Apparatus and method for volume control

description

Embodiments of the present invention relate to an apparatus and a method for Lautstärkenreguiierung for at least two audio sources as well as on a radio tuner with a corresponding Lautstärkenreguiierung which may also be referred to as two-stage loudness normalization. Another embodiment relates to a corresponding computer program for performing the method for Lautstärkenreguiierung or loudness normalization.

The perceived volume or loudness of different radio stations will vary from station to station. So-called ain stream channels like Bayern 3 or Antenne Bayern are compared to classical stations like Bayern perceived classical music much louder.

These differences are now matched by manually Nachregein over the Lautstär-keknopf. For the user, it can be distracting in the long run. If radio is one in a vehicle, is has it's distracted necessarily from the traffic during manual readjustment even safety significance since the driver.

There are some approaches the volume and loudness depending on the signal (adaptive) adapt. For example, the ITU standard BS.1770 describes a method how the acoustically correct calculation of the loudness should occur. Disadvantages of these methods are that the audio signal is adjusted during the hearing. It produced artifacts such as "pumping" (Audible, quick volume adjustments), strong readjustments in Plosivlau th or reduction of dynamic range.

These methods can not meet the demands for transparent, clean audio reproduction due to their nature. In applications such as high quality audio systems HiFi claims vehicles these algorithms, therefore, are not used. Therefore, there is a need for an improved approach.

The object of the present invention is to provide a concept for automatic volume control, which leaves the audio reproduction is substantially undistorted.

The problem is solved by the independent claims.

Embodiments of the present invention provide a device to adjust the volume for at least two audio sources such. For example, two radio stations. The apparatus comprises a Lautheitsanalysator as well as a volume control. The Lautheitsana-lyst is adapted to an audio signal of the first of said two audio sources, so that is to be analyzed, for example, a first transmitter, a time period (for example, 1 to 5 minutes), depending on this to determine a first loudness value, and this with assignment to to store the first of the two audio sources. Further, the Lautheitsanalysator is adapted to an audio signal of the second of said two audio sources, that is, for example, a second transmitter, for a time period (which may be, for example, the-same) to analyze and therefrom to determine depending on a second loudness value and those of which are assigned to storing second of the two audio sources. The volume control is formed to adjust the audio signal of the currently selected first and / or second of the two audio sources corresponding to the associated first and / or second loudness value.

The object underlying the invention realization is to first analyze the different audio sources or radio stations with respect to its loudness and to store based on the analysis, a corresponding loudness information (loudness value) and then, depending on the analysis result of each associated audio source Lautstärkenre-gelung each audio source or to choose. per transmitter. Analyzing preferably taking place (but not necessarily) over a longer period of time, for example 5 minutes to get a good representative average for the audio source here. The volume control in the second step is preferably carried out so that during playback, the resulting audio signal for the first and the second source in approximately the same volume or loudness. As such may also speak of normalization in this context. This approach has the advantage that the analysis, if not takes usually several seconds, even minutes to complete, a good average value is obtained, and it does not come to the above-mentioned adverse effects such as "pumping" or "transient". Next so maintained and the dynamic range of the audio signal. the fact that each audio source is a loudness value is stored in an associated manner, wherein selection of the audio source or switching the correct volume choice can speak with take place (no delay).

The newly described process can be as a major step in the loudness normalization be-distinguished. In order at the first selection of a transmitter to which no loudness value is present, as well as to achieve an acceptable normalization, can according execution beispieien in a preliminary stage a short-term normalization carried out based on a currently determined loudness value. Therefore, the method according to further embodiments includes the step of determining a preliminary loudness value, and of regulating the volume of the currently selected source (transmitter) based on the preliminary loudness value and the currently determined provisional loudness value. This loudness normalization in the precursor is continued until a loudness value representing a period of time (learning phase each source) is determined and stored. Since according to this embodiment, the loudness normalization is subdivided into pilot and main stage can be spoken (of an automatic two-stage volume control or a two-stage loudness normalization.

According to further embodiments of the once determined and stored loudness value per audio source during operation of the audio source is updated in exceptional cases. For this, the loudness, loudness value when selecting the audio source and analyzed for the case that a significant difference exists updated and stored. The updating is done in accordance with embodiments so that the update has a low impact on the loudness value and therefore on the volume control, The result is that it is audible to any change in volume after the learning phase, it is nevertheless ensured that with changes in the audio source, For them accordingly into account. Here, a kind of weighting can be performed according to embodiments, the weighting being then chosen so that the adaptation of the loudness value in the adjustment phase enjoys a lower weighting than the adaptation of the loudness value in the learning phase. Entspre-accordingly further embodiments can also only take place the adaptation of the loudness value when a significant deviation of the newly determined loudness value from the stored loudness value is present. This significant difference can be given, for example, a percentage of 2% or 10%.

According to further embodiments, the updating of the loudness values ​​and / or according to still further embodiments, determining a

carried out new loudness value for a new source (transmitter) in the background when here the technical conditions are created for the analyzer. In the example, a radio tuner It would mean that a second tuner portion is provided to receive the second transmitter in the background and analyzed. These two execution examples have the advantage of immediately switching a determined or updated loudness value is present, so that the loudness can be effectively normalized.

Further embodiments relate to a radio tuner, comprising the above-mentioned device to adjust the volume. According to further Ausführungsbeispie-len these radio tuner can also have two tuner units.

Another embodiment relates to a corresponding method for volume control comprising the steps of: analyzing an audio signal of the first of said two audio sources and storing the corresponding loudness value, analyzing an audio signal of the second of said two audio sources and storing a respective loudness value, and adjusting the volume of the audio signal of the first and / or the second audio source corresponding to the respective first and / or second loudness value. According to other embodiments, this method can also be performed by a computer program.

Further developments are defined in the dependent claims. Exemplary embodiments will be explained with reference to the accompanying drawings. Show it:

FIG. 1a is an apparatus for volume control in accordance with an exemplary embodiment game;

Fig 1 b, a corresponding method for volume control in accordance with another embodiment. and

Fig. 2 shows a radio tuner to a corresponding apparatus for volume reg u iierung according to embodiments.

Before describing embodiments of the present invention will be explained with reference to the figures in detail, it should be noted that the same or equivalent elements and structures with the same reference numerals so that the description thereof is applicable to each other or exchangeable.

Fig. 1 a shows an apparatus 10 for volume control for at least two audio sources AQ1 and AQ2. The apparatus 10 includes a Lautheitsanalysator 12 and a volume control 14, 10 In addition, the device comprises also a memory 16. The Lautheitsanalysator 12 is the input side, that is arranged in a switchable manner connectable to the audio sources and AQ1 AQ2. The signal from AQ1 and AQ2 is forwarded either from the audio analyzer 12 to the volume control 14 gebypasst.

The different audio sources AQ1 and AQ2 could, for example, two different radio stations, as well as other input sources such. B. CD and radio darsteilen, which are switched either by the radio tuner or by means of a preamplifier. The audio signal (analog or digital) of the audio sources AQ1 or AQ2 is received by the Lautheitsanalysator 12 of this game, in-analyzed over a period of 60 seconds or 300 seconds or even more, depending on a loudness value associated with the relevant audio source AQ1 or AQ2 determined. Due to the long time constant (for example, 1 to 5 minutes), the mean value of the loudness (LW1 LW2 or) for this channel and the audio source can be calculated, which corresponds to the actual loudness.

The loudness value determined (LW1 for the source AQ1 and LW2 for the source AQ2) is stored in the memory sixteenth Normally, the memory 16 is a nonvolatile memory, so that the loudness values ​​remain LW1 or LW2 even after a power cycle. It should also be noted that the memory 16 usually already exists in the radio tuners to store, for example, the transmitter speed dial keys or the last set volume level. The volume control 14 now fits directly the Audiosigna! the selected source AQ1 or AQ2 starting at from the stored loudness value LW1 or LW2.

This behavior of the device 10 can also be explained by the process 100, which is shown in Fig. 1b. The method 100 comprises either the parallel or sequentially (ie at different times, depending on the audio source (AQ1 or AQ2) just chosen) steps executed 110 and 120. Step 1 10 refers to analyzing the audio source AQ1 and storing the loudness value LW1, while the step 120 to the analyzing the audio source AQ2 and storing the loudness value LW2 relates. Based on the gespei-

cherten values ​​LW1 and LW2 is precisely adjusted the volume of the selected source in a third step, the 130th

As already explained above, the loudness measurement and carried out in the first step, the adjustment at a slow time control is connected, so that the change of the volume in step 130 takes place barely audible. Thus, the above-mentioned disadvantages can be avoided.

The step 130 can be repeated at a later Wiederanwahi the respective source AQ1 and AQ2 in order to level the volume level. This use of the result obtained in a so-called learning phase volume values ​​LW1 and LW2 for leveling the volume when the Wiederanwahi of a transmitter based on the assumption that a certain radio station very long periods (several months up to several years) a unitary base volume and average volume maintains. By storing the volume values ​​LW1 and LW2 and the step 130, the advantage is created that can be changed from any transmitter to a transmitter with a pre-stored loudness value, wherein the normalization of the volume takes place immediately at the output. Here, no adjustment is therefore necessary, so that a transparent, dynamic sustaining musical enjoyment is guaranteed.

To during the learning phase - that is, for example, at the first selection of a transmitter if no loudness value could be determined - also to allow a normalization of the volume, in a so-called precursor can also be a short-term (in contrast to the above-mentioned main stage in the loudness normalization) carried out control. For this, then in the preliminary stage, a preliminary loudness value during operation, ie from the first second, the transmitter selection, determined and based on this (current) loudness value performed regulating the volume. Although these short-term control in the precursor to distortions, in particular regarding. The dynamic range, the current source can result, thus a normalization can be ensured for each time point and each source.

The loudness normalization of the precursor is continued until the learning phase of the current source is finished, for example, may be so changed in the main stage to 300 seconds 60 seconds, at least, the step 110 or 120 run parallel to the precursor.

At this point it should be noted that the method 100 and in particular, steps 1 10 and 120, therefore, shown in parallel because, as will be described in reference to FIG. 2, in accordance with further embodiments, determining the loudness values ​​LW1 and LW2 by analyzing the Audio sources AQ1 and AQ2 simultaneously (ie, for an audio source in the background) can take place.

According to other embodiments, is carried out performing the steps 1 10 and 120, not only initially, ie in a so-called learning phase, but also during the continuous operation. In order to respond to possible changes in the volume of Radiosen-DERS over time, runs in the background measurement with passive. the measured value from the stored value over time deviates, can be adjusted subtly. But this readjustment is no significant interference with the dynamics of the music.

Referring to Fig. 1 a is to be noted that it would alternatively be possible that the actual adjustment of the audio signal AQ1 or AQ2 not carried out in the apparatus 10, but that the device 10 by means of the volume control 14, only a sound-volume control signal for adjusting outputs the volume of the currently selected audio signal.

Fig. 2 shows a further embodiment, namely a radio tuner 40 which has a first tuner portion 42. The first tuner 42 is connected to the antenna 44 and can receive and select AQ1 AQ2 and so the plurality of radio transmitter or radio sources by switching to the appropriate carrier frequency by the tuner 42nd downstream from the radio tuner 42, reference 1 is to FIG. explained a device 10 for volume control.

According to further embodiments, 40 a second parallel tuner part 42 'include the tuner, which is also connected to the antenna 44 and is used, inter alia, that the Lautheitsanalysator 12 parallel to the current receiving a first radio source (for. Example, the radio source AQ1) receiving a second radio source (z. B. AQ2) and this analyzed for their loudness. Thus, advantageously, the learning phase, which typically takes 1 to 5 minutes, in the background SUC-gen. Such parallel tuner parts (radio receiver), for example, in today's pre-miumfahrzeugen the rule. Currently, the task of this second radio tuner is DA rin to look in the background for available radio stations without the audio playback of the current station is interrupted. The radio stations found are mostly with station name (RDS) in HMI (display in the vehicle) as a list of available stations. This parallel tuner 42 'can therefore be used to determine the loudness of the radio stations is searched. Turning now to one of these stations changed, the calculated loudness value LW is already ready, so can sound-stärkenreguiierung, as described above, work without audible adjustments must be made.

This second tuner 42 serves not only to reduce or avoid the learning time, as this runs in the background, but can also be used to the station for which a loudness value is already stored, evaluated to update the stored loudness value.

Even if was always assumed in the above embodiments that the audio source is a radio transmitter, the concept proposed here can be used in any other sources which, for example, one in the middle! having constant loudness.

It should also be noted again that the aforementioned long time constant, for example 1 to minutes or 1 can be shorter to several hours or several days, then being expected from the disadvantage that occurs an audible adjustment during its first use , In this way the volume is adjusted accordingly in advance with renewed calls of the transmitter.

Although the above embodiments have been always described in the context of an apparatus, create further embodiments, a method for adjusting the volume or loudness of an audio signal provided by a station, but is performed with performing a loudness measurement and adjustment according to known Vorgehenswei-sen with reduced control time, to determine a value of the actual loudness of the transmitter upon a change from any other station to the station using the determined loudness value to output the audio signal with the normalized volume.

Although some aspects related to a device have been described, it should be understood that these aspects also represent a description of the corresponding encryption driving, so that a block or component of a device is also known as a corresponding process step or to be understood as a feature of a method step , Analogously, aspects described in connection with or as a method step also represent a description of a corresponding block or details or feature of a corresponding apparatus. Some or all of the method steps may be a hardware apparatus (or using a hardware apparatus) such as a microprocessor, for example, a programmable computer or an electronic circuit be executed. In some embodiments, some or several of the most important method steps may be executed by such an apparatus.

Depending on certain implementation requirements of embodiments of the invention in either hardware or software can be implemented. The implementation can be performed using a digital storage medium such as a floppy disk, a DVD, a Blu-ray disc, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, a hard disk or other magnetic be performed or optical memory, are stored on the electronically readable control signals, which can cooperate with a programmable computer system in such a way or that the respective method is performed cooperate. Therefore, the digital storage medium may be computer readable.

Some embodiments according to the invention thus comprise a data carrier having electronically readable control signals capable of cooperating with a programmable computer system such that one of the methods described herein be-performed.

In general, embodiments of the present invention may be implemented as a computer program product with a program code, the program code being operative to perform one of the methods when the computer program product runs on a computer.

The program code may for example be stored on a machine readable carrier.

Other embodiments comprise the computer program for performing one of the methods described herein, wherein the computer program is stored on a machine readable carrier.

In other words, an embodiment of the method according to the invention is therefore a computer program comprising the procedure described program code for performing one of the herein when the computer program runs on a computer.

Another embodiment of the method according to the invention is thus a data carrier (or a digital storage medium or a computer readable medium), is recorded on which the computer program for performing one of the methods described herein.

Another embodiment of the method according to the invention is thus a data stream or a sequence of signals which represents or represent respectively the methods described, the computer program for performing one of the herein. The data stream or the sequence of signals may or may for example be configured to provide a data communication connection, for example via the Internet to be transferred.

A further embodiment comprises a processing means, such as a computer or a programmable logic device that is configured to the effect or adapted one of the methods described herein perform.

A further embodiment comprises a computer on which the computer program for performing one of the methods described herein is installed.

Another embodiment according to the invention comprises an apparatus or a system which is designed or to transmit a computer program for performing at least one of the methods described herein to a receiver. The transfer may for example be electronically or optically. The receiver can be for example a computer, a mobile device, a memory device or a similar device. The device or system may include, for example a file server for transfer of the computer program to the receiver.

In some embodiments, a programmable logic device (for example, a field programmable gate RARRAY, an FPGA) may be used to perform some or all the described functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. In general, the processes are carried out in some embodiments, by any hardware apparatus. This can be a universeil usable hardware such as a computer processor (CPU) or specific for the process hardware, such as an ASIC.

The embodiments described above are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and the details described herein will be apparent to others skilled. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented herein with reference to the description and explanation of the embodiments.

The apparatus (10) to adjust the volume for at least two audio sources (AQ1, AQ2), having the following features:

a Lautheitsanalysator (12) which is configured to analyze an audio signal of the first of said two audio sources (AQ1, AQ2) over a period of time and to determine in response thereto a first loudness value (LW1) and this (in association with said first of said two audio sources AQ1 to store AQ2), and an audio signal of the second of said two audio sources (AQ1, AQ2) to analyze a period of time and as a function thereof to determine a second loudness value (LW2), and this (in association with said second of said two audio sources AQ1, storing AQ2);

a volume controller (14) which is adapted to the audio signal of the currently selected first and / or second of the two audio sources (AQ1, AQ2) corresponding to the respective first and / or second loudness value (LW1, LW2) adapt.

The apparatus (10) according to claim 1, wherein the at least two audio sources (AQ1, AQ2) different but similar audio sources (AQ1, AQ2) are and / or wherein the two audio sources (AQ1, AQ2) are two different radio stations.

The apparatus (10) according to claim 1 or 2, wherein the first and / or second loudness value is an average over the duration of the measured loudness of the first and / or second of said two audio sources (AQ1, AQ2).

The apparatus (10) according to one of the preceding claims, wherein the period of time in a learning phase, each audio source (AQ1, AQ2) at least 30 seconds preferably at least 60 or 150 seconds, with the Lautheitsanalysator (12) then performs the learning phase if, for the particular audio source (AQ1, AQ2) no loudness value (LW1, LW2) is stored.

The apparatus (10) according to one of the preceding claims, wherein the Lautheitsana-lyst (12) is configured to analyze the audio signal of the selected first and / or second of the two audio sources (AQ1, AQ2) during the learning phase and for the audio signal of the used selected first and / or second of said two audio sources (AQ1, AQ2) to determine a preliminary loudness value or a current, indicative loudness value,

wherein the volume control (14) is formed to adjust the audio signal of the currently selected first and / or second of the two audio sources (AQ1, AQ2) corresponding to the provisional loudness value or the current, provisional loudness value.

The apparatus (10) according to one of the preceding claims, wherein the first and / or second loudness value (LW1, LW2) remains unchanged during operation.

The apparatus (10) according to any one of claims 1 -to 5, wherein the period of time in an adaptation phase for the respective channels at least 5 seconds, or preferably at least 60 seconds or 300 seconds, where the sound-heitsanalysator (12) in the adaptation phase the first and / or second loudness value (LW1, LW2)) adjusts.

The apparatus (10) according to one of the preceding claims, wherein the first and / or second loudness value (LW1, LW2) is selected so that the resulting after the adjustment mean loudness and / or average volume of the audio signal of the first of said two audio sources (AQ1 , AQ2) compensates the resultant after adjusting loudness and / or volume of the audio signal of the second of said two audio sources (AQ1, AQ2) with a deviation of +/- 10%.

The apparatus (10) according to claim 7 or 8, wherein adjusting (130) the first and / or second value is effected in that in the adaptation phase, a respective further first and / or second loudness value (LW1, LW2) is determined and wherein for adaptation takes place of the respective first and / or second loudness value (LW1, LW2) offsetting of the respective further first and / or second loudness value (LW1, LW2) to the respective first and / or second loudness value (LW1, LW2).

10. Device (10) according to claim 9, wherein in connection with clearing a weighting of the respective first and / or second loudness values ​​(LW1, LW2), and a weighting of the respective further first and / or second loudness values ​​(LW1, LW2) ER- follows and wherein the weighting is chosen such that the respective further first and / or second loudness values ​​(LW1, LW2) is less influence each new first and / or second loudness value (LW1, LW2) and the respective stored first and / or second loudness values ​​(LW1 , LW2).

1. 1 The apparatus (10) according to one of claims 9 or 10, wherein new respective first and / or second loudness values ​​(LW1, LW2) are only determined and stored when the respective further first and / or second loudness values ​​(LW1, LW2) is at least 2% of the respective stored first and / or second loudness values ​​(LW1, LW2) differ.

12. Device (10) according to one of the preceding claims, wherein the Lautheitsana-! Ysator (12) is configured to analyze the audio signal of the currently selected first and / or second of the two audio sources (AQ1, AQ2).

13. Radio tuner (40) with a device (10) according to one of claims 1 to 12th

14. Radio Tuner (40) according to claim 13, wherein the radio tuner (40) is designed as a double-tuner.

15. Device (10) according to one of the preceding claims, wherein the Lautheitsana- lyst (12) is formed, the audio signal does not currently selected first and / or second audio source (AQ1, AQ2) to analyze.

16. The method (100) to adjust the volume for at least two Audioquei ene (AQ1, AQ2), comprising the steps of!:

Analyzing (110) an audio signal of the first of said two audio sources (AQ1, AQ2) over a period of time and determining in response thereto a first loudness value (LW1) and store this first loudness value (LW1) with assignment of to the first audio source (AQ1, AQ2 );

Analyzing (120) an audio signal of a second of said two audio sources (AQ1, AQ2) over a period of time and determining in response thereto a second loudness value (LW2) and storing this second loudness value (LW2) in association with said second audio source (AQ1, AQ2); and

Adjusting (130) the volume of the audio signal of the first and / or second audio source (AQ1, AQ2) corresponding to the respective first and / or second loudness value (LW1, LW2).

Computer program having a program code for performing the method (100) according to claim 16 when the program runs on a computer.