JP2013178216A - Time-code history update type loudness meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that operation for finishing the whole volume to a desired loudness value is required in edition or MA operation which is a production process of a broadcast program or CM, however, when a finished result is deviated from an allowable range of a desired loudness target value, operation from a top of a program up to the end should be performed again and corrected.SOLUTION: In a loudness meter for measuring volume history in time series in the order of time-codes by simultaneously recording a sound signal to be a loudness measurement target and a time-code synchronous with the sound signal, a loudness value of the whole program up to the end time of mixing operation can be calculated before final finishing operation, and the final finishing operation is performed by using a difference between the calculated value and a target value as an offset value, so that operation for making a loudness value for finishing coincide with the target value can be logically performed only by one operation while keeping volume changes and balance.

Description

  The present invention relates to measurement of “loudness” indicating an average volume of a broadcast program or the like.

  There is “loudness” as a numerical value indicating the average volume of a broadcast program or CM, and “loudness meter” is a measuring instrument for measuring it.

  Radio Industry Association ARIB TR-B32

  Conventional loudness meters measure real time (real time), measure the volume history in the real time sequence of the audio signal input to the loudness meter from time A to time B, and calculate the loudness value. It was to calculate.

  In finishing work such as editing and MA work that is the production process of broadcast programs and commercials, it is required to finish the entire volume so as to achieve the required loudness value. Therefore, the finished result is the required loudness target value. If it deviates from the permissible range, the work must be restarted and corrected from the beginning to the bottom of the program.

  The present invention is a loudness meter that simultaneously records an audio signal to be measured for loudness and a time code synchronized therewith, and measures a volume history in a time sequence in a time code order. It is possible to calculate the loudness value of the entire program at the end of the mixing work up to that point, and theoretically target the final loudness value by performing the final finishing using the difference between the calculated value and the target value as an offset value. Matching the values can be done with a single operation.

  This eliminates the need for correction work when the allowable range of the loudness value is deviated in the production process of a broadcast program or CM.

Example of block diagram of MA work using conventional loudness meter Flow chart of MA work process using conventional loudness meter Flow chart of MA work process using the loudness meter of the present invention. Illustration of conventional loudness meter operation Illustration of loudness meter operation according to the present invention An example of a block diagram of MA work using the loudness meter of the present invention

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  For example, in normal MA work, as shown in FIG. 1, the used mixing amplifier 2 has a volume reproduction function based on fader position storage linked to the time code 4, and the “mixing” in the work flowchart shown in FIG. After the completion of the “volume adjustment by” operation 7, a “sound return” operation 9 is performed to record the final finished sound on an audio track such as a VTR, thereby completing the program VTR.

  In this case, in the measurement by the conventional real-time type loudness meter 3, it is possible to measure an accurate loudness value by continuously reproducing the program from the beginning to the end without stopping it. If the measured value deviates from the allowable range of the target value as a result, it is necessary to perform the correction again by performing the volume adjustment operation 7 by mixing again by 11.

  However, if the loudness measurement value of the whole program by the previous work is known at the time before the sound return, that is, at the time when the volume adjustment work 7 by mixing is completed, the work flow chart shown in FIG. By reflecting the difference between the measured value and the target value on the master fader 5 of the mixing amplifier 2 as an offset value, the loudness value of the completed program can be theoretically matched with the target value in the subsequent sound return operation 18. it can.

  However, in the volume adjustment work 15 by mixing, the same part is often reproduced twice or three times by rewinding or fast-forwarding for partial volume correction.

  In this case, only the volume history of the last reproduced part should be valid as the complete sound of the entire program.

  However, when the entire volume adjustment work 15 by mixing is measured with the conventional loudness meter of the real time history, the part of the sound that is played back for the second time and the third time after rewinding is reproduced in duplicate. Therefore, it is calculated as a total of three playbacks, resulting in a measurement value different from the exact loudness value of the original program as a whole.

For example, for easy-to-understand explanation, a volume adjustment by mixing a 60-second program material with a constant volume between the time code TC = 0 seconds at the beginning 22 of the program and the time code TC = 60 seconds at the program tail 28 15 If you want to
23 TC = Play 30 seconds from 0 to 30 seconds at medium volume,
next,
24 Rewind from TC = 30 seconds to TC = 20 seconds,
next,
25 TC = 20 seconds to TC = 50 seconds of 30 seconds of playback at low volume,
next,
26 Rewind from TC = 50 seconds to TC = 40 seconds,
next,
Assuming that 20 seconds of 27 TC = 40 seconds to TC = 60 seconds are reproduced at a high volume, the conventional loudness meter 3 that measures in real time records the history as shown in FIG. The time average excluding the silent section of the area of the rectangular portion is calculated as the loudness value.

  However, in this loudness value, the history sections 29 and 30 of the old volume state different from the new volume state overlap in two sections of TC = 20 seconds to 30 seconds and TC = 40 seconds to 50 seconds, This is not accurate because it is calculated including the old overlapping sections 29 and 30 that should not be reflected in the volume of the final finished program and should be invalidated.

  On the other hand, in the time code history update type loudness meter of the present invention, as shown in FIG. 5, the horizontal axis of the recorded volume history is not the actual work time (time) 31 but the time code 32. When 34 to 38 corresponding to the same operation as the above 23 to 27 is performed, only the latest time code playback portion that normally advances is validated for the volume history of the overlapping playback portions generated by the rewinds 35 and 37. By updating, the final loudness value is calculated.

  That is, as shown in the shaded portion in FIG. 5, the old section to be invalidated is overwritten and updated with the volume history of the section to be valid, so the old volume history of the overlapping section caused by rewinding is reflected. It is not deleted and is always updated to the latest non-overlapping volume history.

  Therefore, the time average excluding the silent section of the area indicated by the oblique lines in FIG. 5 is calculated as a more accurate loudness value.

  When the volume of the entire program is changed by 1.0 dB, the loudness value also changes by 1.0. Therefore, for example, the block shown in FIG. 6 is used by using the time code history update type loudness meter of the present invention which operates as shown in FIG. By measuring the loudness value according to the configuration and performing the MA operation in the flowchart shown in FIG. 3, once the loudness value of the completed program is theoretically matched with the target value while maintaining the volume change and balance. Only possible.

  That is, when the volume adjustment work 15 by mixing is completed, the loudness measurement value of the entire program by the previous work is known, so the difference between the measurement value and the target value is set as an offset value to the master fader 44 of the mixing amplifier 41 and the like. By reflecting this, it is possible to theoretically match the loudness value of the completed program with the target value in the subsequent sound return operation 18 only once.

  Therefore, in 19 in FIG. 3, since it is theoretically eliminated from deviating from the allowable range, the redoing operation of 20 does not occur.

  As a specific example, for example, when the target value of loudness is −24 LKFS, the allowable range ± 1, and the loudness measurement value at the time of completion of the volume adjustment work 15 by mixing is −22.6 LKFS, the master fader 44 of the mixing amplifier 41. Is set to -1.4 dB and the sound return operation 18 is performed, it is theoretically possible to finish the loudness value of the completed program to the target -24 LKFS only once.

Claims (2)

  A loudness meter capable of simultaneously recording an audio signal to be measured for loudness and a time code synchronized with the audio signal, and recording history in a time sequence in the order of the time code.   A loudness meter that updates the history of the time code overlap range with an audio signal synchronized with the latest time code when the same time code range as a part of the time code range input in the past is input again.

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