TW200425745A - Quantization matrix adjusting method for avoiding underflow of data - Google Patents

Abstract

A quantization matrix adjusting method for avoiding underflow of VBV by enlarging the default quantization matrix. The adjusting method comprising the steps of: updating a used bits BB_X and an average quantizer scale Avg_Q; allocating the bit budget BB_C for the current picture; calculating an estimated quantizer scale Est_Q according to the used bits BB_X, average quantizer scale Avg_Q and the bit budget BB_C; deciding the operation mode, the encoder entering an alert mode when the estimated quantizer scale Est_Q is larger than a threshold Th_Q, otherwise the encoder remaining at normal mode; enlarging the default quantization matrix as a new quantization matrix when the operation mode is the alert mode; and coding the current picture, the encoder coding the current using the new quantization matrix and default quantization matrix in the alert mode and normal mode, respectively.

Description

V. Description of the invention (1) 1. [Technical field to which the invention belongs] The invention relates to a quantization matrix adjustment method for avoiding insufficient data amount. 2 Offsets, using an enlarged quantization matrix to avoid the adjustment of the quantization matrix in the video buffer checker data. method. 2. [Previous Technology] In order to reduce the amount of poor material in the image, the image is generally compressed, for example, MPEG-based image coding (coding). The basic unit of image coding is a macroblock (macr0_bioc). If the sampling is in the 4: 2: 0 format, each macro block has 6 blocks (bloc ^ k), which are 4 Y blocks, 1 CD block, and 1 & block. . Each block must undergo discrete cosine transform (hereinafter referred to as DCT), and then the DCT coefficients (coefficient) are converted into integers. A zigzag scan or other alternative scanning method is used to arrange two-dimensional (two-hmension) quantization coefficient arrays into one-dimensional (oneydimension) data. Finally, the so-called variable-length coding (VLC for short) is used for entropy coding. Generally, the quantization of the DCT coefficient F [v] [u] can be expressed as: QF [v] [u] 16 * F [v] [u] / (q * w [v] [u]) ... (1), Where 'v, u are indexes of a two-dimensional array, ranging from 0 to 7. Q is a quant scale of each block in the parent macro block, which can be changed with different macro blocks. Take ¥] [11] as the whole picture 200425745 V. Description of the invention (2) The quantization matrix (qUantization matrix) defined by picture is used to specify the weighting factor of each different DCT coefficient. Figure 1 shows the preset dithering matrix defined for the intra block in the MPEG-2 specification. As shown in the quantization matrix of Fig. 1, the value of the quantization matrix gradually increases as the array indexes V and U increase. This characteristic makes quantization coefficients with high frequencies easier to become 0, because human eyes are more sensitive to low-frequency signals and less sensitive to high-frequency signals. In addition, 'inverse-quantization' is used to recover DCT coefficients. The inverse quantization of the commonly quantized DCT coefficient QF [v] [u] is defined as: F '[v] [u] = QF [V] [U] * Q * w [v] [u] / 16… (2 ) Where F '[v] [u] is the DCT coefficient of the reply. The difference between the original DCT coefficient F [v] [u] and the returned DCT coefficient F, [v] [u] is called the quantization error and is defined as: E [v] [u] = F [v] [u]-F '[v] [u] ... (3) and the quantization scale factor Q is used to adjust the scale of the content of the quantization matrix w [v] [u]' Q value range Department from 1 to 3 1. Applied to mpeg-1 and adaptive quantization of MPEG-2 (adaptive quantization) can change the Q value of each macroblock at will, but in MPEG-4 can only adjust the neighboring macros slightly (slig ^ tly) Sets the Q value of the block. In addition, MPEG-2 has a function of quantizing the scale factor from (1 to 3 1) to the non-linear actual quantizing scale factor from (0.5 to 5 6). Adjusting the quantization scale factor Q can control the bit consumption and coding quality of the macro block. for

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Car parent, the Q value will make the quantized DCT coefficient smaller, and cause more coefficients to be 0. Therefore, the encoded bit stream (stream) after VLC processing becomes shorter. However, the result will be that the quantization error will change = the image quality will deteriorate after coding. If we want to get better image quality, we must set a smaller Q value to reduce the quantization element stream will become longer. Zuo Renyi coded bits ^ In general applications, ... are constrained at the bit-rate of the bitstream. For example, in the standard of Digital Versatile Disk (DVD), which means that the bit rate of MpEG-2 video stream cannot be higher than 98 cents per second, so the bit must be controlled during the encoding process. Consume to meet this limit. The content of each image in a series of video diurnal changes, and the complexity of the encoding varies from part to part. Although used for MPEG-1 video buffer verifier (VideObuffer verifier hereinafter referred to as VBV), it provides the bit rate consumption flexibility (f 1 ex ibi 1 ity) for different images, but the overall bit for a long time. The bit rate is still a constant bit rate (constant bit rate, hereinafter referred to as CBR). MPEG-2 introduces a variable bit rate (VBR) operation mode, which provides greater flexibility in the change in bit rate consumption of each image. The VBV buffer is used to emulate the input buffer of the MPEG decoder, and the bit stream generated by the MPEG encoder must not violate the restrictions of the VBV buffer, otherwise the bit stream cannot be decoded properly . Figure 2 shows the VBV buffer in CBR operation mode. As shown in the figure, the oblique line represents the coded data input to the buffer at a fixed bit rate, while the vertical line

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Part indicates the data of the decoded image that is momentarily removed from the buffer. In order to make the bit stream meet the requirements of MPEG bit control, when the decoder needs to decode the image, the image data must have been stored in the buffer. The decoder's buffer must not be overfiu. Referring to Fig. 2, if an image consumes too many bits', the V B V buffer may have insufficient data (underflow), so the upper bound of allocable bits (all0cataMe Mts) is UB. Similarly, if an image consumes too few bits, the VBV buffer may overflow the data (〇verfl0w), so the lower limit (10wer b〇und) of allocableable bits is u.

FIG. 3 shows the VBV buffer in VBR operation mode. The difference between VBR and cbr operation modes is that the VBR operation mode is input into the VBV buffer at the specified maximum bit rate until the VBV buffer is fully loaded, so the average bit rate input rate of the VBR operation mode is variable. Therefore, VBR does not have a limitation on the minimum bit rate, only a limitation on the maximum bit rate υβ that can be allocated.

In order to meet the limitation of VBV, the encoder must allocate a bit budget to each image, and then try to control the actual consumption bit π close to the bit budget. Generally, a virtual buffer mechanism is used to control the bit consumption. When the buffer occupancy is low = 0, the quantization scale factor Q is corresponding to i; and when the buffer occupancy is the same as the gate loose value R (ΐ h r e s h ο 1 d), the quantization scale factor q is corresponding to 31. The threshold value R is generally called a response factor (react factor). Before encoding an image, the occupancy of the virtual buffer]) is initially dO ′, and the initial quantization scale factor q is q0, | Jd0 = R * / 31. The encoder uses the quantization scale factor q to perform the first macro block amount.

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V. Description of the invention (5) Transform and encode. If the amount of bits consumed by a macro block is greater than the average bit budget value, the virtual buffer occupancy D increases, otherwise the virtual buffer occupancy & D decreases. If the virtual buffer occupancy d increases beyond ⑽ + R / 31, the quantization scale factor Q is set to q0 + 1. This condition means that the bit consumption is too much, so the quantization scale factor q is increased to try to reduce the bit consumption rate. If the virtual buffer occupancy D decreases below dO-R / 31, the quantization scale factor Q is set to q0-1. This situation means that the bit consumption 'is lower than expected, so the quantization scale factor q is reduced in an attempt to increase the bit two consumption rate. The problem of using the virtual buffer mechanism to control the bit consumption is how to specify the initial occupied amount of virtual buffer d0. The initial occupancy of the virtual buffer can be regarded as an estimated value of the coding complexity of the current picture (estimation). For a fixed budget value of 7C, if the complexity of the current image is relatively high, you must choose a higher initial occupancy of the virtual buffer, so that the quantization scale factor of each macro block Q is relatively high. However, the encoder does not know the complexity of the current image until the image is actually encoded. One solution is to inherit the virtual buffer occupancy of the previous image. This simple method can handle most situations without serious problems, but when the content of a series of video images changes rapidly, VBV data will be insufficient. The range of the quantization scale factor 9 of each macro block is from i to 31, and this range can handle most situations of video coding. However, when a series of videos are very complicated ’and the target bit rate is low, it is impossible to avoid the underhow of VBV. Even when the quantization scale factor 卩 is set to 31,

Page 10 ----- 461 200425745 V. Description of the invention (6) For each macro block, women still need to follow from a-while too much bit consumption. U.S. Patent No. 5,8 0,1,77,9 proposes a "kidney | li 々 ::: 七 ^^ panic mode" to overcome this situation. The far emergency mode is the flat one —— 1. Hachiman monitors the VBV buffer's occupancy after encoding each macro block. If the girl Xi a a a L 卞 dagger visits t stupidly, too many bits on the right are consumed and Will the VBV data stone be generated after the entire image is encoded? ^. ^ / 枓 is insufficient, when the encoder enters the emergency mode soil f f emergency mode 2, the encoder would prefer to use the inter mode to perform the giant: no encoding. If the giant The set block is coded with ―style 2 macro block (the macro block of 1 image must be in intra mode), only a part of the coefficients are encoded, and the rest of the sun ^ M _ /, the co coefficient is 0 to reduce the bits Although this method can avoid the lack of VBV data, 乂 ,, s door is low. M 7 ten + feet 'but the image quality is severely reduced. The upper part of the upper part contains the measuring device for measuring the root. It is included in the package; The value-tightening code is sent to the beta method. It is estimated to be compiled as follows: the square factor is pre-determined, the whole factor is V, and VB is adjusted. The problem is described below. The purpose of the present invention is to provide a quantization matrix that can avoid the serious degradation of image quality at the same time. The present invention avoids a quantization matrix with insufficient data volume. The following steps: update the used bits And the average quantization of the current specified bit budget value of the image; the number of calculations based on the measured bit rate *, the average quantization scale factor, and the ratio of the calculation and measurement scale to determine whether the scale factor for emergency modeling is greater than-quantization When the threshold value of the scale factor is set, the weight formula 'otherwise remains in the normal mode; adjust the quantization moment to enter the emergency mode Risi, and enlarge the preset quantization matrix;

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V. Description of the invention (7) and encoding, when the encoder enters the tight matrix for encoding, and when the encoder encodes for the matrix. Since the invention is in the emergency mode, this can effectively reduce the quantization scale factor space ', so that the amount of data of the encoded video product is insufficient. In emergency mode, according to the quantization after zooming In normal mode, according to the preset quantization

When the preset quantization matrix is enlarged, the factor ’allows the quantization scale factor to be adjusted. The quality can be improved without causing VBV. 4. Implementation

With reference to the drawings, the matrix adjustment method of the present invention to avoid insufficient data amount will be described in detail. That is, the lack of VBV material occurs when the current image is encoded with a default = W = V [V] [U] and the largest quantization scale factor Q. Since the quantization scale factor Q is established by regulations from 31 to 31 and cannot be changed, the present invention enlarges the preset quantization matrix? [v] [u] to reduce the quantized DCt coefficient QF [v] [u] (refer to equation (1)).

/ In the MPEG-1 and MPEG-2 specifications, a sequence of header data must be placed at the beginning of each encoded bit stream, and this header can be added to subsequent bit streams. Once the decoder receives the header data, the quantization matrix W [v] [u] will be set to the default value. In Mp ^ — 丨, the customized (quantized) quantization matrix w [v] [u] can only be set in the header, and the header can only be inserted into a group of pictures (hereinafter referred to as "Group of pictures" for short) GOP). This means that when the decoder wants to change the quantization matrix, decoding 1§ must restart a G 〇 P, insert a header data before G 0 P, and

Page 12 200425745 V. Description of the invention (8) A new quantization matrix is configured in the header information. The MPeg matrix can not only be placed in the header data, but also a new quantization matrix can be inserted. Therefore, if the decoder is to change the quantization matrix, it is equal to the γ epitaxial quantization moment before encoding. Every image must be shown in Figure 4. Figure 4 shows the flow chart of the first embodiment of the present invention to avoid insufficient data. The process of this embodiment is the method of adjusting the image before the image is analyzed in advance, that is, the encoding of the current image is performed. The complexity of the image is not scanned and analyzed in advance, that is, the image is known to the encoder. (TM5) Bit rate = system control = 2 Like (rate control aig0rithm), the encoder can only use the method to estimate the complexity of the current image. Steps of the first embodiment of the stomach: Code Step: 4.2: Update the used bit quantity ββ-χ and the average quantization factor Avg-Q. In a χ image (χ contains j, the code is obtained by the encoder.) Finally, the virtual buffer occupies the used bit quantity-= S404. · Ready to encode a class x image and assign bits to the current image ^ Different = Dan—c. Under normal circumstances, the initial virtual buffer occupation s in the next image dO — X will be set to the final virtual buffer occupation d — X, and the initial dilation scale factor will be set The average quantization scale factor is specified by the frame — ievei rate control to specify the bit budget value BB_C of the current image. Step S406: Calculate the estimated scale factor EstQ_c. Because of the same pagei. 200425745 V. Description of the invention (9) Adjacent pictures in format (9) have approximately the same degree of activity, so the decoder uses the used bit amount BB-X of the previous picture and the bit budget value BB- of the current picture C, and the average quantization scale factor Avg-Q to calculate the estimated measurement scale factor EstQ_C of the current image:

EstQ_C = (BB-X / BB-C) * Avg-Q. &Quot; (4) Step S408: Detect whether to enter the emergency mode. When the measured scale factor EstQ_C is greater than a scale factor threshold ThQj, for example, ThQ_X is 2 4 to 2 8 ′, which indicates that the image content of the video is quite complicated for the given bit rate. If the used bit amount ββ_χ of the previous coded image and the bit budget value BB-C assigned to the current image are approximately equal, it can be guessed that the bit budget value BB_C assigned to the current image will not be easy to match. The image is currently encoded. Therefore, when the estimated scale factor 仏 CD ^ is greater than the scale factor threshold ThQ-X, the encoder enters the emergency mode of step S410, otherwise it is processed in the general mode of step S4 16. Step S 41 0: Enlarge the preset quantization matrix into a new quantization matrix. In the emergency mode, the encoder may wish to reduce the final average quantization scale factor of the current image to a safety value SQ_X, and the safety value SQ_X may be less than or equal to the scale factor threshold ThQ_X. Therefore, the present invention uses an adjustment factor S to enlarge the preset quantization matrix, and the initial virtual buffer occupancy is reduced to dO_X / S. The adjustment factor S is a value greater than 1, and can be calculated by the following formula: S = EstQ—C / SQ—X-(5) and the new quantization matrix W '[v] [u] is: W' [v ] [u] = W0 [v] [u] * S… (6)

Page 14 200425745 V. Description of the Invention (ίο) Where v and u are indexes of 0 ~ 7. w〇 [v] [u] can be a preset quantization matrix or a user-defined quantization matrix. Therefore, the smaller the safety value is, the larger the adjustment factor S is. Since the maximum value of the quantization matrix is 255, the maximum value of the content of W '[v] [u] is limited to 255. In addition, the encoder uses two quantization matrices, one for intra blocks and the other for inter blocks. Since updating a quantization matrix requires 5 丨 2 bits to encode the quantization matrix itself and some additional bits, the number of quantization matrix updates can be minimized when the bit usage is limited. For example, the image only needs the internal quantization matrix, and the B image may only need to update the interrelated quantization matrix. For a P picture, it depends on how many internally encoded macro blocks exist in the picture. If the internally coded macroblock is larger than a threshold value, the internal quantization matrix and the interrelated quantization matrix must be updated; otherwise, only the interrelated quantization matrix needs to be updated. Step S412: encode the current image with a new quantization matrix. Step S 4 1 4 • Check whether the current image is encoded. If the encoding is completed, skip back to step S402. If it is not completed, skip back to step s41. Step S41 6: encode the current image with a preset quantization matrix. Step S418: Check whether the encoding of the current image is completed. If the encoding is completed, skip back to step S402. If the encoding is not completed, skip back to step s41. In the above steps, if the encoded χ image enters the emergency mode, the quantization matrix will be enlarged by S times. Since the macro block is quantized by the new quantization matrix, it must also be used to calculate the average quantization scale factor Avg — Q. Will be

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200425745 V. Description of the invention (π) The Q value of macro blocks such as (π) is enlarged by S times to reflect the actual situation. When the two-dimensional code difference for adjacent images is changed ^ The quantization matrix is changed for each image to reflect the slight difference. Not big 'regular expression. Therefore, the difference in the adjustment factor 3 can be more than two; the change of the child's square quantization matrix. In addition, when there is a solution = the value is entered into S to preset several ranges ®, and the corresponding quantities are calculated. The adjustment factor SO can be set to 丨 .1, 丨 .2, 丨 .3 Assume

The corresponding quantization matrices are W1, W2, and W3 respectively. Therefore, when the pair is h 21 18, l 16, 1.22, or 1.2, 1 updates Tian Zhi 1 Dan Ji S Han 2 and only the first image is needed. The quantization moment is used to quantize the matrix stream, and the remaining images also use the quantization matrix W2 = in place. Figure 5 shows the flow chart of the present invention to avoid the insufficient amount of data. The process of the embodiment of Example is to edit the current image after the previous image analysis, to analyze the image in advance to collect the complexity estimation information m, and to more accurately decide whether to change the quantization matrix and how to change it. In one or two words, the complexity of the current image can be estimated by performing motion estimation. for! In terms of images, there are 2 sets of block variations. For? And ^ images and a, mode decisis must be determined according to the internal coding and interrelated coding mode. The sum of the differences-generally called the activity of the target image. Before encoding the image, the encoder can obtain the degree of activity of the image, Act_c. After image coding, the average quantization scale factor Avg_Q and the actual bits ΒΒχ can be

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EstQ—C = (BB—X / BB—C) * Avg—Q * (Act—C / Act—X) ··· (? The difference between formula (7) and formula (4) is that formula (7) is calculating The degree of activity of the estimated measurement scale factor is higher than the estimated measurement scale factor EstQ-C of the previous image. The bit rate after the meeting will not exceed the bit budget 200425745 V. Description of the invention (12) Used to calculate the figure The complexity of the image Com. When the coding exhauster cannot analyze the current image in advance, the encoder can only decide whether to change the quantization matrix and how to change it based on the previous decoded image. But when the This decision may be wrong when the image content changes rapidly. For example, when the average quantization scale factor Avg-Q of the current image is only slightly lower than the scale factor threshold ThQ-X, the current picture will not enter Emergency mode. However, if the encoding complexity of the current image is much larger than the complexity of the previous image, the bit rate of the current image after encoding will far exceed the bit budget value, resulting in insufficient VBV data. On the contrary , If the complexity of the previous image is quite high, but the complexity of the current image is quite low Then the over-enlarged quantization matrix will cause the image quality to be greatly attenuated. Therefore, the difference between the method of the second embodiment and the method of the first embodiment is that this embodiment estimates the current degree of activity of the current image, Act-C, and then The calculation of the estimated scale factor estQ-C is performed according to the activity level Act —C. The calculated scale factor E st Q-C is calculated as follows: When the sub-EstQ-C is considered, in addition to the bit budget value and the average quantized scale The factor Avg_Q 'also considers the degree of activity Ac1; that is, when the bit budget value is equal to the average quantization scale factor Avg-Q, if the current degree of image activity, the calculated pair increases, Make the current image encoding value too much. Conversely, if the current image

The activity level of the image is lower than the activity level of the previous image, it is calculated

Page 17 200425745 V. Description of the invention (13) The estimated scale factor Es tQ-C will be relatively lowered 'so that the current bit rate after image coding will not be lower than the remaining bit budget value. After the estimated measurement scale factor Est tQ-C is calculated, the second embodiment is the same as the first embodiment, and both use the estimated measurement scale factor EstQ-C to determine whether to enter the emergency mode. When the measured scale factor EstQ-C is greater than the scale factor threshold ThQ-X, it enters the emergency mode, otherwise it is processed in the general mode. When entering the emergency mode, the encoder enlarges the quantization matrix into a new quantization matrix. In the emergency mode, the encoder will hope to reduce the last average quantization scale factor of the current image to a safe value SQ_X, and the safety value SQ-X may be less than or equal to the scale factor threshold ThQ_X. Therefore, the present invention will use an adjustment factor S to enlarge the preset quantization matrix, and the initial virtual buffer occupancy will be reduced to dO_X / S. The adjustment factor S is a value greater than 1, and can be calculated by equation (5). The new quantization matrix W '[v] [u] can be calculated from equation (6). Since the maximum value of the quantization matrix is 255, the maximum value of the content of w, [v] [u] is limited to 2 5 5. The subsequent operations are the same as those of the first embodiment, and will not be described repeatedly. Although the present invention has been described by way of examples, the scope of the present invention is not limited thereby, as long as it does not deviate from the gist of the present invention, those skilled in the art can make various modifications or changes.

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A matrix of preset quantization maps defined in the MPEG-2 specification for internal blocks is displayed. Fig. 2 shows the operation of the VBV buffer in CBR. Fig. 3 shows the operation of the VBV buffer in VBR. Fig. 4 shows a flowchart of the first embodiment of the present invention to avoid data volume. Fig. 5 shows a flow chart of a second embodiment of the present invention for avoiding the amount of data. Schematic diagram of the mode. Schematic diagram of the mode. Full quantization matrix adjustment method Full quantization matrix adjustment method

Claims (1)

200425745 6. Scope of patent application 1. A method for avoiding insufficient data volume by using a 〆 / 〆 encoder to carry out a series of image correction on a series of images, using a matrix. The adjustment method includes the following: The editor has a preset quantization 3 Steps to list: Update the used bit quantity to specify a quantization scale factor for the current image; Leaf calculation estimates the measured scale factor, describe the average quantization scale factor, use x to specify the used bit quantity, and the scale factor ； Then the bit budget value is calculated to estimate whether to enter the emergency mode. ♦ When the threshold value of the quantization scale factor is: The measurement scale factor is estimated, otherwise it is set to the normal mode, and the coding mode is set to The emergency mode withdraws the quantization matrix. When the quantization matrix set by the encoding mode * is enlarged; and, ",,,, ~, mode, the aforementioned pre-encoded image is encoded, and when the encoding mode matrix is used for image editing, When encoding; ΪΓ ', according to the enlargement, the image is compiled according to the preset quantization matrix. 2 When the formula is a general wedge, 2 · As in the first patent application, A matrix adjustment method, wherein the aforementioned calculation includes the avoidance data in the estimation step. The aforementioned estimation measures the scaling factor = (two_b, the step value of the factor) * the average quantization scaling factor. Volume / bit budget 3. If the second scope of the patent application is for the quantification extension tuna, the soft man 4 ^ ^ H ^ 5 contains the avoided data | especially σ to ΐ ΐ Γ to adjust the two to one adjustment of the quantization matrix The factor is used to enlarge the preset quantization matrix, which is 4. As described in section 3 of the scope of patent application for avoiding shortages, page 20, 200425745 6. Method for adjusting the scope of quantization matrix of patent application, in which the aforementioned steps of adjusting the quantization matrix Here, the aforementioned adjustment factor is a ratio of the aforementioned estimated measurable scale factor to a safe quantified scale factor. 5 · The quantization matrix adjustment method for avoiding insufficient data as described in item 4 of the scope of patent application, wherein the aforementioned security quantization scale factor is 2 8. 6 · The quantization matrix adjustment method for avoiding insufficient data as described in item 4 of the scope of patent application, wherein the encoder includes a plurality of preset adjustment factors and a plurality of corresponding enlarged quantization matrices. When entering the emergency mode, select The magnification and reduction matrix corresponding to the group of the preset adjustment factors closest to one of the aforementioned adjustment factors is used as the quantization matrix after the magnification. 7. · A method for adjusting the quantization matrix to avoid insufficient data, which uses a coder to encode a series of images. The coder has a preset quantization matrix. The adjustment method includes the following steps: updating the used bit amount, The degree of activity of the coded image Act — X, and the average quantization scale factor; Specify a bit budget value for the current image; Calculate the degree of activity of the current image A ctc; Previously used bit amount Soil average quantified scale factor, the aforementioned activity level Act c, other-specified bit budget value calculation and measurement scale factor; judge one by one whether to enter the emergency mode, go to Shu, +, #, ηϊ s ^, and pit field to measure measurement scale Scale factor—When the threshold value of the scale factor is reduced, set the coding mode to emergency, otherwise, keep the normal mode; adjust the quantization matrix when the coding mode A 1A is the emergency mode , The aforementioned 200425745 VI. The scope of the patent application is set to enlarge the quantization matrix; and image coding is performed. When the quantization matrix after the encoding mode is used to encode the image, according to the enlargement, the map is based on the quantization matrix; encoding. When the formula is in the normal mode, 8. The method of adjusting the quantization matrix as described in item 7 of the scope of the patent application, wherein in the step of calculating the lack of loading and exempting the amount of shellfish, the foregoing estimation and measurement scale factor = the step of using the scale factor Value) * (Activity level Act C / Activity _ ^ Volume / bit budget.-/ Tongue activity ACT-X) * Average quantization ratio due to 9 · Avoid quantization matrix as described in item 8 of the scope of patent application The adjusting method, wherein the aforementioned insufficient Berry is enlarged by a preset quantization matrix with an adjusting factor.糸 θ 乂 The two methods described in the patent scope No. 9 to avoid the lack of data: matrix adjustment method, where the aforementioned adjustment amount g is the ratio of the aforementioned estimated measurement scale factor and a safe amount = example = sub. 1 1. As described in the scope of the patent application, 1 n is & — 1 The quantization matrix adjustment method contained in item 1 U of the military army to avoid insufficient data, the aforementioned security quantization scale factor in # is 28. Day 12: As described in Item 10 of the scope of patent application, a method for adjusting the quantization matrix to avoid insufficient data volume, the encoder in # includes a plurality of preset adjustment factors and a plurality of corresponding enlarged quantization matrices to enter the emergency mode. In this case, an enlarged quantization matrix corresponding to a group of the preset adjustment factors closest to one of the foregoing adjustment factors is selected as the enlarged quantization matrix. 1 3 · As described in item 7 of the scope of patent application to avoid insufficient data 473 200425745 VI. Method for adjusting patented quantization matrix, wherein in the aforementioned step of calculating the current degree of activity Act_C of the image, for the I image, the difference between each internally encoded macro block is obtained, and for the P As for the B picture, the mode judgment is performed according to the difference between the internal coding and the interrelated coding modes. The sum of the differences is the current degree of activity Act_C. Page 23