 3 of the present invention exchanges the H.263 figure of the content of coding stream.

Figure 20 is the structured flowchart of the heading message analysis portion of expression example 3 of the present invention.

Figure 21 is the figure of the image communication system of expression example 5 of the present invention.

Figure 22 is the figure of the image communication system of expression example 6 of the present invention.

Figure 23 is the structured flowchart of the heading message analysis portion of expression example 7 of the present invention.

Figure 24 is the figure of beginning and end of the coding stream of explanation example 7 of the present invention.

Figure 25 is the block diagram of the coded bit stream converter of expression example 8 of the present invention.

Figure 26 is that expression GOB heading message reaches the figure of the structure of synchronizing information again.

Embodiment

Below, in order to illustrate in greater detail the present invention, the optimal morphology that the present invention uses is implemented in explanation with reference to the accompanying drawings.

Example 1

Fig. 2 is the figure of the structure of the coding stream that receives of the image decoder of expression example 1, and Fig. 2 (a) is that MPEG-4 exchanges H.263 coding stream 203, and Fig. 2 (b) is a MPEG-4 coding stream 204 in addition.H.263 MPEG-4 among Fig. 2 (a) exchanges, and coding stream 203 is to increase VO opening code 231, VO identiflication number 232, VOL opening code 233 and H.263 exchange identifying information 226 in the H.263 coding stream 201 shown in existing Fig. 1 (a).In addition, the MPEG-4 coding stream 204 shown in Fig. 2 (b) is to increase H.263 to exchange identifying information 226 in the MPEG-4 coding stream 202 shown in existing Fig. 1 (b).In addition, MPEG-4 exchanges the H.263 exchange identifying information 226 that increases in the H.263 coding stream 203 and MPEG-4 coding stream 204, as distinguishing the two information, for example establish promptly H.263 exchanging identifying information and be the position of " 0 " wherein, establish the position that another person is " 1 ".

Fig. 3 is the structured flowchart of the image decoder that VO (Video Object) is deciphered of expression example 1.Among the figure, the 1st, the coding stream that receives, the 2nd, syntactic analysis variable-length decoding part according to coding stream 1, is analyzed grammer (multiplexed vision signal), exports coded shape data 3, structured coding data 6, structural change data 7 simultaneously.The 4th, coded shape data 3 is deciphered, ask the shape decoding part of decoding shape data 5, the 8th, change compensation according to structural change data 7, ask the change compensation section of predict data 9, the 10th, according to structured coding data 6 and predict data 9, ask the structure decoding part of the decoding architecture data of deciphering 11.

Secondly, working condition is described.

Here, main explanation is exchanged the H.263 work decoding of coding stream 203 as the MPEG-4 among Fig. 2 (a) of emphasis of the present invention.Therefore, illustrate under the rectangular situation of the shape of each VOP, promptly in bit stream, do not comprise under the situation of coded shape data, structured data or be coded in situation in each macro block about the information of change.

The work decoding of the MPEG-4 coding stream 204 among Fig. 2 (b) is basically with identical in the past in addition.

At first, syntactic analysis variable-length decoding part 2 is separated into significant data according to the diadic bit stream with the coding stream of importing 1.This syntactic analysis variable-length decoding part 2 can carry out MPEG-4 and exchanges the H.263 decoding of coding stream 203 then.Change compensation section 8 changes compensation, prediction of output structured data 9 according to the structural change data 7 by 2 outputs of syntactic analysis variable-length decoding part.10 inputs of structure decoding part obtain decoding architecture data 11 by the structured coding data 6 of syntactic analysis variable-length decoding part 2 outputs and the predict data of being exported by change compensation section 89.

Secondly, syntax of declaration is analyzed the work of variable-length decoding part 2.

Fig. 4 is the structured flowchart of expression syntactic analysis variable-length decoding part 2.Among the figure, the 21st, take out the heading message that is attached in the coding stream 1, set the heading message analysis portion of necessary various heading messages in the later encoded control, the 22nd, according to coding stream 1, ask the macroblock layer structural analysis portion of structured coding data 6 and structural change data 7.

Fig. 5 is the structured flowchart of expression heading message analysis portion 21.Among the figure, the 30th, the VO opening code test section of the VO opening code 231 in the detection coding stream 1, the 31st, according to the VOL opening code test section of coding stream 1 detection VOL opening code 233, the 32nd, the coded system judging part, be used for judging that coding stream 1 is that MPEG-4 exchanges H.263 coding stream 203, or MPEG-4 coding stream 204, and H.263 output exchange identifying information 33.The 34th, the switching part that the coded system that basis is concluded is switched, the 35th, exchange at MPEG-4 under the situation of coding stream 203 H.263, to distinctive image coding information in the mode H.263 is that image header information 222 is deciphered, distinctive image coding information is the H.263 visual heading message analysis portion of VOL heading message 234 and VOL heading message 236 in the setting MPEG-4 mode, the 36th, exchange at MPEG-4 under the situation of coding stream 203 H.263, H.263GOB (Group of Block) heading message 224 is deciphered, according to the GOB heading message 224 after the decoding, carry out the H.263GOB heading message analysis portion of the change of the VOP heading message 236 set by visual heading message analysis portion 35 H.263, the 37th, under the situation of MPEG-4 coding stream 204, the VOL heading message decoding part that VOL heading message 234 is deciphered, the 38th, under the situation of MPEG-4 coding stream 204, the VOL heading message analysis portion that VOL heading message 236 is deciphered.

Secondly, the work of heading message analysis portion 21 is described.

If VO opening code test section 30 detects MPEG-4 shown in Figure 2 and exchanges VO opening code 231 in coding stream 203 H.263 or the MPEG-4 coding stream 204, just begin to carry out following work decoding.VOL opening code test section 31 detects VOL opening code 233 according to coding stream 1.Then, coded system judging part 32 is according to coding stream 1, decipher H.263 exchanging identifying information 226, according to H.263 exchanging identifying information 226, judge that coding stream 1 is that MPEG-4 exchanges H.263 coding stream 203, still MPEG-4 coding stream 204 is exported and is H.263 exchanged identifying information 33.

At coding stream 1 is that MPEG-4 exchanges under the situation of coding stream 203 H.263, and coding stream 1 is input in the H.263 visual heading message analysis portion 35 by switching part 34.

Fig. 6 is a structured flowchart of representing H.263 visual heading message analysis portion 35.If H.263 image opening code test section 41 is according to coding stream 1 detected image opening code 221, then secondly H.263 image header information decoding portion 42 according to coding stream 1 image header information 222 is deciphered.Then, VOP heading message 234 and VOP heading message 236 are set according to the image header information 222 after deciphering in MPEG-4 heading message configuration part 43.

Fig. 7 represents the H.263 structured flowchart of image header information decoding portion 42.Temporalreference (interim standard) (TR) decoding part 51 inputs deciphers blank between the image that is transmitted or unreferenced picture number (TR) from the bit stream 1 of image opening code test section 41 H.263.As required, use this information during demonstration.

Secondly, image type (PTYPE) decoding part 52 carries out the decoding of image type (PTYPE).Comprise information such as picture format 301, image encoding type 302, optional approach Warning Mark 303 in the image type.Picture format 301 after the decoding, image encoding type 302 are exported to the MPEG-4 heading message configuration part 43 among Fig. 6.

Image type (PTYPE) decoding part 52 is judged whether ON (effectively) of optional approach Warning Mark 303 in addition.Under situation H.263, though prepared several optional approach, but in the described image decoder of this example, comprise the bit stream interchangeability unconfirmed of these optional approach, the coding stream that these optional approach become ON (effectively) is input to work decoding end portion 54 by switching part 53.Then, work decoding end portion 54 finishes the work decoding to this coding stream.Though comprise in the image type about other and show the information that waits regulation, also can use them as required.

On the other hand, the optional approach bit stream that becomes OFF (invalid) is input to the image quantization rank apart from (PQUANT) decoding part 55 by switching part 53.The decoding of image quantization rank apart from (PQUANT) 304 is carried out apart from (PQUANT) decoding part 55 in the image quantization rank.Image quantization rank after the decoding are apart from the 304 MPEG-4 heading message configuration parts 43 that are exported among Fig. 6.The image quantization rank do not need owing in the decoding afterwards apart from 304 later image header information, so abandon.

Secondly, the work of the MPEG-4 heading message configuration part 43 in the key diagram 6.

MPEG-4 heading message configuration part 43 as VOL heading message 234, is set shape information and the target size of VOL according to the image header information 222 of decoding.Exchange under the situation of coding stream H.263 at MPEG-4 in addition, each bit stream is corresponding to frame, so MPEG-4 heading message configuration part 43 is set at rectangle with shape information.In addition since target size corresponding to frame size, so frame size is asked according to the picture format 301 of one of image header information 222 in MPEG-4 heading message configuration part 43, be set in the target size.In addition, whether the level that carries out each pixel is 8 setting.Under situation H.263, because the level of each pixel is not predefined in beyond 8, so the level of each pixel is set at 8.

Secondly, MPEG-4 heading message configuration part 43 will be as sprite coding, mistake tolerance coding, the inner AC/DC prediction of the encoding condition of MPEG-4 benchmark, that ス ケ-ラ PVC リ テ イ coding is set at is invalid.In addition, under the situation of MPEG-4 since can according to H.263, these two kinds of methods of MPEG-1/2 select quantization methods, so exchange at MPEG-4 under the situation of coding stream 203 H.263, H.263 quantization method is set at.

VOP heading message 236 is set in MPEG-4 heading message configuration part 43 in addition.As VOP heading message 236, set prediction type, the quantization step distance of VOP.In the type of prediction of VOP, only have with the situation of the inside of the digital coding in the VOP and the situation of the inside of the digital coding of the VOP before and after using.Can be according to the prediction type of setting VOP as the image encoding type 302 of one of image header information 222.The quantization step of VOP can be used as image quantization rank distance 304 settings of image header information 222 apart from too in addition.

Under the situation of MPEG-4,, prepared to specify the sign indicating number of the exploration scope of dynamic vector in addition owing to can from 7 kinds, select the exploration scope of dynamic vector.Different therewith, under situation H.263, since only corresponding with a kind of exploration scope wherein, so MPEG-4 heading message configuration part 43 need be set at the exploration scope designated code of dynamic vector the sign indicating number corresponding with the exploration scope of the dynamic vector that uses in H.263.In addition under the situation of MPEG-4, though corresponding to interlaced image, under situation H.263, do not correspond to interlaced image, so often the interlace mode indication information is set at invalid.

If the analysis of the image header information that the H.263 image header information analysis portion 35 among Fig. 5 carries out finishes, then under GOB opening code 223 and GOB heading message 224 are inserted into situation in the coding stream, then just carry out the analysis of GOB heading message 224 by heading message analysis portion 36 H.263GOB.Under GOB opening code 223 and GOB heading message 224 were not inserted into situation in the coding stream, H.263GOB heading message analysis portion 36 was not worked.

Fig. 8 is the structured flowchart of the H.263GOB heading message analysis portion 36 in the presentation graphs 5.If GOB opening code test section 61 detects the GOB opening code 223 that is attached in the coding stream 1, just GOB heading message decoding part 62 is deciphered GOB heading message 224.

Fig. 9 is the figure of explanation GOB.As shown in the figure, GOB is divided into several macro block strings with image, is included in the decoding side-draw and gets synchronous necessary information again in GOB heading message 224.In the position of coding stream, cause under the wrong situation, when carrying out variable length code and predictive coding, can not correctly decipher and propagate errors later macro block data.If detect the GOB heading message, then before the macro block decoding to the GOB beginning, owing to can obtain the synchronous again of coding stream, needed information in the time of setting later macro block decoding again is so can prevent wrong propagation.Owing to carry out predictive coding that the difference of the quantization step distance of the macro block of whole codings and dynamic vector is encoded,, need set their information again so obtain again under the synchronous situation at the quantization step distance and the dynamic vector of each macro block.

Figure 10 is the structured flowchart of expression GOB heading message decoding part 62.GOB numbering decoding part 71 is deciphered GOB numbering (GN) according to coding stream 1.72 pairs of the GOB frame identiflication number decoding parts identiflication number (GFID) that belongs to the image of GOB is deciphered then.The GOB quantization step is deciphered apart from (GQUANT) 305 apart from 73 pairs of GOB quantization steps of decoding part in addition, exports to the MPEG-4 heading message changing unit 63 among Fig. 8.

MPEG-4 heading message changing unit 63 is according to the GOB heading message 224 of decoding, and change is by the VOP heading message 236 of MPEG-4 heading message configuration part 43 settings.Information with 224 changes of GOB heading message is the quantization step distance, GOB quantization step distance is set at the quantization step distance of VOP.More than each information of She Dinging is exported to the macroblock layer syntactic analysis portion 22 among Fig. 4.

Under the situation of H.263 exchanging identifying information 226 expression MPEG-4, the coded system judging part 32 among Fig. 5 concludes that coding stream 1 is a MPEG-4 coding stream 204, outputs to and H.263 exchanges identifying information 33.MPEG-4 coding stream 204 is switched portion 34 and is input to VOL heading message decoding part 37 then.VOL heading message decoding part 37 is deciphered VOL heading message 234 according to coding stream, and 38 pairs of VOP heading messages 236 of VOP heading message analysis portion are deciphered, and exports to the macroblock layer syntactic analysis portion 22 among Fig. 4.

If above information is set, then macroblock layer syntactic analysis portion 22 analyzes according to the grammer of MPEG-4, and macro block data 225,239 is deciphered.But, the coding method of blocks of data MPEG-4 with H.263 in some is different, so even also need switch operating in the decoding side.

Figure 11 is the figure that the MPEG-4 of expression in the example 1 exchanges the layer structure of the macro block data 225 in the coding stream 203 H.263.Macro block is made of 4 luminance block and 2 aberration pieces.As shown in the figure, the blank judgement information 251 of macro block, the effective aberration piece of macro block (mb) type identifying information 252, active block identifying information 253, differential quantization rank apart from 254 and each attribute information of incremental data 255 in each macro block all by multiplexed.

Here, macro block is blank judges that information 251 is that whole coefficient datas that whether the moving amount of owing is zero and macro block is interior among the VOP in being illustrated in (make received image signal (be original signal under the inner situation, under the interior situation be differential signal with reference VOP) behind the DCT, the data that are quantized) whether be zero information, be zero at dynamic vector, coefficient data all is under zero the situation, not comprise the later information about this macro block in the bit stream.Therefore, in next macro block, form blank.

In addition, when macro block data is encoded, (inside) under the situation that the original signal that uses macro block is encoded or changing compensation prediction and to the situation of encoding with the differential signal of reference macro block under (interior), the macro block (mb) type of the effective aberration piece of macro block (mb) type identifying information 252 is that expression uses quantization step with previous macro block apart from the information of different quantization steps apart from the macroblock encoding types such as situation of encoding.

Active block identifying information 253 is whether the coefficient data of each piece of expression all is zero information in addition.Though coefficient data is under the situation of invalid block by multiplexed (being equivalent to blocks of data 256) at this active block identifying information 253 of expression in each piece after above-mentioned attribute information, does not have the coefficient data of this piece.

And macro block (mb) type represent with the quantization step of previous macro block under different situations, the differential quantization rank are apart from 254 being multiplexed information, the difference value of expression and the quantization step distance of previous macro block.

Figure 12 is the structured flowchart of expression macroblock layer syntactic analysis portion 22.Among the figure, the 81st, the switching part that the shape information 311 that utilization is set in MPEG-4 heading message configuration part 43 is switched, the 82nd, the coded shape data decoding part that the coded shape data in the coding stream is deciphered, the 83rd, the switching part that the VOP type of prediction 312 that utilization is set in MPEG-4 heading message configuration part 43 is switched, the 84th, be under the inner situation in addition in the VOP type of prediction, the blank of macro block is judged the blank judgement information decoding portion that information 251 is deciphered, the 85th, the switching part that utilizes blank judgement information 251 to switch, the 86th, under forming blank situation, make the dynamic vector of this macro block and structured data all be zero blank the time data setting portion, the 87th, in VOP type of prediction 312 for inner situation or do not have under the blank situation, the effective aberration piece of the macro block (mb) type identifying information decoding part that macro block (mb) type 313 and effective aberration piece identifying information are deciphered.

Other 88 is the switching parts that utilize the inside AC/DC prediction mode indication information 315 set in MPEG-4 heading message configuration part 43 to switch, the 89th, the AC that AC prediction indication information is deciphered predicts the indication information decoding part, the 90th, the active block identifying information decoding part that active block identifying information 253 is deciphered, the 91st, the switching part that utilizes the macro block (mb) type 313 by 87 outputs of the effective aberration piece of macro block (mb) type identifying information decoding part to switch.

Other 92 is apart from differential quantization rank distance zero configuration part that is set at zero with the differential quantization rank, the 93rd, to the differential quantization rank apart from the 317 differential quantization rank of deciphering apart from decoding part, the 94th, with the differential quantization rank after the decoding apart from 317 and last VOP quantization step apart from 318 additions, with the quantization step distance 319 addition portions that export to the structure decoding part 10 among Fig. 3, the 95th, be used to the switching part that the interlace mode indication information 316 from MPEG-4 heading message configuration part 43 switches, the 96th, the staggered information decoding portion that staggered information is deciphered, the 97th, according to exploring scope appointed information 320 by the macro block (mb) type 313 of the effective aberration piece of macro block (mb) type identifying information decoding part 87 outputs and by the VOP type of prediction 312 and the dynamic vector of 43 outputs of MPEG-4 heading message configuration part, the dynamic vector decoding part that dynamic vector (structural change data 7) is deciphered, the 98th, the encoding block data are deciphered, structured coding data 6 are exported to the blocks of data decoding part of structure decoding part 10.

Next illustrates the work of macroblock layer syntactic analysis portion 22.

Here illustrate that coding stream 1 is that MPEG-4 exchanges the H.263 situation of coding stream 203.About the situation of MPEG-4 coding stream 204, owing to be documented among the ISO/IECJTC1/SC29/WG11 MPEG-4 Video VM8.0, so with its omission.

According to the shape information of in MPEG-4 heading message configuration part 43, setting 311, switch output encoder bit stream 1 by switching part 81.At coding stream 1 is that MPEG-4 exchanges under the situation of coding stream 203 H.263, because shape information 311 is set to rectangle, so coding stream 1 is not transfused to switching part 83 by coded shape data decoding part 82.

Secondly switching part 83 switches according to the VOP type of prediction of setting in MPEG-4 heading message configuration part 43 312.In VOP type of prediction 312 is under the situation of inside, and 87 pairs of macro block (mb) types of the effective aberration piece of macro block (mb) type identifying information decoding part 313 and effective aberration piece identifying information are deciphered.In the VOP type of prediction is under the inner situation in addition, and the blank judgement information 251 of 84 pairs of macro blocks of blank judgement information decoding portion is deciphered.Switching part 85 is judged information 251 according to the blank after deciphering, switch, represent to form under the blank situation at this macro block, data setting portion 86 all is set at zero with the dynamic vector and the structured data in the macro block of this macro block when blank, about the decoding end of this macro block.Judging information 251 according to blank, this macro block is represented not form under the blank situation, and 87 pairs of macro block (mb) types of the effective aberration piece of macro block (mb) type identifying information decoding part 313 and effective aberration piece identifying information are deciphered.

Secondly switching part 88 switches according to the inside AC/DC prediction mode indication information of setting in MPEG-4 heading message configuration part 43 315.Exchange at MPEG-4 under the situation of coding stream 203 H.263, owing to do not carry out the function of inner AC/DC prediction, so when setting VOL heading message 234, it is invalid that inner AC/DC prediction is set to, and can not be transfused to active block identifying information decoding part 90 by AC prediction indication information decoding part 89.

Secondly the luminance block in 90 pairs of macro blocks of active block identifying information decoding part is carried out the decoding of active block identifying information 253.Switching part 91 is according to the macro block (mb) type 313 after being deciphered by the effective aberration piece of macro block (mb) type identifying information decoding part 87, switch, the quantization step of this macro block apart from previous decoding after the quantization step of macro block under different situations, the differential quantization rank distance 317 of the quantization step distance of the macro block of differential quantization rank behind 93 pairs of decoding parts and the previous coding is deciphered.Utilize adder 94, the differential quantization rank distance 317 after the decoding and the VOP quantization step of previous macro block apart from 319, are exported to the structure decoding part 10 among Fig. 3 as quantization step apart from 318 additions.

On the other hand, under identical situation, the differential quantization rank are zero apart from being set at the differential quantization rank apart from zero configuration part 92 at the quantization step of the quantization step of the macro block macro block after expression and the previous decoding.

Secondly switching part 95 switches according to the interlace mode indication information 316 from MPEG-4 heading message configuration part 43.Exchange at MPEG-4 under the situation of coding stream 203 H.263, because not corresponding,, be not transfused to dynamic vector decoding part 97 by the information decoding portion 96 that interlocks so that interlace mode is set to is invalid with staggered image.Then, in the VOP prediction mode of being set by MPEG-4 heading message configuration part 43 312 is under interior situation, dynamic vector decoding part 97 is according to exploring scope appointed information 320 by the macro block (mb) type 313 after 87 decodings of the effective aberration piece of macro block (mb) type identifying information decoding part with by the dynamic vector that MPEG-4 heading message configuration part 43 is set, dynamic vector (structural change data 7) is deciphered, exported to the change compensation section 8 among Fig. 3.

Secondly the encoding block data in 98 pairs of coding streams of blocks of data decoding part are deciphered.Figure 13 is the structured flowchart of expression blocks of data decoding part 98.Among the figure, the 101st, the input coding blocks of data, the switching part that while switches according to the macro block (mb) type 313 by 87 outputs of the effective aberration piece of macro block (mb) type identifying information decoding part, the 102nd, the switching part that the inside AC/DC prediction mode indication information 315 that basis is set by MPEG-4 heading message configuration part 43 switches, the 103rd, predict when invalid at inner AC/DC, according to level 321 from each pixel of MPEG-4 heading message configuration part 43, export the DC coefficient regular length decoding part of the decoding internal DC coefficient 111 of the decoding of carrying out DC coefficient regular length, the 104th, predict when effective at inner AC/DC, the DC coefficient is deciphered the DC coefficient decoding part of output internal DC coefficient 111.

The 105th, the switching part that the active block identifying information 253 that basis is exported from active block identifying information decoding part 90 switches, the 106th, according to by the macro block (mb) type 313 of the effective aberration piece of macro block (mb) type identifying information decoding part 87 outputs and the H.263 exchange identifying information of exporting by coded system judging part 32 33, switch AC coefficient VLD (Variable LengthDecoding: variable-length decoding) the AC coefficient VLD table switching part of table.

The 107th, the AC coefficient data is carried out variable-length decoding, the AC coefficient data variable-length decoding part of output decoding AC coefficient data 112, the 108th, according to H.263 exchanging the switching part that identifying information 33 switches by coded system judging part 32 output, the 109th, the AC coefficient data regular length decoding part of output decoding AC coefficient data 112, the 110th, the AC coefficient data Esc coding decoding part of output decoding AC coefficient data 112, the 113rd, be zero AC coefficient zero configuration part with the AC coefficient settings.

Secondly the work of illustrated block data decoding portion 98.

At first, according to the macro block (mb) type 313 by 87 outputs of the effective aberration piece of macro block (mb) type identifying information decoding part, switching the encoding block data with switching part 101, is under the inner situation in addition at macro block (mb) type 313, exports to switching part 105.At macro block (mb) type 313 is that the encoding block data are transfused to switching part 102 under the situation of inside, switches according to the inside AC/DC prediction mode indication information of being set by MPEG-4 heading message configuration part 43 315.

Exchange at MPEG-4 under the situation of coding stream 203 H.263, because that AC/DC prediction mode 315 is set to is invalid, so by DC coefficient decoding part 104, and be transfused to DC coefficient regular length decoding part 103.DC coefficient regular length decoding part 103 carries out regular length decoding, will decipher internal DC coefficient 111 and export to structure decoding part 10, simultaneously the encoding block data is exported to switching part 105.At this moment the code length after the regular length decoding equals the level (default value 8) 321 of each pixel of being set by MPEG-4 heading message configuration part 43, because the level 321 of each pixel is set to 8 of default value, so identical with the situation of H.263 corresponding code translator.

Switching part 105 is according to being switched by the active block identifying information 253 after 90 decodings of active block identifying information decoding part, at this piece is under the situation of invalid block, AC coefficient zero configuration part 113 is set at zero with the decoding AC coefficient data 112 in the piece, exports to structure decoding part 10.At this piece is under the situation of active block, and the encoding block data are transfused to AC coefficient VLD table switching part 106.

In code device one side, according to the sequence number of in piece, determining coefficient is scanned, with the expression nonzero coefficient in piece whether in groups in level (LEVEL) combination of last sign (LAST), continuous zero number (RUN) and the nonzero coefficient thereafter that continues, the AC coefficient in the piece is carried out variable length code.In the decoding side, by coded data being carried out variable-length decoding, obtain the combination of (LAST, RUN, LEVEL), according to this combination, can reproduce the AC coefficient in the piece.In addition when variable length code is carried out in the combination of (LAST, RUN, LEVEL), under the situation of MPEG-4, according to macro block (mb) type, utilize different VLC (Variable Length coding: variable length code) table, carry out variable length code, different therewith, under situation H.263, irrelevant with macro block (mb) type, utilize identical VLC table to carry out variable length code.

Therefore in the image decoder of this example, AC coefficient VLD table switching part 106 switches AC coefficient VLD table according to by the macro block (mb) type 313 of the effective aberration piece of macro block (mb) type identifying information decoding part 87 outputs and the H.263 exchange identifying information of being exported by coded system judging part 32 33.Be set under H.263 the situation H.263 exchanging identifying information 33 then, irrelevant with macro block (mb) type (inner, interior) 313, AC coefficient variable length decoding part 107 utilizes a VLD table, carry out variable-length decoding, will decipher AC coefficient data 112 and export to structure decoding part 10 as coding structure data 6.

Do not have in VLC table in addition under the situation of combination of (LAST, RUN, LEVEL), MPEG-4 is also different with coding method H.263.Do not have in the VLC table when MPEG-4 under the situation of combination of (LAST, RUN, LEVEL), after escape character was encoded, the value of modified R UN or LEVEL was carried out variable length code or is carried out fixed-length code (FLC).On the other hand, under situation H.263, after escape character encoded, the value of each LAST, RUN, LEVEL is carried out fixed-length code (FLC).

Therefore in the image decoder of this example, from AC coefficient coding Data Detection during to escape character, coding stream is imported into switching part 108 by AC coefficient data variable-length decoding part 107.Be set under H.263 the situation H.263 exchanging identifying information 33 then, coding stream is not by AC coefficient data Esc coding decoding part 110, utilize the code length of having determined respectively about the sign indicating number of LAST, RUN, LEVEL by AC coefficient regular length decoding part 109, carry out regular length decoding successively, will decipher AC coefficient data 112 and export to structure decoding part 10 as structured coding data 6.

By above work, distributed to structure decoding part 10, change compensation section 8 respectively by structured coding data 6, the dynamic vector (structural change data 7) of 22 outputs of macroblock layer syntactic analysis portion.

After as above handling, in the syntactic analysis variable-length decoding part 2 in Fig. 3, the prediction mode of VOP is deciphered and set.Prediction mode at VOP is under interior situation, and the differential vector of structure dynamic vector is deciphered.The differential vector of the structure dynamic vector after the decoding is the differential vector of the predictive vector of trying to achieve with near the dynamic vector of 3 macro blocks and actual dynamic vector, therefore, as dynamic vector (structural change data 8), calculate predictive vector is added in vector in the differential vector of dynamic vector.

Shown in Figure 14 (a), utilize near the dynamic vector of 3 macro blocks (MV1, MV2, MV3) of having deciphered, calculate predictive vector.But in nigh 3 macro blocks under the situation of some outside that is positioned at VOP, shown in Figure 14 (b), (d), the value of dynamic vector of macro block that will be positioned at the outside of VOP is set at zero vector, perhaps shown in Figure 14 (c), sets with the dynamic vector of the macro block in the VOP.Under coded system is H.263 situation, when having defined the GOB title, in the border of GOB, need to carry out the setting of predictive vector.The establishing method of predictive vector is identical with the situation of VOP.According to the vector after the decoding, take out predictive vector as predict data 9, export to structure decoding part 10.

On the other hand, under the prediction mode of VOP is inner situation, do not change compensation prediction.

Structure decoding part 10 receives structured coding data 6, and structured data 11 is restored.

Figure 15 is the structured flowchart of expression structure decoding part 10.114 pairs of structured coding data of re-quantization portion 6 are carried out re-quantization.

Figure 16 is the structured flowchart of expression re-quantization portion 114.

Switching part 17 switches according to the macro block (mb) type 313 that comprises in the structured coding data 6.Under the macro block (mb) type 313 of decoding object piece be situation in interior coded system, do not comprise the DC coefficient data owing in the structured coding data 6, so structured coding data 6 are imported into AC coefficient re-quantization portion 120.Macro block (mb) type 313 at decoding object piece is that structured coding data 6 are imported into switching part 118 under the situation of in-line coding mode.

Switching part 118 switches according to H.263 exchanging identifying information 33.Exchange under the situation of coding stream 203 H.263 H.263 exchanging identifying information 33 expression MPEG-4, DC coefficient linear inverse quantization unit 119B carries out the re-quantization of the DC coefficient data that comprises in the structured coding data 6.On the other hand, under the situation of H.263 exchanging identifying information 33 expression MPEG-4 coding streams 204, DC coefficient nonlinear inverse quantization unit 119A carries out the re-quantization of DC coefficient data, output DC coefficient 306.By with the DC coefficient divided by a certain definite value (being called quantization scale), fractional part is cast out, carry out the quantification of DC coefficient.Therefore,, multiply by quantization scale, DC coefficient 306 is restored by quantizing the DC coefficient in the decoding side.In DC coefficient linear inverse quantization unit 119B and DC coefficient nonlinear inverse quantization unit 119A, the setting difference of the value of this quantization scale.In DC coefficient linear inverse quantization unit 119, quantization scale adopts fixed value 8 to carry out re-quantization.On the other hand, in DC coefficient nonlinear inverse quantization unit 119A,, non-linearly set the value of quantization scale, utilize this quantization scale to carry out re-quantization, output DC coefficient 306 according to the scope of quantization step distance 319.

Secondly AC coefficient re-quantization portion 120 carries out the re-quantization of AC coefficient data, output AC coefficient 307.Be used as DCT coefficient 308 by the DC coefficient of re-quantization when in-line coding mode (only exist) 306 and AC coefficient 307 and give DCT portion 115, implement after the inverse DCT, as 309 outputs of decoding predictive error signal.After predictive error signal 309 and predict data 9 additions by 8 acquisitions of change compensation section will be deciphered by addition portion 116, as 11 outputs of decoding architecture data.But, under the situation of in-line coding mode, do not carry out the add operation of predict data 9.

H.263 exchange identifying information 33 by under the multiplexed situation in coding stream 1, shown in Fig. 2 (a), sequential end code (EOS) 227 that also has the end of expression sequential is by multiplexed situation.Carry out the detection of sequential end code 227 by image opening code test section 41, if detect sequential end code 227, then work decoding finishes.

As mentioned above, if adopt this example 1, then owing to receive VO opening code 231, VOL opening code, VO identiflication number 232 and H.263 exchange the MPEG-4 that identifying information 226 is multiplexed in the coding stream 201 H.263 and exchange H.263 coding stream 203, these information are deciphered, so can obtain such effect: the image decoder that can obtain H.263 to have interchangeability with MPEG-4.

Example 2

Figure 17 is the structured flowchart of the picture coding device in the expression example 2, with generating the coding stream that the image decoder described in the example 1 can be deciphered.Among the figure, the 121st, received image signal, the 122nd, mode encoding section H.263, the 123rd, coding stream H.263, the 124th, MPEG-4 exchanges sign, and the 125th, the multiplexed portion of heading message, the 126th, MPEG-4 exchanges H.263 coding stream.

Following explanation work.

At first, H.263 mode encoding section 122 bases grammer is H.263 encoded to received image signal 121, generates H.263 coding stream 123.Secondly multiplexed 125 reception of heading message represents that the MPEG-4 of the bit stream that the code translator of generation MPEG-4 benchmark can be deciphered exchanges sign 124, before the image header of bit stream H.263, make the image decoder described in the example 1 decipher needed VO opening code 231, VO identiflication number 232, VOL opening code 233 and H.263 to exchange identifying information (expression is the sign 0 or 1 of the H.263 bit stream of benchmark) 226 multiplexed.Like this, exchanged the content of coding stream 126 H.263 by multiplexed MPEG-4 and become the content shown in Fig. 2 (a) in the example 1.

In addition, as shown in figure 18, H.263 carrying out under the situation of real time communication between code device 127 and the MPEG-4 code translator 128, from MPEG-4 code translator 128 1 sides MPEG-4 is exchanged sign 124 and send to H.263 code device 127, if H.263 code device 127 receives MPEG-4 and exchanges sign 124, then can in mode bit stream 123 H.263, make the image decoder described in the example 1 decipher needed VO opening code 231, VO identiflication number 232, VOL opening code 233 and H.263 to exchange identifying information 226 multiplexed.

As mentioned above, if adopt this example 2, then since make VO opening code 231, VO identiflication number 232, VOL opening code 233 and H.263 exchange identifying information 226 multiplexed in mode bit stream 123 H.263, so can obtain such effect: the picture coding device that can obtain to be created on the coding stream that can decipher in the image decoder of MPEG-4 correspondence.

Example 3

Figure 19 is that the MPEG-4 in the expression example 3 exchanges the H.263 structure chart of coding stream 205, is that increase VO opening code 231, VO identiflication number 232 reach H.263 opening code 228 in the H.263 coding stream 201 shown in existing Fig. 1 (a).And H.263 opening code 228 has VOL opening code 233 multiplexed in example 1 and H.263 exchanges both functions of identifying information 226.

In addition, MPEG-4 coding stream 202 identical with shown in existing Fig. 1 (b).

Just heading message analysis portion 21 is different in image decoder in this example and the example 1 described image decoder.Figure 20 is the structured flowchart of the heading message analysis portion 21 in the expression example 3.Among the figure, the 131st, opening code/VOL opening code test section H.263, the 132nd, H.263 the coded system judging part VO opening code test section 30, exchanges identifying information 33, switching part 34, H.263 structure caption information analysis portion 35, shown in Figure 5 identical in heading message analysis portion 36, VOL heading message decoding part 37, VOP heading message analysis portion 38 and the example 1 H.263GOB.

Secondly explanation work.

If VO opening code test section 30 detects VO opening code 231, just begin to carry out following work decoding.At first, H.263 opening code/VOL opening code test section 131 exchanges under the situation of coding stream 205 H.263 at MPEG-4, detects H.263 opening code, under the situation of MPEG-4 coding stream 202, detects VOL opening code 233.

Under the situation of MPEG-4, the opening code of each layer is that the intrinsic opening code of each layer continues fixing length (5) at common sign indicating number (0,000 0,000 0,000 0,000 0,000 0001) in whole opening codes afterwards.In bit stream, except opening code, can not detect common opening code.Therefore, H.263 opening code 228 also adds the sign indicating number that can discern the regular length (5) that is H.263 coding stream after common opening code.

Secondly, be under the situation of H.263 opening code 228 at detected opening code, H.263 coded system judging part 132 will exchange identifying information 33 and be set at H.263.In addition, under the situation of VOL opening code 233, will H.263 exchange identifying information 33 and be set at MPEG-4.After this work is identical with example 1.

As mentioned above, if adopt this example 3, then owing to receive VO opening code 231, VOL opening code, VO identiflication number 232 and H.263 exchange the MPEG-4 that identifying information 228 is multiplexed in the coding stream 201 H.263 and exchange H.263 coding stream 205, these information are deciphered, so can obtain such effect: the image decoder that can obtain H.263 to have interchangeability with MPEG-4.

Example 4

This example is the picture coding device that generates the bit stream that example 3 described image decoders can decipher, its structure and example 2 shown in Figure 17 identical.

Secondly explanation work.

At first, H.263 mode encoding section 122 bases grammer is H.263 encoded to received image signal 121, generates H.263 coding stream 123.Secondly multiplexed 125 of heading message receives MPEG-4 and exchanges sign 124, before the structure caption of coding stream 123 H.263, make the image decoder described in the example 3 multiplexed for deciphering needed VO opening code 231, VO identiflication number 232 and H.263 exchanging identifying information 228.Multiplexed like this MPEG-4 exchanges the content shown in Figure 19 that the content of coding stream 126 H.263 becomes example 3.

In addition, as implementing the shown in Figure 180 of form 2, MPEG-4 exchanges sign 124 and can be sent by MPEG-4 code translator 128.

As mentioned above, if adopt this example 4, then since in bit stream 201 H.263, make VO opening code 231, VO identiflication number 232 and H.263 exchange identifying information 228 multiplexed, so can obtain such effect: the picture coding device that can obtain the coding stream that generation can decipher with the image decoder of MPEG-4 correspondence.

Example 5

This example is to make MPEG-4 exchange multiplexed multiplexed and the code device independence of heading message of usefulness, for example is the device that has on the network.Figure 21 is the figure of the image communication system in the expression example 5.Among the figure, the 141st, code device H.263, the 142nd, the MPEG-4 code translator, the 143rd, coded bit stream converter, H.263 code device 141, MPEG-4 code translator 142 and coded bit stream converter 143 are connected on the network.

Secondly explanation work.

If receiving by MPEG-4 code translator 142 or user, coded bit stream converter 143 ask MPEG-4 to exchange the H.263 MPEG-4 exchange sign 147 of coding stream 148, then coded bit stream converter 143 receives H.263 coding stream 146 by code device 141 H.263, as implement as described in form 2 or the example 4, it is multiplexed to make the MPEG-4 code translator decipher needed heading message in coding stream 146 H.263, sends to MPEG-4 code translator 142.

As mentioned above, if adopt this example 5, then have coded bit stream converter 143, so can obtain such effect: the image communication system that can obtain H.263 to have interchangeability with MPEG-4 owing on the network.

Example 6

Figure 22 is the figure of the image communication system in the expression example 6.Among the figure, the 141st, code device H.263, the 143rd, coded bit stream converter, the 144th, server, the 145th, the picture tube of installing in the MPEG-4 code translator (Off ヅ ゲ ザ), they all are connected on the network.

Secondly explanation work.

The picture tube of installing in the MPEG-4 code translator 145 is under the situation that the H.263 coding stream 146 to transmission over networks conducts interviews, and the picture tube of installing in the MPEG-4 code translator 145 will represent that the MPEG-4 code translator exchanges sign 147 at the MPEG-4 that deciphers and sends server 144 to.If server 144 receives MPEG-4 and exchanges sign 147, just H.263 coding stream 146 sends coded bit stream converter 143 to.

As implement described in form 2 or 4, coded bit stream converter 143 generations are exchanged H.263 coding stream 148 to the MPEG-4 that the H.263 coding stream 146 that receives has increased heading message, so that the MPEG-4 code translator can be deciphered, and send the picture tube of installing in the MPEG-4 code translator 145 to.In the picture tube of in the MPEG-4 code translator, installing 145, exchange H.263 coding stream 148, coding stream 146 is H.263 deciphered by receiving MPEG-4, can display image.

The picture tube of installing in the MPEG-4 code translator in addition 145 itself can be installed coded bit stream converter 143 in inside.In the case, the picture tube of installing in the MPEG-4 code translator 145 receives H.263 coding stream 146 from server 144, it is transformed into MPEG-4 exchanges H.263 after the coding stream 148, in the MPEG-4 of inside code translator, decipher, can display image.

As mentioned above, if adopt this example 6, then owing on network, having coded bit stream converter and server, so can obtain such effect: the image communication system that can obtain H.263 to have interchangeability with MPEG-4.

Example 7

In the image decoder described in example 1 and the example 3, can discern H.263 bit stream or MPEG-4 bit stream., it is multiplexed to make MPEG-4 exchange the heading message of usefulness in the beginning of the H.263 bit stream that is generated by code device H.263, and can not directly receive H.263 bit stream.Example 7 is directly to receive the H.263 image decoder of bit stream, the row decoding of going forward side by side.

Figure 23 is the structured flowchart of the heading message analysis portion 21 in the expression example 7.Among the figure, the 151st, detect the H.263 image opening code test section of image opening code 221 H.263 multiplexed in the coding stream H.263, the 152nd, the coded system judging part, the 153rd, according to multiplexed image header information 222 in the coding stream H.263, set the H.263 image header information analysis portion of VOL heading message, VOP heading message.Other VO opening code test section 30, H.263 exchange identifying information 33, switching part 34, H.263GOB heading message analysis portion 36, VOL heading message decoding part 37 and VOP heading message analysis portion 38 are identical with example 1.The structure of the part beyond the heading message analysis portion 21 is identical with the image decoder of example 1 in addition.

Secondly explanation work.

H.263 image opening code test section 151 often monitors the beginning and the end of the coding stream shown in Figure 24 (a) and (b).Under the situation of coding stream 201 H.263, will be from image opening code 221 to macro block data 225 monitor as a coding stream, under the situation of MPEG-4 coding stream 202, will be from VO opening code 231 to macro block data 239 monitor as a coding stream.

Receiving under the situation of coding stream 201 H.263, H.263 image opening code test section 151 detected image opening codes 221 are exported to coded system judging part 152 with its result.Coded system judging part 152 is according to the image opening code 221 that detects, and concludes that H.263 the coding stream that is received is a coding stream 201 H.263, will exchange identifying information 33 and be set at H.263.On the other hand, if detect VO opening code 231 by VO opening code test section 30, then coded system judging part 152 concludes that the coding stream that is received is a MPEG-4 coding stream 202, will H.263 exchange identifying information 33 and be set at MPEG-4.

Under the situation of coding stream 201 H.263, switching part 34 H.263 coding stream 201 is input to H.263 image header information analysis portion 153.H.263 153 pairs in image header information analysis portion H.263 in the coding stream 201 multiplexed image header information 222 decipher, identical with example 1, carry out the setting of VOL heading message, VOP heading message.After this work is identical with example 1.

On the other hand, under the situation of MPEG-4 coding stream 202, switching part 34 is with MPEG-4 coding stream 202 input VOL heading message decoding parts 37.After this work is identical with example 1.

As mentioned above, if adopt this example 7, then under the situation that detects image opening code 221, predicate H.263 coding stream 201, owing to set VOL heading message and VOP heading message, so can obtain such effect: the image decoder that can obtain H.263 to have interchangeability with MPEG-4.

Example 8

This example relates to the coded bit stream converter that the H.263 coding stream 201 shown in Fig. 1 (a) is transformed into the MPEG-4 coding stream 202 shown in Fig. 1 (b).

Figure 25 is the block diagram of the coded bit stream converter of expression example 8, among the figure, the 161st, coding stream 201 H.263 is separated into image header message code word 401, the syntactic analysis portion of GOB heading message code word 402 and macro block data code word 403, the 162nd, the image header information decoding portion that image header message code word 401 is deciphered, the 163rd, the GOB heading message analytic transformation portion that GOB heading message code word 402 is deciphered, the 164th, the MPEG-4 heading message configuration part of carrying out the setting of VOL heading message 234 and VOP heading message 236, the 165th, the multiplexed portion of output MPEG-4 coding stream 202.

Secondly explanation work.

If syntactic analysis portion 161 detects image opening code 221 from coding stream 201 H.263, the coding stream that then will be connected on its back is separated into image header message code word 401, GOB heading message code word 402 and macro block data code word 403, and exports to image header information decoding portion 162, GOB heading message analytic transformation portion 163 and multiplexed 165 respectively.It is multiplexed that but GOB heading message code word 402 is not limited in coding stream 201 H.263, is only limited under the situation that detects GOB opening code 223 multiplexed.Under the situation that detects GOB opening code 223, the GOB title is detected information 404 export to MPEG-4 heading message configuration part 164.Image header information decoding portion 162 is the same with example 1, and image header message code word 401 is deciphered, and the image header information 405 after the decoding is exported to MPEG-4 heading message configuration part 164.

MPEG-4 heading message configuration part 164 is the same with example 1, according to the image header information 405 after the decoding, carries out the setting of VOL heading message 234 and VOP heading message 236.Also can be set at disclosed a certain value among the ISO/IECJTC1/SC29/WG11 MPEG-4 Video VM8.0 about NM heading message in the example 1.Under the situation that has received GOB title detection information 405, wrong tolerance coding indicating mode is set at effectively in addition.

As described in the example 1, H.263 with the situation of MPEG-4 under, the part of the decoding handling procedure of macro block data is different.Therefore in the decoding side, need switch interpretation method according to handover information.Therefore be necessary following handover information is set at the VOL title.

(1) AC coefficient VLC table handover information

As described in the example 1, under the different situation of the VLC table that when the coding side is carried out variable length code to the AC coefficient data, uses, switch the information of the AC coefficient data being carried out the VLD table usefulness of variable-length decoding usefulness in the decoding side.

(2) Esc Coding handover information

As described in the example 1, when the coding side is carried out variable length code to the AC coefficient data, under the different situation of coding method, switch the information that interpretation method is used during the AC coefficient data in the VLC table, not desiring to encode in the decoding side.

(3) internal DC coefficient re-quantization handover information

As described in the example 1, under the different situation of the quantization method of coding side internal DC coefficient, switch the information that DC coefficient inverse quantization method is used.

In addition the handover information in (1)～(3) is gathered, can be used as method that in H.263, adopts and the information of switching in other cases and set.

After the MPEG-4 heading message of being set by MPEG-4 heading message configuration part 164 is carried out variable length code,, export to multiplexed 165 as MPEG-4 heading message code word 406.

GOB heading message analytic transformation portion 163 is the same with example 1, and GOB heading message code word 402 is deciphered, and GOB heading message 224 is transformed into synchronizing information again 238 as the representation of MPEG-4.

The synchronizing information again 238 of MPEG-4 is the information of using in order to strengthen wrong tolerance, under the effective situation of wrong tolerance coding indication information of VOL heading message 236, is multiplexed information.If synchronizing information 238 is decoded again in the decoding side, then obtain synchronous again to coding stream, the predictive vector that uses when carrying out macro block decoding and the setting again of quantization step distance.Under situation H.263,, then carry out the setting again of predictive vector and quantization step distance in addition if GOB heading message 224 is decoded.Therefore by utilizing again 238 pairs of GOB heading messages of synchronizing information 224 to carry out conversion, GOB heading message 224 can be transformed into the representation of MPEG-4.

Figure 26 is that expression GOB heading message 224 reaches the structure chart of synchronizing information 238 again.Macro block in the synchronizing information 238 numbering 271 is numberings of the position of the macro block in the expression VOP again.Therefore can calculate the position in that received and the image macro block that H.263 macro block data is corresponding.Because it becomes the macro block of beginning in GOB, so can calculate with the GOB numbering.Quantization table 272 also can be set GOB quantization step distance.Launching indication code 273 at title is under the situation of " 1 ", and time reference point 274 and VOP elapsed time 275 are by multiplexed.These information are the information of using when showing each VOP, so as required, title is launched indication code 273 be set at " 1 ", carry out time reference point 274, the setting in VOP elapsed time 275.Synchronizing information 238 is carried out variable length code again, exports to multiplexed 165 with having added the code word of synchronizing information again 407 of synchronous indication code again, and above-mentioned synchronous again indication code is to represent that again synchronizing information 238 is by the single sign indicating number of multiplexed regular length.

Make MPEG-4 heading message code word 406 for multiplexed 165, synchronizing information code word 407, macro block data code word 403 are multiplexed in coding stream again, output MPEG-4 coding stream 202.

In this example, though under the effective situation of wrong tolerance coding indication information of VOL heading message 234, synchronizing information is as by multiplexed information again, but also can be with wrong tolerance coding indication information effective, invalid irrelevant, make it multiplexed.

In coding stream 201 H.263, after macro block data 225, added under the situation of sequential end code 227 in addition,, then analyzed and finish if syntactic analysis portion 161 detects sequential end code 227.

As mentioned above, if adopt this example since will be H.263 coding stream 201 be transformed into MPEG-4 coding stream 202, so can obtain the effect that can decipher coding stream H.263 with the image decoder of MPEG-4.

Example 9

In example 7, H.263 image opening code test section 151 in Figure 23 detects under the situation of image opening code 221, coded system judging part 152 concludes it is coding stream 201 H.263, H.263 image header information analysis portion 153 sets VOL heading message and VOP heading message, but in this example, according to the image header information 222 of the decoding in image header information decoding portion 42 H.263 among the Fig. 6 that comprises in the image header information analysis portion 153 H.263, switch the work of macroblock layer syntactic analysis portion 22.At this moment, do not need MPEG-4 heading message configuration part 43.In addition, in example 7, H.263, GOB opening code test section 61 among Fig. 8 is detecting under the situation of GOB opening code 223 in the coding stream 201,62 pairs of GOB heading messages 224 of GOB heading message decoding part are deciphered, in MPEG-4 heading message changing unit 63, carried out the setting again of the VOP quantization step distance that comprises in the VOP heading message 236.In this example, under to the situation that H.263 coding stream 201 is deciphered, use image header information 222, carry out the decoding of macro block data, so can carry out the setting again apart from 304 of the image quantization rank that comprise in the image header information 222.

Secondly, illustrate, carry out the work of the macroblock layer syntactic analysis portion 22 of macro block data when deciphering according to the image header information 222 after decoding in the image header information decoding portion 42 H.263.

In this example, because the work of the work of the switching part 81,83,85,88,95 of the macroblock layer syntactic analysis portion among Figure 12, the work of addition portion 94 and change vector decoding part 97 is only different with the work of switching part 102 of blocks of data decoding part 98 among Figure 13, so this part only is described.

Under the situation that MPEG-4 coding stream 202 is deciphered, promptly, under the situation of setting in the coded system judging part 152 in Figure 23 of H.263 exchanging identifying information 33 expression MPEG-4, switching part 81 switches according to by the shape information after 37 decodings of VOL heading message decoding part.Under to the situation that H.263 coding stream 201 is deciphered, that is, H.263 exchanging under the identifying information 33 expressions situation H.263, coding stream 1 by coded shape data decoding part 82, unconditionally is not transfused to switching part 83.

Under the situation that MPEG-4 coding stream 202 is deciphered, switching part 83 switches according to by the VOP type of prediction after 38 decodings of VOP heading message analysis portion.Under to the situation that H.263 coding stream 201 is deciphered, according to switching by the image encoding type 302 after H.263 image header information decoding portion 42 deciphers.Switch operating is identical with example 1, and image encoding type 302 can switch to inside or other types.

Under the situation that MPEG-4 coding stream 202 is deciphered, switching part 88 is according to being switched by the inside AC/DC prediction indication information after 37 decodings of VOL heading message decoding part.Under to the situation that H.263 coding stream 201 is deciphered, that is, H.263 exchanging under the identifying information 33 expressions situation H.263, coding stream 1 by AC prediction indication information decoding part 89, unconditionally is not imported into active block identifying information decoding part 90.

Under the situation that MPEG-4 coding stream 202 is deciphered, the VOP quantization step of the macro block of addition portion 94 after with previous decoding is apart from being added in differential quantization rank after the decoding in 254, as quantization step apart from output.Under to the situation that H.263 coding stream 201 is deciphered, with the image quantization rank of the macro block after the previous decoding apart from being added in differential quantization rank after the decoding in 254, as quantization step apart from output.

Under the situation that MPEG-4 coding stream 202 is deciphered, switching part 95 is according to being switched by the interlace mode indication information after 38 decodings of VOP heading message analysis portion.Under to the situation that H.263 coding stream 201 is deciphered, that is, H.263 exchanging under the identifying information 33 expressions situation H.263, coding stream 1 unconditionally is imported into change vector decoding part 97 not by staggered information decoding portion 96.

Under the situation that MPEG-4 coding stream 202 is deciphered, change vector decoding part 97 is deciphered change vector (structural change data 7) according to exploring the scope appointed information by the change vector after 38 decodings of VOP heading message analysis portion.Under to the situation that H.263 coding stream is deciphered,, change vector (structural change data 7) is deciphered according to exploring scope by the change vector of H.263 stipulating.

Under the situation that MPEG-4 coding stream 202 is deciphered, the switching part 102 of blocks of data decoding part 98 is according to being switched by the inside AC/DC prediction indication information after 37 decodings of VOL heading message decoding part.Under to the situation that H.263 coding stream 201 is deciphered, that is, H.263 exchanging under the identifying information 33 expressions situation H.263, coding stream 1 unconditionally is imported into DC coefficient regular length decoding part 103.After this work is identical with example 1.

As mentioned above, if adopt this example 9, then because under the situation that detects image opening code 221, predicate H.263 coding stream 201, image header information 222 is deciphered,, carried out the decoding of macro block data according to the image header information 222 after the decoding, so do not set VOL heading message and VOP heading message, so can obtain such effect: the picture coding device that can obtain H.263 to have interchangeability with MPEG-4.

The possibility of industrial utilization

As mentioned above, image decoder of the present invention, picture coding device, Image Communication system Even system and the different coding stream of coded bit stream converter coded system also can be with simple Structure receive and dispatch letter.

Claims (3)

1. picture coding device is characterized in that having:

With first coded system picture signal is encoded, generate the code device of first coding stream with first heading message; And

Before above-mentioned first heading message, the multiplexed heading message multiplex machine that is used to guarantee with the heading message of the interchangeability of first coding stream that adopts second coded system coding.

2. picture coding device according to claim 1 is characterized in that: above-mentioned heading message multiplex machine makes the heading message of the opening code that comprises above-mentioned second coded system multiplexed, as the heading message that is used to guarantee interchangeability.

3. picture coding device according to claim 1; it is characterized in that: it is that the coded system identifying information of above-mentioned first coded system is multiplexed that above-mentioned heading message multiplex machine makes the opening code of above-mentioned second coded system and expression, as the heading message that is used to guarantee interchangeability.

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