DE10101473A1 - Method for recognizing tempo and phases in a piece of music in digital format approximates tempo and phase by statistical evaluation of time gaps in rhythm-related beat information and by clock pulses in audio data. - Google Patents

Abstract

An approximate tempo (A) for a piece of music is determined by a statistical evaluation (STAT) of time gaps (Ti) for rhythm-related beat information in digital audio data (Ei). An approximate phase (P) for a piece of music is determined by using the position of clock pulses in the digital audio data in a time-slot pattern for a reference oscillator with a frequency proportionate to detected tempo. A phase shift in the reference oscillator corrects phase and tempo. Independent claims are also included for a method for synchronizing pieces of music in digital format, for a music-playing device for synchronizing pieces of digital format music in real time and for a method for preparing digital audio data for pieces of music from a CD ROM data source with only one reader unit in real time.

Description

The invention relates to the detection and adaptation of pace and phase of pieces of music, especially for the realization of an egg interactive music player, which, among other things, Ability to reproduce from several to a new whole offers synchronized pieces of music. Here digi tale music data according to an advantageous embodiment a simultaneous playback of several pieces of music a standard CD-ROM drive in real time.

The profession of disk jockey (short: DJ) is experiencing today dance culture characterized by modern electronic music an enormous technical upgrade. About the craft of this Beru Arranging the music tracks is part of an overall work (the set, the mix) with its own tension arc. there among other things, it is essential to include the individual titles in your tempo and its phase, i.e. the position of the bars in time grid, to adjust like this (English: "Beatmatching"), that the pieces merge into a whole in the transitions zen and the rhythm is not interrupted.

In this context, the technical problem arises Tempo and phase alignment of two pieces of music or Audi otracks in real time. It would be desirable if one Possibility of automatic tempo and phase adjustment two pieces of music or audio tracks are available in real time would stand to the DJ from this technical aspect of mixing free, or a mix automatically or semi-automatically, without the help of an experienced DJ.  

So far, this problem has only been solved in part. So there are software players for the MP3 format (a standard form mat for compressed digital audio data), the pure real Realize time-tempo detection and adjustment. The detection However, the phase must continue to be heard and heard fit the DJ manually. This makes a considerable ch level of attention from the DJ otherwise for artistic aspects such as musical composition lung etc. would be available.

There are also hardware effects devices for processing audio known information, although real-time tempo and phases Realize recognition, but do not adjust speed and speed Can make phase on the audio material if this only ana log is fed. It can only be the relative phases shift of the two audio tracks are displayed optically.

However, no devices are known which Information on the calculation of loops (these are short audio Sections that are continuously repeated can) and uses loop lengths. These are used in the so far playback devices used either previously cut and loaded (software MP3 player) or manually sets and adjusts (hardware CD player).

An object of the present invention is therefore in Creation of an option for automatic tempo and pha Realization of two pieces of music or audio tracks time with the highest possible accuracy.

This represents an essential technical hurdle to be overcome in the accuracy of a tempo and phase measurement, wel with the time available for this measurement sinks. The problem therefore arises primarily for an Er averaging the pace and phase in real time as u. a. is the case with live mixing.  

According to the present invention, this object is achieved by a method for detecting the tempo and phase of a piece of music in digital format with the following procedural steps:

• - Approximately determining the tempo of the piece of music a statistical evaluation of the time intervals rhyth mus-relevant beat information in the digital audio data,
• - Approximately determine the phase of the piece of music based on the position of the bars in the digital audio data in the time grid one with a frequency proportional to the determined tempo oscillating reference oscillator,
• - successive correction of the determined pace and phase of the Piece of music based on a possible phase shift of the Reference oscillator relative to the digital audio data by evaluating the resulting systematic phase ver shift and regulation of the frequency of the reference Oscillator proportional to the determined phase shift.

So there is a gradual approach to the ideal Value in a control loop.

It has proven to be beneficial if rhythm-relevant te beat information by bandpass filtering the underlying lying digital audio data in different frequencies rich can be won.

This works particularly well if rhythm intervals of the Au Diodata if necessary by multiplying their frequency with powers of 2 in a predefined frequency octave trans be formed where these time intervals for pace determination deliver. If the frequency transform a grouping rhythm intervals, especially in pairs or threes groups, preceded by the addition of their time values, so erge there are additional relevant intervals.

According to an advantageous embodiment, the one obtained Amount of data from time intervals of the rhythm-relevant  Beat information examined for cluster points. The proximity Approximate pace is then determined using the information ons of a cluster maximum.

According to a further advantageous embodiment of the procedure rens according to the present invention is used to approximate Determine the phase of the piece of music, the phase of the ref renz oscillators selected so that the largest possible Correspondence between the rhythm-relevant beat information mations in the digital audio data and the zero crossings of the reference oscillator.

It has also proven to be beneficial if a successive Correction of the determined tempo and phase of the piece of music in at regular intervals in such short time intervals, that resulting correction movements and / or correction ver shifts remain below the audibility limit.

By making all successive corrections of the determined pace and Phase of the piece of music can be accumulated over time Building on this, further corrections are steadily increasing of precision.

Instead of making such gradual corrections permanently alternatively, this can be done until a before falls below the given tolerable error limit. This is particularly suitable for the determined pace Error limit less than 0.1%.

So that an adaptation to possible tempo changes in music piece is reached in the event that the correction Ren always ne over a predetermined period are positive or positive, another approximate investigation pace and phase with subsequent successive corrections rection.  

In addition to the above automatic detection of pace and phase of pieces of music is required to solve the initially mentioned task also an adjustment of pace and Phase of the pieces of music.

This problem is solved by first sewing determination of the tempo and the phase of the music piece successively adapt the result and the adjustment through feedback kung on the playback speed of the piece of music verbes sert.

According to the invention, this is done by a method for synchronizing at least two pieces of music in digital format, with the following method steps:

• - Complete determination of pace and phase of the first Mu piece as described above,
• - Approximate determination of pace and phase of the further Piece of music as described above,
• - Adjustment of the playback speed and the playback phase of this further piece of music by gradually adapting the Frequency and the phase of this additional piece of music ordered reference oscillator to the frequency and phase of the reference oscillator assigned to the other piece of music.

It has proven to be advantageous if for Adjustment of the playback speed and the playback phase of the another piece of music based on a possible phase shift exercise of the reference assigned to this further piece of music Oscillator relative to the other's reference oscillator Piece of music an evaluation of the resulting systemati phase shift and frequency regulation of the reference oscillator assigned to the further piece of music is proportional to the determined phase shift.

So there is a gradual approach to the ideal Value in a control loop in which the tempo and phase  Information on controlling the playback speed of the audio material.

To play pre-produced music nowadays different types of devices for different storage media such as Record, CD or cassette used. These formats were which, however, was not developed for the playback process to edit the music in a creative way. However, this option is desirable and is used nowadays despite the given limitations mentioned by the beginning disk jockeys. Vinyl are preferred Records used because it is easiest to use the Hand influence the playback speed and position can.

Today, however, digital formats such as audio CDs are predominantly used and MP3 used to store music. With the previous one The invention described will now be the creative mentioned Dealing with music in any digital format possible light.

By the above-described method according to the Erfin It is namely possible from a collection of music ti to create a mix in a fully automated way which the pieces are lined up in time and in phase become.

This is made possible by a music player where at least two pieces of music in digital format Can be synchronized in real time as shown above are.

This works particularly effectively with such a music Player with the rhythm-relevant beat information mations of a given past period starting from a current play position of the piece of music as Serve the basis for determining the pace in real time.  

The automatic speed detection allows the Hö rers the content of a music data source, e.g. B. a compact Disk CD, in a selectable z. B. Tempo-dependent Rei order can be reproduced as a homogeneous mix.

The invention therefore also includes such a music play in which synchronized pieces of music automatically become one Complete works can be arranged with a uniform rhythm and from are playable.

In order to be able to intervene in a targeted manner, it is important to have a graphic to have a representative representation of the music in which the current elle play position and also a certain period in the Recognizes the future and the past. To do this you put certainly the amplitude envelope of the sound waveform a period of several seconds before and after the Ab play position. The representation shifts in real time at the speed at which the music plays.

The basic need is as much as possible have helpful information in the graphic display, in order to be able to intervene in a targeted manner. You also want ergono can intervene in the playback process, on comparison bare art with the "scratching" often practiced by DJ's on vinyl record players with the platter during the Playback paused and moved forward and backward becomes.

To solve this problem, the present invention proposes an interactive music player that

• - a means for graphical representation of with a tempo and phase detection function, especially such as described above, certain clock limits one in the Playback of music in real time,
• - A first control for switching between a first Operating mode in which the piece of music with a constant  Tempo is played, and a second operating mode, in which the play position and / or play speed from User can be directly influenced in real time, and
• - A second control element for manipulating the playback position tion in real time includes.

According to an advantageous embodiment of this interactive music player, it is additionally equipped with

• - A means of graphically displaying the current Ab play position with which an amplitude envelope of the sound world lenform of the piece of music played over a pregiven the period before and after the current playhead is adjustable, the representation in real time with the Tempo of the playback of the piece of music shifts, and with
• - a means for smoothing a gradual course over time limited Ab specified with the second control element game position data to be even with one of the Change audio sampling rate according to the temporal resolution the signal.

It has proven to be advantageous if for smoothing a staged course of temporary play items a data for ramp smoothing is provided, through that with any given play position message a ramp with a constant slope can be triggered, which in egg nem predeterminable time interval the smoothed signal from from the previous value to the value of the playback position to drive. Alternatively or additionally, a linear di gital low-pass filter, in particular a resonance filter two order, given for smoothing a gradual course serve temporally limited playback position data.

To avoid jumps during playback, ei is used in the case nes switching between the operating modes the previous Mode reached position as starting position in the new mode.  

In the event of a change between the operating modes, Avoiding abrupt changes in speed in the previous mode reached current playback speed speed by a smoothing function, in particular a ramp smoothing or a linear digital low-pass filter on the playback speed corresponding to the new operating mode guided.

In order to play with rapidly and rapidly changing Ge similar to the most authentic reproduction possible to achieve "scratching" with a vinyl record player, uses a further advantageous embodiment of the in interactive music player according to the invention for audio signal a scratch audio filter, the audio signal being a Subjected to pre-emphasis filtering (pre-distortion) and in one Buffer memory is stored, from which it depends on the respective playback speed with variable speed can be read out in order to subsequently carry out de-emphasis filtering (Equalization) to be subjected and reproduced.

The length of a or can be determined from the tempo information several clocks with sufficient accuracy to determine Push the button to set the length of a loop so that this "crack free" and with the pace of the original Audi lets otracks play. With such an interactive music Player, the tempo information in the manner described determined according to the invention is before another partial configuration for one or more of the synchro music pieces based on the determined tempo information the length of the respective piece of music over a or playback of several bars of this piece of music Loop real-time definable and playable.

The phase information can be used, in turn at the touch of a button, jump labels within the track, so-called te cue points, or entire loops exactly at one bar start To lay beat. An advantageous interactive music player  is thus further developed in that for one or more the synchronized pieces of music based on the determined Pha clock information of the respective piece of music in real time synchronous jump labels definable and within this Mu sikstückes shiftable by integer multiples of bars are. Such cue points and loops can also be pressed at the push of a button ver by integer multiples of measures within the track be pushed. Both are done in real time, during the how distribution of the audio track.

Furthermore, the information obtained about the Tempo and the phase of an audio track so-called control called tempo-synchronous effects. The audio signal manipulated to fit your own rhythm, which rhythmically ef enables real-time sound changes. In particular the tempo information can be used to loop with clock-accurate lengths in real time from the audio material cut.

Another advantageous interactive music player draw is therefore characterized by the fact that every reproduced audio data flow through signal processing means in real time mani can be pulverized, in particular by filter devices and / or audio effects.

Traditionally when mixing multiple pieces of music the audio sources of sound carriers on several players, z. B. record players or CD players, played and over a Mixing desk mixed. Restricted to this practice an audio recording on a record of the final result Based on computer systems with audio interfaces with suitable audio processing software such as Audio sequencers or so-called sample editing program where digital audio information is manipulated is an interactive user intervention during playback not possible.  

For a reproduction of the mixing process or to become one later exactly at a predeterminable position inside It would be nice to be able to continue mixing half of a piece of music It's worth it if not only the end result could be saved re.

According to the invention, this requirement is met by an inter resolved active music player, which further trained is that real time interventions over time as digital control information can be stored, in particular those of a mixing process of several pieces of music and / or additional signal processing.

By mixing music pieces and / or interactive Interventions in pieces of music with audio signal processing means as a new complete work independent of digital audio information mations of pieces of music in the form of digital tax information can be stored, in particular for reproductive purposes, the process of interactive mixing and one Record interactive effects processing and at any time how dergeben.

According to a further advantageous embodiment of the invention stored digital control information assign a format on, the information used to identify the processed Pieces of music and a respective temporal assigned to them Sequence of play positions and status information of the Actuators of the music player includes.

A decisive advantage of this recording option and the proposed format is the fact that a digital record of the mixing process independently from the audio data of the mixed pieces of music and thus without copying of this audio data which is problematic under copyright law can be done. The overall result can be the same at any time continuously reproduced, processed, reproduced and be transmitted.  

A particularly advantageous interactive music player is through a suitably programmed with audio interfaces equipped computer system realized. It can stan standard data storage of the computer system for recording the Serve control file. This also makes it particularly interesting ter exchange of the usually less memory-intensive tasks drawing files e.g. B. also possible via the Internet.

In this context, the problem arises that frequently there is only one audio data source, e.g. B. a CD player or in the case of a computer system, a CD-ROM drive. the and other players is usually common, that they have only one reading unit. to Execution of the function described above, esp the mixing of several pieces of music in particular, however Audio data of at least two pieces of music at the same time Will be provided. It would therefore be desirable if this also with a player with only one reader length.

The invention solves this problem by a method for loading Provision of digital audio data of at least two music pieces from a data source with only one reading unit in real time when the data source compared audio data with one to their playback speed higher reading speed provides by one for each piece of music to be played temporary buffer memory, in particular ring buffer memory, is provided, and the higher reading speed ge is used, the respective buffer storage is also included to fill the audio data that is always before and after a current play position of the respective piece of music Audio data are available.

It has proven to be advantageous if the The status of each buffer memory is monitored to determine whether sufficient data is available, and if it falls below one  Predefinable threshold one from the playback of the music pieces decoupled central instance with the provision the required audio data is ordered, which automatically tig the required ranges of audio data from the data source and the associated buffer memory with the data received. After another advantageous Embodiment are when filling up a buffer memory data no longer required is overwritten. It has continued proven to be advantageous when the central instance runs in parallel incoming requirements in a sequential Order brings.

This method is particularly well suited in connection with a CD-ROM drive and introduces a novel and partial form of what the expert calls CD grabbing Read such drives.

Another advantageous interactive music player serves a be according to the method described above Driven CD-ROM drive as a data source for the pieces of music.

Since the invention described above is particularly advantageous also adheres to a suitably programmed computer system can be realized, the invention Measures also in the form of a computer program product reali s that directly into the internal memory of a digital Computer can be loaded and includes software sections with which the measures according to the invention are carried out if the program product is running on a computer.

In this context, the invention also enables the provision of a data carrier, in particular a compact disc

• - A first data area with digital audio data or several pieces of music and
• - a second data area with a control file with digi tal control information for controlling a music  Player includes, especially one such as in the previous described, whereby
• - The control data of the second data area on audio data of the first data area.

It is particularly advantageous if the digital tax information of the second data area mixing operations of Pieces of music and / or interactive interventions in pieces of music with audio signal processing means as a new complete work the digital audio information of pieces of music of the first Represent data area.

Furthermore, it has proven to be beneficial if saved digital control information of the second data area Format that contain information to identify the processed music pieces of the first data area and one respective sequence of playback po associated with this sitions and status information of the actuators of the Mu sik player includes.

Such a data carrier can also be used advantageously Arrange computer program product that directly into the internal Memory of a digital computer can be loaded and Software sections with which this digital Compu ter takes over the function of a music player, in particular of such as described above, with the ent speaking the control data of the second data area of the Da Carrier based on audio data of the first data area of the Reference data carrier, one represented by the tax data complete work is playable if the program product running on a computer.

Because the interactive music player plays the audio Playback, signal analysis and signal transformation combined by effects and loops, there is the possibility for the first time both real-time recognition of the tempo and the Phase of an audio track as well as its automatic adjustment  to realize. The analysis also provides the necessary information output data for the control of tempo-synchronous effects and loops.

Advantages include the possibility that this creates automation of so-called beat matching, but not one easy to learn basic requirement of DJ mixing, which at each transition of two pieces of music a significant part of the Takes the DJ's attention. Still exists the possibility to automate the entire mixing process.

Further advantages and details of the invention emerge the following description of advantageous embodiments play and in connection with the characters. It shows in Prin zipdarstellung:

Fig. 1 is a block diagram illustrating relevant information from extraction rhythm and their evaluation for the approximate determination of speed and phase of a music data stream,

Fig. 2 is a further block diagram for successive Cor rection of detected speed and phase,

Fig. 3 is a block diagram showing the structure for parallel readout of a CD-ROM drive according to the invention,

Fig. 4 is a block diagram of an interactive music Abspielers according to the invention with Eingriffsmög friendliness in a current playback position,

Fig. 5 is a block diagram of an additional signal processing chain for realizing a scratch audio filter according to the invention and

Fig. 6 shows a data carrier, the audio data and control files of the present invention combines issued overall works in accordance with the reproduction of the audio data from.

The following is a possible realization of the approximation instruct tempo and phase detection as well as tempo and phase fit according to the invention.

The first step of the procedure is a first, approximately Determination of the tempo of the piece of music. This is done by a statistical evaluation of the time intervals of the so-called Beat events. A way to gain rhythm rhythm vanter events from the audio material is done by narrow Bandpass filtering of the audio signal in different frequencies areas. To determine the pace in real time, for the following calculations only show the beating events of the last seconds used. 8 to 16 events correspond to this nisse in about 4 to 8 seconds.

Due to the quantized structure of music (16th notes Grid) can not only be used for quarter-note beat intervals Tempo calculation can be used. Other intervals too (16th, 8th, ½ and whole notes) can be done by octave (e.g. by multiplying their frequency by powers of 2) into a predefined frequency octave (e.g. 80-160 bpm, English for beats per minute) and thus be transformed Provide temporally relevant information. Faulty octave conditions (e.g. triplet intervals) fall later because of their relatively rare in statistical analysis not weight.

To also triplets or shuffled rhythms (some easy grades offset from the 16th grid), the time intervals obtained in the first point additionally in Pairs and groups of three by adding their time values grup piert before they are octave. Through this procedure the rhythmic structure between the bars from the time calculated intervals.

The amount of data obtained in this way is based on accumulation points tersucht. There are usually three accumulation maxima  due to the octave and grouping processes, their value in rational ratio (2/3, 5/4, 4/5 or 3/2) to stand by each other. Should be one of the maxima from the strength not clear enough that this is the actual Indicates the tempo of the piece of music, the correct maxi mum from the rational relationships of the maxima among themselves determine.

For the approximate determination of the phase, a reference Oscillator used. This oscillates with the previously determined pace. Its phase is advantageously chosen so that the best match between beat events of the audio materials and zero crossings of the oscillator results.

Then there is a gradual improvement in tempo and phase determination. Because of the natural inadequacy The first approximate pace is going to be first after a few seconds the phase of the reference oscillator re move relative to the audio track. These systematic phases Shift provides information about how much the pace of the reference oscillator must be changed. A correction The tempo and phase are advantageously carried out regularly distance to below the audible limit of Ver shifts and the corrective movements to stay.

All phase corrections starting from the approximate Pha correlation have occurred, accumulate over time liert, so that the calculation of the tempo and phase based on an ever increasing time interval. Because of who which the tempo and phase values are increasingly precise and ver late the flaw of approximate authenticity mentioned at the beginning timekeeping. After a short time (approx. 1 min) the error drops below the tempo value determined using this method 0.1%, a measure of accuracy, the prerequisite for the Be calculation of loop lengths.  

The illustration in Fig. 1 shows a possible technical realization of the approximate tempo and Phsenerkennung a music data stream in real time described with reference ei nes block diagram. The structure shown can also be called a 'Beat Detector'.

As input there are two streams of audio events or audio events E _i with the value 1, which correspond to the peaks in the frequency bands F1 at 150 Hz and F2 at 4000 Hz or 9000 Hz. For the time being, these two event streams are treated separately by using bandpass filters with respective cutoff frequencies. F1 and F2 can be filtered.

If an event follows the previous one within 50 ms, the second event is not considered. A time of 50 ms corresponds to the duration of a 16th at 300 bpm, so it is far below the duration of the shortest interval in which the Mu Sic pieces are usually located.

From the stream of the filtered events E _i , a stream is then formed in the respective processing units BD1 and BD2 from the simple time intervals T _i between the events.

From the stream of simple time intervals T _1i , two additional streams of the band-limited time intervals le are formed in the same processing units BPM_C1 and BPM_C2, namely with time intervals T _2i , the sums of two successive time intervals, and with time intervals T _3i , the sums of three consecutive time intervals. The events used for this may also overlap.

As a result, the current: t ₁ , t ₂ , t ₃ , t ₄ , t ₅ , t _6,. , , in addition the following two streams are generated:
T _2i : (t ₁ + t ₂ ), (t ₂ + t ₃ ), (t ₃ + t ₄ ), (t ₄ + t ₅ ), (t ₅ + t ₆ ),. , , and
T _3i : (t ₁ + t ₂ + t ₃ ), (t ₂ + t ₃ + t ₄ ), (t ₃ + t ₄ + t ₅ ), (t ₄ + t ₅ + t ₆ ),. , ,

The three streams T _1i , T _2i , T _3i are now time-octaved in corresponding processing units OKT. The time octave OKT is carried out in such a way that the individual time intervals of each stream are doubled until they are within a predetermined interval BPM_REF. In this way, three data streams T _1io , T _2io , T _3io,. , , The upper limit of the interval is calculated from the lower bpm limit according to the formula:

t _{hi [ms]} = 60000 / bpm _low .

The lower limit of the interval is 0.5.t _hi .

Each of the three streams thus obtained we now for both Fre quenz Bands F1, F2 in respective further processing units CHK checked for consistency. This is mitit whether a certain number of successive, Time-octave interval values within a given Error limit. To do this, check, for example, in individual with the following values:

For T _1i one checks its last 4 events t _11o , t _12o , t _13o , t _14o to determine whether:

(t _11o - t _12o ) ² + (t _11o - t _13o ) ² + (t _11o - t _14o ) ² <20 a)

If this is the case, the value t _{11o is output} as a valid time interval.

For T _2i one checks its last 4 events t _21o , t _22o , t _23o , t _24o to determine whether:

(t _21o - t _22o ) ² + (t _21o - t _23o ) ² + (t _21o - t _24o ) ² <20 b)

If this is the case, the value t _{11o is output} as a valid time interval.

For T _3i one checks its last 3 events t _31o , t _32o , t _33o , and then whether:

(t _31o - t _32o ) ² + (t _31o - t _33o ) ² <20 c)

If this is the case, the value t _{31o is output} as a valid time interval.

The consistency check takes precedence over b) and b) takes precedence over c). If a value is output for a), b) and c) are no longer examined. If no value is output for a), then b) is examined, etc. If, however, a consistent value is not found for either a), b) or c), the sum of the last 4 non-octave individual intervals (t ₁ + t ₂ + t ₃ + t ₄ ) output.

The value stream determined in this way from the three streams is consistent The time intervals are in turn in a downstream Processing unit OKT in the specified time interval BPM_REF octave. Then the octave time Interval converted into a BPM value.

As a result there are now two streams BPM1 and BPM2 from bpm- Values before - one for each of the two frequency ranges F1 and F2. In a prototype, these streams are fixed with a th frequency of 5 Hz and the last eight Events from both streams for statistical evaluation range covered. At this point, however, you can also use a variable (event-driven) sampling rate and man can also use more than just the last 8 events at for example 16 or 32 events.

These last 8, 16 or 32 events from each frequency band F1, F2 are merged and in a downstream Ver work unit STAT considered at accumulation maxima N. In the prototype version will have an error interval of 1.5 bpm used, d. H. as long as events are less than 1.5 bpm apart  differ, they are considered to belong together and add up in weighting. The processing unit STAT determines the BPM values at which clusters occur occur and how many events the respective cluster points are to be assigned. The most weighted cluster point can be considered the local BPM measurement and provides the ge wish speed value A.

In a first development of this method, in addition to the local BPM measurement, a global measurement, in which you can count the number of events used on 64, 128 etc. expands. With alternating rhythm patterns, in which only every 4th bar the tempo gets through clearly can often Event number of at least 128 may be necessary. Such a measurement is more reliable, but also takes more time.

Another decisive, improvement can be achieved by the following measure:
Not only the first cluster maximum is considered, but also the second. This second maximum is almost always the result of triplets and can even be stronger than the first maximum. However, the tempo of the triplets has a clearly defined relationship to the tempo of the quarter notes, so that the ratio of the tempos of the first two maxima can be used to determine which cluster maximum is assigned to the quarters and which to the triplets.

Assuming T1 as the speed of the first maximum in bpm and T2 as that of the second maximum, the following rules apply:
If T2 = 2 / 3.T1, then T2 is the pace.
If T2 = 4 / 3.T1, then T2 is the pace.
If T2 = 2 / 5.T1, then T2 is the pace.
If T2 = 4 / 5.T1, then T2 is the pace.
If T2 = 3 / 2.T1, then T1 is the tempo.
If T2 = 3 / 4.T1, then T1 is the pace.
If T2 = 5 / 2.T1, then T1 is the pace.
If T2 = 5 / 4.T1, then T1 is the pace.

An approximate phase value P is determined on the basis of one of the two filtered simple time intervals T _i between the events, preferably on the basis of those values which are filtered with the lower frequency F1. These are used to roughly determine the frequency of the reference oscillator.

The illustration according to FIG. 2 shows a possible block diagram for the successive correction of determined speed A and phase P, hereinafter referred to as 'CLOCK CONTROL'.

First, the reference oscillator or the reference clock MCLK is started in a first step 1 with the coarse phase values P and tempo values A from the beat detection, which is equivalent to a reset of the control circuit shown in FIG. 2. The time intervals between beat events of the incoming audio signal and the reference clock MCLK are then determined in a further step 2 . For this purpose, the approximate phase values P are compared with a reference signal CLICK, which has the frequency of the reference oscillator MCLK, in a comparator V.

If a "critical" deviation is systematically exceeded (+) in the case of several successive events with a value of, for example, more than 30 ms, the reference clock MCLK is changed in a further processing step 3 by a brief change in tempo

A (i + 1) = A (i) + q or

A (i + 1) = A (i) - q

contrary to the deviation (again) to the audio signal fits, where q is used to lower or raise the  Represents tempo. Otherwise (-) the tempo becomes constant held.

In the further course, in a further step 4, all the correction events from step 3 and the time that has elapsed since the last “reset” are summed up in separate memories (not shown). At approximately every 5th to 10th event of an approximately accurate synchronization (difference between the audio data and the reference clock MCLK approximately less than half a ms), the tempo value is based on the previous tempo value, the correction accumulated up to that point Events and the recalculated in a further step S since the time elapsed as follows.

With

• q as the reduction or increase in tempo used in step 3 (for example by a value of 0.1),
• - dt as the sum of the time for which the total pace has been lowered or raised (positive increase, lowering negative),
• - T as the time interval that has elapsed since the last reset (step 1 ), and
• - bpm as the tempo value A used in step 1

the new, improved speed is calculated using the following simple formula:

bpm_new = bpm. (1 + (q.dt) / T)

It is also checked whether the corrections in step 3 are always negative or positive over a certain period of time. In such a case, there is probably a change in tempo in the audio material that cannot be corrected using the above procedure. This status is recognized and when the next approximately perfect synchronization event (step S) is reached, the time and the correction memory are deleted in a step 6 in order to reset the starting point in phase and tempo. After this "reset", the procedure begins again with a touchdown on step 2 to optimize the pace.

A second piece of music is now synchronized by adjusting its pace and phase. The adjustment of the second piece of music takes place indirectly via the reference Oscillator. According to the approximate tem Po and phase determination of the piece of music become these values successively to the reference oscillator using the above procedure adjusted, only this time the play phase and the play speed of the track itself changed. The original Tempo of the track can be easily reversed from the necessary change in its playback speed compared to Calculate the original playback speed.

The following is now to be described earlier Able possibility to play several at the same time Pieces of music on a standard CD-ROM drive or one other data source with only one reader become. The present invention thus makes this possible one to synchronize a second piece of music required provision of two or more music pieces cke with such a unit in real time.

State of the art is the playback of an audio track from CD-ROM using a computer (so-called "grabbing"), ver similar to playing a piece on a conventional one CD player.

CD-ROM drives, like audio CD players, have only one Reading unit, so at a given time too Read the audio data at only one point.

The solution is a paral decoupled from the audio output leler thread (thread) generated as a so-called scheduler, the  in the background the requests for the pieces of music to be played accepts and reloads the required audio data. Multithreading is the term for the ability of software to perform certain functions of an application to be able to execute the application simultaneously. So it doesn't work several programs in parallel on a digital computer (Mul titasking), but within a program are ver different functions from the user's perspective at the same time executed. A thread represents the smallest unit of executable program code, which is part of the operating system tems (the thread scheduler) according to a specific one Allocation of computing time priority. Coordinating the individual Threads are made through synchronization mechanisms, so-called Locks that are used to merge the individual threads The reading unit, here the laser of the CD-ROM drive, is operated in multiplex mode in order to use buffer storage data and a higher reading rate to be available in real time.

The main technical hurdle that is overcome is that CD-ROM drives, just like audio CD players, have only one reading unit. At a certain time point can only deliver the data for one track become.

This problem is solved by playing for everyone sufficiently large buffer leads and the higher reading speed of the CD-ROM Drive is used to provide the required data for the Read out buffer. This measure fits seamlessly into the Environment of the described music player. For the An It is more transparent when playing CD tracks just as if the data were in a digital format a computer hard drive. Through the digita Reading the CD, it is possible to process the audio data using Sig nal processing means such as filters or audio effects CKEN. Among other things, this enables reverse playback,  Pitching (speed and pitch change), Beatdetec tion and filtering of normal audio CDs.

The illustration of FIG. 3 shows the basic structure ei ner structure for parallel readout of a CD-ROM drive according to the invention. The main step is to introduce a buffer P1. , .Pn (preferably a ring buffer) for each audio track TR1 to be played. , .Trn. Here the audio data is buffered in such a way that S1. , .Sn in the case of ring buffers before and after the respective current play position A1. , Data is still available. A monitoring mechanism always keeps this invariant by the state of the respective buffer P1. , .Pn is checked to see how much data is still available. If a threshold value is undershot (for example, audio data is available less than n seconds after the current playback position), a request is made to a central entity S to reload new audio data.

This central instance, hereinafter also called the scheduler S be draws, runs decoupled from the actual playback of the Au diotracks TR1. , .TRn in its own thread and brings the of different tracks may arrive in parallel the requests in a sequential order. The scheduler S in turn now sends the requests for ei a section of a track to the CD-ROM drive CD-ROM. This reads the requested sectors from a data carrier with the corresponding digital audio data. The schedu ler S then fills the corresponding buffer P.. .Pn with these received data, with data no longer required about be written.

Playing pre-produced music is becoming more conventional wise different devices for different storage sizes such as vinyl, compact disk or cassette.  

These formats were not designed to be used in the playback process to intervene in a creative way to edit. This possibility is desirable, however is used today by the mentioned DJ's practiced. Vinyl are preferred Records used because it is easiest to use the Hand influence the playback speed and position can.

Today, however, digital formats such as audio CD and MP3 are mainly used to store music. MP3 is a compression process for digital audio data according to the MPEG standard (MPEG 1 Layer 3 ). The method is asymmetrical, ie the coding is much more complex than the decoding. It is also a lossy process. The present invention now enables the aforementioned creative handling of music in any digital format by a suitable interactive music player, which makes use of the new possibilities created by the measures according to the invention described above.

In order to be able to intervene in a targeted manner, it is important to have a graphic to have a representative representation of the music in which the current El play position recognizes and also a certain period recognizes in the future and in the past. To do this usually the amplitude envelope of the sound waveform over a period of several seconds before and after the Play position. The representation shifts in real time at the speed at which the music plays.

In principle, you want as much helpful information as possible have in the graphical representation to intervene in a targeted manner can. In addition, you want to be as ergonomic as possible can intervene in a similar way to the game process called "scratching" on vinyl record players, which includes  stopping and moving the plate forward or backward understands during playback.

In the interactive music player created by the invention, musically relevant points in time, in particular the beats, can now be extracted from the audio signal with the previously described ( FIG. 1 and FIG. 2) clock recognition function and displayed as markings in the graphic representation, e.g. , B. on a display or on a screen of a digital computer on which the music player is realized by suitable programming.

A hardware control element R1 is also provided, e.g. B. a button, especially the mouse button, with which you can switch between two operating modes:

• a) music runs freely, with constant tempo,
• b) Play position and speed is di directly influenced.

The mode a) corresponds to a vinyl record that you can not on and their speed is the same as that of the turntable is. Mode b), on the other hand, corresponds to a vinyl record that you stop with your hand and slide it back and forth.

In an advantageous embodiment of an interactive Mu sik-Abspielers is the playback speed in mode a) further influenced by the automatic control for Syn the clock of the played music to a ande ren clock (chronisation see. Fig. 1 and Fig. 2). The other measure can be generated synthetically or given by other music playing at the same time.

A further hardware control element R2 is also provided hen, with which in the operating mode b) the plate positions one determines. This can be a continuous controller, too be the computer mouse.  

The illustration of FIG. 4 shows a block diagram of such an arrangement, the processing means with the explained in the following Signalver with which an interactive music player is provided according to the invention with the possibility of intervention in a current playback position.

The positions specified with this further control element R2 ons data usually have a limited time resolution solution, d. H. it will only be regular or irregular Intervals sent a message indicating the current position transmitted. The play position of the stored audio signal But nals should change evenly, with a temporal Resolution that corresponds to the audio sampling rate. Therefore ver the invention applies a smoothing function at this point, the staged from the control element R2 Signal a high-resolution, evenly changing signal generated.

One method of doing this is to trigger a ramp with a constant gradient with each predetermined position message, which ramps the smoothed signal from its old value to the value of the position message in a predetermined time. Another option is to send the step waveform into a linear digital low-pass filter LP, the output of which represents the desired smoothed signal. A 2-pole resonance filter is particularly suitable for this. A combination (series connection) of the two smoothings is also possible and advantageous and enables the following advantageous signal processing chain:
→ given step signal → ramp smoothing → low pass filter → exact play position or
Predefined stage signal → low-pass filter → ramp smoothing → exact play position

The block diagram of Fig. 4 illustrates the ze in an advantageous embodiment in the form of a schematic diagram. The control element R1 (here a button) serves to change the operating modes a) and b) by triggering a switch SW1. The controller R2 (here a continuous slide controller) provides the position information with a temporally limited resolution. This serves as a low-pass filter LP for smoothing as an input signal. The smoothed position signal is now differentiated (DIFF) and provides the playback speed. The switch SW1 is controlled with this signal at a first input IN1 (mode b). The other is a gear IN2 with the tempo value A, which can be determined as described in Fig. 1 and Fig. 2, applied (mode A). The control element R1 switches between the input signals.

If you switch from one mode to another (corresponds to holding and releasing the turntable), the position must not jump. For this reason, the proposed interactive music player takes the position reached in the previous mode as the starting position in the new mode. Likewise, the playback speed (1st derivation of the position) should not change abruptly. That's why you take over the current speed and lead it through a smoothing function, as described above, to the speed that corresponds to the new mode. According to FIG. 4, this is done by a slew limiter SL, which triggers a ramp with a constant gradient, which moves the signal from its old value to the new value in a predetermined time. This position-dependent or speed-dependent signal then controls the actual playback unit PLAY to reproduce the audio track by influencing the playback speed.

When "scratching" with vinyl records, ie playing with changing rapidly and rapidly changing speed the sound waveform in a characteristic way, due to the egg of the recording process that is standard for  Records is used. When creating the press Masters for the record in the recording studio goes through that Sound signal after a pre-emphasis filter (pre-distortion filter) RIAA standard that raises the heights (so-called "cutting characteristics never "). In any system that plays vinyl records is used, there is a corresponding de-emphasis Filter (equalization filter) that reverses the effect, see above that you get approximately the original signal.

But if the playback speed is no longer the same is like recording what u. a. when "scratching" occurs, all frequency components of the signal on the Record shifted accordingly and therefore from the de- Emphase filter damped differently. This results in a characteristic sound.

According to a further advantageous embodiment of an inventive interactive music player according to the invention with a structure according to FIG. 4, a scratch audio filter is provided for simulating the characteristic effect described. For this purpose, in particular for a digital simulation of this process, the audio signal within the play unit PLAY from FIG. 4 is subjected to a further signal processing, as shown in FIG. 5. For this purpose, the audio signal is read after a decoding of the digital audio data of the piece of music to be played back from a medium D or sound carrier (e.g. CD or MP3) and (especially in the case of the MP3 format) DEC, a corresponding pre- Emphasized filtering subjected to PEF. The signal thus pre-filtered is then stored in a buffer memory B, from which it is read out in a further processing unit R depending on the operating mode a) or b), as described in FIG. 4, according to the output signal from SL with varying speed. The read out signal is then treated with a de-emphasis filter DEF and then reproduced (AUDIO_OUT).

For the pre- and de-emphasis filter PEF and DEF, which should have the same frequency response as defined in the RIAA standard, a digital IIR filter 2nd order is advantageously used, ie with two favorably chosen pole positions and two favorably chosen zeros. If the poles of one filter are equal to the zeros of the other filter, the effect of the two filters is canceled, as desired, if the audio signal is played back at the original speed. In all other cases, the filters mentioned produce the characteristic sound effect during "scratching". Of course, the described scratch audio filter can also be used in connection with any other type of music player with "scratching" function.

In combination with the proposed CD grabbing process among other things, there is also the advantageous possibility of one and the same track twice in the interactive music Load player and the automix process with it to mix or 'remix' or as a one-song Let mix run without ever getting out of step. Very short tracks can be extended by the DJ become.

The tempo of a mix can also be increased or decreased gradually over the course of a set of several hours via a targeted frequency change on the master clock MCLK (the reference oscillator from FIG. 2) in order to achieve targeted effects of increasing or calming the To generate public.

As already mentioned at the beginning, conventionally the Mixing several pieces of music the audio sources of sound carriers Played on multiple players and on a mixer mixed. This procedure limits one  Audio recording on a record of the end result. A Reproduction of the mixing process or putting on one later exactly at a predeterminable position inside half of a piece of music is not possible.

This is exactly what the present invention achieves by File format proposed for digital tax information which offers the possibility of interac tive mixing and possible effects processing of Au record and accurately reproduce dio sources. This is especially with a music as described above Player possible.

The record is divided into a description of the ver applied audio sources and a timing of tax information about the mixing process and additional effects bar processing.

There will only be information about the actual mixing process gear and via the source audio sources needed to re play the result of the mixing process. The actual di Gital audio data are made available externally. This avoids copying processes of copyright problems protected pieces of music. It can be saved by saving digital control information thus mixing processes of several audio pieces with regard to play positions, synchro nization information, real-time interventions with audio signal processing means etc. as a mix of audio sources and their effects processing as a new complete work with comparative wise long playing time can be realized.

This has the advantage that the description of the machining the audio sources compared to the audio data generated ten of the mixing process are low, the mixing process depends on other places can be edited and restarted. Au In addition, existing audio pieces can be summarized in different ways  or as a longer coherent interpretation can be played back.

It was with previous sound carriers and music players however, it is not possible for a user to interact draw and play back, since the known players the technical prerequisites are missing, these too precise Taxes. This is only through the present invention possible by playing multiple digital audio sources and their play positions are determined and controlled can. This makes it possible to digitalize the whole process to process and corresponding tax data in a file save. This digital tax information is pre preferably stored in a resolution that the sampling rate of processed digital audio data.

The recording is essentially divided into two parts:

• - a list of the audio sources used, e.g. B. digital on drawn audio data in compressed and uncompressed Shape such as B. WAV, MPEG, AIFF and digital sound carriers such as a compact disk and
• - the timing of the tax information.

The list of audio sources used includes:

• - Information to identify the audio source
• - additionally calculated information, the characteristics of the Audio source describes (e.g. play length and tempo information tions)
• - Descriptive information on the origin and originator information tion of the audio source (e.g. artist, album, publisher etc.)
• - Meta information, e.g. B. Additional information about the Hin informed of the audio source (e.g. music genre, info mation to artist and publisher)

The tax information stores, among other things:

• - the chronological sequence of tax data  
• - The chronological sequence of exact play positions in the audio source
• - Intervals with complete status information of all positions links to serve as restart points of playback

The following is a possible example of managing the list of audio pieces in an XML format. XML stands for Extensible Markup Language. This is a name for a meta language for describing pages on the WWW (World Wide Web). In contrast to HTML (Hypertext Markup Language), it is possible for the author of an XML document to define certain extensions of XML in the document type definition part of the document and to use it in the same document.
<? xml version = "1.0" encoding = "ISO-8859-1"? <
<MJL VERSION = "Version Description"<
<HEAD PROGRAM = "Program name" COMPANY = "Company name" / <
<MIX TITLE = "Title of the mix"<
<LOCATION FILE = "ID of the control information file" PATH = "Storage location of the control information file" / <
<COMMENT <comments and comments on the mix </ COMMENT <
</ MIX <
<PLAYLIST <
<ENTRY TITLE = "Title entry 1 " ARTIST = "Name of the author" ID = "ID of the title"<
<LOCATION FILE = "ID of the audio source" PATH = "Storage location of the audio source" VOLUME = "Storage medium of the file" / <
<ALBUM TITLE = "Name of the associated album" TRACK = "ID of the track on album" / <
<INFO PLAYTIME = "Play time in seconds" GENRE_ID = "Music genre identifier" / <
<TEMPO BPM = "playback tempo in BPM" BPM_QUALITY = "quality of the tempo value from the analysis" / <
<CUE POINT1 = "Position of the 1st marking point". , , POINTn = "Position of the n. Marking point" / <
<FADE TIME = "Fade time" MODE = "Fade mode"<
<COMMENT <comments and remarks on the audio piece <
<IMAGE FILE = "Identification of an image file as an additional option" / <
<REFERENCE URL = "ID for further information on the audio source" / <
</ COMMENT <
</ ENTRY <
, , ,
<ENTRY. , . <
, , ,
</ ENTRY <
</ PLAYLIST <
</ MJL <

The control information data, referenced by the list of audio pieces, is preferably stored in binary format. The basic structure of the saved control information in a file can be described as an example:
[Number of control blocks N]
Repeat for [number of control blocks N]
{[Time difference since last control block in milliseconds]
[Number of control points M]
Repeat for [number of control points M]
{[Controller ID]
[Controller channel]
[New controller value]}}

[Controller ID] denotes a value that a control element (e.g. volume, speed, position) of the interactive music player. such a Control elements can have several subchannels [controller channel], z. B. number of the playback module. A clear one Control point M is identified by [controller ID], [Controller channel] addressed.

The result is a digital recording of the mix process that is saved, non-destructive in relation to that Reproduced, reproduced and transmitted audio material can be, e.g. B. on the Internet.  

An advantageous embodiment with such control files is represented by a data carrier D, as is illustrated by means of FIG. 6. This has a combination of a normal audio CD with digital audio data AUDIO_DATA of a first data area D1 with a program PRG_DATA accommodated on a further data part D2 of the CD for playing such mix files MIX_DATA which are also present and which directly affect the audio files stored on the CD. Access data AUDIO_DATA. The playback or mix application PRG_DATA does not necessarily have to be part of such a data carrier. A combination of a first data area D1 with digital audio information AUDIO_DATA and a second data area with one or more files with the aforementioned digital control data MIX_DATA is also advantageous, because such a data carrier contains all the necessary information in connection with a music player of the invention mations for the reproduction of a new complete work created earlier from the existing digital audio sources.

However, the invention can be particularly advantageously applied to egg nem suitably programmed digital computer with correspond Realize the appropriate audio interfaces by using software program the procedural step outlined above on the computer system (e.g. the playback or Mix application PRG_DATA). The disk described in Connect to that on a standard CD-ROM drive then enables advantageous CD grabbing processes the complete functionality of the invention.

All mentioned in the above description or in the Features shown are intended, provided that the known State of the art allows this, alone or in communication combination can be regarded as falling under the invention.  

The foregoing description of preferred embodiments according to the invention is for the purpose of illustration give. These embodiments are not exhaustive. Also, the invention is not to the exact form specified limited, but there are numerous modifications and changes changes within the scope of the above technical Teaching possible. A preferred embodiment was chosen and described the principal details of the invention and clarify practical applications to the professional to be able to implement the invention. A A variety of preferred embodiments and other modifi cations are used in special areas of application costume.  

LIST OF REFERENCE NUMBERS

E _i

Events of an audio data stream
T _i

time intervals
F1, F2 frequency bands
BD1, BD2 detectors for rhythm-relevant information
BPM_REF reference time interval
BPM_C1, BPM_C2 processing units for speed detection
T _1i

ungrouped time intervals
T _2i

Pairs of time intervals
_{M 3i}

Triplets of time intervals
OCT time octave units
T _1io

, , .T _3io

time-octave time intervals
CHK consistency check
BPM1, BPM2 independent streams of tempo values bpm
STAT Statistical evaluation of tempo values
N cluster points
A, bpm approximate tempo of a piece of music
P approximately determined phase of a piece of music

1

, , ,

6

steps
MCLK reference oscillator / master clock
V comparator
+ Phase match
- phase shift
q Correction value
bpm_new resulting new tempo value A
RESET restart when changing tempo
CD-ROM audio data source / CD-Rom drive
S central instance / scheduler
TR1. , .TRn audio data tracks
P1. , .Pn buffer memory
A1. , At current play positions
S1. , .Sn beginnings of the data
R1, R2 controllers / controls
LP low pass filter
DIFF differentiators
SW1 switch
IN1, IN2 first and second input
a first operating mode
b second operating mode
SL means for ramp smoothing / slew limiter
PLAY playback unit
DEC decoder
B buffer memory
R readout unit with variable speed
PEF pre-emphasis filter / pre-emphasis filter
DEF de-emphasis filter / de-emphasis filter
AUDIO_OUT audio output
D sound carrier / data carrier
D1, D2 data areas
AUDIO_DATA digital audio data
MIX_DATA digital tax data
PRG_DATA computer program data

Claims (39)

1. Method for recognizing the tempo and phase of a piece of music in digital format using the following procedural steps:

• - approximate determination of the tempo (A) of the piece of music by means of a statistical evaluation (STAT) of the time intervals (Ti) of rhythm-relevant beat information in the digital audio data (Ei),
• - Approximately determining the phase (P) of the piece of music based on the position of the clocks in the digital audio data in the time pattern of a reference oscillator (MCLK) vibrating with a frequency proportional to the determined tempo,
• - Successive correction of the determined tempo (A) and phase (P) of the piece of music based on a possible phase shift of the reference oscillator (MCLK) relative to the digital audio data by evaluating the resulting systematic phase shift and regulating the frequency of the reference oscillator in proportion to the determined phase shift.

2. Procedure for recognizing the pace and phase of one in digi talem format present piece of music according to claim 1, wherein rhythm-relevant beat information (Ti) through bandpass fil (F1, F2) of the underlying digital audio data can be obtained in different frequency ranges. 3. Procedure for recognizing the pace and phase of a digi talem format present piece of music according to claim 1 or 2, with rhythm intervals of the audio data if necessary by multiplying their frequency by powers of 2 into one predefined frequency octave are transformed (OCT) where these time intervals (T1io. .T3io) to determine the tempo remote. 4. Procedure for recognizing the pace and phase of a digi talem format present piece of music according to claim 3, wherein the frequency transformation (OCT) a grouping of rhythm intervals  (Ti), especially in pairs (T2i) or threes groups (T3i), by adding up their time values. 5. Procedure for recognizing the pace and phase of a digi talem format of this piece of music according to one of the preceding going claims 2 to 4, wherein the amount of Da obtained th of time intervals (BPM1, BPM2) of the rhythm-relevant Beat information is examined for cluster points (N) and the approximate pace determination based on the information of a maximum. 6. Procedure for recognizing the pace and phase of a digi talem format of this piece of music according to one of the preceding outgoing claims, the approximate determination of the Phase (P) of the piece of music the phase of the reference oscillator (MCLK) is chosen in such a way that the greatest possible over Attunement between rhythm-relevant beat informa tion in the digital audio data and the zero crossings of the reference oscillator (MCLK). 7. A method for detecting the tempo and phase of a piece of music in digital format according to one of the preceding claims, wherein a successive correction ( 2 , 3 , 4 , 5 ) of the determined tempo and phase of the piece of music at regular intervals in such short intervals Time intervals occur that the resulting correction movements and / or correction shifts remain below the audibility limit. 8. A method for recognizing the tempo and phase of a piece of music in digital format according to one of the preceding claims, wherein all successive corrections of the determined tempo and phase of the piece of music are accumulated over time ( 4 ) and, based on this, further corrections with continuous increasing precision. 9. Method of recognizing the pace and phase of one in digi talem format present piece of music according to claim 8, wherein  successive corrections are made until a specified one is below the tolerable error limit, in particular until an error limit value is lower for the determined speed is less than 0.1%. 10. A method for recognizing the tempo and phase of a musical piece in digital format according to one of the preceding claims, wherein in the event that the corrections are always negative or positive over a predeterminable period of time ( 6 ), a new one (RESET) approximate determination of pace (A) and phase (P) followed by successive correction ( 2 , 3 , 4 , 5 ). 11. Method for synchronizing at least two music pieces in digital format with the following method steps:

• - complete determination of the pace and phase of the first piece of music according to one of the preceding claims,
• - approximately determining the tempo and phase of the further piece of music according to one of the preceding claims,
• - Adjustment of the playback speed and the playback phase of this further piece of music by successively adjusting the frequency and the phase of the reference oscillator assigned to this further piece of music to the frequency and the phase of the reference oscillator assigned to the other piece of music.

12. Procedure for synchronizing at least two in di musical format according to claim 11, whereby to adjust the playback speed and the Ab play phase of the further piece of music based on a possible Phase shift associated with this further piece of music th reference oscillator relative to the reference oscillator of the other piece of music an evaluation of the resulting systematic phase shift and regulation of the Frequency of the reference assigned to the further piece of music Oscillator proportional to the determined phase shift he follows.   13. Music player with at least two in digital Format music pieces according to claim 11 or 12 in Can be synchronized in real time. 14. Music player according to claim 13, wherein each rhythm relevant beat information (Ti) of a given back period based on a current playback po sition of the piece of music as the basis for determining the tempo in Serve in real time. 15. Music player according to one of the preceding claims 13 or 14, with synchronized pieces of music automatically can be arranged with a uniform rhythm and are playable. 16. Interactive music player, in particular according to one of the preceding claims 13 to 15, the
a means for the graphical representation of the clock limits of a piece of music being reproduced in real time with a tempo and phase detection function, in particular one according to one of claims 1 to 10,
a first control element (R1) for changing between a first operating mode (a), in which the piece of music is played at a constant tempo, and a second operating mode (b), in which the play position and / or play speed can be influenced directly by the user in Is real time, and
comprises a second control element (R2) for manipulating the play position from in real time. 17. Interactive music player according to claim 16, with
a means for graphical representation of the current play position, with which an amplitude envelope of the sound wave form of the reproduced piece of music can be represented over a predeterminable period of time before and after the current play position, the representation shifting in real time with the tempo of the reproduction of the piece of music, and With
a means for smoothing (LP, SL) a staged course of time-limited, with the second control element (R2) before given playback position data to a signal that changes uniformly with a time resolution corresponding to the audio sampling rate. 18. Interactive music player according to claim 17, wherein for Smoothing a gradual course of time-limited playback Position data provided a means for ramp smoothing (SL) is through that with any given play positions a ramp with a constant gradient can be triggered, the smoothed signal in a predefinable time interval from its previous value to the value of the play position tion message drives. 19. The interactive music player of claim 17, wherein a linear digital low-pass filter (LP), especially a Re Second order sonance filter, for smoothing a stepped Predefined playback positions over time data serves. 20. Interactive music player according to one of the preceding Claims 16 to 19, wherein in the event of a change between the operating modes (a, b) that reached in the previous mode Position serves as the starting position in the new mode. 21. Interactive music player according to one of the preceding Claims 16 to 20, wherein in the event of a change between the operating modes (a, b) that reached in the previous mode current playback speed (DIFF) by smoothing function, especially a ramp smoothing (SL) or a li neares digital low-pass filter (LP) to which the new Be drive mode corresponding playback speed is feasible.   22. Interactive music player according to one of the preceding Claims 16 to 21, wherein an audio signal is a scratch audio Filter passes through the audio signal of a pre-emphasis Filtering (PEF) subjected and in a buffer storage (B) is filed from which it depends on the particular Playback speed can be read at variable speed (R), to then undergo de-emphasis filtering (DEF) and to be played. 23. Interactive music player according to one of the preceding Claims 13 to 22, wherein for one or more of the syn chronized pieces of music based on the determined tempo information tion of the respective piece of music the length of one over or reproduction of several bars of this piece of music Loop real-time definable and playable is. 24. Interactive music player according to one of the preceding Claims 13 to 23, wherein for one or more of the syn chronized pieces of music based on the determined phase information mation of the respective piece of music in real time isochronous Jump marks definable and within this piece of music integer multiples of measures can be shifted. 25. Interactive music player according to one of the preceding Claims 13 to 24, wherein each reproduced audio data manipulate current through signal processing means in real time bar, in particular through filter devices and / or Au dioeffekte. 26. Interactive music player according to one of the preceding Claims 13 to 25, wherein real-time interventions over the time Save the process as digital control information (MIX_DATA) can be saved, in particular those of a mixing process pieces of music and / or additional signal processing.   27. Interactive music player according to one of the preceding Claims 13 to 26, wherein mixing operations of pieces of music and / or interactive interventions in pieces of music with audio sig nal processing means as a new complete work independently of digital audio information of pieces of music in the form of di gital tax information (MIX_DATA), especially on Re production purposes, are storable. 28. Interactive music player according to one of the preceding Claims 26 or 27, wherein stored digital control formations have a format that provides information about the identities tification of the processed pieces of music and a respective one the associated chronological sequence of playback positions and status information of the actuators of the music Player includes. 29. Interactive music player according to one of the preceding Claims 13 to 28 by a suitably programmed Reali computer system equipped with audio interfaces is. 30. Procedure for the provision of digital audio data at least at least two pieces of music from a data source (CD-ROM) only one reading unit in real time, especially for its syn Chronization according to one of claims 11 or 12, wherein the Data source audio data with a compared to their Ab game speed provides higher reading speed, in one for each piece of music to be played (TR1... TRn) buffer memory (P1... PN), in particular ring buffer Memory, is provided, and the higher reading speed is used to store the respective buffer memory (P1.. .Pn) to fill with associated audio data in such a way that always time Lich before and after a current play position (A1 ... An) of the respective piece of music (TR1 ... TRn) audio data hen.   31. Procedure for providing digital audio data according to Claim 30, wherein the state of each buffer memory (P1... PN) is monitored to determine whether there is sufficient data stand by, and if it falls below a predeterminable Threshold one from the playback of the pieces of music (TR1... TRn) decoupled central instance (S) with the ready the required audio data is commissioned, the automatically the required areas of audio data from the data source (CD-ROM) and the associated puf fer memory (P1 ... Pn) filled with the data received. 32. Procedures for providing digital audio data according to Claim 31, wherein when filling a buffer memory (P1.. .Pn) data that are no longer required are overwritten. 33. Process for providing digital audio data according to The claim 31 or 32, wherein the central entity (S) is parallel incoming requirements in a sequential Order brings. 34. Interactive music player according to one of the preceding Claims 13 to 29, which according to one of the preceding An say 30 to 33 operated CD-ROM drive (CD-ROM) as Data source of the pieces of music (TR1 ... TRn) is used. 35. Computer program product that directly into the internal memory cher of a digital computer can be loaded and soft includes product sections with which the process steps ge executed according to one of claims 1 to 12 or 30 to 33 when the program product is released on a computer leads. 36. data carrier (D), in particular compact disc, the
a first data area (D1) with digital audio data (AUDIO_DATA) of one or more pieces of music (TR1... TRn) and
comprises a second data area (D2) with a control file (MIX_DATA) with digital control information for controlling a music player, in particular one according to one of claims 13 to 28 or 33, wherein
the control data (MIX_DATA) of the second data area (D2) refer to audio data (AUDIO_DATA) of the first data area (D1). 37. data carrier (D) according to claim 36, wherein the digital Control information (MIX_DATA) of the second data area (D2) Mixing of pieces of music and / or interactive interventions in pieces of music with audio signal processing means as one new complete work of digital audio information (AUDIO_DATA) of music pieces of the first data area (D1) represent. 38. A data carrier (D) according to claim 36 or 37, wherein saved saved digital control information (MIX_DATA) of the second Data area (D2) have a format that information to identify the processed pieces of music (TR1. .TRn) of the first data area (D1) and a respective one ordered chronological order of play positions and status information of the actuators of the music player. 39. Computer program product (PRG_DATA) based on a data Carrier (D) is arranged according to one of claims 36 to 38 and directly into the internal memory of a digital computer can be loaded and includes software sections with which this digital computer functions as a music player takes over, especially one according to one of the claims che 13 to 29 or 34, with the according to the tax data (MIX_DATA) of the second data area (D2) of the data carrier (D) based on audio data (AUDIO_DATA) of the first data area (D1) of the data carrier (D) refer to a by the Steuerda entire (MIX_DATA) represented work is playable, if the program product (PRG_DATA) on a computer leads.