JPH01293773A - Digital video processor - Google Patents

Abstract

PURPOSE:To switch the picture of a reproduced picture synchronously with the rhythm, etc., of a sound signal by forming a timing signal by detecting a large level equal to or larger than the prescribed value of the output signal of a filter and expanding and correcting the time base width of a detected signal. CONSTITUTION:The rise of the large level equal to or larger than the prescribed value of the output signal of a filter 7 is detected from the level of the half- wave rectification waveform of the output signal of an ALC circuit 8 by a level detecting circuit 9, and the detected signal having a minute pulse width synchronizing with the rise is outputted from the circuit 9 to a pulse width correcting circuit 10. In the circuit 10, the pulse width of the detected signal is expanded and corrected so that the pulse width can be a unit time width for switching the picture, and the corrected detected signal is supplied to a stroboscope processing circuit 11 as a switching timing signal. Since the switching timing signal to be inputted to the circuit 11 is formed synchronously with the change of the strength of the input sound signal, the picture of a stroboscopic reproduced picture is switched synchronously with the rhythm, etc., of music reproduced and outputted from a speaker, etc.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention digitally processes input video signals for screen playback obtained by tape playback, reception, etc., and performs special playback using still images such as strobe playback. The present invention relates to a digital video processing device such as a video tape recorder that performs processing.

[Conventional technology]

Conventionally, video tape recorders and television receivers with digital video processing functions, called digital VTRs and digital TVs, use digital video processing devices equipped with memory for generating still images, such as field memory, to perform tape playback, reception, etc. The input video signal for screen playback obtained by is updated and formed, and special playback using still images such as strobe playback is performed.

For example, the strobe playback of a multi-screen configuration of a digital TV is described in Japanese Patent Application Laid-Open No. 181-1981 (HQ 4N5/2
65), the input video signal and the write signal.

Based on the switching timing signal formed by the read signal, writing and reading of the memory for still image generation is controlled, periodically writing still images of a multi-screen configuration to the memory, and still images written to the memory are controlled. A still image video signal is repeatedly read out and updated every time the screen is switched in synchronization with the edge of the timing signal, and the video signal is reproduced on the screen instead of the input video signal.

As described in the above-mentioned publication, the switching timing signal that sets the timing of screen switching is conventionally composed of a pulse signal with a preset constant cycle.

That is, the conventional digital video processing apparatus of this type is equipped with a switching timing signal forming circuit shown in FIG. 5 in order to periodically switch the screen.

Then, a pulse generator fil consisting of a crystal oscillator etc.
A clock pulse of a predetermined period shown in FIG. 6(a) is outputted to the counter (2) from the counter (21), and the clock pulse is counted by the counter (21), and the count value of the counter (2) is output to the count value designation circuit (3 ( Every time the designated number N set in 1 is reached, a count-up pulse signal shown in FIG.

In addition, the song in Figure 6 is the counter f when the specified number N is 4.
21 output signals are shown.

Then, the processing circuit (4) updates the still image in the memory in synchronization with the rising or falling edge of the switching timing signal input from the counter C2+, and performs strobe playback at a constant cycle set by the specified number N. Screen switching is performed.

[Problem to be solved by the invention]

By the way, for example, during strobe playback, an additional audio signal of the input video signal or an external input audio signal separate from the input video signal is played back and output from a speaker, etc., and the strobe playback image and the played music or audio are simultaneously played. It is possible to enjoy it.

At this time, the strobe reproduced image changes and changes at a constant cycle based on the switching timing signal, regardless of the rhythm of the reproduced music 9 audio.

Therefore, there is a problem in that the switching of images played by the strobe does not match the rhythm of the music or audio, making it impossible to perform effective strobe playback.

SUMMARY OF THE INVENTION An object of the present invention is to provide a digital video processing device that switches the screen of a reproduced image in synchronization with the rhythm of an audio signal reproduced and output from a speaker or the like when performing strobe reproduction.

Further, it is an object of the present invention to provide a digital video processing device that performs intermittent still playback that intermittently becomes a still image state as special playback, and also performs screen switching of the intermittent still playback in synchronization with the rhythm of an audio signal to be reproduced and output. It is also aimed at.

Another object of the present invention is to synchronize the screen switching of strobe playback with 9 amounts of intermittent and still playback to the rhythm of a desired musical instrument sound of the music being played back and output.

[Failure to solve the problem]

The means for achieving the above object will be explained below.

The present invention provides: a strobe processing means for digitally processing an input video signal for screen reproduction to form and output a still image video signal that is updated in synchronization with the edge of a switching timing signal; and an input audio for reproduction output. a filter section that extracts a part of band components of a signal; an automatic level adjustment section that suppresses and adjusts level changes of the output signal of the filter section; and a predetermined level adjustment of the output signal of the filter based on the rectification level of the output signal of the adjustment section. A technical measure is taken that includes a level detection unit that detects a large level greater than a value and outputs a detection signal, and a signal width correction unit that expands and corrects the time axis width of the detection signal to form the timing signal. ing.

The input video signal for screen playback is digitally processed,
an intermittent still processing means that intermittently replaces the input video signal with a still image video signal in synchronization with the edge of the switching timing signal; and a filler that extracts a part of the band component of the input audio signal for playback output. an automatic level adjustment section that suppresses and adjusts level changes in the output signal of the filter section; and detects a large level of the output signal of the filter equal to or higher than a predetermined value from the rectified level of the output signal of the adjustment section and generates a detection signal. A technical measure is taken to include a level detection section that outputs the output, and a signal width correction section that expands and corrects the time axis width of the detection signal to form the timing signal.

Furthermore, if you want to be able to switch in synchronization with changes in a desired musical instrument sound in the music being played back and output, the filter section should include multiple band filters that extract each of the multiple band components of the input audio signal. , and an output selection switch that switches and outputs the output signal of each filter.

[Effect]

Therefore, a switching timing signal is formed in synchronization with the strength of some band components of the input audio signal for reproduction output,
When equipped with a strobe processing means, the switching of still images during strobe playback is performed in synchronization with the rhythm of the music being played back and output, and when equipped with an intermittent stillness processing means, the switching of still images during strobe playback is performed in synchronization with the rhythm of the music being played back and output. Intermittent still playback is performed in which the image is intermittently turned into a still image state.

Furthermore, by providing a plurality of bandpass filters and an output selection switch in the filter section, the screen switching of strobe playback with 1 volume intermittent and still playback can be synchronized with the rhythm of a desired musical instrument sound in the music being played back and output. It can be done by

〔Example〕

Next, the present invention will be explained in detail with reference to FIGS. 1 to 3 showing an embodiment thereof.

(1st Embodiment) First, FIGS. 1 to 3 showing one embodiment will be explained.

In Figure 1, +51 is an audio input terminal, (6) is a buffer amplifier connected to the input terminal +51, (7) is a bypass filter that forms a filter section, and +81 is an automatic level adjustment that forms an automatic level adjustment section. circuit (hereinafter referred to as ALC circuit), C9) is a level detection circuit forming a level detection section, aO is a pulse width correction circuit forming a signal width correction section, OD is a strobe processing circuit having a memory for still image generation, etc. This forms a strobe processing means.

The input terminal +51 and the correction circuit tIO constitute a switching timing signal forming circuit provided in place of the conventional switching timing signal forming circuit shown in FIG.

Further, an input audio signal for reproduction output consisting of an additional audio signal of the input video signal for screen reproduction or an external input audio signal which is digitally processed by the processing circuit ON is input to the input terminal C51.

The input terminal (51 input audio signal is connected to the amplifier (6)
The signal is inputted to the filter f71 via the filter f71, and high frequency band components of 7KI4z or more of the input audio signal are extracted by filtering (7).

In other words, the rhythm of music is usually determined by high frequency band components of 7K)lz or higher, so the filter (7K)
), 7K of the input audio signal as some band components.
Only high frequency components above Hz are extracted.

Then, the output signal of the filter (7) is transmitted to the ALC circuit [81
As the input audio signal increases, the level of the output signal of the filter (7) is adjusted to be lowered by feedback control of the ALC circuit (8), thereby suppressing level fluctuations of the output signal of the filter (7). be done.

That is, the level of the output signal of screen IV (7) is automatically adjusted by the ALC circuit (8) so that the screen can be switched stably depending on changes in strength, regardless of whether the average level of the input audio signal is high or low. suppressed, then the filter r
relatively small level changes in the output signal of 71 are removed;
A waveform C signal is formed that changes only by following a large level change of a predetermined value or more in the output signal of the filter (7).

Furthermore, the output signal of the ALC circuit (8) is detected by the detection circuit r91.
is input to the ALC circuit (8) by the detection circuit (9).
From the level change of the half-wave rectified waveform of the output signal of the filter (7), a rise of the output signal of the filter (7) at a large level equal to or higher than the predetermined value is detected, and the detection circuit (9) sends the output signal to the correction circuit aO in synchronization with the rise. A detection signal with a minute pulse width is output.

Then, from the retriggerable monostable multi-pipe lake (hereinafter referred to as mono-multiply) of the correction circuit nG, the time axis width of the input detection signal, that is, the unit time width of screen switching where the pulse width is set in advance. The pulse signal formed by the expansion correction is supplied to the processing circuit (111) as a switching timing signal.

At this time, the processing circuit 01) updates the still image in the memory in synchronization with the rising or falling edge of the input switching timing signal, and switches the screen for strobe playback.

Since the switching timing signal input to the processing circuit 011 is formed in synchronization with changes in the strength of the input audio signal, the screen switching for strobe playback is synchronized with the rhythm of music played back and output from speakers, etc. It will be done.

By the way, the amplifier (6) or the correction circuit O0 in FIG. 1 is formed as shown in FIG. 2 using an integrated circuit for operational amplification and an integrated circuit for monomulti.

In addition, in Fig. 2, (ICI), (IC2), (
IC3) is a model number LA64585S operational amplifier integrated circuit with built-in two operational amplifiers each having a differential amplifier configuration, and (IC4) is a model number TC4 with two built-in monomultis.
5288P monomulti integrated circuit, (Ql),
(C2) are two transistors for feedback control of the ALC circuit (8), and (C3) is a transistor at the output stage of the detection circuit C91.

In addition, ■, ■, ..., ■, [phase] in the figure are integrated circuits (
The terminal numbers of IC1) to (IC4) are shown.

Further, each of the integrated circuits (ICI) to (IC4) is supplied with a DC power supply having a voltage Vcc (=12V) at a power supply terminal (10B).

Then, one operational amplifier (AI) of the integrated circuit (ICL)
) forms an amplifier (6), and the input audio signal at the input terminal +5+ is outputted from the AC suspect capacitor (C1) via the amplifier (AI).

In addition, the voltage dividing circuit formed by the voltage dividing resistors (R1) and (R2) and the filter capacitor (C2)
An operating bias voltage of C,/2 is created.

Furthermore, both operational amplifiers (A2) of the integrated circuit (IC2)
.

(83) and filter resistor (R3), (14), (
R5).

(R6), capacitors (C3), (C4), and (C5) fill the filter f71, and the high frequency component of the input audio signal output from the capacitor (CI) is extracted by the filter (7). The extracted high frequency component is output from the amplifier (A3) to the other operational amplifier (A4) of the integrated circuit (ICL) via a coupling resistor (R5), capacitors (C6) and (C7).

Nao, amplifier (A2), (83) operation reference point wovCC
/2, the operating bias voltage of the voltage divider circuit is connected to the resistor (
1t4), (R6) to the amplifier (A2), (A
3) is injected into the input signal.

Amplifier (A4), I-Langinuta (Ql),
(C2) and amplifier (A4) characteristic setting resistor (RJ
3), (R9).

Capacitor (C8), resistance for operating bias voltage injection (RIO), resistance for filter (R11), (R12)
), a capacitor (09>, (CIO)), and a half-wave rectifier diode (1) I) form an ALC circuit (8).

Then, the high frequency component output from the filter (7) is biased by the operating bias voltage and sent to the amplifier (A4).
At the same time, the DC bias component of the amplified output signal of the amplifier (A4) is input to the capacitor (C9).

Reduced and removed by resistor (几11), amplifier (A4)
The AC component of the output signal, that is, the AC component proportional to the high frequency component of the input audio signal is input to the diode (DI) as shown in FIG. 3(a).

At this time, the half-wave rectification of the diode (DI) and the resistance (11
12) Due to the smoothing of the capacitor (eIa), the positive half-wave component of the AC component is extracted, and minute level changes in the waveform of the extracted positive half-wave component are suppressed, and the diode (Dl) is smoothed. A signal having a rectified waveform shown by the solid line in FIG. 3(b) is generated at the cathode.

Note that the broken line waveform in the third output) indicates the waveform in FIG. 3(a).

2.The collector of the transistor (Ql) changes depending on the large or small change in the cathode level of the diode (DI).
The impedance between the emitters changes, and the transistor level changes depending on the large or small change in the cathode L/bell.

Furthermore, the transistor (Q
2) When the impedance between the emitter and collector changes and the input audio signal becomes high level and the output signal of the amplifier (A4) increases, the level of the output signal of the filter (7) input to the amplifier (A4) will change. is lowered, and the input level of the amplifier (A4) is automatically adjusted by feedback control.

Then, the signal of the rectified waveform of the cathode of the diode (1')1) is inputted to one operational amplifier (A5) of the integrated circuit (IC3) via the differential capacitor (C11).

At this time, a differential pulse synchronized with the rising and falling edges of the rectified waveform is formed based on the differentiation of the capacitor (C11), and the differential pulse is passed through the operating bias voltage injection resistor (RI3). The waveform of the input signal to the amplifier (A5) becomes as shown in FIG. 3(C).

And capacitor (C11), resistor (RI3),
Amplifier (A5), I-transistor (Q8), and resistors (R14) and (R15) for setting the characteristics of the amplifier (A5)
, capacitor (C12).

Resistor for enemy (RI6), capacitor (C1B),
) The input signal is AC amplified, and the amplifier (A5) outputs a signal with a waveform in which the change in the differential puff frequency is increased, as shown in FIG. 3(d).

Furthermore, only the AC component of the output signal of the amplifier (A5) is extracted by the capacitor (C13) and resistor (R16), and the base of the transistor (Q3) is connected to the ground level as shown in Figure 3(e). A pulse waveform signal that changes as the frequency changes is input.

(-, the on-voltage Vbe between the base and emitter is the threshold voltage of the transistor (Q3), and the emitter color integrated circuit of the transistor (Q3) is
IC:4) as shown in Figure 3(f), the filter (
7) A detection signal having a minute pulse width is output in synchronization with the rise of a large level change of a predetermined value or more of the output signal.

In addition, the other operational amplifier (A6) of the integrated circuit (103)
is not used.

Further, the correction circuit GO is formed using one monomulti of the integrated circuit (IC4), and the time constant terminal, reset terminal, rising trigger terminal, falling trigger terminal, Q output terminal, and Q output terminal of the monomulti Terminals ■, ■ and terminals ■, ■, ■, ■ of the integrated circuit (IC4).

■The time constant resistance (R2('
)).

Capacitor (C14) and recovery diode (
D2) is externally attached to the integrated circuit (IC4).

- At LL, the detection signal of the emitter of the transistor (Q3) is input to the terminal ■, and the detection signal rises t.
l, t2. t3. t4. ...Integrated circuit (IC4)
) is triggered, the pulse width of the detection signal is extended to a fixed time T determined by a time constant, and the integrated circuit C
A switching timing signal having a waveform shown in FIG. 3(g) is output from the terminal (2) of the IC4> to the processing circuit 011 via the resistor (R21).

Incidentally, in the above embodiment, the processing circuit 011 outputs a video signal of a still image stored in the memory that is updated in synchronization with the switching timing signal, and performs strobe playback, but instead of the processing circuit 011, An intermittent still processing circuit, that is, an intermittent still processing means, is provided, which alternately switches and outputs the input video signal and the video signal of the still image in the memory in synchronization with the switching timing signal. If you replace the input video signal with a still image video signal and output it for the period from 1 to 4, that is, for the time constant T, the still image state will be intermittently synchronized with the rhythm of the music being played back and output. Intermittent static playback can be performed.

(Other examples) Next, FIG. 4 showing another embodiment will be explained.

In FIG. 4, the difference from FIG. 1 is that a plurality of band pass filters (12B) are used instead of the filter (7).

(12) +), (12C), =-, (+2n) and the output signals of each filter (12B) to (+21) are ALC
The point is that a filter section α4 consisting of an output selection switch Q3 for switching output to the circuit (8) is provided.

Each of the filters (12a) to (+2n) extracts each of the plurality of band components of the input audio signal, and based on the switching of the switch a3, the filters (128) to
(+2n) output signals are input to the ALCu path (8).

Therefore, the screen switching for strobe playback is synchronized with changes in the strength of the selected band component of the input audio signal, that is, the rhythm of the desired band sound such as the desired instrument sound of the music being played back and output. It will be done.

It is of course possible to provide the above-mentioned intermittent still processing circuit in place of the processing circuit QllO to perform intermittent still playback in synchronization with the sound of a desired band.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

A video tape recorder capable of rhythmically switching screens for strobe playback in synchronization with music, etc. being played back and output, based on a switching timing signal synchronized with changes in the strength of an input audio signal being played back and output.

Effective strobe playback on television receivers, etc.

Further, by providing an intermittent still processing means instead of the strobe processing means, it is possible to perform intermittent still playback in which a still image state is intermittently synchronized with the music being reproduced and output.

Furthermore, by providing the filter section with a plurality of band filters and an output selection switch that switches and outputs the output signal of each filter, the strobe can be synchronized with the rhythm of a desired musical instrument sound in the music that is being played back. It is possible to switch the screen for one-volume intermittent still playback, and to perform two-layer effective strobe playback and intermittent still playback.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the digital video processing device of the present invention, FIG. 1 is a block diagram of one embodiment, FIG. 2 is a detailed wiring diagram of the main parts of FIG. 1, and FIG. Figure (al~(g)
is a timing chart for explaining the operation in FIG. 2, FIG. 4 is a block diagram of another embodiment, FIG. 5 is a block diagram of a conventional digital video processing device, FIG.
FIG. 3 is a timing chart for explaining the operation in the figure. FIG. (7)...Bypass fill, f8)...ALC circuit, 9)...Level detection circuit, mouth O...Pulse width correction circuit, 01)...Strobe processing means, (+21)
~(121)...Band pass filter, (3)...
Output selection switch, 04)...filter section.

Claims (3)

[Claims] (1) Digitally process the input video signal for screen playback,
a strobe processing means for forming and outputting a still image video signal that is updated in synchronization with an edge of a switching timing signal; a filter section for extracting a part of band components of an input audio signal for playback output; and the filter. an automatic level adjustment section that suppresses and adjusts level changes in the output signal of the filter; and a level detection section that detects a large level of the output signal of the filter equal to or higher than a predetermined value from the rectified level of the output signal of the adjustment section and outputs a detection signal. A digital video processing device comprising: a signal width correction section that expands and corrects a time axis width of the detection signal to form the timing signal. (2) Digitally process the input video signal for screen playback,
an intermittent still processing means that intermittently replaces the input video signal with a still image video signal in synchronization with an edge of a switching timing signal; and a filter section that extracts a part of band components of the input audio signal for playback output. , an automatic level adjustment section that suppresses and adjusts level changes in the output signal of the filter section, and detects a large level of the output signal of the filter equal to or higher than a predetermined value from the rectified level of the output signal of the adjustment section, and outputs a detection signal. A digital video processing device, comprising: a level detection section that performs expansion correction on a time axis width of the detection signal to form the timing signal. (3) Claim (3) characterized in that the filter section is provided with a plurality of band filters that extract each of a plurality of band components of the input audio signal, and an output selection switch that switches and outputs the output signal of each of the filters. The digital video processing device according to 1) or (2).