JP2004248261A - Moving-picture code amount control method, moving-picture recording method, moving-picture code amount control apparatus and moving- picture recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that a double processing time is conventionally required for tentative encoding since it is necessary to perform tentative encoding separately from actual encoding, a code stream resulting from tentative encoding is used just for observing a code amount and is finally discarded. <P>SOLUTION: An information extractor 9 extracts information on encoding difficulty (code amount required for obtaining a predetermined reproduced picture quality) and information on quantization from a first code stream reproduced from a primary recording medium 3. A target rate generator 10 sets a target code amount by correcting a pseudo generated code amount of a secondary recorded moving-picture to be matched with capacity of a secondary recording medium 6, and secondary recorded moving-pictures for the total time are held and imparted to a code stream converter 4. Which moving-picture in primary recorded moving-pictures is to be recorded is set by a recording setter 11 according to information imparted from a recording setting input terminal 12. Thus, the target code amount can be calculated without performing tentative encoding. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a moving image code amount control method, a moving image recording method, a moving image code amount control device, and a moving image recording device. In particular, in order to efficiently transmit, store, and display moving images, the image information is reduced. High-efficiency coding that converts a digital signal into a digital signal with a code amount, particularly a moving image code amount control method, a moving image recording method, and a moving image code for recording a moving image code string on a medium recordable at a variable bit rate without any empty space. The present invention relates to a quantity control device and a moving image recording device.

  In inter-picture prediction coding such as the MPEG (Moving Picture Experts Group) standard, the coding difficulty of a moving image (the amount of code required to obtain a predetermined image quality) greatly varies depending on the portion (time) of the moving image. Therefore, when recording a moving image code string on a recording medium that can record at a variable bit rate such as an HDD (Hard Disc Drive) or a DVD (Digital Versatile Disc), encoding is performed at a variable bit rate while maintaining a constant image quality. It is desired. However, since the capacity of the recording medium is determined, appropriate control of the code amount is required to store the target moving image (program) in the recording medium.

  Therefore, the present inventor has previously proposed a moving image code amount control device and a moving image recording device capable of recording a target moving image on a recording medium with a uniform image quality without excess or deficiency of the code amount (for example, see Patent Document 1). ). In this method, a moving image to be recorded is provisionally encoded by fixed quantization in advance, a distribution of generated code amounts is obtained, a target code amount of each part (time) of the moving image is set, and the target amount code amount is adjusted. To perform actual encoding.

  FIG. 4 shows a block diagram of an example of a conventional moving image code amount control device and a moving image recording device described in Patent Document 1. In the figure, the encoding process is performed twice, that is, temporary encoding using the encoder 42 and real encoding using the encoder 44. An uncompressed digital moving image signal coming from the image input terminal 1 is supplied to a primary recording medium 41 and an encoder 42. The primary recording medium 41 records and holds all target moving images.

  The encoder 42 encodes the uncompressed digital video signal so as to make the reproduction image quality uniform without performing control based on the generated code amount. To supply. The code amount observer 43 observes the generated code amount in units of GOP (Group Of Picture), frame, slice (16 lines), etc., and holds the information for the entire time of the moving image. To supply. The target rate generator 10 sets the target code amount by correcting the generated code amount to match the capacity of the secondary recording medium 5 at the stage when the temporary encoding is completed, and sets the target code amount to the total time of the moving image. Hold with.

  In the actual encoding process, the moving image signal read from the primary recording medium 41 is encoded by the encoder 44 while controlling the generated code amount so as to match the target code amount given from the target rate setting unit 10. . The actual code amount with respect to the target code amount causes an error in each unit such as a GOP, but the error is reflected in the control of the next GOP. It is less than a fraction of the code amount of one GOP. Therefore, if the target code amount is made small considering only the slight final error, the total code amount can be accommodated in the medium capacity.

  Also, since the primary recording medium 41 holds the input uncompressed digital moving image signal as it is, a VTR or the like for supplying a moving image to image input may be used again. In that case, the signal supplied to the encoder 42 in the provisional encoding is supplied to the encoder 44 in the actual encoding.

  The code sequence thus encoded is supplied from the encoder 44 to the secondary recording medium 5 and recorded. The secondary recording medium 5 actually used for reproduction is a DVD or the like. The code string read from the secondary recording medium 5 is decoded by the decoder 7 to become a reproduced image, which is output from the image output terminal 8.

  On the other hand, there is a moving image recording device that has a plurality of media such as an HDD and a DVD and can record and reproduce both media. In this case, the encoding method and code amount control for recording are common regardless of the type of medium.

Japanese Patent No. 2950065 (Page 3-5, FIG. 1)

  In the above-described conventional moving image code amount control device, provisional encoding is performed by fixed quantization, and a target code amount is set based on the distribution of generated code amounts. In this case, it is necessary to perform tentative encoding separately from actual encoding, and the code string obtained by tentative encoding is used only for code amount observation, and is eventually discarded. This requires twice as much processing time. Further, in the above-described conventional moving image recording apparatus, when a plurality of recording media are provided, a code sequence encoded by the same code amount control is recorded, so that the code amount control is inappropriate depending on the recording medium. .

  The present invention has been made in view of the above points, and a parameter of image difficulty is extracted from a code string recorded on a primary recording medium, and a target code amount is set based on the extracted parameter and a secondary recording medium capacity. A moving image code amount control method, a moving image recording method, a moving image code amount control device, and a moving image recording device capable of recording on a secondary recording medium at an ideal variable transfer rate without encoding. Aim.

  In order to achieve the above object, a moving image code amount control method according to the present invention is directed to a method for re-encoding a first code sequence obtained by encoding a moving image signal with high efficiency into a second code sequence. In the generated code amount control method, at least one of information on a code amount and information on quantization is extracted from a first code string as a parameter indicating a coding difficulty of a moving image, and the extracted coding difficulty is extracted. A first step of obtaining a pseudo-generated code amount estimated to be necessary to obtain a predetermined reproduction image quality from a parameter indicating the degree at every predetermined unit time, and recording on a recording medium for recording a predetermined portion of a moving image signal A second method of setting a target code amount obtained by correcting the pseudo-generated code amount for each predetermined unit time to a predetermined portion of the moving image signal so as to match the total code amount of the predetermined portion of the moving image signal with the total code amount. Steps and While the code amount control in accordance with the target code amount, characterized in that it comprises a third step of converting the first code sequence re-encoded to a second code string to be recorded on a recording medium.

  According to the present invention, a parameter of encoding difficulty is extracted from a first code string obtained by performing high-efficiency encoding of a moving image signal, and it is estimated that it is necessary to obtain a predetermined reproduction image quality from a parameter indicating the encoding difficulty. The pseudo-generated code amount to be obtained for each predetermined unit time, so as to match the total code amount of the predetermined portion of the same image signal to the total recordable code amount of the recording medium for recording the predetermined portion of the same image signal, Since the target code amount distribution in which the above-mentioned pseudo generated code amount is corrected for each predetermined unit time is set, the target code amount can be calculated without performing provisional encoding, and the code can be calculated in accordance with the target code amount distribution. By transform-encoding the first code string into the second code string for the recording medium while controlling the amount, the second code string can be recorded on the recording medium at an appropriate variable transfer rate.

  In order to achieve the above object, the moving image recording method according to the present invention, by controlling the amount of code with a target of a predetermined transfer bit rate, encodes a first code string obtained by encoding a moving image signal with high efficiency. A first step of recording on a first recording medium, and extracting at least one of information about a code amount and information about quantization as a parameter indicating the degree of difficulty of encoding a moving image from the first code string; A second step of obtaining, per predetermined unit time, a pseudo-generated code amount estimated to be necessary to obtain a predetermined reproduction image quality from the extracted parameter indicating the encoding difficulty level, and a step of recording a predetermined portion of the moving image signal. A target code amount obtained by correcting the pseudo code amount for each predetermined unit time so as to match the total code amount of a predetermined portion of the moving image signal with the total recordable code amount of the second recording medium is set in a predetermined portion of the moving image signal. Against A third step of re-encoding the first code string and converting it into a second code string having a variable transfer bit rate while controlling the code amount in accordance with the target code amount; Recording the second code string on the second recording medium at a variable transfer bit rate.

  According to the present invention, while performing code amount control in accordance with the target code amount distribution calculated without performing provisional encoding, transform encoding is performed from the first code sequence to the second code sequence for the recording medium, The second code string can be recorded on the second recording medium at an appropriate variable transfer rate.

  Further, in order to achieve the above object, the moving image code amount control device of the present invention uses a first code sequence obtained by performing high-efficiency coding of a moving image signal as a parameter indicating the degree of difficulty in coding a moving image. A pseudo-generated code estimated to be necessary to obtain a predetermined reproduction image quality from information on a parameter indicating the encoding difficulty level of the extracted moving image by extracting at least one of the information on the code amount and the information on the quantization. An information extracting means for determining the amount of the moving image signal for each predetermined unit time; and a pseudo code for matching the total code amount of the predetermined portion of the moving image signal to the total recordable code amount of the recording medium for recording the predetermined portion of the moving image signal. A target code amount setting means for setting a target code amount obtained by correcting the generated code amount for each predetermined unit time for a predetermined portion of the moving image signal; and a first code sequence while controlling the code amount in accordance with the target code amount. Re It is obtained by a structure having a coding means for converting Goka to the second code string to be recorded on a recording medium.

  According to the present invention, a parameter of encoding difficulty is extracted from a first code string obtained by performing high-efficiency encoding of a moving image signal, and it is estimated that it is necessary to obtain a predetermined reproduction image quality from a parameter indicating the encoding difficulty. The pseudo-generated code amount to be obtained for each predetermined unit time, so as to match the total code amount of the predetermined portion of the same image signal to the total recordable code amount of the recording medium for recording the predetermined portion of the same image signal, Since the target code amount distribution in which the above-mentioned pseudo generated code amount is corrected for each predetermined unit time is set, the target code amount can be calculated without performing provisional encoding, and the code can be calculated in accordance with the target code amount distribution. By transform-encoding the first code string into the second code string for the recording medium while controlling the amount, the second code string can be recorded on the recording medium at an appropriate variable transfer rate.

  Further, in order to achieve the above object, the moving picture recording apparatus of the present invention uses a code amount control targeting a predetermined transfer bit rate to convert a first code string obtained by performing efficient coding of a moving picture signal into a first code string. A first recording unit that records on a first recording medium, and extracts at least one of information about a code amount and information about a quantization as a parameter indicating a degree of difficulty of encoding a moving image from the first code sequence. A pseudo-generated code amount generating means for obtaining, per predetermined unit time, a pseudo-generated code amount estimated to be necessary for obtaining a predetermined reproduction image quality from a parameter indicating the degree of difficulty of encoding the extracted moving image; The target code amount obtained by correcting the pseudo-generated code amount for each predetermined unit time so that the total code amount of the predetermined portion of the moving image signal is adjusted to the total recordable code amount of the second recording medium for recording the portion. Moving image signal Setting means for setting a fixed part, and code string conversion for re-encoding the first code string and converting it into a second code string with a variable transfer bit rate while controlling the code amount according to the target code amount. Means and a second recording means for recording the second code string on the second recording medium at a variable transfer bit rate.

  According to the present invention, while performing code amount control in accordance with the target code amount distribution calculated without performing provisional encoding, transform encoding is performed from the first code sequence to the second code sequence for the recording medium, The second code string can be recorded on the second recording medium at an appropriate variable transfer rate.

  According to the moving picture code amount control method and apparatus of the present invention, a parameter of a coding difficulty is extracted from a first code string obtained by highly efficient coding of a moving picture signal, and a parameter indicating the coding difficulty is extracted. From the total code amount recordable on the recording medium to set the target code amount distribution within the time of the moving image signal to be recorded, thereby achieving the target code amount without performing temporary coding. Can be calculated, and while the code amount is controlled in accordance with the target code amount distribution, the first code string is transformed and coded into the second code string for the recording medium. 2 can be recorded on a recording medium. Further, in the present invention, since provisional encoding is not required, the processing time can be shortened, and the means for holding an uncompressed image can be eliminated.

  According to the moving image recording method and apparatus of the present invention, the first code string is controlled to have a predetermined target transfer rate, but the second code string is a variable transfer rate according to the medium capacity. Even when a part of the code string recorded on the first recording medium is arbitrarily selected and recorded on the second recording medium, recording on the second recording medium can be performed at an appropriate variable transfer rate, and an appropriate variable Depending on the transfer rate, reproduced images can be made uniform and have the best image quality.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of a moving picture coding apparatus and a moving picture recording apparatus according to the present invention. 4, the same components as those of the conventional apparatus of FIG. 4 are denoted by the same reference numerals. The first embodiment of FIG. 1 is different from the conventional apparatus of FIG. 4 in that the encoder 2 is provided instead of the encoder 42 and the information extractor 9 is provided instead of the code amount observer 43. ing. In the present embodiment, a recording setting input terminal 12 and a recording setting device 11 are added as compared with the conventional device.

  Next, the operation of the present embodiment will be described. In FIG. 1, an analog moving image signal or an uncompressed digital moving image signal coming from an image input terminal 1 is supplied to an encoder 2, where code amount control is performed so as to reach a predetermined target transfer bit rate. The encoded data is supplied to the primary recording medium 3 and recorded as a first code string. The encoding method of the encoder 2 complies with the MPEG standard and the like. The code amount control in the encoder 2, which is the first encoding process, is feedback control based on the degree of sufficiency of a virtual buffer having a predetermined capacity. However, if the virtual buffer capacity is larger than the actual buffer capacity, the generated code amount greatly fluctuates. Then, it becomes a variable transfer bit rate.

  If the primary recording medium 3 supports such a variable transfer bit rate, image quality can be improved over a fixed transfer rate. However, the point that control is performed so as to reach a predetermined target rate is similar to control of general fixed transfer bit rate. The primary recording medium 3 is basically non-removable, and is capable of recording for a long time even at a high bit rate with an HDD having a capacity of about 100 GB (Byte). For example, at 100 GB, recording for 38 hours at 6 Mbps becomes possible. The predetermined target rate is switched by setting means (not shown), but is not switched in the middle of one moving image.

  The first code string recorded on the primary recording medium 3 is reproduced by a reproducing means (not shown) and supplied to a switch 5 and a code string converter 4. 7 and decoded and re-recorded on the secondary recording medium 6, the code string is supplied to the code sequence converter 4, where the code sequence is converted by re-encoding and then supplied to the secondary recording medium 6. .

  The secondary recording medium 6 is easily removable, and is, for example, a 4.7 GB DVD-R (RAM, RW) or a large capacity disk recording medium having a capacity of about 25 GB. In the former case, if it is attempted to record for about three hours, the transfer rate must be 3 Mbps on average. Since the secondary recording medium 6 has a small capacity unlike the primary recording medium 3, it is desired that a target moving image can be recorded without excessive or insufficient information. Since the length of a general moving image (television program) is 30 minutes to two hours, about two to six moving images (television programs) are recorded on one secondary recording medium 6.

  The code sequence converter 4 re-encodes (converts) an input code sequence into a different code sequence. However, the coding method (format) of the converted code sequence is different even if it is common to the encoder 2. It may be something. This is a conversion of a code string, and in the case of MPEG or the like, it is coded again after decoding. The difference in the encoding process is the method of controlling the generated code amount. The encoder 2 controls the target bit rate to be a constant target bit rate. The code string converter 4 sets the target bit rate set in units of GOP (Group Of Picture), frame, slice (16 lines), and the like. It is controlled to match.

  The second code string re-encoded by the code string converter 4 in this manner is recorded on the secondary recording medium 6. The actual code amount with respect to the target code amount causes an error in each unit such as a GOP, but the error is reflected in the control of the next GOP. It is less than a fraction of the code amount of one GOP. If the target code amount is made small considering only this slight final error, the total code amount will fall within the medium capacity. Accordingly, the target moving image is recorded on the secondary recording medium 6 without excess or deficiency of the code amount. The code string read from the secondary recording medium 6 is supplied to the decoder 7 via the switch 5, where it is decoded and becomes a reproduced image, which is output from the image output terminal 8.

  On the other hand, the information extractor 9 encodes the first code string reproduced from the primary recording medium 3 into encoding difficulties in units of GOPs, frames, slices, and the like (the code amount necessary to obtain a predetermined reproduction image quality). Extract information about That is, the information extractor 9 first extracts generated code amount information (virtual buffer sufficiency information) as encoding difficulty information. Since the first code string is not coded to have a predetermined image quality as in the conventional example, the quantization value fluctuates, and the code amount cannot be directly converted to the target code amount. Therefore, the information extractor 9 further extracts information related to quantization from the first code string. That is, the information extractor 9 uses the average value of the generated code amount and the quantized value (quantization step width, quantization scale) to estimate the pseudo-generated code amount in the corresponding section (estimated as necessary to obtain a predetermined image quality). Is calculated.

  It is known that the pseudo-generated code amount is given by the product of the code amount and the quantized value when the quantized value is medium, and the product of the obtained code amount and the quantized value is simply calculated as Used. In order to obtain a more accurate value, the quantization value may be corrected from the relationship with the subjective image quality. Specifically, the quantization value is set to a power of 1.2 instead of the quantization value in consideration of the subjective image quality. Furthermore, the quantization value may be corrected using information on a motion vector or information on an inter-picture prediction processing mode. If any of the parameters of the information on the code amount and the information on the quantization is almost a fixed value, only the parameter that fluctuates is used as the parameter indicating the degree of difficulty of encoding.

  For example, in the case of MPEG-2 or 4, the quantization value includes a slice value and a macroblock value. For simplicity, only the slice value is used. In addition, when the quantization matrix or the like is modified, it becomes more accurate when it is considered. The information extractor 9 obtains the pseudo-generated code amount in units of a GOP, a frame, a slice, and the like, holds all the time of the moving image, and provides the target rate setting device 10 with the target rate setting device 10.

  The target rate setting device 10 corrects the pseudo code amount of the secondary recording moving image to set the target code amount (target rate) so as to match the total recordable code amount of the secondary recording medium 6, and sets the target code amount (target rate). All the time of the recorded moving image is held and given to the code string converter 4. Which of the primary recorded moving images is to be secondarily recorded is set by the recording setting unit 11 based on information provided from the recording setting input terminal 12.

  The state of the bit rate is shown in FIG. In the figure, the broken line indicates the target rate, and the solid line indicates the actual rate. The actual rate I of the primary-recorded code string is adjusted to a predetermined target rate, and the actual rate II of the secondary-recorded code string follows the fluctuating target rate. Although the code stream to be primarily recorded has a variable transfer rate, the change is small because it is adjusted to a predetermined target transfer rate (6 Mbps in FIG. 5), and conversely, the image quality fluctuates. On the other hand, the average rate of the code sequence to be secondarily recorded is greatly reduced, and the target rate itself changes greatly. Therefore, the actual rate also changes greatly as shown by the solid line II, and the image quality is constant.

  Next, a second embodiment of the moving image code amount control device and the moving image recording device of the present invention will be described. FIG. 2 is a block diagram showing a second embodiment of the moving image code amount control device and the moving image recording device according to the present invention. In the figure, the same components as those in the first embodiment of FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. Compared to the first embodiment of FIG. 1, the second embodiment of FIG. 2 has a code input terminal 21 instead of the image input terminal 1 and a code sequence receiver 22 instead of the encoder 2. There is a feature in the point provided.

  The second embodiment will be described. An encoded signal coming from a code input terminal 21 is subjected to error correction and multiplexing by a code sequence receiver 22, and is converted into a moving image code sequence to form a primary recording. Recorded on the medium 3. This moving image code string is transmitted by digital broadcasting or the like, and generally has a fixed transfer rate, and the fluctuation of the code amount is kept within a range that can be absorbed by a predetermined buffer.

  The processing after the primary recording medium 3 is basically the same as that of the first embodiment shown in FIG. 1, but since the variation in code amount is smaller, the pseudo-generated code amount is mainly determined by the quantization value. become.

  Next, a third embodiment of the moving image code amount control device and the moving image recording device of the present invention will be described. FIG. 3 is a block diagram showing a third embodiment of the moving image code amount control device and the moving image recording device according to the present invention. In the figure, the same components as those in the first embodiment of FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. The third embodiment of FIG. 3 differs from the first embodiment of FIG. 1 in the processing operation and input / output of the information extractor 32 and the primary recording medium 31.

  To explain the operation of the third embodiment, the first code string for the primary recording medium is output from the encoder 2 and supplied to the information extractor 32 at the same time as the code amount. And a quantized value. The information extracted by the information extractor 32 is recorded on the primary recording medium 31 separately from the primary code string for the primary primary medium. The target rate setting unit 10 obtains the target rate from the pseudo code amount information reproduced from the primary recording medium 31, not from the information extractor 32.

  Note that the present invention is not limited to the above embodiments, and includes, for example, a computer program that implements the moving image code amount control device and the moving image recording device of each embodiment by software using a computer.

1 is a block diagram of a first embodiment of a moving image code amount control device and a moving image recording device of the present invention. FIG. 4 is a block diagram of a second embodiment of a moving image code amount control device and a moving image recording device of the present invention. FIG. 10 is a block diagram of a third embodiment of a moving image code amount control device and a moving image recording device of the present invention. It is a block diagram of an example of a conventional moving image code amount control device and a moving image recording device. It is a figure showing the bit rate of each code sequence of an embodiment.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Image input terminal 2, 42, 44 Encoder 3, 31, 41 Primary recording medium 4 Code sequence converter 5 Switch 6 Secondary recording medium 7 Decoder 8 Image output terminal 9, 32 Information extractor 10 Target rate Setting device 11 Recording setting device 12 Recording setting input terminal 43 Code amount observation device

Claims (4)

In a method for controlling a generated code amount in re-encoding when converting a first code string obtained by performing high-efficiency encoding of a moving image signal into a second code string,
From the first code string, at least one of information on code amount and information on quantization is extracted as a parameter indicating the encoding difficulty of a moving image, and the extracted parameter indicating the encoding difficulty is extracted from the extracted parameter indicating the encoding difficulty. A first step of obtaining a pseudo-generated code amount estimated to be necessary to obtain a predetermined reproduction image quality for each predetermined unit time;
The pseudo-generated code amount is changed every predetermined unit time so that the total code amount of the predetermined portion of the moving image signal is adjusted to the total code amount of the recording medium for recording the predetermined portion of the moving image signal. A second step of setting the corrected target code amount for a predetermined portion of the moving image signal;
A third step of re-encoding the first code string and converting it to the second code string for recording on the recording medium while controlling the code amount in accordance with the target code amount. Characteristic video code amount control method. A first step of recording, on a first recording medium, a first code sequence obtained by performing high-efficiency coding of a moving image signal by controlling a code amount targeting a predetermined transfer bit rate;
Extracting at least one of information on a code amount and information on quantization as a parameter indicating the encoding difficulty of a moving image from the first code string, and extracting a predetermined value from the extracted parameter indicating the encoding difficulty A second step of obtaining a pseudo-generated code amount estimated to be necessary for obtaining reproduction image quality for each predetermined unit time;
The pseudo-generated code amount is set to the predetermined unit so that the total code amount of the predetermined portion of the moving image signal is adjusted to the total recordable amount of the second recording medium for recording the predetermined portion of the moving image signal. A third step of setting a target code amount corrected for each time for a predetermined portion of the moving image signal;
A fourth step of re-encoding the first code string and converting it into a second code string having a variable transfer bit rate while controlling the code amount according to the target code amount;
A fifth step of recording the second code string on the second recording medium at a variable transfer bit rate. From a first code string obtained by performing high-efficiency coding of a moving image signal, a code amount is used as a parameter indicating the degree of difficulty in coding a moving image from the first code string Pseudo-generated code amount estimated to be necessary to obtain a predetermined reproduction image quality from information on a parameter indicating the degree of difficulty of encoding the extracted moving image by extracting at least one of information relating to information relating to quantization and information relating to quantization. Information extracting means for obtaining the information for each predetermined unit time,
The pseudo-generated code amount is changed every predetermined unit time so that the total code amount of the predetermined portion of the moving image signal is adjusted to the total code amount of the recording medium for recording the predetermined portion of the moving image signal. Target code amount setting means for setting the corrected target code amount for a predetermined portion of the video signal,
Encoding means for re-encoding the first code string and converting it to a second code string to be recorded on the recording medium while controlling the code amount in accordance with the target code amount. Moving image code amount control device. First recording means for recording, on a first recording medium, a first code string obtained by performing high-efficiency encoding of a moving image signal by code amount control targeting a predetermined transfer bit rate;
Extracting, from the first code string, at least one of information relating to a code amount and information relating to quantization as a parameter indicating the encoding difficulty of a moving image, and indicating the encoding difficulty of the extracted moving image; Pseudo-generated code amount generating means for determining a pseudo-generated code amount estimated to be necessary to obtain a predetermined reproduction image quality from a parameter for each predetermined unit time;
The pseudo-generated code amount is set to the predetermined unit so that the total code amount of the predetermined portion of the moving image signal is adjusted to the total recordable amount of the second recording medium for recording the predetermined portion of the moving image signal. Setting means for setting a target code amount corrected for each time to a predetermined portion of the video signal,
Code string conversion means for re-encoding the first code string and converting it into a second code string with a variable transfer bit rate while performing code amount control in accordance with the target code amount;
And a second recording means for recording the second code string on the second recording medium at a variable transfer bit rate.

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