JP2013255208A - Video encoding device, video encoding method and video encoding program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently keep subjective image quality of respective pieces of video data when a plurality of pieces of video data are encoded in parallel.SOLUTION: A video encoding device includes: means for calculating average values of a plurality of pictures of one picture average value of first and second video data, respectively; means for calculating a differential value of the average values of a plurality of pictures of the first and second video data; means for determining a bit rate setting value when the first and second video data are encoded in accordance with the differential value and a present setting value; means for using a setting value which reduces a bit rate from the setting value which is set at present in the bit rate setting values to encode and output one of the first and second video data; and means for using a setting value which increases the bit rate from the setting value which is set at present in the new bit rate setting values to encode and output the other of the first and second video data after prescribed time elapses from execution of encoding using the new bit rate setting value.

Description

  The present invention relates to a video encoding device, a video encoding method, and a video encoding program for encoding a plurality of video data in parallel.

  Video encoding techniques include MPEG-2, H.264, and the like. H.263, MPEG-4, and recently H.264. The H.264 standard has become mainstream. H. The H.264 standard provides a compression ratio more than twice that of MPEG-2, and is adopted for one-segment broadcasting of terrestrial digital broadcasting (one-segment partial reception service for mobile phones and mobile terminals) and Blu-ray (registered trademark) standards. Has been. H. As a video encoding standard next to the H.264 standard, HEVC (High Efficiency Video Coding) is currently proposed.

  When encoding video, storage media such as the Blu-ray (registered trademark) standard is the most important condition for image quality. Therefore, the encoding rate is changed according to the video characteristics and encoding is performed with high image quality. A VBR (Variable Bit Rate) method is often used. In addition, a video distribution system such as one-segment broadcasting or IPTV (Internet Protocol TeleVision) has a limited transmission rate, and therefore, a CBR (Constant Bit Rate) system that performs encoding with a constant encoding rate is used.

  In recent years, with the widespread use of 3D video services, there has been an increasing need for simultaneous encoding and transmission of two left and right videos, and a multi-display service that enables simultaneous delivery and viewing of multiple channels of video streams. In addition, 4Kx2K video, which is 4 times the resolution of full HD, and SHV (Super High Vision, 16 times the resolution of full HD) advocated by NHK (Japan Broadcasting Corporation), have a larger screen than full HD. Is progressing.

  However, full HD level products are still mainstream for video encoding devices, so when encoding 4Kx2K video and SHV video, encoding may be performed using multiple full HD compatible encoding devices. Many. In addition, there are increasing opportunities to simultaneously encode and transmit a plurality of full HD size images, such as when transmitting images from a plurality of cameras to a broadcasting station at the same time in IPTV multi-channel or sports broadcasting.

  Conventionally, when transmitting multiple video streams within a limited transmission rate, the maximum transmission rate is evenly distributed according to the number of video streams, and encoding is performed individually. There will be a difference in image quality. For example, if one is content with relatively little movement, such as a news program, and the other is content with large movement, such as a sports broadcast, the subjective image quality is good because a sufficient amount of code is allocated for content with little movement. However, there is a problem that the subjective image quality deteriorates because the code amount allocation is small in content with large movement. Also, when encoding and transmitting sports broadcasts on a large screen, a sufficient code amount is allocated in an area where the player is not shown, so the subjective image quality is good, but in areas where the player is moving greatly, the code amount is allocated. Subjective image quality deteriorates because there are few. From the viewpoint of viewing, since the portion where the player is moving is often the gaze area, there is a problem that the overall subjective image quality is felt poor.

  In order to solve such a problem, a statistical multiplex code amount control method is known in which each coding rate is dynamically changed while keeping the total coding rate constant. In this method, the coding rate can be set according to the video characteristics of each, so even if the above problem occurs, both the coding rate of content with little motion is lowered and the coding rate with large motion is raised. The subjective image quality can be kept uniform.

  A video encoding device having a function of realizing adaptive bit rate distribution among a plurality of channels is also known (see, for example, Patent Document 1). This is because each encoding unit generates a variable bit rate encoded stream corresponding to the content of the input image of each channel and multiplexes it into a single stream. Without directly instructing the buffer to switch the output bit rate at the same timing, the sum of the bit rates of the encoded streams output from the stream buffer of the encoding unit is always kept below a certain value. This makes it easier to implement a moving picture coding apparatus having an adaptive bit rate distribution function between a plurality of channels.

JP 2005-252752 A

  However, in the video encoding device described in Patent Document 1, a new bit rate is set based on a value obtained by multiplying a quantization parameter called a complexity index by a generated code amount. For this reason, when the quantization matrix set is adaptively changed, the tendency of the complexity index also changes, so that appropriate control may not be possible. Therefore, there is a problem that the subjective image quality of both cannot be kept good.

  The present invention has been made in view of such circumstances, and when performing a coding process on a plurality of video data in parallel, a video coding apparatus capable of maintaining good subjective image quality of each video data, An object is to provide a video encoding method and a video encoding program.

  The present invention is a video encoding apparatus for encoding a plurality of video data in parallel, wherein the first and second video input means for inputting the first video data and the second video data respectively. Average value calculating means for calculating an average value of one picture of a quantization parameter for each video processing unit, and an average of a plurality of pictures of the average value of one picture of each of the first and second video data A plurality of picture average value calculating means for calculating a value; a difference calculating means for calculating a difference value between the plurality of picture average values of the first video data and the plurality of picture average values of the second video data; A new bit rate setting value for encoding each of the first video data and the second video data is determined according to the difference value and the currently set bit rate setting value. A setting value determining means that performs a setting value that decreases a bit rate from a setting value that is currently set among the new bit rate setting values. A first encoding unit that encodes and outputs the first bit; and after the predetermined time elapses after the first encoding unit executes encoding using the new bit rate setting value, the new bit Second encoding that encodes and outputs the other of the first or second video data using a setting value that increases the bit rate from the currently set setting value among the rate setting values Means.

  The present invention relates to a video encoding device that encodes a plurality of video data in parallel by a plurality of encoding processes, the video input means for inputting each of the plurality of video data, and the encoding process for each of the video data An average value calculating means for calculating an average value of one picture of a quantization parameter for each unit; an average value calculating means for calculating an average value for a plurality of pictures of the average value of one picture for each of the video data; Maximum / minimum value calculating means for calculating the maximum and minimum values of the average value for a plurality of pictures calculated from each data, encoding information used for encoding the video data indicating the maximum value, and the minimum Coding bit rate setting for determining a new coding bit rate setting value using coding information used for coding processing of the video data indicating the value When the determination unit and the encoding process using the encoding bit rate setting value that decreases the setting value of the encoding bit rate that is currently set when the new encoding bit rate setting value is set, First encoding means for performing encoding by setting a set value of the new encoding bit rate, and encoding using the new encoding bit rate set value by the first encoding means When the new encoding bit rate setting value is set after a predetermined time has elapsed after the encoding process with the bit rate setting value decreased, the setting value of the currently set encoding bit rate increases. And a second encoding means for performing encoding by setting the new encoding bit rate setting value for the encoding process using the encoding bit rate setting value to be To do.

  In the present invention, the encoding bit rate setting value determining means calculates a difference value between a maximum value and a minimum value of a plurality of picture average values calculated from the video data, and calculates the difference value and a plurality of values calculated from the video data. The new encoding bit rate setting value is determined according to the encoding bit rate setting value of the encoding process in which the average value for pictures is the minimum value.

  In the present invention, after the encoding bit rate setting value determining means determines the encoding bit rate setting value, two or more encoding processes that have not been used for the encoding bit rate setting value change process remain. In this case, the determination of the encoding bit rate setting value is repeatedly performed until the number of encoding processes not used for the encoding bit rate setting value changing process is one or less.

  The present invention is a video encoding method performed by a video encoding device that performs encoding processing on a plurality of video data in parallel, wherein the video input step inputs the first video data and the second video data, respectively. An average value calculating step of calculating a one-picture average value of a quantization parameter for each encoding processing unit for each of the first and second video data; and the one-picture average value of each of the first and second video data A plurality of picture average value calculating step for calculating an average value for a plurality of pictures, and a difference value between the plurality of picture average values of the first video data and the plurality of picture average values of the second video data. Each of the first video data and the second video data is encoded according to a difference calculation step and the difference value and the currently set bit rate setting value. A setting value determining step for determining a new bit rate setting value at the time of use, and a setting value for reducing the bit rate from the currently set setting value among the new bit rate setting values. A first encoding step for encoding and outputting one of the first and second video data, and encoding using the new bit rate setting value by the first encoding step; After the predetermined time elapses, the other one of the first and second video data using the setting value that increases the bit rate from the currently set setting value among the new bit rate setting values. And a second encoding step for encoding and outputting.

  The present invention is a video encoding method performed by a video encoding apparatus that encodes a plurality of video data in parallel by a plurality of encoding processes, the video input step for inputting each of a plurality of video data, and the video An average value calculating step of calculating an average value of one quantization parameter for each encoding processing unit for each data, and an average value of a plurality of pictures for calculating an average value for a plurality of pictures of the one picture average value of each of the video data A calculation step; a maximum / minimum value calculation step for calculating a maximum value and a minimum value of the average value for a plurality of pictures calculated from each of the video data; and a code used for encoding the video data indicating the maximum value A new encoding bit rate setting using the encoding information and the encoding information used for encoding the video data indicating the minimum value. An encoding bit rate setting value determining step for determining a value, and an encoding bit rate setting in which the set value of the currently set encoding bit rate is reduced when the new encoding bit rate setting value is set A first encoding step for performing encoding by setting a set value of the new encoding bit rate for the encoding processing using a value, and the new encoding by the first encoding step. When the new encoding bit rate setting value is set after the elapse of a predetermined time after executing the encoding process using the bit rate setting value to reduce the encoding bit rate setting value, the current setting is performed. For the encoding process using the encoding bit rate setting value that increases the encoding bit rate setting value, the encoding value is set by setting the new encoding bit rate setting value. And having a second coding step.

  In the present invention, the encoding bit rate setting value determining step calculates a difference value between a maximum value and a minimum value of a plurality of picture average values calculated from the video data, and calculates the difference value and a plurality of values calculated from the video data. The new encoding bit rate setting value is determined according to the encoding bit rate setting value of the encoding process in which the average value for pictures is the minimum value.

  In the present invention, the encoding bit rate setting value determining step includes two or more encoding processes that are not used for the encoding bit rate setting value changing process after the encoding bit rate setting value is determined. In this case, the determination of the encoding bit rate setting value is repeatedly performed until the number of encoding processes not used for the encoding bit rate setting value changing process is one or less.

  The present invention is a video encoding program for causing a computer to function as the video encoding device.

  According to the present invention, when encoding a plurality of video data in parallel, the video encoding process is performed while dynamically changing the encoding bit rate of each of the plurality of input video data. Encoding processing can be performed with an optimal code amount while keeping the bit rate constant. Therefore, an effect that the subjective image quality of the video can be improved is obtained.

It is a block diagram which shows the structure of 1st Embodiment of this invention. It is explanatory drawing which shows the change amount of a bit rate. It is explanatory drawing which shows an example of a response | compatibility of Qmat and Qoffset. It is a block diagram which shows the structure of 2nd Embodiment of this invention. It is explanatory drawing which shows an example of a response | compatibility of Qmat and Qoffset. It is a block diagram which shows the structure of 3rd Embodiment of this invention.

<First Embodiment>
Hereinafter, a video encoding apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. In this figure, reference numeral 10 denotes video encoding that inputs at least two video content data (first and second video content data), performs encoding, and outputs a multiplexed transport stream (TS). Device.

  Reference numerals 11 and 12 denote video encoding units, which encode video content and calculate an average value of one quantization parameter parameter from the encoding result. Further, the average value of the average values of one picture for the past several pictures is calculated from the currently encoded picture. The number of pictures for calculating the average value is arbitrarily set in advance. The number of pictures corresponding to 1 GOP (Group of Pictures) may be set according to the encoding configuration. The video encoding units 11 and 12 include control units 111 and 121 that control and control operations, respectively, and stream generation units 112 and 122 that generate streams.

  Reference numeral 13 denotes a host CPU, which includes an output bit rate determination control unit 131 that performs overall control of two video encoding units and determination processing of a new bit rate setting value. Reference numeral 14 is a multiplexing unit that multiplexes the two elementary streams (ES) output from the video encoding units 11 and 12 and outputs the multiplexed stream as one transport stream (TS).

  Next, the operation of the video encoding device 10 shown in FIG. 1 will be described with reference to FIG. First, each of the control units 111 and 122 of the video encoding units 11 and 12 uses the quantization parameter for each processing block used when encoding the input first video content data and second video content data, respectively. The average value of one picture is calculated. Furthermore, each of the control units 111 and 122 calculates an average value of one-picture average values for the past several pictures from the currently encoded picture.

Here, the average value of multiple pictures of the quantization parameter calculated by the control unit 111 is Qave _1, and the average value of multiple pictures of the quantization parameter calculated by the control unit 121 is Qave ₂ . Each of the control unit 111 and the control unit 121 outputs the calculated multiple picture average value of each quantization parameter to the host CPU 13. At the same time, output bit rate set values (respectively referred to as BR ₁ and BR ₂ ) set in the respective video encoding units 11 and 12 and quantization matrix numbers (Qmat ₁ and Qmat ₂ ) used for encoding the picture ) Is also output to the host CPU 13.

ここで、Ｑｏｆｆｓｅｔ_１，Ｑｏｆｆｓｅｔ_２は量子化マトリックスセットに応じたオフセット値であり、予め任意に設定しておく。係数の小さい量子化マトリックスの場合はＱｏｆｆｓｅｔは小さな値に、係数の大きい量子化マトリックスの場合はＱｏｆｆｓｅｔを大きな値に設定しておけばよい。図３に、ＱｍａｔとＱｏｆｆｓｅｔの対応の一例を示す。 Next, the output bit rate determination control unit 131 calculates the difference Diff_Q of the quantization parameter average value. The difference Diff_Q of the quantization parameter average value is calculated by the equation (1).

Here, Qoffset ₁ and Qoffset ₂ are offset values according to the quantization matrix set, and are arbitrarily set in advance. In the case of a quantization matrix having a small coefficient, Qoffset may be set to a small value, and in the case of a quantization matrix having a large coefficient, Qoffset may be set to a large value. FIG. 3 shows an example of the correspondence between Qmat and Qoffset.

  Then, when Diff_Q is a positive value, the output bit rate determination control unit 131 increases the bit rate setting value of the video encoding unit 11 because the video encoding unit 11 is assumed to have poor subjective image quality. The bit rate setting value of the video encoding unit 12 is decreased. On the other hand, when Diff_Q is a negative value, it is assumed that the video encoding unit 12 has a lower subjective image quality. Therefore, the bit rate setting value of the video encoding unit 12 is increased, and the bit of the video encoding unit 11 is increased. Decrease the rate setting.

これらの値からビットレートの変更量ＢＲｖａｌは（３）式により示される。

The bit rate value to be increased or decreased is calculated as in equation (2). Let BRdec be the current bit rate on the side where the bit rate setting value is to be lowered.

From these values, the bit rate change amount BRval is expressed by equation (3).

  When actually mounted on hardware or software, BRval is rounded off as appropriate. BRbase is a parameter that is a source of the bit rate change width. When BRbase is increased, the bit rate is changed abruptly, and when BRbase is decreased, the bit rate is gradually changed.

  In addition, by setting the current bit rate on the side where the bit rate setting value is going to be lowered to BRdec, the bit rate difference between the two video encoding units gradually changes and the two video images change. It changes sharply in the direction in which the difference between the bit rates of the encoding units 11 and 12 decreases. This has the effect of preventing the deterioration of the subjective image quality even when the video characteristics change suddenly such as a scene change.

  FIG. 2 shows a table structure that defines the relationship between Diff_Q and BRdec according to BRdec when BRbase = 0.01. The table shown in FIG. 2 is held in the host CPU 131, and the output bit rate determination control unit 131 refers to this table to determine the bit rate change amount.

Next, the output bit rate determination control unit 131 obtains new bit rate setting values (BRnew ₁ , BRnew ₂ ) according to equation (4).

  When changing the bit rate, transmission to the video encoding unit on the bit rate lowering side is performed first, and the bit rate changing process is executed. Thereafter, after a predetermined time has elapsed, the bit rate setting value on the video encoding unit that increases the bit rate is transmitted, and the bit rate changing process is executed. As a result, it is possible to avoid the occurrence of underflow in the decoder buffer due to the total code amount exceeding the set value.

  Next, the output bit rate determination control unit 131 outputs the obtained new bit rate setting values to the video encoding units 11 and 12, respectively. In response to this, the video encoding units 11 and 12 generate and output a stream using the new bit rate setting value. The multiplexing unit 14 multiplexes and outputs the streams output from the two video encoding units 11 and 12.

In the above description, the output bit rate determination control unit 131 in the host CPU 131 is configured to perform the bit rate changing process. However, either one of the video encoding units may perform the above arithmetic process. For example, the quantization parameter average value Qave ₂ , the output bit rate setting value BR _2, and the quantization matrix set number calculated in the video encoding unit 12 are output to the video encoding unit 11 via the host CPU 13, and the video encoding unit 11 is output. The new bit rate set values BRnew ₁ and BRnew ₂ are calculated at, and the BRnew ₂ is converted to the video encoding unit 12 via the host CPU 13. Thereby, the processing load of the host CPU 13 can be reduced.

  In this way, it is possible to reliably control the bit rate changing process under the condition that the transmission rate is constant when encoding a plurality of videos in parallel, and the subjective image quality of both videos is good. Can be kept in. In particular, in the video encoding device described above, since the offset value corresponding to the quantization matrix set is set when calculating a new bit rate, the subjective image quality of the first and second video data is kept good. be able to.

Second Embodiment
Next, a video encoding apparatus according to the second embodiment of the present invention will be described. FIG. 4 is a block diagram showing the configuration of the embodiment. In this figure, the same parts as those in the apparatus shown in FIG. The apparatus shown in this figure is different from the apparatus shown in FIG. 1 in that video encoding units 15 and 16 are newly provided, and accordingly, a host CPU 130 and a multiplexing unit 140 are provided. It is. The video encoding apparatus 100 inputs four video content data (first, second, third, and fourth video content data), encodes each, and multiplexes TS streams (transport streams). Output.

  The video encoding units 11, 12, 15, and 16 encode video content and calculate an average value of one quantization parameter parameter from the encoding result. Further, the average value of the average values of one picture for the past several pictures is calculated from the currently encoded picture. The number of pictures for calculating the average value is arbitrarily set in advance. It suffices to set at least the number of pictures corresponding to one GOP (Group of Pictures). The video encoding units 11, 12, 15, and 16 include control units 111, 121, 151, and 161 that collectively control operations and stream generation units 112, 122, 152, and 152 that generate streams, respectively.

  The host CPU 130 includes an output bit rate determination control unit 131 that performs overall control of the four video encoding units 11, 12, 15, and 16 and processing for determining a new encoding bit rate setting value. The multiplexing unit 140 multiplexes the elementary streams (ES) output from the video encoding units 11, 12, 15, and 16 and outputs them as a single transport stream (TS).

  Next, the operation of the video encoding device 100 shown in FIG. 4 will be described with reference to FIG. First, each of the control units 111, 121, 151, 161 calculates an average value of one picture of a quantization parameter for each processing block used when the input first to fourth video content data is encoded. Further, each of the control units 111, 121, 151, and 161 calculates an average value of one-picture average values for the past several pictures from the picture that is currently encoded.

  Here, the average values of multiple pictures of the quantization parameters calculated by the control units 111, 121, 151, and 161 are Qave1, Qave2, Qave3, and Qave4, respectively. Each of the control units 111, 121, 151, 161 outputs the calculated multiple picture average value of each quantization parameter to the host CPU 130. At the same time, the output bit rate setting values (respectively referred to as BR1, BR2, BR3, and BR4) set in the respective video encoding units 11, 12, 15, and 16, and the quantization matrix number used for encoding the picture (Qmat1, Qmat2, Qmat3, Qmat4) are also output to the host CPU.

  Next, the output bit rate determination control unit 131 selects the maximum value and the minimum value from the quantization parameter average values Qave1 to Qave4, and sets these values as Qmax and Qmin, respectively. Also, the output bit rate setting value corresponding to the video encoding unit for which Qmax is selected, the output bit rate setting value corresponding to the video encoding unit for which Qmin is selected, and the quantization matrix numbers are BRmax and Qmat_max, respectively. The quantization matrix numbers are BRmin and Qmat_min, respectively.

ここで、Ｑｏｆｆｓｅｔ＿ｍａｘ、Ｑｏｆｆｓｅｔ＿ｍｉｎは量子化マトリックスセットに応じたオフセット値であり、予め任意に設定しておく。量子化係数が比較的小さい量子化マトリックスの場合はＱｏｆｆｓｅｔは小さな値に、量子化係数が比較的大きい量子化マトリックスの場合はＱｏｆｆｓｅｔを大きな値に設定しておけばよい。図５にＱｍａｔとＱｏｆｆｓｅｔの対応の一例を示す。 Next, the output bit rate determination control unit 131 calculates the difference Diff_Q of the quantization parameter average value. The difference Diff_Q of the quantization parameter average value is calculated by the equation (5).

Here, Qoffset_max and Qoffset_min are offset values according to the quantization matrix set, and are arbitrarily set in advance. In the case of a quantization matrix having a relatively small quantization coefficient, Qoffset may be set to a small value, and in the case of a quantization matrix having a relatively large quantization coefficient, Qoffset may be set to a large value. FIG. 5 shows an example of the correspondence between Qmat and Qoffset.

実際にハードウェア又はソフトウェアに実装する際はＢＲｖａｌは適宜四捨五入して用いる。ＢＲｂａｓｅは符号化ビットレート変更幅のもととなるパラメータであり、ＢＲｂａｓｅを大きくすると符号化ビットレートが急峻に変更され、ＢＲｂａｓｅを小さくすると符号化ビットレートは緩やかに推移する。 The change amount BRval of the encoding bit rate is expressed by equation (6).

When actually mounted on hardware or software, BRval is rounded off as appropriate. BRbase is a parameter that is a source of the change width of the encoding bit rate. When the BRbase is increased, the encoding bit rate is changed abruptly, and when the BRbase is decreased, the encoding bit rate is gradually changed.

  In addition, this causes a gradual transition in the direction in which the difference between the encoding bit rates of the two video encoding units increases, and a steep transition in the direction in which the difference between the encoding bit rates of the two video encoding units decreases. . This has the effect of preventing the deterioration of the subjective image quality even when the video characteristics change suddenly such as a scene change.

  Finally, the output bit rate determination control unit 131 adds BRval to the output bit rate setting value of the video encoding unit corresponding to BRmax, and subtracts BRval from the output bit rate setting value of the encoding unit corresponding to BRmin. Thus, a new encoding bit rate is set.

  In the case of a video encoding device composed of four or more video encoding units, output bits using the information of the remaining encoding units excluding the encoding unit information used for calculating the encoding bit rate change amount this time The above processing by the rate determination control unit 131 is performed, and the processing is repeated until the remaining encoding unit information becomes one or less.

  When changing the encoding bit rate, transmission to the video encoding unit that lowers the encoding bit rate is performed first, and the encoding bit rate changing process is executed. Thereafter, after a predetermined time has elapsed, the encoding bit rate setting value is transmitted to the video encoding unit that increases the encoding bit rate, and the encoding bit rate changing process is executed.

  FIG. 4 shows an example configured with four video encoding units 11, 12, 15, and 16. However, if the encoding device is configured with two or more arbitrary number of video encoding units, Processing operations are applicable.

<Third Embodiment>
Next, a video encoding device according to a third embodiment of the present invention will be described. FIG. 6 is a block diagram showing the configuration of the embodiment. In this figure, reference numerals 21, 22, 23, and 24 denote video encoding apparatuses, which encode video content and calculate an average value of one picture of a quantization parameter from the encoding result. One of the plurality of video encoding devices is set as a master device, and the other video encoding devices transmit encoding parameters to the master device. The master device executes output bit rate determination processing performed by the host CPU 130 shown in FIG. 4 and transmits a new encoding bit rate to each encoding device. In FIG. 6, it is a figure at the time of setting the encoding apparatus 21 as a master apparatus. The control units 211, 221, 231, and 241 included in each of the video encoding devices 21, 22, 23, and 24 are the control units 111, 121, 151, and the video encoding units 11, 12, 15, and 16 illustrated in FIG. Since it is equivalent to 161, detailed description of the processing operation will be omitted. Also, the stream generation units 212, 222, 232, and 242 shown in FIG. 6 are equivalent to the stream generation units 112, 122, 152, and 162 shown in FIG.

  As described above, when encoding two or more videos in parallel, the coding bit rate changing process under the condition that the transmission rate is constant can be reliably controlled. The subjective image quality of the video can be kept good.

  1, 4, and 6, a program for realizing the functions of the processing unit is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. Thus, the video encoding process may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

  As mentioned above, although embodiment of this invention has been described with reference to drawings, the said embodiment is only the illustration of this invention, and it is clear that this invention is not limited to the said embodiment. is there. Accordingly, additions, omissions, substitutions, and other changes of the components may be made without departing from the technical idea and scope of the present invention.

  The present invention can be applied to a video encoding apparatus in which it is indispensable to encode a plurality of video data in parallel.

  DESCRIPTION OF SYMBOLS 10 ... Video coding apparatus, 11 ... Video coding apparatus, 111 ... Control part, 112 ... Stream production | generation part, 12 ... Video coding apparatus, 121 ... Control part, 122 ... Stream generation unit, 13 ... Host CPU, 131 ... Output bit rate determination control unit, 14 ... Multiplexing unit

Claims (9)

A video encoding device for encoding a plurality of video data in parallel,
Video input means for inputting the first video data and the second video data respectively;
Average value calculating means for calculating an average value of one picture of a quantization parameter for each encoding processing unit for each of the first and second video data;
A plurality of picture average value calculating means for calculating a mean value of a plurality of pictures of the one picture average value of each of the first and second video data;
Difference calculating means for calculating a difference value between the plurality of picture average values of the first video data and the plurality of picture average values of the second video data;
Setting value determining means for determining a new bit rate setting value for encoding each of the first video data and the second video data according to the difference value and the currently set bit rate setting value When,
Of the new bit rate setting values, a setting value that decreases the bit rate from the currently set value is used to encode and output either one of the first or second video data. First encoding means for:
After a predetermined time has elapsed since the first encoding means performed encoding using the new bit rate setting value, the bit rate from the currently set setting value among the new bit rate setting values And a second encoding means for encoding and outputting the other of the first or second video data using a set value for increasing the video encoding device. A video encoding device that encodes a plurality of video data by a plurality of encoding processes in parallel,
Video input means for inputting each of a plurality of video data;
Average value calculating means for calculating an average value of one picture of a quantization parameter for each encoding processing unit for each of the video data;
A plurality of picture average value calculating means for calculating a mean value of a plurality of pictures of the one picture average value of each of the video data;
Maximum / minimum value calculating means for calculating a maximum value and a minimum value of the average value for a plurality of pictures calculated from each of the video data;
A new encoding bit rate setting value is obtained using the encoding information used in the encoding process of the video data indicating the maximum value and the encoding information used in the encoding process of the video data indicating the minimum value. A coding bit rate setting value determining means for determining;
When the new encoding bit rate setting value is set, the new encoding bit rate setting value that reduces the currently set encoding bit rate setting value is reduced with respect to the encoding process using the encoding bit rate setting value. First encoding means for performing encoding by setting a set value of an encoding bit rate;
After the predetermined time has elapsed after executing a coding process in which the first coding means uses the new coding bit rate setting value to decrease the coding bit rate setting value, the new coding bit When the rate setting value is set, the new encoding bit rate setting is set for the encoding process using the encoding bit rate setting value that increases the currently set encoding bit rate setting value. And a second encoding means for performing encoding by setting a value. The encoding bit rate setting value determining means includes:
The encoding process in which a difference value between a maximum value and a minimum value of a plurality of picture average values calculated from the video data is calculated, and the difference value and the average value for a plurality of pictures calculated from the video data are minimum values. The video encoding apparatus according to claim 2, wherein the new encoding bit rate setting value is determined in accordance with the encoding bit rate setting value. The encoding bit rate setting value determining means includes:
After the determination of the coding bit rate setting value, when two or more coding processes that have not been used for the coding bit rate setting value change process remain, they are used for the coding bit rate setting value change process. 3. The video encoding apparatus according to claim 2, wherein the determination of the encoding bit rate setting value is repeatedly executed until there is one or less encoding process. A video encoding method performed by a video encoding device for encoding a plurality of video data in parallel,
A video input step for inputting the first video data and the second video data respectively;
An average value calculating step of calculating an average value of one picture of a quantization parameter for each encoding processing unit for each of the first and second video data;
A plurality of picture average value calculating step of calculating an average value of a plurality of pictures of the one picture average value of each of the first and second video data;
A difference calculating step of calculating a difference value between the plurality of picture average values of the first video data and the plurality of picture average values of the second video data;
A setting value determining step for determining a new bit rate setting value when encoding each of the first video data and the second video data according to the difference value and the currently set bit rate setting value. When,
Of the new bit rate setting values, a setting value that decreases the bit rate from the currently set value is used to encode and output either one of the first or second video data. A first encoding step,
After a predetermined time has elapsed after executing the encoding using the new bit rate setting value in the first encoding step, the bit rate from the currently set setting value among the new bit rate setting values. And a second encoding step of encoding and outputting the other of the first or second video data using a set value that increases the video encoding method. A video encoding method performed by a video encoding device that encodes a plurality of video data by a plurality of encoding processes in parallel,
A video input step for inputting each of a plurality of video data;
An average value calculating step of calculating an average value of one picture of a quantization parameter for each encoding processing unit for each of the video data;
A plurality of picture average value calculating step of calculating a mean value of a plurality of pictures of the one picture average value of each of the video data;
A maximum / minimum value calculating step of calculating a maximum value and a minimum value of the average value for a plurality of pictures calculated from each of the video data;
A new encoding bit rate setting value is obtained using the encoding information used in the encoding process of the video data indicating the maximum value and the encoding information used in the encoding process of the video data indicating the minimum value. An encoding bit rate setting value determination step to be determined;
When the new encoding bit rate setting value is set, the new encoding bit rate setting value that reduces the currently set encoding bit rate setting value is reduced with respect to the encoding process using the encoding bit rate setting value. A first encoding step for performing encoding by setting a setting value of an encoding bit rate;
After a predetermined time has elapsed after executing the encoding process in which the encoding bit rate setting value is decreased using the new encoding bit rate setting value in the first encoding step, the new encoding bit is set. When the rate setting value is set, the new encoding bit rate setting is set for the encoding process using the encoding bit rate setting value that increases the currently set encoding bit rate setting value. And a second encoding step for performing encoding by setting a value. The encoding bit rate setting value determining step includes:
The encoding process in which a difference value between a maximum value and a minimum value of a plurality of picture average values calculated from the video data is calculated, and the difference value and the average value for a plurality of pictures calculated from the video data are minimum values. The video encoding method according to claim 6, wherein the new encoding bit rate setting value is determined in accordance with the encoding bit rate setting value. The encoding bit rate setting value determining step includes:
After the determination of the coding bit rate setting value, when two or more coding processes that have not been used for the coding bit rate setting value change process remain, they are used for the coding bit rate setting value change process. 7. The video encoding method according to claim 6, wherein the determination of the encoding bit rate setting value is repeatedly executed until the number of encoding processes that have not been reached is one or less.   A video encoding program for causing a computer to function as the video encoding device according to any one of claims 1 to 4.

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