WO1996016509A1

WO1996016509A1 - Video animation device based on the production of audio-influenced video signals

Info

Publication number: WO1996016509A1
Application number: PCT/EP1995/004583
Authority: WO
Inventors: David Althammer; Benjamin Kleinke
Original assignee: David Althammer; Benjamin Kleinke
Priority date: 1994-11-21
Filing date: 1995-11-21
Publication date: 1996-05-30
Also published as: AU4175096A

Abstract

The invention concerns a video animation device based on the production of audio-influenced video signals. An audio signal (5) is applied to the input of an audio signal processing unit (1) and a frequency-dependent, digitised control signal (11) which can be selected via a controllable switch (9) is produced. The control signal is fed into a modified control input (12) of a digital video special-effect (13) which is provided with a control PC (16) and at least one video input (14) and one video output (15). Starting from the control PC, various frequency bands of the applied audio signal are captured and alteration of the applied external video signal is carried out in accordance with the digitised audio values.

Description

Device for video animation by means of generating audio-influenced video signals

description

The invention relates to a device for video animation by means of generating audio-influenced video signals, and to a method for operating such a device.

DE 38 16 545 A1 discloses a device for generating sound and randomly controlled images, with the aid of which abstract, colored representations on a screen can be realized. These representations can either be changed depending on the output signal of a microphone or randomly.

A provided video signal generator can generate several different images and overlay the individual images. These pictures consist of areas and lines of different colors.

In the known device for generating sound and randomly controlled images, a frequency band filter is connected downstream of the microphone, the output of the frequency band filter leading to a multiplexer and A / D converter. A selector switch can be used to switch between tone-controlled and random-controlled positions. A personal computer calculates shapes and colors depending on the digitized audio signal. On the output side, the personal computer is connected to the video signal generator for image generation. The video signal generated in this way is via a

Video amplifier fed to a monitor. With the device described above, although sound-dependent video signals can be artificially generated as pure computer images in a digitized manner, it is not possible to feed existing video clips or live video information and to control or influence them in an audio-dependent manner.

On the other hand, video trick mixers are known, with the help of which the operator of such a trick mixer is able to make manual adjustments according to his personal feeling or depending on the music rhythm in order to alienate a video signal present.

Known video mixers allow editing of adjacent video sources. With simple devices, however, the image can only be used to a small extent, e.g. B. can be influenced by changing the color saturation, the image contrast or the brightness. More complex, mostly digital devices are able to carry out more complex image processing. So z. B. the setting of a mosaic effect in the sense of a rasterization of the image, freezing, three-dimensional scrolling of the image and the like possible. Up to now, the functions mentioned above have only been able to be called up manually manually using key controls and other operating elements and their intensity and speed of execution have been defined. As an operating aid, known video mixers have alphanumeric displays or the like and in some cases have the option of pre-programming the desired parameters in order for this data to run automatically.

In the known video mixers, however, the user must have extensive knowledge of the technology in order to to be able to use the offered effects optimally. The purely manual control, like the operation supported by pre-programming, requires a lot of experience and skill. But even if this experience is available, the operator must constantly pay full attention to the operation of the mixer so that he can make continuous changes to the video image depending on the music. The moment that there is no more operation, the video image no longer changes and the congruence of image and sound is missing.

Even preset, automatically running video effects can only be regarded as an unsatisfactory emergency solution, because they constantly change the image, because they cannot be synchronized with the music and therefore there is no exact match between visual and acoustic stimuli.

All in all, the known assignment between, for example, audio and video images by manual means is ineffective and therefore in no way enables the permanent use of the entire range of possible video effects. In particular, manual operation of a trick mixer with fast music with a large number of beats per minute is almost impossible. Ultimately, it is detrimental to the life of the mixer if the controls and keyboards are operated mechanically with an abnormal frequency.

It is therefore an object of the invention to provide a device for video animation by means of generating audio-influenced video signals and a method for operating such a device, with which a direct connection between video and audio signal can be established, as a result of which the viewer is affected is improved and a large number of video effects can be selected and controlled automatically according to the intensity and / or type of the audio signal. The object of the invention is achieved with the features of patent claims 1 and 6, the subclaims comprising at least expedient refinements and developments of the invention.

An essential basic idea of the invention is to influence an externally provided or generated video signal as a function of a frequency-selected audio signal by means of a predeterminable number of video effects and to output it to a video output for further processing or display. The audio signals are automatically influenced in this case, certain video effects being assigned to selected frequency ranges and / or amplitudes of the audio signal by means of software.

According to a further basic idea of the invention, a computer-controlled video trick mixer is used, the video signal to be influenced being fed to the video trick mixer via at least one video input.

The video trick mixer is connected to an audio signal processing device, which audio signal processing device transmits digitized current amplitude values of selected, for example three, frequency bands to the control computer of the video trick mixer.

A specific keyboard unit can be used to assign a specific video effect or a video effect combination to each of the frequency bands.

The software uses the information from the keyboard unit and the digitized audio signal values to assign video effects, which the viewer perceives as particularly appealing. The video effects themselves are executed to a greater or lesser extent in accordance with the respective audio signal amplitude. In one embodiment of the invention, the audio signal processing device contains at least three frequency band filters with downstream rectifiers, the respective outputs of the rectifiers each leading to an input of a switchable multiplexer. The output of the multiplexer is connected to an analog / digital converter which, via a corresponding output bus, supplies the control PC of the video trick mixer with digitized amplitude values of the respective frequency band filter selected by means of the multiplexer.

The control PC of the video trick mixer delivers a switchover or trigger signal to the multiplexer of the audio signal processing device. The keyboard unit is arranged between the outputs of the analog / digital converter and the corresponding inputs of the control PC and serves for the adjustable, logical assignment of video effects to each frequency band.

By means of the device according to the invention it is possible to establish a direct, direct relationship between the audio and video image without having to operate a controller manually, for example in time with the music. Accordingly, music in particular can be optically accompanied by a corresponding video, the video being alienated in a varied and appealing manner by the large number of possible adjustable video effects. The individual video effects can be automatically activated or deactivated according to the intensity and / or type of the sound signal, which simplifies the operation of the device and ensures a corresponding relationship between the sound or audio signal with different types of sound.

The device according to the invention can be used, for example, as a video effects device in discotheques and for video productions.

The device according to the invention and the associated method are described below using exemplary embodiments and with the aid of help near a block diagram showing the basic structure of the device are explained in more detail.

According to the exemplary embodiment and the block diagram according to the single figure, an audio signal processing device 1 is provided, which in the example shown has three frequency band filters, namely a high pass 2, a band pass 3 and a low pass 4. The inputs of the frequency band filters 2 to 4 form the audio input 5 of the audio signal processing device 1.

On the output side, each frequency band filter 2 to 4 is connected to a rectifier 6 to 8.

The respective outputs of the respective rectifiers 6 to 8 are each connected to an input of a multiplexer 9.

An analog / digital converter 10 is connected on the output side of the multiplexer 9. In the example shown, the A / D converter 10 has a conversion width of 8 bits. The output bus 11 with z. B. 8 lines is placed on a modified control input 12 of a video trick mixer 13.

The video trick mixer 13 has at least one video input 14 and one video output 15. The video trick mixer 13 has an internal control PC 16. A modified printer input of the control PC 16 can be used, for example, as the modified control input 12, with respect to the data transmission direction.

A control and trigger signal is sent from the control PC 16 of the video trick mixer 13 to the multiplexer 9 of the audio signal processing device 1.

According to one embodiment, a part, for example 4, of the data lines of the output bus 11 of the A / D converter 10 can be routed to a special keyboard unit (not shown) in order to have an externally specifiable assignment of video to be able to make effects for the respective frequency band filters 2 to 4.

With such a presetting using the keyboard unit, an effect can be specified without having to intervene in the special software of the device.

In a further embodiment of the invention, the conversion or conversion rate of the A / D converter 10 can be influenced by means of the control PC 16 of the video trick mixer 13.

In the exemplary embodiment shown, a digital audio signal for the respective frequency band, its respective instantaneous amplitude on the output bus, is thus provided with the aid of the frequency band filters 2 to 4 and the downstream rectifiers 6 to 8 as well as the multiplexer 9 and the analog / digital converter 10 11 is present as a data word and can be stored in the control PC 16 or in a separate register.

By switching the multiplexer 9 starting from the control PC 16, the conversion for the next following frequency band is carried out after completion of a conversion cycle of a frequency band filter and storage of the received signal. The required switchover is carried out with the multiplexer 9.

Alternatively, it is also possible to either completely digitize the audio signal with downstream digital filtering at the audio input 5 or to provide an A / D converter for each frequency band filter, which means that the multiplexer can be dispensed with.

The above-mentioned digital filtering has the particular advantage that the cut-off frequencies of the respective filter sections can be changed or adjusted at any time without effort and under software control. This enables the device to be individually adapted to the respective type of audio signals present. Of course, showed embodiment of the analog frequency-selective audio signal preprocessing changeable bandpass characteristics or switchable bandpasses are provided in order to enable the above-mentioned adaptation of the device to different sound or sound spectra.

The table below shows an example of the assignment of the video effects to the individual frequency band filters 2 to 4.

Combination high pass band pass low pass

1 1 negative | Posterize 1 | zoom

2 1 Keying 1 | Posterize 2 | Shrink

3 1 Keying 2 | Mosaic | Strobe

4 1 Flip | Play of colors | Spots

With the individual combination options, which can be switched or selected using the keyboard unit, an optically appealing, varied audio / video assignment can be carried out.

This assignment will be explained below.

For example, when a bass signal is applied and the combination 1 setting is used, the video signal is so distorted with every bass pulse that the image virtually flies towards the viewer. The louder or stronger the impulse, the more the image is enlarged.

With combination 2, i.e. the "Shrink" position, the louder the bass signal, the smaller the picture.

With combination 3, i.e. the position "strobe", that will

Video image initially frozen. With a next bass pulse, a new image of the incoming video signal is created, similar to displayed in a slide show where the image changes with each beat of a base drum.

In combination 4, when a bass signal is applied, the video image is reduced, displayed in part of the monitor and jumps to a different position with each pulse. The strength of movement depends on the strength of the respective impulse.

So-called "posterize effects" are particularly suitable for bandpass 3. With these effects, the color or brightness spectrum of the video image is reduced. As a result, color and brightness transitions are given levels and the image is given a quasi-painted character. The stronger the sound signal in this frequency range, the fewer gradations the video signal or the image obtained and displayed.

With the mosaic effect, the image is rasterized, whereby the size of the raster points increases with the volume. The "color play" effect can also be used when there is no external video signal. The screen or the projection screen shows a color that changes depending on the amplitude of the sound signal.

The effects for high pass 2 shown in the table are as follows.

With combination 1, i.e. position "negative", the brightness information of the video signal or the image is reversed as soon as the audio amplitude exceeds a certain threshold value.

In combination 2, "Keying 1", the portions of the image which are below a brightness value which increases with the intensity of the audio signal are punched out, as a result of which the content of a second video signal, which is virtually underneath, is visible. This content of the second video signal preferably contains the feedback output signal, that at the video output of the video trick mixer 13, whereby flowing color mixtures can be generated.

The combination 3, "keying 2", results in a slowly flowing movement which can be accelerated to a tunnel-like effect by zooming the respective video channel accordingly.

The combination 4, "flip" position, is characterized by that on the head ends of the video image as a function of a specific audio signal threshold.

On the process side, after the program has started, the modified control input 11 is initialized and the respective video input is selected, the video system or video standard is defined and the audio signal processing device 1 is activated.

Then by setting e.g. two of the lines of the output bus 11 of the multiplexers 9 of the audio signal processing device 1 are connected to the high-pass filter 2. The read / write line of the A / D converter 10 is addressed by a further set signal and the conversion process of the respectively present audio signal begins.

The status of the A / D converter 10 is now continuously queried by means of the software of the control PC 16 of the video trick mixer 13 until it is recognized that the conversion is complete.

The relevant data is then transferred to a register. This register also contains the position of the keyboard unit for the assignable assignment of the video effects.

This process is now repeated for the other frequency band filters 3 and 4. The software is used to check whether the

Setting the keyboard unit after the last conversion changed gear. If so, a new combination of effects is put together.

In accordance with the audio signals present, which are available as digital amplitude values, the effects are now prepared by means of the video trick mixer 13. The audio signal strength either determines how intensely an effect, e.g. Zoom, is executed, or whether a corresponding effect, for. B. a negative display is to be switched on.

After a vertical sync pulse in the video signal at the video input 14 has been recognized by means of the video trick mixer 13, the effects are passed on to the video hardware for execution and forwarding to the video output 15.

This sequence is repeated continuously, so that audio-influenced control of the video signals is possible continuously and up to date.

The video trick mixer 13 used in the exemplary embodiment has, for example, two mutually independent video channels which support both composite (FBAS) and S-video signals in PAL, NTSC and SECAM. After digitization, the mixer synchronizes video sources on the video output or on an external synchronizing pulse. Existing video devices can be connected in this way without additional time base correction. Internally, the video trick mixer digitizes the input signal with double oversampling in PAL quality. The video output signal is generated as FBAS or Y / C signal by a digital encoder in PAL or NTSC.

Alternatively, it is possible to provide a midi interface or a midi card instead of an audio signal processing device, with the aid of which midi sound data or

Sequences can be used directly to control the video effects. For example, it is possible on CD's Use existing midi tracks in order to achieve an optimal video animation bypassing complex analog signal preprocessing directly and immediately depending on the tone and rhythm.

In addition, the video trick mixer has effect modules that are independent and programmable. As a result, video effects can be carried out in real time with the two video sources which are present on the video channels. Using a digital, linear keyer, smooth transitions, desolves and keying effects between the video and graphic levels are achieved.

A video trick mixer software can be used to predefine digital video effects so that a large number of video effects can be selected and combined via a corresponding user level, without having to intervene in the internal program, or other complicated setting work is necessary are.

All in all, the device according to the invention and the associated method for operating such a device allow sounds, in particular music, to be automatically and alternately underpinned optically by external video signals, with a predetermined relationship between the

Audio or sound signal and the external video signal is guaranteed.

Claims

Patent claims

1. Device for video animation by generating audio-influenced video signals, characterized by the combination of the following features: - switching an audio signal to the input of an audio signal processing device (1), which is a frequency-dependent and digitized, via a controllable switch (9 ) provides a selectable control signal which contains amplitude values of different frequency bands;

^• - supply of the control signal to a modified

Control input (11) of a digital video mixer (13), this having a control PC (16) and at least one video input (14) and a video output (15); - Deriving a start signal and changeover signals from the control PC (16) of the video trick mixer (13) in order to achieve a triggered changeover of the frequency bands of the audio signal processing device (1), whereby, if necessary via a variable presetting, on the basis of the digitized amplitude values different frequency bands (2, 3, 4), an external video signal fed to the video trick mixer (13) is subjected to video effects that can be predetermined and programmed in a manner controlled by amplitude and is provided at the video output (15).

2nd Device according to claim 1, characterized in that the audio signal processing device (1) has at least three frequency band filters (2, 3, 4) with downstream rectifiers (6, 7, 8), the respective outputs of the rectifiers (6, 7, 8) lead to one input of a multiplexer (9) and the output of the multiplexer (9) at the input of one Analog / digital converter (10) is connected, which uses its output bus (11) for each position of the multiplexer (9) to digitize amplitude values of the respective frequency band filter (2, 3, 4) to the control PC (16) of the video trick mixer ( 13) supplies, the control PC (16) delivering switching signals for triggering and switching the multiplexer (9).

3. Apparatus according to claim 1 or 2, characterized in that between the output bus (11) of the analog / digital converter (10) and the corresponding input of the control PC (16), a keyboard unit for adjustable logical assignment of video effects to each Frequency band is arranged.

4. Apparatus according to claim 2 or 3, d a d u r c h g e k e n n z e i c h n e t that the conversion or conversion rate of the analog / digital converter (10) via the control PC (16) of the video trick mixer (13) is adjustable.

5. The apparatus of claim 1, d a d u r c h g e k e n n z e i c h n e t that with the detection of a vertical sync pulse in the applied external video signal, the audio-influenced video signals are present at the video output (15).

6. A method of operating a device according to claims 1 to 5, characterized in that, after program start of control software in the control PC of the video trick mixer, the connection to the audio signal processing device is established, the video inputs and the video standard or the video system are established, and the ana - log / digital converter is activated; then the multiplexer switches to a first frequency band filter and the signal conversion is initiated and after complete conversion, the result is stored and this cycle is repeated for the other frequency band filters; After querying the keyboard unit and, if necessary, changing the video effect assignment, in accordance with the stored, digitized amplitude values of the frequency band filters, the external video signal present at the video input in question is subjected to the video effects and switched through to the video output with the applied vertical synchronizing pulse, the control the respective amplitude values the intensity and / or a threshold-dependent start of the effects.

7. The method of claim 6, d a d u r c h g e k e n n z e i c h n e t that by means of the audio signal processing device, a digitization of the applied audio signal and a subsequent digital filtering is carried out, the limit frequencies of digital bandpass filters can be changed.

8. The method of claim 6, d a d u r c h g e k e n n z e i c h n e t that an audio-amplitude-selective control signal is used instead of frequency band filtering.

9. The method according to claim 6, so that a midi interface is used instead of an audio signal processing device, so that midi sound data or sequences can be used as a control signal.