KR20150002388U - Method for measuring the loudness range of an audio signal, measuring apparatus for implementing said method, method for controlling the loudness range of an audio signal, and control apparatus for implementing said control method - Google Patents

Abstract

The present invention relates to a measurement method for measuring a loudness range of an audio signal. In particular, the loudness range is measured in real time. Measuring devices for implementing the method are also proposed (Figures 1 and 2). These measurement devices 920 and 1020 are additionally used in control devices for controlling the loudness range of an audio signal in real time (Figs. 9 and 10).

Description

TECHNICAL FIELD [0001] The present invention relates to a method for measuring a loudness range of an audio signal, a measurement device for implementing the method, a method for controlling a loudness range of an audio signal, and a control device for implementing the control method AUDIO SIGNAL, MEASURING APPARATUS FOR IMPLEMENTING SAID METHOD, METHOD FOR CONTROLLING THE LOUDNESS RANGE OF AN AUDIO SIGNAL, AND CONTROL APPARATUS FOR IMPLEMENTING SAID CONTROL METHOD,

The invention relates to a measuring method as disclosed in the preamble of claim 1, a control method as disclosed in the preamble of claim 12, a measuring device as disclosed in the preamble of claim 14, and a control device as disclosed in the preamble of claim 19, .

EBU R128, Tech. 3342 The recommendation describes a measurement method as described in the preamble of claim 1.

The purpose of the present invention is to provide improved measurement and control methods and suitable measurement and control devices.

The measurement method disclosed by the present invention has the features disclosed in claim 1. The control method disclosed by the present invention has the features disclosed in claim 12. The measuring device disclosed by the present invention has the features disclosed in claim 14, and the control device disclosed by the present invention has the features disclosed in claim 19. Claims 2 to 11 describe advantageous variant implementations of the proposed measurement method. One advantageous variant implementation of the control method is described in claim 13. Claims 15 to 18 describe advantageous variant implementations of the proposed measuring device. One advantageous variant implementation of the proposed control device is described in claim 20.

The present invention continues to derive the audio signal to a desired "to be" value of the measurand of the loudness dynamics of the audio signal by using a dynamics processor during execution of the program, During the execution of a program, the problem of detecting continuous measurements of the dynamics metric needed for the above-mentioned purposes is addressed. Conventional measurement methods are not suitable for the above because they only provide individual measurement values at the end of the program duration interval.

One of the measured quantities of the dynamics of the audio signals is the loudness range. The dynamic metric may be used to create and monitor audio programs, e.g., radio broadcasts, with a view to minimizing the likelihood that listeners will perceive a program that is too loud or too low to be subjective and to manually adjust the playback volume . Subjective influences are considered when the measurand is taken, so that the loudest and softest parts with fewer time distributions will have no intuitive influence on the perception of the loudness range of the program.

When playing an audio program, it is necessary to operate on the audio signal in such a way that it does not require the listener to take any action while listening to programs that are created upon observation of target measurements suitable for that particular listener and which are not being monitored .

Dynamic processors are used to continuously control the enforcement of audio signals, for example, depending on their instantaneous loudness to maintain average loudness stability (leveler) or compress (compress) dynamics. do. The processors are based on instantaneous loudness and are not based on dynamics measurements. This means that this dynamics processor will only change its loudness parameters based on its own settings, for example on its own characteristic curve, which means that the measured dynamics values which its output signals will have Is impossible to predict.

Known methods for measuring audio signal loudness range (EBU R128, Tech. 3342 Recommen- dation) operate with reference to time intervals: within a separate time interval, usually from the start to the end of the program, Lt; / RTI > The measurement starts at the beginning of the time interval and stops at the end of the interval.

In the known measurement method, at the end of the time interval, two threshold values (percentiles) are calculated based on the frequency distribution of all the loudness values in the time interval for the purpose of deriving the measured loudness range values. One disadvantage of the known methods is that the reference to a given time interval is dependent on the dynamics values measured in the same way before the end of the program or the time intervals at any distance back in time, To prevent acquisition of measured dynamics values applicable to time intervals prior to the start of the program. The values measured using known methods are not continuous and are therefore not suitable for the dynamics processor to continue deriving the audio signal to the desired "to be" values of the measured dynamics.

This invention is based on the inventive idea described below.

The creative proposal is to continue to derive the progressive measurements for the loudness range from the instantaneous histogram, as well as continue to detect the measured loudness values in an instantaneous histogram.

Other favorable aspects of the present invention are possible with the following additional creative suggestions:

Normally, in each sample, periodically, the instantaneous histogram is multiplied by a factor less than one. This produces a time weight of the previous gradual loudness values of the audio signal, which decreases as the time interval increases.

A regulator or controller is applied to the audio signal to derive the loudness range of the audio signal, in operation, to the desired "to be" value. The measured amount of the regulator or controller is the loudness range. The control factor of the regulator or controller is a characteristic parameter of the dynamics processor, preferably a characteristic parameter of the enforcement gradient. The inputs and outputs of the regulator or controller are an audio signal and a dynamics-processed audio signal, respectively. Principles generally known in the art of continuous signal control engineering are also applicable.

The present invention will now be further described with reference to the accompanying drawings, which illustrate some examples of embodiments of the present invention.

1 shows a first embodiment of a measuring apparatus according to the present invention.
Fig. 2 shows a second embodiment of the measuring device according to the present invention.
Figure 3 shows a histogram of loudness values (Figure 3a) and a cumulative histogram of loudness values (Figure 3b).
Figure 4 shows an embodiment of a unit for deriving instantaneous loudness values.
Figure 5 shows an embodiment of a unit for deriving instantaneous histograms.
Figure 5A shows the unit of Figure 5 with some variations.
Figure 6 shows an embodiment of a unit for deriving instantaneous cumulative histograms directly from loudness values.
Figure 6a shows the unit of Figure 6 with some variants.
Figure 7 shows an embodiment of a unit for deriving instantaneous loudness ranges from instantaneous cumulative histograms.
Figure 8 shows an embodiment of a comparator circuit included in the unit of Figure 7;
Fig. 9 shows an embodiment of a control device for controlling the loudness range of an audio signal of a certain duration. And,
Figure 10 shows an embodiment of a regulator for adjusting the loudness range of an audio signal of any duration.

1 shows a first embodiment of a measuring device according to the present invention. The measuring device is provided with an input 100 for receiving an audio signal. The first unit 102 provided with an input terminal 104 and an output terminal 106 associated with the input 100 of the measurement device is used to infer the audio signal loudness value from the audio signal and to transmit the loudness value to its own output terminal Lt; / RTI > There is also a second unit 110 provided with an input terminal 108 and an output terminal 112 associated with the output terminal 106 of the first unit 102. The second unit 110 is adapted to infer the histogram from the loudness values provided to the second unit 110 by the first unit 102. There is also a third unit 116 provided with an input terminal 114 and an output terminal 118 associated with the output terminal 112 of the second unit 110. [ The third unit 116 is adapted to derive the cumulative histogram from the loudness value histogram provided to the third unit 116 by the second unit 110. [ There is also a fourth unit 122 provided with an input terminal 120 associated with the output terminal 118 of the third unit 116 and an output terminal 124 associated with the output 126 of the measurement device. The fourth unit 122 inferences the loudness range from the cumulative histogram provided to the fourth unit 122 by the third unit 116 and outputs the loudness range to its own output terminal 124 and accordingly to the output Gt; 126 < / RTI >

Within first unit 102, the manner in which loudness values are obtained from the audio signal provided at input 100 is well known, and therefore requires no further explanation. Also, in the second unit 110, the manner in which the histogram is obtained from the series of loudness values provided at its input terminal 108 is well known and therefore does not require any further explanation. Also, in the third unit 116, the manner in which the cumulative histogram is obtained from the histogram provided at its input terminal 114 is well known and therefore does not require any further explanation. Also, within the fourth unit 122, the manner in which the loudness range is obtained from the cumulative histogram provided at its input terminal 120 is well known, and thus does not require any further explanation. In particular, an in-depth explanation of the above is given in EBU R128, Tech. 3342. ≪ / RTI > In this case, however, it is a goal first to obtain a histogram of loudness values for the entire duration of the audio signal for an audio signal of an arbitrary duration. From this, a cumulative histogram and a loudness range for the entire audio signal are obtained only once.

Instead, the present invention provides for obtaining a plurality of values of the loudness range for the audio signal "in real time " during the duration of the audio signal. This result is obtained by repeatedly in the first unit 102 repeated instantaneous loudness values of the audio signal during consecutive time instants composed of time intervals of the audio signal; In the second unit 110, iteratively estimating an instantaneous histogram of loudness values from successive instantaneous loudness values during the successive time instants; In the third unit 116, iteratively estimates the instantaneous cumulative histogram during the successive time instants; And in the fourth unit 122, iteratively estimates loudness ranges from the instantaneous cumulative histograms during the successive time instants.

Fig. 2 shows a second embodiment of the measuring device according to the present invention, which is simpler than the measuring device of Fig. 1, even though it shows many similarities to the measuring device of Fig.

2 is provided with an input 200 for receiving an audio signal. The first unit 202 provided with the input terminal 204 and the output terminal 206 associated with the input 200 of the measurement device can similarly derive the audio signal loudness values from the audio signal, To provide its own output terminal. There is also a second unit 216 provided with an input terminal 214 and an output terminal 218 associated with the output terminal 206 of the first unit 202. [ Unit 216 is configured to direct cumulative histograms directly from the loudness values provided to unit 216 by first unit 202. [ In this case as well, there is a fourth unit 222 provided with an input terminal 220 associated with the output terminal 218 of the unit 216 and an output terminal 224 associated with the output 226 of the measurement device.

Again, the first unit 202 inferences a plurality of values of the loudness range for the audio signal "in real time" during the duration of the audio signal. In unit 216, instantaneous cumulative histograms are inferred repeatedly directly from the loudness values of the first unit 202 during the successive time instants. Again, the fourth unit 222 repeatedly infers loudness ranges from the instantaneous cumulative histograms during the successive time instants.

Next, with reference to FIG. 3, a description will be given of how instantaneous histograms and instantaneous cumulative histograms are obtained in the measurement apparatus of FIG.

It should be noted that, as a general teaching, when estimating instantaneous histograms and instantaneous cumulative histograms from successive loudness values, the old loudness values are weighted differently. This may mean that old values are weighted more. However, old loudness values are preferably weighted less, as described below.

Figure 3A shows a histogram of loudness values (L). The detectable loudness values (L _i) is shown along the horizontal axis. The vertical axis shows the number (n (n _i )) of loudness L values L _i detected from the beginning of the measurement to the time instant t ₁ . Thus, this histogram is an instantaneous histogram at time instant t ₁ . When measured over, at a time instant (t ₂₎ after, a loudness value _(K L) is detected, a value _(K n) are (normally) will be increased by one, a different value of the histogram will be kept unchanged.

However, as will be described later, instantaneous histogram, the time instant the instantaneous histogram for (t ₂₎ is a loudness value of the time instant (L _k (t ₂₎₎ and the immediately preceding the time instant (t ₁₎ according to the present invention .

except for i = k, and for all loudness values L _i,

n _i (t ₂ ) = n _i (t ₁ ) * α,

n _k (t ₂ ) = n _k (t ₁ ) * 留 + 1

Where, n _i (t ₁₎ and n _i (t ₂₎ is deulyigo histogram value for the loudness value (L _i) of the instantaneous histogram for the time instant (t ₁ and _{t 2), n k (t} 1 ) And n _k (t ₂ ) are histogram values for the loudness value (L _k ) in instantaneous histograms for time instants t ₁ and t ₂ , and α is a constant value smaller than one. In this way, during generation of instantaneous histograms, the incidence of old loudness values will be less weighted. This leads to the following instantaneous histogram related to the time instant (t ₂ ).

Figure 3A shows a cumulative histogram of loudness values (L). Loudness values (L _i) is shown along the horizontal axis. The vertical axis shows the cumulative number (m (m _i )) of detected loudness (L) values L _i starting from the beginning of the measurement. Therefore, for all values of _i , m _i = Σn _j and j ≤ i. Thus, this cumulative histogram is an instantaneous cumulative histogram at time instant t ₁ .

During the measurement, the value m _k and all other values m _i (i> k) will be increased by one if the loudness value L _k is detected at the next instant t ₂ . The values m _i (i < k) will remain unchanged. This leads to the next instantaneous cumulative histogram on time instant t ₂ .

3B, M represents the maximum value of the values m _i . At this time, the loudness range (LR) is obtained as follows. The vertical axis shows two threshold values. In the normalized cumulative histogram, the maximum value of the cumulative histogram is normalized to 1 (therefore, all histogram values are divided by M). In this particular case, the threshold values are denoted as T _L and T _H. In the non-normalized cumulative histogram, the threshold values are M * T _L and M * T _H.

..., LR ₁ , LR ₂ , ...) for each instantaneous cumulative histogram (and thus for each time instant (..., t ₁ , t ₂ , ....) it is possible to obtain a ...), where the lower limit (L _u) is cumulative histogram value _(u m) is m and T _L * "as is" and at a loudness value (L) (i.e., a cumulative curve of the histogram value intersects the T _L * M) for the same L and L _u, the upper limit (L _o) is, in the cumulative histogram value (m _o) is T _H * M and the "as is" a loudness value (L) (i.e. , The cumulative curve of the histogram crosses the value (T _H * M) for L equal to L _o ). In this way, loudness range values are derived from instantaneous cumulative histograms for the time instances, for each time instant.

The following will illustrate how loudness range values are obtained in the measurement device of FIG. From the instantaneous cumulative histogram of the time instant t ₁ shown in FIG. 3B, an instantaneous cumulative histogram for the next instant instant t ₂ can be directly also deduced, as described above.

As may be seen below, the time instant (t ₂₎ the instantaneous cumulative histogram is the loudness value of the time instant (L _k (t ₂₎₎ and the immediately preceding the time instant (t ₁₎ from about according to the present invention Directly inferred from the instantaneous cumulative histogram:

M _i (t ₂ ) = m _i (t ₁ ) * α for all loudness values L _i (i is smaller than k)

For j ≥ k, m _j (t ₂ ) = m _j (t ₁ ) * α + 1.

wherein m _i (t ₁ ) and m _i (t ₂ ) are cumulative histogram values for the loudness value (L _i ) in instantaneous cumulative histograms for time instants (t ₁ and t ₂ ) It is a constant value. In this way, during the production of instantaneous cumulative histograms, the incidence of older loudness values will be less weighted.

This leads to the next instantaneous cumulative histogram on time instant t ₂ .

Figure 4 shows an example of an embodiment of the unit 102 of Figure 1 designated by reference numeral 402 adapted to approximate loudness L values L (t). The unit 402 is interposed between the input terminal 404 and the output terminal 406 of the unit 402 and has a rectifier circuit 410 connected in series to the unit 402, Circuit 414 is provided. The principles of operation of the different circuits within the unit 402 are self-describing, so that no further description of these circuits is required. Circuit 402 generates loudness values L (t) starting at the signal received by its own input terminal 404 during consecutive time instants t and outputs its loudness value L Lt; RTI ID = 0.0 &gt; a &lt; / RTI &gt;

FIG. 5 shows an example of an embodiment of the unit 110 of FIG. 1, designated by reference numeral 510 in FIG. 5, adapted to approximate the instantaneous histograms of FIG. Unit 510 is provided with branch circuits 520.1, 520.2, ...., 520.k, .... 520.N. The input terminal 508 of the unit 510 is associated with the inputs 522.1, ..., 522.N of all of the branch circuits 520.1 through 520.N. All outputs 524.1 through 524.N of the branch circuits 520.1 through 520.N are directed to an output terminal 512 of the circuit 510. [

The branch circuits 520.1 through 520.N are structured in the same manner and are connected to the output of the comparator circuit 526.k, the switching circuit 528.k, the memory 530.k, the multiplier circuit 532.k, The circuit 534.k and the constant value generator 536.k are provided to the branch circuits 520.1 through 520.N. For each branch circuit of N branch circuits 520.k, the following applies. The comparator circuit 526.k, via its own input, is associated with the input 522.k of the branch circuit 520.k. The output of comparator circuit 526.k is associated with the control input of switching circuit 528.k. In addition, the switching circuit is provided with two inputs and one output. The output of the switching circuit is associated with the input of memory 530.k. The output of memory 530.k is associated with the inputs of the output 524.k of the branch circuit 520.k and the inputs of the multiplier circuit 532.k. The output of the multiplier circuit 532.k is associated with a first input of the signal mixer circuit 534.k and a first input of the switching circuit 528.k. The output of the constant value generator 536.k is associated with a second input of the signal mixer circuit 534.k and the output of the signal mixer circuit 534.k is coupled to the second input of the switching circuit 528.k .

The operation principle of the unit 510 is as follows. An input terminal 508, and all of the comparator circuits accordingly (526.k) receives a loudness values L (t) for a successive time instant _{(t 1, t 2, ....} ). In the comparator circuit 526.1, the loudness values are compared with a threshold value L ₁ . In comparator circuits 526.2 through 526.N, the loudness values are compared to threshold values (L _k and L _k-1 ) for two threshold values, e.g., comparator circuit 526.k. This comparison is made as shown in Fig. 5 with reference to the comparator circuit 526.k.

As with the threshold values, the following relationship applies: L ₁ <L ₂ <... <L _{k -1} <L _k < _.

Therefore, if the loudness value L (t) is positioned below L ₁ within the threshold range, a switching signal will be generated by the comparator unit 526.1. Instead, if the loudness value L (t) is positioned between L _{k - 1} and L _k within the threshold range, a switching signal will be generated by the comparator unit 526.k. Within the switching circuit itself, the switching signal will drive the switching circuits 528.1 and 528.k in such a way that the position taken by the switch is at a high position (i.e., a position not shown in FIG. 5). In all other cases, the switch will be in the marked position. A (t ₁ in the range of between ₁ and L _k up to the time _{instant-memory} (530.k) the value n _k, for storing (t ₁₎ the value _k n (t ₁₎ is L _k To the included time instant) the number of loudness values already received and detected. Therefore, if a new loudness value contained between L _{k - 1} and L _k is received and detected, switch 540.k will be switched to the second input of switching circuit 528.k and a new value n _k t ₂₎ will be stored in the memory (530.k), the new value n _k (t ₂₎ is multiplied by the previous value n _k (t ₁₎ in a multiplier circuit (532.k) to a value of α - where by adding the value 1 in the mixer circuit 534.k and again providing this value to the input of the memory 530.k via the high position switch 540.k - Will be stored in the database. In all other switching circuits 528.j, -j is different from k-the switch 540.j will be at the position shown. Therefore, only a single value resulting from the memory 530.j, which is multiplied by the factor a, will again be stored in memory.

Thus, the instantaneous histogram values n ₁ through n _N are always available at outputs 524.1 through 524.N and are provided at output terminal 512.

In an example of the under consideration, it is assumed that the loudness values L (t) can not be greater than L _N. If the maximum value of L (t) is unknown, the circuit of Fig. 5 will be slightly different. The above is shown in Fig. 5A. Here, the inference unit is designated by reference numeral 510a. The only differences relate to block 520N of FIG. 5 designated in FIG. 5A by reference numeral 520a.N. In this case, only the threshold values (L ₁ to L _{N -1} ) exist. At this point, the comparator circuit 526a.N in the branch circuit 520a.N verifies whether the loudness values L (t) is greater than or equal to the value L _{N -1} . In the positive case, a switching signal will be generated to induce switch 528.N (not shown) to a high position.

FIG. 6 shows an example of an embodiment of the unit 216 of FIG. 2 designated in FIG. 6 by reference numeral 616, adapted to infer instantaneous cumulative histograms of FIG. 3B. Circuit 616 is provided with branch circuits 620.1, 620.2, ..., 620.k, ... 620.N. The input terminal 614 of the unit 616 is associated with the inputs 622.1 ... 622.N of all the branch circuits 620.1 through 620.N. All of the outputs 624.1 through 624.N of the branch circuits 620.1 through 620.N lead to the output terminal 618 of the circuit 616. [

Similar to the branch circuits of Fig. 5 only, the branch circuits 620.1 through 620.N include comparator circuit 626.k, a switching circuit 628.k, a memory 630.k, a multiplier circuit 632.k, k, a signal mixer circuit 634.k and a constant value generator 636.k are provided. The structure of the various elements of branch circuits 620.k is substantially the same as that of branch circuits 520.k of Fig.

One difference consists of a slightly different structure of comparator circuit and switching circuit, as will be shown later.

The operation principle of the unit 616 is as follows. An input terminal 614, and all of the comparator circuits accordingly (626.k) receives a loudness values L (t) for a successive time instant _{(t 1, t 2, ...} ). In the comparator circuits 626.k, the loudness values are compared to the threshold value L _k . This comparison occurs as shown in FIG. 6 with reference to the comparator circuit 626.k.

For the threshold values, the following relationship applies: L ₁ <L ₂ <... <L _{K -1} <L _K <... <L _N.

Thus, if the loudness value L (t ₂ ) is positioned below the L _{K in the} threshold range, a switching signal will be generated by the comparator circuit 626.k. The switching signal will drive the switching circuit 628.k in such a way that the position taken by the switch is at a high position (i. E., Position not shown in Figure 6) within the switching circuit itself. In L (t) <K, for j> k, L _j is greater than L _{K in} comparator circuits 626.j as well as (j> k) in all other comparator circuits 620.j , L (t) will also be less than L _j , a switching signal will be generated. Thus, in all these switching circuits 628.j, (j? K), the switch 640.j will be in the high position.

It is assumed that there is a loudness value L (t ₂ ) so that no switching signal is generated in the comparator unit (k-1). This means that the loudness value L (t ₂ ) is greater than L _{K -1 and} is therefore also greater than L _j (j <k). Thus, in all these switching circuits 628.j (j &lt; k), the switch 640.j will be in a low position as shown in FIG.

The memory 630.k stores a value m _k (t ₁ ) representing the instantaneous cumulative histogram value L _K based on the number of loudness values that have been received up to that instant (up to a time instant including t ₁ ) do. Thus, when a new loudness value contained between L _{K -1} and L _K is received and detected, the switches 640.j (j? K) will be switched to the second input of the switching circuit 628.k , the new value mk (t ₂₎ is multiplied by the multiplier circuit (632.k) before the value mk (t ₁₎ to a value α in the (α <1), adding to the value 1 in the mixer circuit (634.k), Is obtained by providing this value (whose value will be stored) to the input of the memory 630.k again via the high position switch 640.k, which will be stored in the memory 630.k. In all other switching circuits 628.j, (j &lt; k), the switch 640.j will be in the position shown. Thus, only one value arising from the memory 630.j multiplied by the factor a will be stored back into the memory.

The instantaneous cumulative histogram values m ₁ to m _N are thus always available at outputs 624.1 to 624.N and are provided at output terminal 612. m _N is equal to the value M in Fig. 3B.

In the example of the embodiment under consideration, it is now assumed again that the loudness value L (t) can not be greater than L _N. If the maximum value of L (t) is unknown, the circuit of Fig. 6 will be slightly different. The above is shown in Fig. 6A. Here, the inference unit is designated by reference numeral 616a. The only differences are involved in block 620.N of FIG. 6 designated in FIG. 6A, reference numeral 620a.N. In this case, only the threshold values (L ₁ to L _{N -1} ) exist. The branch circuit 620a.N includes only a constant value generator 636.N, a memory 630.N, a signal mixer circuit 634.N, and a multiplier circuit 632.N ). For all the time instants (t ₁ , t ₂ , ...,), loudness values that are L _{N -1} less than or equal to or greater than L _N-1 are provided. Thus, in all cases (and thus in the case of each time instant), the value of memory 630.N will be multiplied by the value alpha, where alpha < 1, incremented by the value 1.

FIG. 7 shows an example of an embodiment of a unit 122 (or 222) of FIG. 1 (or FIG. 2) adapted to infer an instantaneous loudness range from an instantaneous cumulative histogram. In Figure 7, the unit is designated by reference numeral 722. [ Unit 722 includes an input 720 for receiving values of instantaneous cumulative histograms m ₁ (t), m ₂ (t), ... m _N (t), and an input 720 of the loudness range LR An output 726 is provided to provide instantaneous values. The unit is also provided with one signal mixer circuit 734 in the form of two comparator circuits 730 and 732 and in particular a subtracter circuit. In the comparator circuit 730, the histogram values m ₁ to m _N are sequentially compared with a threshold value M * T _H so that the histogram value m ₀ has a loudness value L ₀ equal to M * T _H . This loudness value is provided to the output 740 and sent to the first input of the signal mixer circuit 734. To the comparator circuit 732, to identify a loudness value, the histogram values (m _u) a loudness value (L _u), such as the M * T _L a (L _u), the histogram values (m ₁ to m _N) is the threshold Value &lt; / RTI &gt; (M * T _L ). This loudness value is provided to an output 742 and transmitted to a second input of the signal mixer circuit 734. By subtracting the two loudness values, it thereby obtains the loudness range LR (t) provided to the output terminal 726.

Of course, a comparison with the normalized values of instantaneous cumulative histograms can also be performed in unit 722. [ In this case, the values m ₂ (t), ... m _N (t) are first divided into M and then provided to comparator circuits 732 and 734. There, the normalized values are compared with the threshold values (T _H and T _L ) to obtain the loudness range values.

FIG. 8 shows an example of an embodiment of a comparator circuit 732 included in the unit of FIG. In Figure 8, the comparator circuit reference number (which is designated as 832, 801 and 802 designate an input for receiving the histogram values (m ₁ to m _N) and the value (M _* T _L), and 810 is a loudness value, (L _u ) to the comparator circuit 832. N circuit units 803.1 to 803.N are provided in the comparator circuit 832. All the circuit units 803.1 to 803.N are provided with a comparator circuit The first inputs 804.1 through 804.N associated with the input 801 of the comparator circuit 832, the second inputs 805.1 through 805.N associated with the input 802 of the comparator circuit 832, And outputs 807.1 through 807. N. The output 807.k of the circuit unit 803.k is connected to the third input of the circuit unit 803.k-1, 2 ≤ k ≤ N is applied to k. The output 807.1 of the circuit unit 803.1 is associated with the output 810 of the comparator circuit 832.

Each of the circuit units 803.k is provided with a comparator 811.k and a switching unit 812.k. The first input of the switching unit 812.k is associated with the third input 806.k of the circuit unit 803.k. The second input of switching unit 812.k receives L _k , and L _k is one of (threshold) loudness values (L ₁ through L _N ). The output of the switching unit 812.k is associated with the output 807.k of the circuit unit 803.k. The input to the control signal of the switching unit is associated with the output to the control signal of the comparator 811.k. The comparator 811.k is also provided with two inputs associated with the first and second inputs 804.k and 805.k of the circuit unit 803.k. In the comparator 811.k, the histogram value m _k is compared with the value M _* T _L. M _* T _L yi m and _k may be the same or a control signal generated at the output of the comparator (811.k) to be positioned in a smaller case, with a switch (812.k) than the position shown m _k. In this manner, the value L _k will be provided to the output 807.k. Otherwise, the switch will be placed in another position, and input 806.k will be associated with output 807.k.

The principle of operation of the comparator circuit 832 is as follows. As shown in FIG. 3, M _* T _L is greater than m ₁ . This means that at circuit unit 803.1, output 807.1 is associated with input 806.1. The same applies to the circuit units 803.2, 803.3, .... Now, in the circuit unit (803.k), it is assumed that M _* T _L is the first time the detection is the same as or smaller than m _k m _k. As can be seen in Figure 3, this means that m _k is equal to m _u, and L _k is equal to L _u . The position of the switch of switching unit 812.k will now be at the position shown because L _k is provided at output 807.k and the circuit units 803.1 through 803.k- , The output 810 receives the lowest value L _u of the loudness range.

The comparator circuit 730 of FIG. 7 has the same structure as the comparator circuit 732 described in FIG. 8, the only difference is that the input 802 will receive M _* T _H instead of M _* T _L .

Fig. 9 shows an example of an embodiment of a control device for controlling the loudness range of an audio signal. This embodiment shows a counter-reaction control device. The control device is provided with an input terminal 901 for receiving an audio signal. The input terminal 901 is associated with the input 903 of the control unit 905. The output 907 of the control unit 905 is associated with an output terminal 909 for providing an audio signal that is controlled within its loudness range. A generating unit 911 including an input 913 associated with the output 907 of the control unit 905 and an output 915 associated with the input 917 of the control unit 905 intended for the control signal exist.

The generating unit 911 includes a block 920 implemented as in any one of the examples of embodiments of the measuring apparatus shown in Figs. 1, 2, and 4-7. Thus, the loudness range signal LR (t) is available at the output 921 of block 920. [ The generating unit 911 further includes a converter circuit 922 adapted to convert the loudness range signal into a control signal CS ₁ (t), which is provided at an output 915 of the generating unit 911 And is thus provided to the input 917 of the control unit 905.

The converter circuit 922 is known per se and will not be described any further.

Unit 905 is also a known control unit and likewise does not require further explanation.

Fig. 10 shows an example of an embodiment of a regulating device for regulating the loudness range of an audio signal. An example of this embodiment shows a feed-forward adjustment device. The adjusting device is provided with an input terminal 1001 for receiving an audio signal. The input terminal 1001 is associated with the input 1003 of the adjustment unit 1005. The output 1007 of the adjustment unit 1005 is associated with an output terminal 1009 for providing an audio signal that is controlled within its loudness range. There is also a generating unit 1011 that includes an input 1013 associated with input terminal 1001 and an output 1015 associated with input 1017 of the regulating unit 1005 intended for the regulating signal.

The generating unit 1011 includes a block 1020 implemented as in any one of the examples of embodiments of the measuring apparatus shown in Figs. 1, 2 and 4-7. Accordingly, the loudness range signal LR (t) is available at the output 1021 of block 1020. [ The generating unit 1011 further includes a converter circuit 1022 adapted to convert the loudness range signal to an adjusting signal CS ₂ (t), which is provided at an output 1015 of the generating unit 1011 And is thus provided to the input 1017 of the control unit 1005.

The converter circuit 1022 is known per se and will not be described any further. Unit 1005 is also a known conditioning unit and likewise requires no further explanation.

It should also be recalled that the present invention is not limited to the examples of the embodiments described above. The present invention is also applicable to other embodiments that depart slightly from the examples described herein. For example, the invention may be implemented at a software level or at a hardware level.

Claims (20)

A measurement method for measuring a loudness range of an audio signal,
The loudness range value is inferred for an audio signal of any duration,
Wherein a plurality of loudness range values are inferred in real time for the audio signal during the duration of the audio signal,
A measurement method for measuring the loudness range of an audio signal. The method according to claim 1,
For instantaneous loudness values of the audio signal are repeatedly inferred for consecutive time instants included in the time interval of the audio signal and for the successive time instants an instantaneous histogram of loudness values wherein a histogram is repeatedly derived from the continuous instantaneous loudness values and, for the continuous time instantes, a loudness range is inferred from the instantaneous histograms,
A measurement method for measuring the loudness range of an audio signal. 3. The method of claim 2,
When deriving the instantaneous histograms from successive instantaneous loudness values, the earlier loudness values are different, preferably less weighted,
A measurement method for measuring the loudness range of an audio signal. The method according to claim 2 or 3,
Instantaneous histogram for the time instant (t ₂₎ is derived from the histogram of the instantaneous loudness value (L _k (t ₂₎₎ and the immediately preceding time instant (t ₁₎ of said time instant,
for i = k all loudness values (L _{i), except, n i (t 2) =} n i (t 1) * α a, and _{n k (t 2) = n} k (t 1) * α + 1,
Where n _i (t ₁ ) and n _i (t ₂ ) are the histogram values for the loudness values (L _i ) in the instantaneous histograms for the time instants (t ₁ and t ₂ )
n _k (t ₁ ) and n _k (t ₂ ) are histogram values for the loudness values (L _k ) in the instantaneous histograms for the time instants (t ₁ and t ₂ )
alpha is a constant value less than 1,
A measurement method for measuring the loudness range of an audio signal. 5. The method of claim 4,
Wherein instantaneous cumulative histograms for each instant of time are derived from the instantaneous histograms of each instant of time and loudness ranges for each instant of time are inferred from the instantaneous cumulative histograms,
A measurement method for measuring the loudness range of an audio signal. 6. The method of claim 5,
Normalized instantaneous cumulative histograms for each instant of time are derived from the instantaneous histograms of each instant of time and loudness ranges for each instant of time are inferred from the normalized instantaneous cumulative histograms,
A measurement method for measuring the loudness range of an audio signal. The method according to claim 6,
The lower limit value L _u (t ₂ ) and the upper limit value L _o (t ₂ ) of the loudness range for the time instant t ₂ are inferred from the normalized instantaneous cumulative histogram for the time instant, Wherein the curve of the normalized instantaneous cumulative histogram for instant is compared with first and second threshold values (T _L , T _H ), the first threshold value is less than the second threshold value, The loudness value equal to the first threshold value is equal to the lower limit value L _u (t ₂ ) of the loudness range, and the loudness value having the histogram curve value equal to the second threshold value is equal to the upper limit Lt; RTI ID = 0.0 &gt; _L0 (t2) &lt; / _RTI &
A measurement method for measuring the loudness range of an audio signal. The method according to claim 1,
Wherein the instantaneous loudness values of the audio signal are repeatedly inferred for consecutive time instants included in the time interval of the audio signal and an instantaneous cumulative histogram of the loudness values is repeatedly inferred And for the successive time instances, a loudness range is inferred from the instantaneous cumulative histograms,
A measurement method for measuring the loudness range of an audio signal. 9. The method of claim 8,
When deriving the instantaneous cumulative histograms from successive instantaneous loudness values, the earlier loudness values are different, preferably less weighted,
A measurement method for measuring the loudness range of an audio signal. 10. The method according to claim 8 or 9,
Time instant the instantaneous cumulative histogram for the (t ₂₎ is derived as follows from the cumulative histogram of the instantaneous loudness value (L _k (t ₂₎₎ and the immediately preceding time instant (t ₁₎ of said time instant:
For all loudness values L _i , m _i (t ₂ ) = m _i (t ₁ ) * α, i is less than k, and
m _j (t ₂ ) = m _j (t ₁ ) *? + 1 for _j ? k,
m _i (t ₁ ) and m _i (t ₂ ) are the histogram values for the loudness values (L _i ) in the instantaneous cumulative histograms for the time instants (t ₁ and t ₂ )
m _j (t ₁ ) and m _j (t ₂ ) are histogram values for the loudness values (L _j ) in the instantaneous cumulative histograms for the time instants (t ₁ and t ₂ )
alpha is a constant value less than 1,
A measurement method for measuring the loudness range of an audio signal. 11. The method of claim 10,
The lower limit value L _u (t ₂ ) and the upper limit value L _o (t ₂ ) of the loudness range for the time instant t ₂ are inferred from the instantaneous cumulative histogram for the time instant, Wherein the curve of the normalized instantaneous histogram is compared with the first and second threshold values (T _L * T _H , T _H * M), the first threshold value is less than the second threshold value, Wherein the loudness value equal to the first threshold value is equal to the lower limit value L _u (t ₂ ) of the loudness range, and the loudness value having the histogram curve value equal to the second threshold value is the loudness value of the loudness range the upper limit value (L _o (t ₂₎₎ and be equal,
A measurement method for measuring the loudness range of an audio signal. A control method for controlling a loudness range of an audio signal of an arbitrary duration,
Wherein the loudness range of the audio signal is controlled in dependence on a control signal and a plurality of control signal values are inferred in real time during the duration of the audio signal,
A control method for controlling a loudness range of an audio signal of an arbitrary duration. 13. The method of claim 12,
Characterized in that for instantaneous time instants included in the time interval of the audio signal an instantaneous value of the control signal is repeatedly inferred and the instantaneous value of the control signal is measured in accordance with one of the claims 1 to 11 &Lt; / RTI &gt; derived from the instantaneous loudness range values obtained by the method,
A control method for controlling a loudness range of an audio signal of an arbitrary duration. 1. A measurement device for measuring a loudness range of an audio signal of an arbitrary duration,
An input 100 for receiving the audio signal,
A unit for analogizing the value of the loudness range LR of the audio signal,
And an output (126) for providing a value of a loudness range,
The units 110, 116, 122, 216 and 222 are adapted to derive a plurality of values of the loudness range LR (t) for the audio signal in real time during the duration of the audio signal 2),
A measurement device for measuring a loudness range of an audio signal of an arbitrary duration. 15. The method of claim 14,
And a first unit (102) for deriving loudness values for successive time instants of the audio signal,
In the measuring apparatus,
except for i = k, all loudness values for _{(L i), n i (} t 2) = n i (t 1) * α, and _{n k (t 2) = n} k (t 1) * α + 1 person
A second unit 110 for inferring an instantaneous histogram for a time instant t ₂ from an instantaneous histogram of the loudness value L _k (t ₂ ) of the time instant and the immediately preceding time instant t ₁ , ) Is provided,
n _i (t ₁ ) and n _i (t ₂ ) are the histogram values for the loudness values (L _i ) in the instantaneous histograms for the time instants (t ₁ and t ₂ )
n _k (t ₁ ) and n _k (t ₂ ) are histogram values for the loudness value (L _k ) in the instantaneous histograms for the time instants (t ₁ and t ₂ )
α is a constant value smaller than 1 (FIGS. 1 and 5)
A measurement device for measuring a loudness range of an audio signal of an arbitrary duration. 15. The method of claim 14,
And a first unit (202) for inferring loudness values for successive time instants of the audio signal,
In the measuring apparatus,
For all loudness values L _i , m _i (t ₂ ) = m _i (t ₁ ) * α, i is less than k, and m _j (t ₂ ) = m _j t ₁ ) *? + 1
A third unit for inferring an instantaneous cumulative histogram for a time instant t ₂ from the instantaneous cumulative histogram of the loudness value L _k (t ₂ ) of the instant of time and the immediately preceding instant instant t ₁ , (216) is provided,
m _i (t ₁ ) and m _i (t ₂ ) are histogram values for the loudness values (L _i ) in the instantaneous cumulative histograms for the time instants (t ₁ and t ₂ )
m _j (t ₁ ) and m _j (t ₂ ) are histogram values for the loudness value (L _j ) in the instantaneous cumulative histograms for the time instants (t ₁ and t ₂ )
α is a constant value smaller than 1 (FIGS. 2 and 6)
A measurement device for measuring a loudness range of an audio signal of an arbitrary duration. 16. The method of claim 15,
The second unit 510 is provided with an input terminal 508 for receiving successive loudness values L (t) of the audio signal and N histogram values n ₁ (t) for each instantaneous histogram of successive instant histograms. (t), n ₂ (t), ....., n _k (t), ..., n _N (t)
The second unit is also provided with N branching circuits 520.1, ... 520.k, ... 520.N,
Each branch circuit 520.k includes:
a. A comparator circuit 526.k, comprising an input, and an output associated with the input terminal 508 of the second unit 510,
b. A switching circuit 528.k, comprising a control input, a first input and a second input, and an output associated with the output of the comparator circuit,
c. A memory 530.k, comprising an input associated with the output of the switching circuit 528.k and an output associated with the output terminal 512 of the second inference unit,
d. A multiplier circuit 532.k comprising an input associated with an output of the memory 530.k and an output associated with a second input of the switching circuit 528.k,
e. A signal mixer circuit 534.k comprising a first input, a second input, and an output associated with the first input of the switching circuit 528.k, associated with the output of the multiplier circuit 532.k, Adder circuit,
f. A constant value generator (536.k) comprising an output associated with a second input of the signal mixer circuit,
(Fig. 5),
A measurement device for measuring a loudness range of an audio signal of an arbitrary duration. 17. The method of claim 16,
The third unit 616 is provided with an input terminal 614 for receiving successive loudness values L (t) of the audio signal and N histogram values for each instantaneous cumulative histogram of successive instantaneous cumulative histograms an output terminal 618 is provided for providing m ₁ (t), m ₂ (t), ....., m _k (t), ..., m _N (t)
The third unit is also provided with N branch circuits 620.1, .... 620.k, ... 620.N,
Each branch circuit 620.k includes:
a. A comparator circuit 626.k, which includes an input associated with the input terminal 614 of the third unit 616 and an output,
b. A switching circuit 628.k, including a control input, a first input and a second input, and an output associated with the output of the comparator circuit,
c. A memory 630.k, including an input associated with an output of the switching circuit 628. k, and an output associated with an output terminal 618 of the third inference unit,
d. A multiplier circuit 632.k comprising an input associated with an output of the memory 630.k and an output associated with a second input of the switching circuit 628.k,
e. A signal mixer circuit 634.k comprising a first input associated with an output of the multiplier circuit 632.k, a second input, and an output associated with a first input of the switching circuit 628.k, Adder circuit,
f. A constant value generator 636.k, comprising an output associated with a second input of the signal mixer circuit,
(Fig. 6),
A measurement device for measuring a loudness range of an audio signal of an arbitrary duration. A control device for controlling a loudness range of an audio signal of an arbitrary duration,
An input (901, 1001) for receiving the audio signal,
Generation units 911 and 1011 for generating control signals,
A control unit (905, 1005) for controlling the loudness range of the audio signal depending on the control signal,
Outputs 909 and 1009 for providing a controlled audio signal to its own loudness range,
(T), CS ₂ (t)), wherein the generating unit (911, 1011) is adapted to derive, in real time, a plurality of values of the control signals (CS ₁
A control device for controlling a loudness range of an audio signal of an arbitrary duration. 20. The method of claim 19,
The generating units 911 and 1011 comprise measuring devices 920 and 1020 according to any one of claims 12 to 16 for providing a loudness range signal LR (t)
The generation unit is further provided with conversion units 922 and 1022 for converting the loudness range signal to obtain the control signals CS ₁ (t) and CS ₂ (t) , Fig. 10)
A control device for controlling a loudness range of an audio signal of an arbitrary duration.

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