DE102017214237A1 - Media playback device for playing back content-like media signals - Google Patents

Abstract

The invention relates to a media reproduction apparatus (1) for reproducing content-identical media signals (3, 4) by means of a mobile terminal, the media reproduction apparatus (1) being adapted to reproduce a first one of the content-related media signals (3) and from a predetermined time offset value (dt ), which indicates a time offset of the first of the content-identical media signals (3) to a second of the content-identical media signals (4), and a predetermined adjustment factor (f) of the first of the same content media signals (3) to calculate a synchronization period (tc). The media player (1) is adapted to set a playback speed (rc) of the first media signal (3) according to the adjustment factor (f) during the synchronization period (tc), and thereafter, reproducing the first of the same content media signals (3) at a same content playback time (T1 ') to finish and the second of the same content media signals (4) from the same content playback time (T2) play.

Description

The invention relates to a media playback device for reproducing content-like media signals, a motor vehicle and a method for operating the media playback device.

A media content can be received via different content-identical media signals. This makes it possible to continue to play the media content by means of a change of the transmission path even if a first transmission path can no longer be received. In the context of the technology "hybrid radio", when leaving a reception area of a e.g. VHF-transmitted media content to playback of the media content, e.g. converted over mobile Internet. The method is supported by open standards such as "radiodns.org" and also commercial providers, by being able to retrieve addresses of the same contents of the media content from the Internet ("online stream"). For technical reasons, it may be that the media content of two media signals has a time offset. When changing from a first media signal to a second media signal, which transmits the same media content, it may therefore happen that a period of the media content is not reproduced or duplicated. For example, media content is time delayed over an "on-line stream" over an FM media signal. This means that the media content of the FM media signal is ahead of the time of the online stream.

In order to be able to solve the problem described, which results from the temporal offset, methods have been developed which enable a seamless reproduction of a media content. One of the methods known as "timestretching" adjusts the playback speed of a first media signal before a change to a second content-same media signal by an adjustment factor during a synchronization period, so that the playback of the media content by the second media signal continues at a same content playback time becomes. By means of techniques such as the Psola method (Pitch Synchronous Overlap and Add) a change of the audio frequency is prevented. In other words, the change is seamlessly "seamless". without time jump in the reproduced media content.

The adjustment factor of the playback speed (timstretching rate) is identical in the prior art for all media contents. This is problematic because the adjustment factor is perceived differently depending on the media content. While voice content makes even larger adjustments to the playback speed barely noticeable, a slight change in the playback speed of classical music is perceived as unpleasant by a listener. The adjustment factor for rock and pop music may have reduction rates in the middle range, whereas adjustment factors for electronic music with fast bass sequences need to have low values so that they are not perceived.

By using a single predefined adjustment factor for all media contents in the current state of the art, the chosen adjustment factor does not represent a media content-specific optimal trade-off between a minimum between a length of media signal to be stored and a high tonal quality.

One method of avoiding said time-hopping using time-stretching when switching between FM and DAB media signals is in Ganesan, Vignesh. "Time Stretching Using Phase Vocoder." Global Journal of Computer Science and Technology (2016). In the publication, the playback speed of an audio signal is adjusted.

In the DE 10 2006 043 701 A1 An apparatus and method for individually switching between shipments is described. It is envisaged that is switched from a first program to a second associated program when an event interrupting the first transmission detected and a continuation time for the second transmission can be specified.

In the DE 10 2015 014 045 B3 an automatic channel change is described in a motor vehicle. It is provided that is changed from an active transmission channel to a background channel, if detected by a detection device in the active transmission channel at least one particular signal pattern of unwanted transmission content and in the background channel at least one particular signal pattern of a desired transmission content. In this case, after a station change by means of a time stretching method, an alignment of a buffered data stream with a real-time data stream can be achieved.

It is an object of the invention to provide a device which makes it possible to carry out a time stretching process optimized for a specific media content.

According to the invention, a media playback device for reproducing content-identical media signals by means of a mobile Provided terminal. The media player is adapted to play back a first one of the same content media signals and to calculate a synchronization period from a predetermined time offset indicative of a time offset of the first of the same content media signals to a second one of the same content media signals and a predetermined adjustment factor of the first of the same content media signals. The media playback device is configured to set a playback speed of the first media signal according to the adjustment factor during the synchronization period and then to stop playing the first of the same content media signals at a same content playback time and to play the second of the same content media signals from the same content playback time. In other words, the media playback device is configured to switch the reproduction of a first media signal to a second media signal which has the same media content as the first media signal. The transition occurs during a transitional period in which the first of the media signals is played back at a customized playback speed, so that a continuous playback of the media content occurs. The change of the playback speed and the time offset are given. For example, it is possible for one and the same media content to be transmitted offset in time via two media signals. A media playback device for reproducing content-like media signals by means of a mobile terminal may be, for example, a car radio, a mobile telephone or a tablet computer and may comprise a microcontroller and / or a microprocessor. The media player may play the media content transmitted via a first one of the media signals, which may be, for example, frequency modulated electromagnetic waves in the FM band. It may be that due to leaving the reception area of the first of the media signals, a reception of the media content via a second media signal, which may be, for example, a signal which is transmitted via mobile Internet, is more suitable. The media content of the second media signal may be offset in time from the media content of the first media signal. So that due to the change to the second of the same content media signals no omission, or no duplicate playback of sections of the media content, can be calculated from a predetermined time offset value and a predetermined adjustment factor ("Timestretchingrate") a synchronization period in which the first same content media signal with is reproduced at a changed playback speed, wherein the reproduction of the first content-same media signal ends at a same content time and the reproduction of the second content-same media signal is continued at the same content point in time. The predetermined adjustment factor can be set so that it is matched to the media content. Thus, the adjustment factor for classical music may be smaller than the adaptation factor for spoken texts, because a change in the playback speed of classical music is generally perceived more clearly by a listener. The invention provides the advantage that despite the change between the two media signals, a media content can be played continuously.

A further development of the invention provides that the media playback device is set up to retrieve the predetermined time offset value of the first of the identical content media signals to the second identical content media signal and / or the predetermined adjustment factor of the first same content media signal from a storage device of the media player. In other words, the media playback device is configured to retrieve the time offset between the same content media signals or / and the adaptation value from a storage device. For example, it is possible for the time offset values or / and the predetermined adaptation factors to be stored in a memory of a motor vehicle infotainment system or a memory card of a mobile telephone and to be read out by the media playback device. This has the advantage that the predetermined time offset value or / and the predetermined adaptation factor are available to the media playback device even if the values are not transmitted in addition to the media signal.

A development of the invention provides that the media playback device is set up to recall the predetermined time offset value of the first of the content-related media signals to the second of the same content media signals and / or the predetermined adjustment factor of the first of the media signals from an external central computer. In other words, the time offset between content-like media signals and the predetermined adaptation factor are provided by a central computer located outside the mobile playback device. For example, the time offset value or / and the predetermined adjustment factor may be stored in a database of a central computer which the media player can access via a mobile internet connection. This has the advantage that the values are managed at a central location. Thus, it is not necessary to store the values locally for the media player, and to transmit them additionally with the same content media signals.

A development of the invention provides that the media playback device is adapted to read the predetermined time offset value of the first of the same content media signals to the second of the same content media signals and / or the predetermined adjustment factor of the first of the same content media signals from an additional signal, which together with one or both the content of the same media signals is transmitted. In other words, the media player is adapted to receive the predetermined time offset value and / or the predetermined adjustment factor by means of additional signals which are sent in addition to one or both of the same content media signals. For example, it is possible for the time offset value of an FM media signal to be received to a streaming media signal and / or the predetermined adjustment factor of the FM media signal to be received via a radio data system of the FM media signal from the media player. This results in the advantage that the values are transmitted to the media signal and thus no local data storage and / or query in a central computer are required. At the same time this is an adaptable solution, because the corresponding transmitter can regularly transmit the optimal values for the current program due to its program scheme.

A further development provides that the predetermined adaptation factor of the first media signal is dependent on a genre and / or a category of media content. In other words, the predetermined adjustment factor is tailored to the type of media content. For example, it is possible that the predetermined adjustment factor in radio stations depends on the PTY value of the radio station. For example, for a classical music broadcaster, a predetermined adjustment factor of 1%, a popular music station, a predetermined adjustment factor of 3%, and a news station broadcasting almost exclusively a spoken program could be assigned a predetermined adjustment factor of 8%. It is also possible that the predetermined adjustment factor depends on the currently transmitted media content. As a result, it would also be possible for a classical music station to set the predetermined adaptation factor to 3% during a news broadcast. This has the advantage that the adjustment factor can be selected such that it is optimized for the respective media content.

A development provides that the media playback device is adapted to receive one or both of the same content media signals via radio. In other words, the media content is transmitted via radio at least one of the same content media signals. These may be, for example, a transmission via VHF, long wave, short wave, medium wave, digital radio, DVB-T, DVB-S, mobile Internet, DRM, satellite radio, etc. This has the advantage that no connection of a cable is required to reproduce the media content.

A development provides that the media playback device is adapted to receive the same content media signals via different transmission paths. In other words, the same content media signals can be transmitted according to different standards. For example, the first content-identical media signal can satisfy the DAB standard and the second content-identical media signal can satisfy a transmission standard of the mobile Internet. This has the advantage that a media content can be received over another transmission path if the first transmission path is not available.

A further development provides that the media signals are audio signals. In other words, tones are encoded by the media signals. For example, the media signals may include radio broadcasts.

A further development provides that the media signals are video signals. In other words, images are encoded by the media signals. For example, the media signals may include TV broadcasts and comply with the DVB-T or DVB-S standard.

The invention also includes a method for reproducing content-like media signals by means of a mobile terminal, wherein a first of the identical content media signals is reproduced by a media playback device and from a predetermined time offset value indicating a time offset of the first of the same content media signals to a second of the same content media signals and calculating a synchronization period of a predetermined adjustment factor of the first one of the content-same media signals. By the media playback device, a playback speed of the first media signal is adjusted according to the adjustment factor during the synchronization period and then stopped the playback of the first of the same content media signals at a same content playback time and reproduced the second of the same content media signals from the same content playback time. In other words, the media content contained in a first signal is reproduced by a media player. From a predetermined value, which describes a time offset of the media content of the first signal to a second signal and a predetermined factor is determined by the Control unit calculated a transitional period. During the transition period, the media content of the first signal is displayed, with the playback speed being adjusted according to the adjustment factor. At the end of the transitional period, playback of the media content from the first signal is terminated and the media content is replayed from the second signal. In this case, the change between the two signals of the type that the media content of the second signal is reproduced from the time at which the reproduction of the first signal is terminated.

The invention also includes a vehicle having a media player.

The invention also includes further developments of the method according to the invention and of the vehicle according to the invention which have features which have already been described in connection with the developments of the media playback device according to the invention. For this reason, the corresponding developments of the method according to the invention and of the vehicle according to the invention are not described again here.

• 1 eine Ausführungsform eines erfindungsgemäßen Fahrzeugs mit einer Medienwiedergabevorrichtung;
• 2 zwei inhaltsgleiche Mediensignale;
• 3 den Ablauf eines erfindungsgemäßen Verfahrens.

In the following an embodiment of the invention is described. This shows:

• 1 an embodiment of a vehicle according to the invention with a media playback device;
• 2 two identical content media signals;
• 3 the sequence of a method according to the invention.

The exemplary embodiment explained below is a preferred embodiment of the invention. In the exemplary embodiment, the described components of the embodiment each represent individual features of the invention that are to be considered independently of one another, which also each independently further develop the invention and thus also individually or in a different combination than the one shown as part of the invention. Furthermore, the described embodiment can also be supplemented by further features of the invention already described.

In the figures, functionally identical elements are each provided with the same reference numerals.

1 shows a media player 1 in a vehicle 2 , The media player 1 can contain content-identical media signals 3 . 4 play. The same content media signals 3 . 4 may be, for example, audio signals which are transmitted via radio from different sources S be transmitted. In this case, it may be that the first of the same content media signals 3 an analogue frequency modulated signal in the FM band and the second of the same content media signals 4 a data stream of the mobile Internet. It may be that the media content 5 of the first same content media signal 3 by a time offset value dt delayed in time to the second same content media signal 4 is. In other words, the media content 5 second same content media signal 4 delayed with respect to the media content 5 of the first same content media signal 3 be. It may be that the media content 5 the media player 1 about the first of the same content media signals 3 but a change to the second of the same content media signals 4 should be done. This may be due, for example, to a leaving of a reception area of the first of the content-identical media signals 3 whereby it may be possible that the media content 5 by means of the second of the same content media signals 4 must be reproduced. A smooth transition to the two same content media signals 3 . 4 to enable the media player 1 from the predetermined time offset value dt the first of the same content media signals 3 to the second of the same content media signals 4 and a predetermined adjustment factor f the first of the same content media signals 3 a synchronization period tc to calculate. The predetermined adjustment factor f the first of the same content media signals 3 may describe the factor to which the playback speed r of the first of the same content media signals 3 can be adjusted. This can be for example of a genre and / or category of media content 5 be dependent. The predetermined adjustment factor f of the first media signal 3 and the predetermined time offset value dt for example, by the media playback device 1 from a storage unit 6 the media player 1 or an external central computer 7 be retrieved. It may also be that the predetermined time offset value dt and the predetermined adjustment factor f from additional signals 8th be read, which together with one or both media signals 3 . 4 be transmitted. A possible additional signal 8th For example, the radio text of an FM media signal or an area in the head of a file of a data stream. The synchronization period tc may be a period in which the playback speed r of the first of the same content media signals by the adjustment factor f is changed. The synchronization period tc can be so long that at its end an identical time T1 the first of the same content media signals 3 with a same content date T1 ' the second of the same content media signals 4 matches.

$$\text{tc}=\text{t0}+\text{dt}$$

$$\text{tc}=\text{t0/f}$$

erfolgen. Der Anpassungsfaktor f könnte beispielsweise 0,92 und der Zeitversatzwert dt 2 Sekunden betragen. Die Abspielgeschwindigkeit wäre somit um den Faktor 0,92 gegenüber der normalen Abspielgeschwindigkeit angepasst. Die Dauer des zu streckenden Wiedergabeabschnitts wurde sich aus der Formel $$\text{t0}=\left(\text{dt*f}\right)/\left(\text{1}-\text{f}\right)=23\text{s}$$

ergeben. Der Synchronisationszeitraum hätte dabei die Länge tc = t0/f = t0+dt=25s. Nach dem Synchronisationszeitraum tc kann die Medienwiedergabevorrichtung 1 Zeitabschnitte e', f ,g' des zweiten der inhaltsgleichen Mediensignale 4 mit der normalen Abspielgeschwindigkeit r0 wiedergegeben. Letztendlich ist die Medienwiedergabevorrichtung dazu eingerichtet, aus den zwei inhaltsgleichen Mediensignalen ein kombiniertes Mediensignal 9 zu generieren, welches sich aus den Zeitabschnitten a, b, c des ersten der inhaltsgleichen Mediensignale 3 und den Zeitabschnitten e', f, g' des zweiten der inhaltsgleichen Mediensignale 4 und einem angepassten Zeitabschnitt d" zusammensetzt. 2 shows the playback of two same content media signals 3 . 4 , It may be that a media content 5 via two identical content media signals 3 . 4 is transmitted. The media player 1 can, for example, three sections a . b . c the first of the two media signals 3 at the normal playback speed r0 played. The media content 5 the two same content media signals 3 . 4 can be a time offset value dt be temporally offset from one another, whereby a respective identical time T1 the first of the same content media signals 3 by a time offset value dt for example, is transmitted earlier than a respective same time point T2 the second of the same content media signals 4 , In this case, a change would be from the first of the same content media signals 3 to the second of the same content media signals 4 cause a section with the length of the time offset value dt would be played twice. To avoid this, the media player may 1 a synchronization period tc from the time offset value dt and the adjustment factor f to calculate. During the synchronization period tc can the normal playback speed r0 with the adjustment factor f be multiplied. A period d of duration t0 would in this case according to the changed playback speed rc for the duration of the synchronization period tc be stretched, so that an identical time T1 of the first same content media signal by the time offset value dt at a time T1 ' is offset, which with the same content time T2 the second of the same content media signals 4 coincides in time.
The calculation can be done by means of the formulas $$\text{rc}=\text{f r0 *}$$

$$\text{tc}=\text{t0}+\text{dt}$$

$$\text{tc}=\text{t0 / f}$$

respectively. For example, the adjustment factor f could be 0.92 and the time offset value dt could be 2 seconds. The playback speed would thus be adjusted by a factor of 0.92 compared to the normal playback speed. The duration of the playback section to be stretched became the formula $$\text{t0}=\left(\text{dt * f}\right)/\left(\text{1}-\text{f}\right)=23\text{s}$$

result. The synchronization period would have the length tc = t0 / f = t0 + dt = 25s. After the synchronization period tc can the media player 1 periods e ' . f . G' the second of the same content media signals 4 at the normal playback speed r0 played. Finally, the media player is adapted to make a combined media signal from the two same content media signals 9 to generate, which is made up of the time periods a . b . c the first of the same content media signals 3 and the time periods e ' . f . G' the second of the same content media signals 4 and a fitted period d ".

3 shows a possible sequence of a method according to the invention. It may be that a transmission area of the first of the same content media signals 3 will leave soon, and a change to the second of the same content media signals 4 is necessary for the media content 5 can still be received. In a first step P1 can through the media player 1 the first of the two identical media signals 3 be played by a mobile terminal. This may, for example, be a video signal which is transmitted according to the DVB-T standard. In a second step P2 can the media player 1 from additional information 8th which in addition to the first of the same content media signals 3 be transmitted, an Internet address for the second of the same content media signals 4 and the predetermined time offset value dt the first of the same content media signals 3 to the second of the same content media signals 4 and the adjustment factor f read. In the second of the same content media signals 4 For example, it may be an Internet data stream. From the adjustment factor f and the time offset value dt can the media player 1 a synchronization period tc to calculate ( P3 ).
Based on the calculated synchronization period tc may be the playback speed of the first of the same content media signals 3 according to the adjustment factor f during the synchronization period tc be set ( P4 ). After the synchronization period tc can playback the first of the same content media signals 3 at a same content playback time T1 ' finished and the second of the same content media signals 4 from the same content date of play T2 be reproduced ( P5 ).

Overall, the example shows how the invention enables an optimized use of the time stretching method.

LIST OF REFERENCE NUMBERS

1

Media player

2

vehicle

3

First of the same content media signals

4

Second of the same content media signals

5

media content

6

storage unit

7

External central computer

8th

additional signals

9

Combined media signal

T1, T1 ', T2

Same-time playback times

tc

Synchronization period

f

adjustment factor

dt

Offset value

d "

Adapted period of time

t0

Duration of a period of time

r0

Normal play speed

rc

Adapted playback speed

a - g

Time segments of the first media signal

a '- g'

Time segments of the second media signal

P1 - P5

steps

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006043701 A1 [0007]
• DE 102015014045 B3 [0008]

Claims (10)

Media playback device (1) for reproducing content-identical media signals (3, 4) by means of a mobile terminal, characterized in that the media playback device (1) is adapted to a.) A first of the same content media signals (3), b.) From a predetermined time offset value (dt) indicative of a time offset of the first of the same content media signals (3) to a second one of the same content media signals (4) and a predetermined adjustment factor (f) of the first of the same content media signals (3) to calculate a synchronization period (tc) , c.) to set a playback speed (rc) of the first media signal (3) according to the adjustment factor (f) during the synchronization period (tc), and thereafter, d.) reproducing the first of the same content media signals (3) at a same content playback time (T1 ') to end and the second of the same content media signals (4) from the same content playback time (T2 ) play. Media playback device (1) according to one of the preceding claims, characterized in that the media playback device (1) is adapted to the predetermined time offset value (dt) of the first media signal (3) to the second media signal (4) and / or the predetermined adjustment factor (f ) of the first media signal (3) from a storage unit (6) of the media player (1). Media playback device (1) according to one of the preceding claims, characterized in that the media playback device (1) is adapted to the predetermined time offset value (dt) of the first media signal (3) to the second media signal (4) and / or the predetermined adjustment factor (f ) of the first media signal (3) from an external central computer (7). Media playback device (1) according to one of the preceding claims, characterized in that the media playback device (1) is adapted to the predetermined time offset value (dt) of the first media signal (3) to the second media signal (4) and / or the predetermined adjustment factor (f ) of the first media signal (3) from an additional signal (8), which are transmitted together with one or both media signals (3, 4). Media playback device (1) according to any one of the preceding claims, characterized in that the predetermined adjustment factor (f) of the first media signal (3) of a genre and / or a category of media content (5) of the media signals (3,4) is dependent. Media playback device (1) according to one of the preceding claims, characterized in that the media playback device (1) is adapted to receive one or both of the media signals (3, 4) via radio. Media playback device (1) according to any one of the preceding claims, characterized in that the media playback device (1) is adapted to receive media signals (3, 4) via different transmission paths. Media playback device according to one of the preceding claims, characterized in that the media signals (3, 4) are audio signals. Method for reproducing content-identical media signals (3, 4) by means of a mobile terminal, characterized in that by a media playback device (1) a. a first of the same content media signals (3) is played, b. from a predetermined time offset value (dt) which indicates a time offset of the first of the content-identical media signals (3) to a second one of the content-identical media signals (4), and a synchronization period (tc) is calculated for a predetermined adaptation factor (f) of the first of the content-identical media signals (3) will, c. a playback speed (rc) of the first medium signal (3) is set according to the adjustment factor (f) during the synchronization period (tc), and thereafter, d. the reproduction of the first of the content-identical media signals (3) terminates at a content-identical playback time (T1 ') and the second of the content-identical media signals (4) is reproduced from the content-identical playback time (T2). Vehicle (2) with a media reproduction device (1) according to one of Claims 1 to 8th ,

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