JP5832925B2 - Program loudness automatic management system and automatic management method thereof - Google Patents

Description

  The present invention relates to a system for automatically managing loudness (loudness perceived by a person) in a program such as a television and radio, and an automatic management method thereof.

  Conventionally, in televisions, radios, etc., there are cases where the volume changes when the channel is changed, and the volume becomes loud when the CM is used, which may disturb the comfortable viewing of the viewer.

  In recent years, there has been a shift from analog broadcasting to terrestrial digital broadcasting, and the volume difference between broadcast channels and programs and the volume difference between programs and CMs have become even more apparent in ordinary households.

  In addition, the conventional volume management of TV and radio programs and CMs has been performed using a VU meter that measures the physical voltage level. However, in the management using the VU meter, even the same voltage level is actually used. There were many cases where the volume of sound that people felt was different.

  Under these circumstances, in recent years, sound management of audio from television broadcasting or the like has been performed using loudness that is closer to the human sense. Also, in March 2011, ARIB TR-B32 was formulated, and an average loudness value indicating the loudness of the entire program as a single value is defined, and the value is operated so as to be constant between programs. (See Non-Patent Document 1).

“Loudness Operation Regulations for Digital TV Broadcasting Programs” ARIB TR-B32 1.0 Edition Radio Industries Association of Japan, page 7

  In the above operation, it is required that the average loudness value of the entire time of a program or CM be within a specified range. In the past, the loudness level was adjusted manually by the mixer operator while monitoring the output meter.

  At this time, it was necessary to visually check the instruction of the loudness meter, and to keep it within a specified range so as not to give a sudden volume change while considering the remaining time of the program. In addition, taking into account the program production within a single program, take into account situations such as the beginning and end of the program that you want to have a volume feeling, and materials that you do not want to change the volume, such as the voice of an announcer. It was also necessary.

  Recorded programs and commercials can be corrected by remixing the recorded material. However, in live broadcast programs, if the average loudness value is not within the specified range after the end of the program, redo will not work, so highly accurate adjustment operations. Was demanded in real time.

  An object of the present invention is to provide a program loudness automatic management system and an automatic management method thereof capable of controlling an average loudness value within a program with high accuracy while performing a desired effect.

In order to achieve the above object, an automatic program loudness management system according to the present invention includes an audio signal input unit including input lines of a plurality of channels, and an audio adjustment process for adjusting an audio signal from the audio signal input unit for each channel. and parts, and the sound addition means for adding the audio signals of each channel of the audio adjustment unit has an output, a master output section for outputting an audio signal added in the sound-adding means, it is added in the sound-adding means A loudness measurement unit for measuring the loudness of a voice signal , and a difference amount between a current loudness level and a target loudness level obtained from the loudness measurement unit is fed back to the voice adjustment processing unit, and the difference amount is distributed for each channel. And a loudness adjustment control unit for adjusting sound.

  In addition, the program loudness automatic management method of the present invention adds a plurality of audio signals input from a plurality of channels to a sound, measures the current loudness level of the added sound, and calculates a difference amount from the target loudness level. The difference amount is distributed to the plurality of channels and fed back, and sound adjustment is performed for each channel.

  According to the present invention, it is possible to control the average loudness value within a program within a specified range with high accuracy while performing a desired effect.

It is a block diagram which shows the program loudness automatic management system of one Embodiment of this invention. It is an example of the program management data input in the program management data input part shown in FIG. It is a block diagram of the loudness adjustment control part shown in FIG. It is a graph explaining the correction method by volume adjustment. It is a graph explaining the correction method (CH correction level +2.5) by sound quality adjustment. It is a graph explaining the correction method (CH correction level +5) by sound quality adjustment. It is a graph explaining the correction method (CH correction level − 5) by sound quality adjustment.

Embodiments of the present invention will be specifically described below with reference to the drawings.
(Constitution)
FIG. 1 is a block diagram showing an automatic program loudness management system according to an embodiment of the present invention.

  The automatic program loudness management system 1 includes an audio signal input unit 2 including four input lines CH1 to CH4, an audio adjustment processing unit 3 that adjusts an audio signal from the audio signal input unit 2 for each channel, A MIX BUS unit 4 that performs voice addition on the audio signal and a master output unit 5 are provided.

  The audio adjustment processing unit 3 includes a TRIM unit 31 that adjusts the volume and a FILTER unit 32 that adjusts the sound quality for each channel.

  Further, the program loudness automatic management system 1 includes a loudness measuring unit 6 that performs voice measurement with a loudness meter between the MIX BUS unit 4 and the master output unit 5, and a loudness measurement by turning off a switch (SW) during the CM. CM tally control unit 7 having a function to be excluded from the program, a program management data input unit 8 for inputting various data relating to the program, a timer unit 9 for managing the progress time of the program, and a loudness adjustment for controlling the loudness adjustment And a control unit 10. Hereinafter, these components will be described in detail.

(Loudness measuring unit 6)
The loudness measuring unit 6 measures the loudness level of the audio signal added by the MIX BUS unit 4 with a loudness meter. The loudness level is measured at a constant cycle, and the measured values are sequentially accumulated until the end of the program, and the average loudness value is calculated in real time. For example, the loudness level can be measured every minute and from 1 minute to 60 minutes after the end of the program. In addition, during CM, the loudness value is excluded from measurement, and the average value is calculated excluding the CM time. The unit of the loudness value is LKFS (Loudness K-weighting Full Scale), and the target loudness level is, for example, -24LKFS, but other values may be used. The current loudness level measured by the loudness measuring unit 6 is transmitted to the loudness adjustment control unit 10.

(Program management data input unit 8)
In the program loudness automatic management system 1, what effect is produced in each time zone in the program for each channel in the program is set in advance using the program management data input unit 8. For example, it is possible to produce an effect that gives a sense of volume at the start and end of a program. Also, consider the characteristics of each input channel, such as an input channel that you do not want to change the volume feeling like MC (microphone) or an input channel that you can change the volume feeling like BG (background). Can be produced for each channel.

  FIG. 2 shows an example of program management data input by the program management data input unit 8. In this example, a target loudness level, an entire program time, a CH weight level, and an effect weight level are set. The target loudness level is set to -24LKFS. In addition, the entire program time is 6 minutes, and the production weight level is set every minute. The production weight level is set to be 1 in total for all time zones of 1 to 6 minutes. Further, CH1 is set as BGM input, CH2 as VTR input, CH3 as relay input, and CH4 as MIC input, and the CH weight level is set so that the sum of CH1 to CH4 becomes 1 for each time zone. In the program management data table, a blank indicates that there is no voice input and the CH weight level is 0.

(Timer part 9)
Based on the entire program time input in the program management data input unit 8, the timer unit 9 manages the progress time of the program and transmits the remaining program time to the loudness adjustment control unit 10.

(Loudness adjustment control unit 10)
FIG. 3 shows a specific configuration of the loudness adjustment control unit 10.
The loudness adjustment control unit 10 includes a reception unit 11, a program management data registration unit 12, a time management unit 13, a calculation unit 14, a control unit 15, and a tally control unit 16.

  The receiving unit 11 receives the current loudness level from the loudness measuring unit 6. The program management data registration unit 12 registers each data of the target loudness level (target loudness value), the CH weight level, and the production weight level input by the program management data input unit 8. The time management unit 13 manages the remaining program time information transmitted from the timer unit 9.

  The calculation unit 14 performs calculation described later based on the target loudness level, the CH weight level, the production weight level data from the program management data registration unit 12 and the remaining time data from the time management unit 13 to make adjustments (that is, The amount to be corrected) is determined. Further, the control unit 15 adjusts the volume or sound quality of the sound adjustment processing unit 3 based on the calculation result in the calculation unit 14. Further, the tally control unit 16 is provided between the MIX BUS unit 4 and the loudness measurement unit 6 with respect to the CM tally control unit 7 based on the data registered in the program management data registration unit 12. A command to turn off the switch is issued.

(CM tally control unit 7)
Audio in a commercial in a broadcast program may include audio in a studio that is not broadcasting, but it is not desirable to include this audio in the average loudness level measurement. For this reason, in this system, the CM tally control unit 7 is provided, and during the CM, the sound input to the loudness measurement unit 6 is turned off automatically by turning off the switch (SW). It has become. The opening / closing control of the switch (SW) is performed based on an opening / closing signal from the tally control unit 16 of the loudness adjustment control unit 10.

(Function)
Next, the operation (mainly the flow of audio signals and control signals) of the program loudness automatic management system 1 of this embodiment will be described based on FIGS.

  The audio signal is input for each channel from the audio signal input unit 2, is added by the MIX BUS unit 4 via the audio adjustment processing unit 3, and is output to the master output unit 5. The loudness measuring unit 6 measures the loudness level of the audio signal added by the MIX BUS unit 4 with a loudness meter. The reception unit 11 of the loudness adjustment control unit 10 receives the current loudness level from the loudness measurement unit 6 and transmits it to the calculation unit 14.

The computing unit 14 computes the current overall program correction level according to the following formula (1).
Current program overall correction level = (target loudness level−current loudness level) × current production weight level (1)

For example, referring to the program management data table shown in FIG. 2, if time zone = 1 minute, target loudness level = −24 LKFS, current loudness level = −14 LKFS, and current production weight level = 0.3, The overall program correction level is
(−24 − (− 14)) × 0.3 = −3.

Moreover, the calculating part 14 calculates the present CH correction level for every CH by the following calculation formula (2).
Current CH correction level =
Current program overall correction level x CH weight level (2)

For example, referring to the program management data table shown in FIG. 2, the time zone = 1 minute, CH = 1, CH weight level = 0.8, and the current overall program correction level calculated by the above equation (1) = − If 3LKFS, the current CH correction level is
−3 × 0.8 = −2.4.

  The computing unit 14 transmits to the control unit 15 the current entire program correction level and the current CH correction level for each CH calculated by the above formulas (1) and (2). The control unit 15 issues a volume adjustment command to the TRIM unit 31 of the audio adjustment processing unit 3 based on the data of the current overall program correction level and the current CH correction level for each CH, and the FILTER unit 32 And issue a sound quality adjustment command.

  Adjusting the volume and sound quality will change the loudness level. In the program loudness automatic management system 1, the loudness adjustment control unit 10 performs adjustment control based on the difference between the current loudness level and the target loudness level, thereby automatically adjusting the average loudness value of the entire program toward the target value.

  For the adjustment of the loudness level, volume adjustment (TRIM) and sound quality adjustment (FILTER) are selected for each material. For example, BGM or the like that emphasizes the volume feeling performs sound quality adjustment, and MC (microphone) or the like that emphasizes the feeling of material performs volume adjustment. In this way, the program loudness automatic management system 1 feeds back the loudness level of the master output to the loudness level of each input material. Hereinafter, volume adjustment (TRIM) and sound quality adjustment (FILTER) will be further described.

(TRIM audio adjustment processing (volume adjustment))
The TRIM unit 31 of the audio adjustment processing unit 3 adjusts the loudness level of the input audio signal by changing the volume. The volume is adjusted for each channel. Here, as shown in FIG. 4, since the adjustment level of the entire program and the CH correction level are in a proportional relationship, the CH correction level for each CH is set so that the adjustment level of the entire program becomes a predetermined value. . This CH correction level is performed using the CH correction level calculated by the above equation (2) from the loudness adjustment control unit 10 as a control amount. Since the TRIM unit 31 adjusts the sound level (physical level), it is possible to minimize a change in sound quality.

(FILTER audio adjustment processing (sound quality adjustment))
The FILTER unit 32 of the audio adjustment processing unit 3 adjusts the loudness level of the input audio signal by changing the sound quality.

  The loudness level, which is a volume sense that can be heard by humans, has a frequency characteristic, and this characteristic is known as an equal loudness curve. In human hearing, a mid-frequency band audio signal is heard loudly and a low frequency band is heard small. The FILTER unit 32 adjusts the loudness level by adjusting the volume of each frequency component of the input sound (sound quality adjustment) according to the equal loudness curve.

  This sound quality adjustment is performed using the CH correction level calculated by the above equation (2) from the loudness adjustment control unit 10 as a control amount, as with the volume adjustment. Hereinafter, specific examples of plus control and minus control will be described.

(Plus control)
First, as shown in FIG. 5, the prescribed curve is a curve that effectively increases the loudness level according to the audibility level. The reference level for determining the correction range is raised or lowered depending on the CH correction level. When the CH correction level is 0 in the range of 0 to +10, it is the top of the graph, and when it is +10, it is the bottom of the graph.

  As shown in FIG. 5, when the reference level of the CH correction level is +2.5, the volume for each frequency is adjusted with respect to the specified curve above the reference level. On the other hand, the specified curve below the reference level does not affect the adjustment.

  Also, as shown in FIG. 6, when the reference level of the CH correction level is +5, the correction level is larger than the case of the CH correction level of +2.5 in FIG. Also become wider.

(Minus control)
On the other hand, in the case of minus control, as shown in FIG. 7, the prescribed curve is a curve that effectively lowers the loudness level according to the audibility level. The reference level is raised or lowered depending on the CH correction level. When the CH correction level is 0 in the range of 0 to −10, the reference level is at the bottom, and when it is −10, the reference is at the top.

  As shown in FIG. 7, when the reference level of the CH correction level is −5, the volume for each frequency is adjusted for the specified curve below the reference level. On the other hand, the specified curve above the reference level does not affect the adjustment.

  Thus, the FILTER unit 32 adjusts the sound quality, so that the loudness level can be adjusted effectively without greatly changing the sound level (physical level).

(effect)
According to this embodiment, the following effects can be achieved.
(1) By performing adjustment control based on the difference between the current loudness level and the target loudness level by the loudness adjustment control unit 10, the average loudness value of the entire program can be automatically adjusted toward the target value. Thereby, a highly accurate adjustment operation becomes possible in real time.

(2) By registering in advance the time zone in which the channel is used for each audio input channel using the program management data input unit 8, the adjustment control time zone can be specified, and the adjustment control becomes larger at the end of the program. Can be prevented.

(3) By adjusting and controlling the timer unit 9 in consideration of the remaining time of the program, it is possible to prevent a sudden volume change and produce a natural volume feeling.

(4) By registering an effect level for each program time zone and performing adjustment control, it is possible to provide an effect on the loudness management in the program.

(5) By changing the weight of the loudness control level for each channel, it is possible to perform loudness adjustment control management for each audio material.

(6) By performing adjustment control for each channel, it is possible to prevent the volume change of the master output (the entire program audio) from becoming large.

(7) As described above, the loudness can be automatically managed without giving a sense of incongruity to the program and without impairing the production effect, and the burden of adjustment work can be reduced.

(8) The CM tally control unit 7 can automatically switch to silence by blocking the voice input to the loudness measurement unit 6 during CM. This eliminates the need to manually switch the input sound to the loudness meter during the CM, thereby reducing the burden on the operator.

(Other embodiments)
(1) In the above embodiment, the number of channels in the audio input unit 2 is four, but it can be any number.

(2) It is also possible to adjust the loudness of the entire mixed audio without dividing the channels.

(3) In the above embodiment, the CM tally control unit 7 is provided and automatically excluded from the target of loudness measurement during the CM. However, in a predetermined case, it may be the target of the loudness measurement even during the CM.

(4) Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Program loudness automatic management system 2 ... Audio | voice signal input part 3 ... Audio | voice adjustment process part 4 ... MIX BUS part (audio | voice addition means)
5 ... Master output unit 6 ... Loudness measurement unit 7 ... CM tally control unit 8 ... Program management data input unit 9 ... Timer unit 10 ... Loudness adjustment control unit 11 ... Reception unit 12 ... Program management data registration unit 13 ... Time management unit 14 ... Calculation unit 15 ... Control unit 16 ... Tally control unit 31 ... TRIM unit 32 ... FILTER unit

Claims (10)

An audio signal input unit comprising input lines of a plurality of channels;
An audio adjustment processing unit for adjusting the audio signal from the audio signal input unit for each channel;
A sound adding means for performing addition on the sound signal for each channel output by the sound adjustment processing unit ;
A master output unit for outputting the audio signal added in the audio adding means ;
A loudness measuring unit for measuring the loudness of the audio signal added by the audio adding means ;
A loudness adjustment control unit that feeds back a difference amount between a current loudness level and a target loudness level obtained from the loudness measurement unit to the sound adjustment processing unit, and distributes the difference amount for each channel to adjust sound.
A program loudness automatic management system characterized by comprising:   The loudness adjustment control unit causes the audio adjustment processing unit to perform audio adjustment within the range of the difference amount based on an effect weight level registered in advance for each time slot obtained by dividing the entire program time into a plurality of time zones. The program loudness automatic management system according to claim 1.   The loudness adjustment control unit causes the audio adjustment processing unit to perform audio adjustment within a range of the difference amount based on a CH weight level registered in advance for each channel. 2. The program loudness automatic management system according to 2. The audio adjustment processing unit is provided for each channel.
A TRIM unit that adjusts the volume based on the distributed difference amount received from the loudness adjustment control unit;
A FILTER unit that adjusts sound quality based on the distributed difference received from the loudness adjustment control unit;
The program loudness automatic management system according to any one of claims 1 to 3, further comprising:   A CM tally control unit is provided between the audio adding unit and the loudness measuring unit, which blocks a voice input to the loudness measuring unit during CM of a program and excludes the audio from being subjected to loudness measurement. The program loudness automatic management system according to any one of claims 1 to 4. Audio adjustment processing for adjusting a plurality of audio signals input from a plurality of channels for each channel;
An audio addition process for adding the audio signal for each channel that has undergone the audio adjustment process ;
A master output process for outputting the audio signal added in the audio addition process;
Loudness measurement processing for measuring the loudness of the audio signal added in the audio addition processing;
Feedback a difference amount between the current loudness level and the target loudness level obtained from the loudness measurement process, and a loudness adjustment control process for adjusting the sound by distributing the difference amount for each channel;
Program Loudness automatic management method, which comprises a. 7. The loudness adjustment control process according to claim 6 , wherein sound adjustment is performed within a range of the difference amount based on an effect weight level registered in advance for each time slot obtained by dividing the entire program time into a plurality of times. Program loudness automatic management method. 8. The program loudness automatic management method according to claim 6 or 7, wherein the loudness adjustment control processing performs audio adjustment within a range of the difference amount based on a CH weight level registered in advance for each channel. . 9. The program loudness automatic management method according to claim 6, wherein the sound adjustment processing is performed by adjusting a sound volume or a sound quality.   10. The program loudness automatic management method according to any one of claims 6 to 9, wherein the program is not subject to loudness measurement during the CM period of the program.

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