TWI232684B - Apparatus for variable bit rate control in video compression and target bit allocator thereof - Google Patents

Abstract

An apparatus for variable bit rate control in moving picture compression. First, a total activity measure for the current picture to be encoded in a set of consecutive pictures is calculated. Based on the total activity measure of the current picture and an activity-to-complexity ratio of a previously encoded picture of the same type in the set of consecutive pictures, a complexity measure of the current picture is estimated. A statistical complexity measure is then calculated from the complexity measure of the current picture. A target bit budget is allocated to the current picture depending on the instantaneous rate, the complexity measure and the instantaneous complexity measure. After encoding the current picture, the activity-to-complexity ratio for the current picture is computed based on the total activity measure, actual bits consumed by the current picture and an average of actual quantization step sizes used to encode the current picture.

Description

1232684

[Technical field to which the invention belongs] Particularly refers to a suitable device. The present invention relates to the field of data compression. It performs variable bit rate control in video coding systems. [Prior art] As we all know, the world of electronic communication is undergoing a digital revolution. The main advantage of representing information digitally is that it can be almost error-free. A bitstream of data that is stored, reproduced, transmitted, processed, and used. For example, NTSC's color video image has 29.97 daylights per second, each written ^

480 visible scan lines' Each scan line requires approximately 480 points of pixels in three colors: red, green, and 誃, but if each color component is edited in 8 bits, then The generated bit rate is about 168 million bits per second (Mbits / 5). Therefore, the uncompressed bit rate of various video formats is very high and uneconomical, so it is not suitable for most applications. The digital audio and video channels integrated with computers, telecommunications networks, and consumer products have further stimulated the advancement of the revolution, and the core of this revolution is digital compression technology for video and audio. Many compression standards, including algorithms based on the essence of common compression technology, such as: I TU-T (formerly CC ITT) Recommendations H.261 and EL 2 63, and ISO / IEC MPEG-1, MPEG -2 and

MPEG-4 standard. The MPEG algorithm was developed by the Moving Picture Experts Group (MPEG), which is an international standard organization (I n t e r n a t i ο n a 1

Standards Organization (ISO) and International Electrotechnical Commission (IEC)

m m

0702-7606twF (nl); 90P132; Lm.ptd Page 6 1232684

The 22 technical committee is dedicated to the development of video and audio compression and multi-channel transmission. These standards specify the syntax of the compressed bit stream and the method of decoding. But for the encoder used As far as the algorithm is concerned, it retains a considerable amount of freedom for the novelty and diversity of coding. According to the investigation, a series of video pictures are divided into a sequence = group of picture (G0p), where each group of G0p starts with Bu, face, followed by p—picture and β— The arrangement of the day and the day, the first drawing shows a typical set of Gop in the order of two. The coding of the diurnal plane does not need to refer to the previous and future diurnal planes, and the P-diurnal plane refers to the I-dimensional plane or the diurnal plane that is closest in time in the series of video pictures to encode, and the B_ picture is scattered in Between I-picture and P-day. And use the previous, future or both ^ -neighbor I-day and P-picture to encode. Although several β-day surfaces can appear next to each other and appear continuously, the B-day surface must not be used to estimate other day surfaces. Each diurnal surface has three components: a brightness value (represented by γ), a red color difference (represented by cr), and a blue color difference (represented by ⑶). For the MPEG 4: 2: 0 format, the sampling points for each Cr and ⑶ component are only half of the γ component in the horizontal and vertical directions. As shown in Figure 2 *, an MPEG picture is basically composed of large blocks (ick, represented by 0). Taking 4: 2: 0 video as an example, each 0 contains an array of ¥ 16} [16 sampling points, and two blocks of 8x8 sampling points of Cr and Cb components, where the array of 16x16 sampling points of Y component is actually It consists of 4 blocks of 8 × 8 sampling points. The role of the flat horse is to determine what type of day-surface coding and what kind of prediction

1232684 V. Description of Invention (3) — ΐϊίίίί. For each 1-picture, each 8x8 square in the fairy is subjected to cosine transform (dlscrete c〇sine transf rn), κ ί array of conversion coefficients, and the conversion coefficients are then subjected to a quantization matrix from y to two. zigzag (zig_zag) scans the quantized result of the Dc coefficients of the cat and two / a series of DCT coefficients, and this dCT coefficients are ordered. (such as the available length code, VLC) the length of each MB is set to I type MB Or p-type ==, depends on the above-mentioned Fang Yeyan — the coding of the horse type Mβ is previously checked, and for each P-plane, you need to get the prediction of B before you! This prediction is obtained by β (first vector), and the motion vector symbolizes the current picture movement ^ 〇t1〇n

The prediction error between the MB of the variable _ code and its estimated Mβ in the previous picture is DCT, the estimated MB and the current Mβ code. When Z-shape scanning and VLC editing and processing of B-pictures, it must be deleted: Which MB mode is used for ί mode, F mode, and β mode to encode each body without using motion compensation to encode (such as the type 1 method) .I mode is based on the MB forward prediction coding, which is based on the previous book); F mode is a one-way MB—like); on the other hand, mode b is ^ to estimate the motion compensation (such as the day of P) Pre-backward prediction coding with motion compensation in the front, which is backward prediction coding. The forward and backward $ FB modes are used, which are double interpolation (interpolati〇n) to get ° = motion compensation estimation. Both for F, B, and FB modes, the prediction error-like motion compensation estimation. Shape scan and VLC for editing. To use DCT, quantization, z video encoder must be integer & t Μ & _ Refine the ranks to give 0702-7606twF (nl): 90P132; Lin.ptd Page 8 1232684 V. Description of the invention (4) Make visible distortions, however, the selected quantization ranks will know 'In reality; number ,: inevitably at the quantization level reached after real encoding,' first, The fu number can be edited in a given desired video; with: point 2 bit rate control. The important thing in Jane is to operate at a fixed bit rate: T: the limit of the number of bits used by the plane. (nde = f shape at first glance, this restriction is implemented by video buffering each written and ancient VBVuLft 1 f 1 er, νβν). If the data rate is the same at a fixed bit ^ rate, the video can be said to be virtual The buffer is also a Γ solution; _ encoding. Νβν is the bit rate, and the brown p is divided into two]; into the buffer model 'to fix the buffer will not overflow or be depleted ;: Alignment: The quota must be completely streamed, and the specific bit rate is used for the parent bit rate. The encoded bits and no more bit inputs are: the bit rate is actually recordable until the bit rate is saturated. It is explained that for the variable bit rate into the VBV buffer, ^ I " b reaches the above-mentioned maximum bit rate. Therefore, the variable bit control is not sufficient. The quality can also be maintained, and I can improve decoding. The method of the rate of the rear video is different, variable position, in-field, and fixed-bit number. To allocate additional variable bit-rate control architectures, it is quite similar ... However, the traditional processing of video coding is usually complicated several times. In view of this, a new type of Variable position 0702-7606twF (nl); 90P132: Iin.ptd Page 9 1232684 V. Description of the invention (5) Element rate control technology, which can be used for ^ ^ We also look forward to providing a kind of encoder for everyone: , And more. ^ The Tongtong is applied to the integrated circuit and Nonggudan, and the controlled dynamic image compression has a variable bit rate. [Summary of the Invention] According to the present invention, the target position of each daytime surface is * AA. The power match of i ~, the previous coding results of the day and the target to be coded are based on the analysis of the amount of activity, and furthermore, by pretending to be sexually assaulted in advance by the second month and the second day. Zhuang went to hunt the relationship between the actual analysis of the pre-analyzed live picture and the actual complexity of the pre-coded picture, and the degree can be estimated by eye movement. Because the complexity of the day and the day has quality information after ^ is complex, the estimated current picture surface code ^ is very thin, and the target bits can be allocated more accurately. J = diurnal plane, in order to achieve a uniform two between different diurnal planes in the video sequence: Zhang Zhi. U see you. The present invention is directed to a variable bit rate protective garment for moving image compression. According to the present invention, the device includes a motion estimation unit, a complex counter, a -target bit dispatcher, and a parameter updater. Mobile Estimation :: The 2-group of consecutive pictures in the received video sequence to be coded to calculate this! Day-to-day activity. Based on the complexity of the current day surface ί =! = And the previously coded written facets of this set of consecutive day-surfaces of the same type. The current picture pre-processor can be used to estimate the momentary complexity of the current day-to-day update of the continuous day-to-day group of this group. The target average bit rate of the target dispatcher is complex and statistically complex. To calculate the group

0702-7606twF (nl); 90P132; Lin.ptd V. Description of the invention (6) Instantaneous bit rate of continuous picture, area = interval complexity and instantaneous ::: complexity of daytime surface, looseness of this group of heads: The amount is allocated to the current day. The upper target bit dispatcher will encode the 'quantization level actually used in the current picture according to the current full-digit updater of the current picture after encoding: the actual number of bits consumed and the amount of activity against the complex m · where, the value, Calculate the current screen degree = ratio and full activity of the current screen = the amount of activity on the diurnal surface versus the number of complex daily consumption levels and the current diurnal surface, which is inversely proportional to the current screen. In addition, the parameter updater also uses The average value is used to calculate the aforementioned statistical complexity. Based on the complexity of the I side, on the other hand, the present invention also discloses a momentary bit rate calculator, a quota suppression & bit dispatcher, including a bit rate calculator to receive the video sequence. 2 f , And a limit unit. The complexity of the current daytime surface of the instant code and the number of connections, which will be edited in the picture, will be updated based on the complexity: the system: complexity, and this group of connections will be calculated according to a function ^ 2 The function of the instantaneous complexity of the picture depends on the set of continuous ς = instantaneous bit rate, its complexity and instantaneous complexity. Quota rate, statistics, and bit rate! Based on the rate and instantaneous complexity, the goal: yuan yield f ::: given the picture screen 'and the limit unit is used to limit the target quota to a predetermined upper limit under. [Embodiment] In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, (7 > V. Description of the invention will be described in detail as follows. A preferred embodiment is given below, in conjunction with the accompanying drawings: At the beginning, the prediction day and P-day surfaces must be decoded in the MPEG encoder. By calculating the root mean square error between the original day surface and the decoded day surface, the decoded day surface can be obtained. An objective measure of quality. Taking the root mean square error as the distortion of the decoding day, the complexity of the decoding day (complex) -C is defined as follows: C = r X d where 'r is the number required to encode the day surface. Bit rate, d is the degree of distortion of the diurnal plane of decoding. In theory, there is a proportional relationship between the average quantization level (quant 丨 zat 丨 〇nste ρ size) and the degree of distortion, so the complexity of the diurnal plane can be defined Cheng: 2 Among them, we can know the diurnal pre-technical complexity of the diurnal surface, which is the same as the coding change. ^ ^ If 0_ is the average quantization bit rate (the actual number of consumed bits) of the diurnal surface in terms of complexity It is also obtained as a result. The essence of the surface uses the complexity of the recently encoded picture and the effects of the I_, P-, and B ~ diurnal planes respectively. If the video sequence is used, this method can achieve a fairly good target bit quota and the content of the actual consumed signal sequence changes significantly. After the daytime encoding, the level is averaged and the level is determined, and the form of the encoding depends on the degree. The degree indicates that the current daytime complex maintains its complexity to reduce the effect of the daytime surface whose content is smooth. However, due to the inconsistency between the number of picture bits, the description method is not suitable for reaching 1232684 V. Invention Description (8) to achieve consistent visual quality. According to the present invention, the current day's surface activity (activhy) is analyzed in advance. And the actual complexity of the previously coded day-plane. 'The current day-plane complexity will be able to be estimated. The live metric is an attempt to measure the bit rate and quality of a picture after it has been coded, assuming a whole sheet The total amount of daytime activity A is proportional to the complexity C, then A: k 乂 where 5 k is a proportional constant. If k 'is the activity-to-complexity ratio? ACR, 1J total>, the tongue momentum A can also be expressed by the following formula: A = ACRxrxg According to the present invention, ACR can be estimated from the previously coded day-plane of the same type. Conceptually, first calculate its full activity before coding a day After measuring a, the complexity of the daytime surface p⑴ to be coded is estimated as follows: rii) where A (1) is the daytime

+, i) full activity, ⑼ is of the same type, ^ encodes the ratio of its activity to complexity on the day. In the following, before μμ XA L · 4; ® (i) .. Ye's pay 3 tigers or the upper part of the variable indicates that the pay number or variable is related to the code to be encoded; similarly, in the symbol or variable The superscript α_υ is related to I. ⑺ and Xiange coding day and night

1232684 V. Description of the invention (9) The estimated complexity can be used to update the complexity of the appropriate types of pictures, so the complexity Ci, Cp, and CB of the three types of day surfaces will be stored separately for subsequent processing. The instantaneous complexity of a set of continuous pictures is also updated as follows: INST-C = X C: + iVp X X. Where N, NP, and NB are the numbers of Bu, P-, and B_ pictures in the group of continuous diurnal planes, respectively, and a group of continuous pictures referred to here includes at least one group of GOP. In addition to G, CP, and CB, I_, P-, and B- daytime complex statistics sq, SCP, and SCB are also stored, and the current daytime complexity is used to update the isomorphic daytime surfaces. Complexity statistics, the statistical complexity of a set of continuous diurnal surfaces is:

STAT ^ C ^ Nj X SCj ^ Npx SCP ^ NBx SCB If the maximum and minimum bit rates have been determined in advance according to the encoding bit rate expected for each group of continuous day-to-day faces, so the instant bit rate of a group of continuous pictures can be determined by It is calculated by the following formula: INST-R = ER ^ an ·

/ (INST C 1 + SF '-= —- 1 \ [static JJ, where ERmean is the predetermined average bit rate of the continuous day and day in this group, and sf is a contraction factor, which ranges from 0 to 1; Instantaneous bit rate INST —R must also advance — is further limited to the set maximum and minimum bit rate of each group of consecutive day and time: ERk < INST_R < ER_

Once the instantaneous complexity ST-C and the instantaneous bit rate INST, the target bit quota TB⑴ of the current day P (1) is ΤΒ (ί) =

INS? C

From the above formula, xINST R shows that the target bit quota is proportional to the system complexity and the instantaneous bit rate INST-R, and is inversely proportional to the instantaneous complexity. All MPEG-2 data bit streams must follow the VBV rules of the MpEG-2 standard, and the allocated target quota must be limited so that the νβν buffer does not overflow or under flow. After the current day's target position = quota is determined, many different types of image coding benefits can be used, such as the Test Prototype 5 (Test Model 5) described in the MPEG-2 standard, based on the target bit quota. Complete the day and night compression. After the coding of the daytime plane is completed, its actual complexity will be known, and the relationship between the full activity of the current picture and the actual complexity, ACR (1) can be calculated from the following ACR (i) = _ AQ {i) x UB [i) where AfRM is directly proportional to the full activity A (υ) and inversely proportional to the current actual consumption level of 7L UB (1) and the average quantization level AQ 位. This ACR (n 可It is used to estimate the complexity of the next picture of the same type. ACR⑴ can be linearly combined with ACR (1 υ to avoid being affected by those pictures that are rich in noise. A single shot (311 ^ 1b1 ^ 3) The video coding can be explained by the example of the car in Figure 3 and the operation flowchart of Figure 4. As shown in Figure 1232684 V. Description of the invention (11): Sound: State? Image compression The device 3 0 0 includes a motion estimation unit 31 〇 complexity estimation crying ^ α vulgarity early diu, 34 0jv., A single head is a dispatcher 330, a parameter updater phase 1 image encoder 35 〇. The mobile estimation unit receives the current picture P⑴ in the continuous pictures of the video sequence rt group to be edited, and is used to calculate the number of blocks when the AC is different. Based on the full activity amount a (i) and the 2 just-coded ACR (1-) in this group of continuous diurnal planes, the complexity estimator 32 0 is available. To estimate the current complexity of the daytime surface ° 2 (step S420). The target bit dispatcher, the complexity of the two t. 2 Update the instantaneous complexity of this group of continuous daytime surfaces (new step S43). At the same time, the target The bit dispatcher 33 0 changes it from the parameters: the statistical complexity of the continuous picture is STAT-C, and according to the "average bit rate of the set average ^, the statistical complexity element rate INST- R (step S44) Γ opens the instantaneous position of this group of consecutive day-to-day positions οο dispatcher 33 〇 Then based on the instantaneous bit rate, complexity = instantaneous plane: complexity--C based on the target Bit quota TB⑴ sub-standard; Second, (: =: Therefore, these $ gradation levels of the image editing wheel are used as the coding of the daytime p⑴t two-dimensional white. The shadow silly gives the masonry area and large block (MB) day The plane P⑴ (step S4e (0. At ^ · t, according to these, the level coding is currently 3 50 will be checked. After the plane coding is completed, the image encoder stage Pingdan mean AQ⑴: Γ consumption according to the number of bits) and actually used to quantify a return to the position number 340. The updater works then in full activity

0702-7606twF (nl); 90P132; Lin.ptd Page 16 1232684 ----- V. Description of the invention (12) A (1), actual number of consumed bits UB⑴ and the real base 3, parameter updater 34 0 is the ratio of the average value to the complexity ACR⑴ (step S4 70). Once the amount of activity is equivalent, the software of the preferred embodiment of FIG. 3 is implemented. According to the present invention, mobile estimation has tested whether the hardware and / or other components can be used to calculate pipeline = Equation 2 = Fan 310 and 320 in Figure 3, and calculate the current complexity of the daytime surface. The estimator must first complete the current day-to-day encoding :: Dynamic estimation early X31 〇 Must: the estimation of the vector, and, when the motion estimation :: the nose and the preparation of the movement, the complexity estimation cries q 9 # Gan made ice for the next picture from 3 1 0 ^ ^ 3 2 0 and other components are still busy with the operations related to the current picture on the office. Connect each element in the clip, Fan Cheng All. Next, the main mode of the private movement estimation unit 3 1 〇 of the preferred embodiment will be described in detail. What kind of prediction is used by the two dissatisfiers? For each MB, if necessary, the post-movement prediction 'can also extract the book' from the block matching operation. First, calculate the amount of each MB ’s own activity (intr ~ a ~ $ CtlVlty) 'Set the pixel intensity of four 8x8 luminance blocks in a MB to m'n' ^ 0 '...', 11 = 〇 ，. 一 ， 7 ， and the flat sentence value of each 8 \ 8 block is F ', then the amount of activity within the parent MB is IntraAct ··

IntmAct = ^ pk where

k ^ O Page 17 0702-7606twF (nl); 90P132; Lin.ptd 1232684 V. Description of the invention (13) ° h = J Σ ni ^ ?? v2 ^ yf

Vwf〇k * 0 If a lower computational complexity is required, it can be replaced with the absolute difference of P ...

IntraAct = λ = 0 where MB in I-day has only one mode: [mode, so IntraAct is the activity of each MB in I-picture. If the diurnal surface is a P- or B-diurnal surface, a motion estimation is required. The technique most commonly used to find the best motion vector is block matching. For nonintra coding (such as p- and B-days), use the minimum and minimum distortion standards such as the number of variations or the absolute value of distortion to choose forward, backward, or bidirectional prediction or not. Motion compensation. Once B or B—The MB mode of each MB in the picture is determined, 4 8 blocks of variation values in each motion compensation difference Mβ can also be obtained. The motion compensation difference MB is to be processed. 0 and The pixel-to-pixel difference between MBs is estimated; the absolute value of distortion and usually have better computational efficiency, so it can be used instead of the number of variations. Change the number of 4 8 乂 8 blocks to 2 = absolute value and add up to find each other's live in non-inner coded picture, (: inter-actlV1ty), InterAct, and then put the mother in the non-inner coded picture MB's IntraAct and its InterAct are compared to judge ij page 18 0702-7606twF (nl); 90P132; Lm.ptd 1232684 V. Description of the invention (14) I ^ iterAct is small, if yes, then InterAct is used as The amount of activity of the Mβ, and the mb is coded in inter-mode; otherwise,

IntraAct is the activity amount of the MB, and encodes the MB in its own mode (intra_m0d. Finally, for the current _, p_, or R 佥; July 7th, J 扪 丄 corpse or daytime, all MB activities篁 is added to obtain the full activity amount (Au), and the motion estimation unit (31) transmits the full activity amount (A) to the complexity estimator (32) and the parameter updater. Next, Complexity Estimator 320 is a certain type of day comfort ⑴ estimates vary its complexity, and the agent in accordance with three multicast One At p] ~ 1 sad face deniers species, the introduction of weighting coefficients to estimate the complexity of the current Coincidentally. Because B ~ Quer and p Ding, Shi m +, it can reduce the B-written plus estimate of the other day surface, and keep more: Yuan to Bu and compare, bit to the B- day surface and produce the most Bits, so p :, but generally, encoding I-pictures will weight coefficients. Computation of complexity: The weighted two coefficients of the daytime surface are less than the miscellaneousness q, cP, or cB of the picture. The φ m is estimated as follows: One, the complexity e of the current picture P⑴ is given by if (I-day Surface) 1se if (P- ACR ^ l) day surface) 'Cp' ACR (^ l) lse if (B- day surface)

1232684 Description of the invention (15)

A (i) ACR (fl) where υ and ^^ are a series of continuous pictures, and the ratio of the activity amount to the complexity of the first w-edited pictures of the ι, ρ, and B types. This is ^ Ci ^ 2l; is stored in the parameter updater 34 0, and the complexity estimator 320 reads the ratio of the corresponding amount of activity to the complexity for the previous picture of the appropriate type. K1, 1? And & The weighting coefficient of Bu and β-day plane is generally in the range of 0 to i · 〇. As for the 丨 _ day plane, the preferred embodiment can use 1 = i, 0.

The target position dispatcher 330 can be three types of capabilities in a set of continuous pictures: I-day face, P-day face, and B-picture respectively store their complexity, complexity, and degree.

Cp and complexity CB. < t So when C2., depending on the current picture p (, the parent and child only update one of the complexity C〗, CP, CB, as follows. if (I-day surface) el se if (P-screen )

GO else if (B-Day Face)

The preferred embodiment 'target bit dispatcher 33o' shown in Fig. 5 is composed of a momentary bit rate calculator 510, a quota calculator 520, and a limit unit 53. Instant bit rate calculator 510 instantly updates the set of continuous pictures

1232684 V. Description of the invention (16) is as follows

Miscellaneous JJVST_C

IN ^ T ^ C ^ NIxCI-l. NpxCp ^ NBxCB where ‘N !, NP, and nb are the numbers of p, p, and B—pictures in a set of continuous daylight planes, respectively. At the same time, the instantaneous bit rate calculator 5 1 0 also reads the statistical complexity of this set of continuous day-to-day surfaces from the parameter updater 340, and calculates the instantaneous bit rate of a set of continuous day-to-day surfaces according to the following formula I nst_r:

(INS7_C KSTA7_C \ where 'ERmean is the predetermined average bit rate of the continuous picture in this group, gp is a scaling factor ranging from 0 to 1; and the instantaneous bit rate INST-R is preferably limited to this group of continuous days The maximum bit rate and minimum bit rate ER_ ^ between the two. The quota calculator 52 0 then allocates the target bit quota TB1 to the current written P (1), and the target bit quota TB is based on | ΤΒ (ϋ = ^ est Jnst c

XINST R However, 'the number of consumed bits will not be equal to the expected bit quota, so develop a feedback strategy to make the actual bits consumed by the day surface "close to the target bit quota" is better implemented In the example, the amount of overused bits that have been encoded so far can be partly amortized from the current day being encoded ...

TB (i) = TB (i) -ARxEB Among them, the amount of overused bits transmitted by the EB-based parameter updater 3 40, and AR is a fixed amortization rate, which generally ranges from 0.05 to 0. Between 2. Follow top 5

1232684 V. Formula of invention description (17), the target bit quota TB⑴ is proportional to the complexity θΐ of the current picture and the instantaneous bit rate IN ST-R of a group of continuous day-planes, and is proportional to a group of continuous day-planes The instantaneous complexity is inversely proportional. The limit unit 5 3 0 can be used to adjust the target bit quota TB (1) to comply with the VBV specification. Therefore, the upper limit (ILbound) and the lower limit (L-bound) of the quota are set in advance. As for the operation of a fixed bit rate (CBR), the target bit quota allocated to a picture must be such that the VBV buffer will not overflow or be scarce. Therefore, the limit unit 5 30 limits the target bit quota D B to Within the upper and lower limits ... if (TB⑴> U-bound) then TB⑴ = U-bound if (TB (1) < L-bound) then TB⑴ = L-bound If it is a variable bit rate (VBR), then You only need to prevent VBV scarcity, so: if (TB (1) > U — bound) then TB⑴ = U-bound Then the 'target bit quota TB⑴ will be transmitted to the parameter updater 3 40 and the image encoder 3 5 0 . Returning to FIG. 3 ', the image encoder 3 50 receives the day-to-day data from the motion estimation unit 3 1 0 through the signal line 31 2 and the motion vector and MB mode of each μB. In order to achieve the best quality of the daytime plane, the image encoder 3 5 〇 determines the quantization level used for each Mβ encoding of the current dayplane based on the target bit quota TB (1). Based on these data, the image coding The device 3 50 starts to encode the current picture PZ and outputs the encoded data ⑶. After the current day plane P (1) encoding, the image encoder 3 5 0 averages the quantization levels used and calculates the actual number of consumed bits UB⑴, and then returns the current picture ϋΒ⑴ and the average value of the quantization levels used by Bayesian AQ⑴ to Parameter updater 340.

1232684 V. Description of the invention (18) Day surface: p-number two meeting is eighty-one: three types of continuous day surface: 1_ ^ 〇Γ One store the complexity statistics sq, SCp Xing 84, and take the day surface Complex — 1

The statistics of the impurity degree of the surface are as follows: · But the coefficient of the weight of I xi T 丨 j I. In other words, according to the type of '' dihedral surface, diurnal surface, and β-diurnal surface plus SCI, SC «C 口 # ^ and the diurnal surface P⑴, only one of the complexity statistics I or SCB parent is Update: if (I-Day) L. Song SC: ^ SCI " (WI ^ 1) + w2 else if (p—picture) scr ^ SCP '(WP ^)) + Wp else if (b-picture)

scr =: " (WB ^ jj + C ^ J is generally between 200 and 2000. The parameter is updated. The program calculates the statistical complex of a set of continuous diurnal surfaces.

Among them, the range of Wi, Wp, and WB. The new device 3 4 0 then follows the degree of heterogeneity STAT_C, STATIC ^ Nj X ^ + ΛΓΡ X + NB x SC ’1232684

V. Description of the invention (19) where 乂, NP and NB are the number of Bu, p- and B-pictures in each group of continuous pictures. The difference between the target bit quota ^ ⑴ of the day plane P (1) and the actual consumed bit Lou UB (1) will be accumulated by the parameter updater wo in order to pay the overused bit amount EB after the picture P is encoded: EBx (^ L-AR) ^ UQa) _ Tβ〇) where 'AR is the established amortization rate. Therefore, the relationship between the amount of activity and the actual impurity level, ACR (1), can be calculated from the following ACRU) = A (i) —AQU) x The ACR⑴ to which the daytime plane P (1) belongs can be used to predict Estimate the complexity of the next Zhang Yi / style picture. To prevent ACR⑴ from being affected by noise-rich pictures, the preferred embodiment uses a linear combination of ACR⑴ and ACRU-1), for example: if (I-day) ACR} 0 = ACR (^ l) x ( l-CW) ^ ACR (i) x CW else if (P—day surface)

ACR (;) = ACR (;-l) x (1 ~ CW) ^ ACR (i) x CW el se i f (B—day surface)

ACR (^ = ACRTl) X fl ~ cw) + ACR (i) x CW Among them, CW is a predetermined weighting coefficient of linear combination. The updated and 〃 are transmitted to the complexity estimator 3 2 0 in order to estimate its complexity for the next day of the day of the appropriate type. In addition,

0702-7606twF (nl); 90P132; Lin.ptd page 24 1232684 V. Description of the invention (20) and statistical complexity STAT_C are sent to the target bit dispatcher 330 for bit allocation. Although the present invention has been disclosed as above with a specific embodiment, it is only for easy explanation of the technical content of the present invention, rather than narrowly limiting the present invention to this embodiment. Any person skilled in the art will not depart from the spirit of the present invention. Within the scope and scope, some modifications and retouching can be made, so the scope of protection of the present invention shall be determined by the scope of the appended patent scope.

0702-7606twF (nl); 90P132; Lm.ptd Page 25 1232684 Brief description of the diagram Figure 1 shows a typical group of pictures (GOP) in the order of display; Figure 2 is a large block of MPEG; Figure 3 Figure 4 is a block diagram of a preferred embodiment of the variable bit rate control device of the present invention; Figure 4 is a flowchart of the operation of the present invention; and Figure 5 is a block diagram of the target bit dispatcher in Figure 3 . [Symbol description] 3 0 0 ~ moving image compression device; 3 0 0 ~ motion estimation unit; 3 2 2 ~ signal line; 3 2 0 ~ complexity estimator; 3 3 0 ~ target bit dispatcher; 3 0 0 ~ parameter updater ; 3 5 0 ~ image encoder; 5 1 0 ~ instantaneous bit rate calculator; 5 2 0 ~ quota calculator; 5 3 0 ~ limit unit; P⑴ ~ day surface; A (1) ~ full activity amount; β ~ Estimated complexity; ACR (1) ~ Ratio of activity to complexity; EB ~ Over-utilized bit amount;

0702-7606twF (nl); 90P132; Lin.ptd page 26 1232684 The diagram briefly illustrates STAT-C ~ statistical complexity; TB (υ ~ target bit quota; AQ (1) ~ average of the quantization level actually used; UB (1) ~ the actual number of bits consumed; CD ~ encoded data; INST_R ~ instant bit rate; INST_C ~ instant complexity.

0702-7606twF (nl); 90P132 i Lm.ptd page 27

Claims (1)

1232684 Including: a variable bit rate control device for moving image compression, at least the momentum to be encoded is included; the motion estimation unit receives the heart & the current day in a video sequence to calculate the total of the current picture The * complexity estimator estimates the ^ complexity of the current picture based on the total activity of the current day and the previously coded day of the same type in the continuous day. ; ^ Head 'bit dispatcher, update the with the complexity of the current day Calculate the instantaneous complexity of a continuous picture, and calculate the instantaneous bit rate of the $, continuous day based on the f 1 I average position rate, a statistical complexity, and the instantaneous complexity of one set of consecutive pictures. , And allocate a target bit quota to the current picture based on the complexity of the current day surface, the instantaneous complexity of the group of continuous day surfaces, and the instant bit rate; and ^ Tea number update The total amount of activity on the diurnal surface, the number of octave cells consumed by the interfacial surface, and an average of one of the quantization levels used to encode the current diurnal surface. Calculate the ratio of the current diurnal activity to the complexity ' And calculating the statistical complexity of the set of consecutive day-surfaces based on the current day-surface complexity; Among them, the ratio of the amount of activity to the complexity of the current day is proportional to the amount of full activity of the current picture, and is proportional to the actual number of bits consumed by the current day and the quantization level actually used by the current day. The average value is inverse 2. The variable bit of the moving image compression as described in item 1 of the patent application range 6. The scope of the patent application rate control device at least includes the above-mentioned target bit quota to determine the state, according to the above-mentioned current day quantization levels, these quantization levels are the complex space area codes used by day f For use, the image describes each of the above current pictures in the picture, and the above-mentioned parameter updater of the quantization level coding and the actual number of consumed bits of the above picture are described above. The above-mentioned average value of the dagger is returned to the above-mentioned cold summer miscellaneous in the "Gongshi" gray fixture; ^ / 士士 + 不 、 & 7 丄 1 The above-mentioned items estimated by the current check ρ ... ^ + degree estimation state Month] The above-mentioned impurity degree is based on a formula: Cest ^ Κχ A ACR where cest is the above-mentioned complexity estimated by the above current picture, and K is a given = weighted =, which ranges from 0 to 丨, △ is the above-mentioned king / tongue movement of the current day and above. ACR is the ratio of the previously coded day-to-day complex activity of the same type to the complexity. / '4. The variable bit rate control device for dynamic image compression as described in item 2 of the scope of the patent application, wherein the parameter updater calculates the ratio of the activity amount to the complexity of the current picture, based on: ACR = A AQxUB Among them, ACR represents the ratio of the current diurnal activity to the complexity, a is the above-mentioned full activity of the current diurnal surface, AQ is the above average value of the quantization levels actually used by the current diurnal surface, and UB is the current diurnal surface Of the above 0702-7606twF (nl); 90P132; Lin.ptd Page 29 1232684 -------- Six 'Patent Application Range Consumption Bits Three types of pictures in the picture 2Γ% = device! The above set of continuous complexity Cl, complexity. And restoration: produce c, face? -Do not store the day and surface t. 6. The complexity of the same type of day and surface among the types. Element rate control device, item j describes the variable bit of the moving image compression-the instant bit c bit device contains at least ... as a basis to update. ":: Link: 2 screens of the above two complexities, where The day of the letter: the above-mentioned instantaneous bit rate, the above-mentioned instantaneous complexity, and the above ;; the above-mentioned complexity and the above-mentioned basis of the above-mentioned instantaneous surface of a predetermined set of continuous pictures are allocated, and the target bit is: ; Rate = said instantaneous complexity is based on the upper limit unit 'used to limit the above-mentioned target bit quota to a predetermined 7. The above-mentioned instantaneous complexity, such as the sixth consecutive day of the patent application scope, is the above-mentioned one Bribe c, xC, NpxCp +: ^ where 'INST-C represents the above-mentioned instantaneous complexity 1, NP and NB are the above 0702-7606twF (nl); 90P132; Lm.ptd Page 30 1232684 6. Scope of patent application, , And the number of the above-mentioned I ~, p-, and B-pictures in the continuous day. A ... 8. According to the variable bit ^ control device for image compression described in item 6 of the scope of patent application, wherein the instantaneous bit rate calculator calculates the above-mentioned set of, the instantaneous bit rate of the picture, based on: neon / 1 + ^ F- (ιι ^ τ ^ οΛ) \ [static) INST R, · ERmean is the predetermined average bit rate of the above set of continuous pictures, and SF is a scaling factor ranging from 0 to Between 1, INST_c, STAT_c = the above-mentioned instantaneous complexity and statistical complexity of the above-mentioned group of continuous pictures, and 'INST-R represents the above-mentioned instantaneous bit rate. A ... 9. The variable bit = rate control device for dynamic image compression as described in item 8 of the scope of the patent application, wherein the instantaneous bit rate is limited to the set of continuous bit = the predetermined maximum bit rate of the day and one The range of the predetermined minimum bit rate. 1, 10 · The variable bit rate control device for dynamic image compression as described in item 6 of the Shengu patent range, in which the above-mentioned quota calculator is assigned to: the strict target bit amount is related to The above-mentioned complexity of the current picture is directly proportional to the above-mentioned instantaneous bit rate of the two sets of continuous day-planes, and is inversely proportional to the above-mentioned instantaneous complexity of the picture. The amount of obituary notice: The above limit of the Eighth Middle School has already further restricted the above-mentioned target bit quota to a predetermined lower limit. 12. The variable position of the dynamic image is willing to shrink as described in item 2 of the scope of patent application 1232684 6. The scope of patent application = rate control device, where the parameter updater is the above-mentioned group of continuous diurnal sounds 2 type: Bu dinar , P-picture and B-picture respectively store their i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, i, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I) The statistics of the complexity of the state ^ are as follows: Work center, = 1 of the subscript x represents the type of ρλβ depending on the current day surface, and Wl and W々Wb are the day surface and the day surface, respectively. And the β-day surface's existing σ push coefficient 'cest is the above-mentioned complexity of the current day surface. / 3 • The dynamic image pressure control device according to item 丨 2 of the scope of patent application, wherein the parameter updater calculates the above-mentioned statistical complexity of the day and time, based on:,,,, and even, and STAT ^ C ^ Nj x SCT + χ SCp + NBxSCB ΐ: The above statistical complexity of the SJA * T plane, and ν々νβ are the numbers of the above I-, P-, and B-day planes among the above-mentioned planes, respectively, and only the day-planes. Rate 1 control 4 twist f ar ^ ,, in the above one, and continuous day surface contains at least one picture group Communication standard. P 〇1) 1 is 111 ^, 〇〇1 >), and the day-to-day group conforms to%? £ 0 as 1 5 · — a kind of target bit dispatcher, including at least: continued * :: Ξ 率 rate calculator 'Receive a video sequence-a group, the complexity of a current day in the forthcoming stone horse, and the group 0702-7606twF (nl); 90P132; Lin.ptd Page 32 1232684 VI. One of the continuation pictures of the scope of patent application is based on the statistics of complex sounds to update the group of continuous pictures. ^ Calculate the group of continuous pictures based on the complexity of the current daytime surface. And according to a function in the group of continuous diurnal planes—two instantaneous bit rates, where the function depends on the instantaneous complexity; 疋 average bit rate, the statistical complexity, and the quota calculator, 誃, — diurnal planes The instant bit rate / the complexity of the face, the set of consecutive bit quotas, and the number of consecutive points are used as a basis to allocate a single order-limit; below the & limit. The target bit quota is limited to a predetermined upper-type diurnal plane, and P check is the three kinds of heterogeneity cp and complex product c in the above set of continuous pictures, and the diurnal plane stores its complexity Cl, complex t Bya uses the above-mentioned complexity of the current picture to further increase the complexity of the isomorphic day surface in the above picture, and the above-mentioned instantaneous complexity of the above-mentioned set of continuous pictures is based on: toilet T-c = NiXC! + NpXCp + NsXCs where 'INST-C represents the above-mentioned instantaneous complexity, and Nm, Np, and Hua are the numbers of the above-mentioned, bu, and bu pictures respectively in the above-mentioned set of continuous day-to-day surfaces. 1 7 · The target bit dispatcher as described in item 5 of the scope of the patent application, wherein the instantaneous bit rate calculator calculates the instantaneous bit rate of the above-mentioned set of continuous day surfaces, according to the following function: I No. 33 Page 0702-7606twF (nl); 90P132; Lin.ptd 1232684 6.Scope of patent application r INSTΛ 'kS7aFc l 1 + SF · Li Yi R = ER ^ an · where ERm⑽ is the above-mentioned predetermined average bit rate of the above-mentioned set of continuous day-surfaces, and SF is a scaling factor ranging from 0 to 1, [Ns T_C, STATC is the above-mentioned instantaneous complexity and statistical complexity of the above-mentioned group of continuous diurnal planes. The degree 'INST-R represents the above-mentioned instantaneous bit rate. "1 8 · The target bit dispatcher as described in item 5 of the scope of the patent application, wherein the quota differentiator allocates a quota of the above target bit to the current day surface and the above-mentioned complexity of the current day surface and The above-mentioned instantaneous bit rate of the above-mentioned set of consecutive $ faces is directly proportional, and is inversely proportional to the instantaneous complexity of the above-mentioned set of consecutive pictures. '-1 19. The target bit as described in item 15 of the scope of patent application Dispatcher, where three types of the above-mentioned set of continuous pictures: I-day, p-written and pictures have complexity statistics SCi, complexity statistics and complexity, statistics SCB, and the three types are the same The complex p-hybrid statistic of the type diurnal surface is updated by taking the above-mentioned complexity of the current diurnal surface and formulating the following equations: a) 1) + b, the type I, P, and B end-views represented by the subscript x The current state of the current picture: fixed, W], W々WB are the existing weighting coefficients of I-picture, P-day plane and B ~ drawing plane, respectively. Cest is the above-mentioned complexity of the current day plane. 20 · The target bit dispatcher as described in item 19 of the scope of patent application, In the above-described statistical above the surface of the complexity of a set of consecutive day, according to the system: ° 1232684 VI. Scope of patent application STAT _C = NjX SCj + ΛΓΡ x SCP ^ NBx SCB where STAT_C represents the above statistical complexity, and N :, NP, and% are the above I-, P-and B-the number of diurnal surfaces. 0702-7606twF (nl); 90P132; Lin.ptd page 35