JPH09107521A - Video and audio signal compression method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the video/audio signal compression method and its device whose configuration and control are simplified by synchronizing an audio signal and a video signal for compression processing. SOLUTION: A video compression means 2 is provided with a video signal receive/separate means 11, an A/D converter 12, a video data compression means 13, and a frame interrupt signal generating means 14. An audio compression means 3 is provided with an A/D converter 15, an audio data compression means 16. A video/audio signal compressing device is provided with a control means 4, a user interface 5, a memory 6 and a compression data recording medium 7. Through the constitution above, since the compression of an audio signal is simultaneously started based on a frame interrupt signal outputted at the start of compression of a video signal, the compression of the video signal is synchronously with the compression of the audio signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video / audio signal compression method and apparatus, and more particularly to a video / audio signal compression processing for synchronizing a video signal and an audio signal associated with the video signal. The present invention relates to an audio signal compression method and apparatus.

[0002]

2. Description of the Related Art It is known that a conventional video / audio signal compression device is provided with a video signal compression device and an audio signal compression device independently.

FIG. 4 shows a video / audio signal compression processing time chart of a conventional video / audio signal compression apparatus. In FIG. 4, when the user gives a command to start compression processing of video and audio at arbitrary timing, for example, at time t ₁ , the video signal compression apparatus and the audio signal compression apparatus are configured to start compression processing simultaneously. It had been.

[0004]

In the conventional video / audio signal compression apparatus, when the video signal compression apparatus and the audio signal compression apparatus simultaneously start the compression processing at the timing of time t ₁ , the audio signal is instructed to start the compression processing. Although the compression processing is started from time t ₂ (frame 1) immediately after, the compression processing of the video signal is started from time t ₃ of the next frame (frame 2).

However, when the command processing for starting the compression processing of the video signal is not in time for the beginning of the frame (frame 2) due to a delay inside the video signal compression device, the beginning () of the next frame (frame 3) The compression process of the video signal may start from time t ₄ ).

Such a difference in the compression processing start time between the audio signal and the video signal is a basic phenomenon that occurs because the compression processing units of the audio signal and the video signal are different, and the compressed audio data and the video data are compressed. When the data is expanded and reproduced, the beginning of the reproduced audio signal and the beginning of the video signal are displaced by several frames, and there is a problem that the audio signal and the video signal cannot be synchronized.

The present invention has been made to solve the above problems, and its object is a simple structure and a video / audio signal compression method and apparatus capable of performing compression processing by synchronizing an audio signal and a video signal. To provide.

[0008]

In order to solve the above problems, the video / audio signal compression method according to the present invention is characterized in that the video signal and the audio signal are synchronized in the following steps. First step: Initialize the video compression means, the audio compression means, and the control means. Second step: A / D conversion of video signal and audio signal is executed. Third step: issue a command to start compression of the video and audio signals. Fourth step: After recognizing the frame interrupt signal, compression of the video signal is started from the beginning of the next frame. Fifth step: The compression of the audio signal is started based on the frame interrupt signal output when the compression of the video signal is started.

Since the video / audio signal compression method according to the present invention includes the step of starting the compression of the audio signal based on the frame interrupt signal output at the start of the compression of the video signal, the compression of the video signal is started. At the same time, the compression of the audio signal can be started.

Further, the video / audio signal compression apparatus according to the present invention is such that the video compression means generates a frame interrupt signal based on the horizontal sync signal and the vertical sync signal separated from the composite video signal. Means for controlling the start of compression of the audio signal by supplying a frame interrupt signal output at the start of compression of the video signal to the audio compression means.

Since the video / audio signal compressing apparatus according to the present invention comprises the frame interrupt signal generating means for generating the frame interrupt signal based on the horizontal synchronizing signal and the vertical synchronizing signal, the video / audio signal compressing apparatus outputs the video signal at the start of compression. It is possible to control the start of compression of the audio signal by supplying the frame interrupt signal to the audio compression means, and to start the compression of the audio signal at the same time when the compression of the video signal is started.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram of the essential parts of a video / audio signal compression apparatus according to the present invention. FIG.
In the video / audio signal compression apparatus 1, a video compression unit 2, an audio compression unit 3, a control unit 4, a user interface 5, a memory 6, and a compressed data recording medium 7 are provided, and a VTR is provided.
Composite video signal S _V, and the composite video signal S the associated (synchronized) to the _V audio signal S _A video signal V _D of the respective digital analog supplied from the video / audio recording and reproducing apparatus of equal, digital The audio signal S _D is converted into the audio signal S _D , and the signals V _D and S _D are synchronized with each other for compression processing, and then the compressed video signal D _V and audio signal D _A are recorded on the compressed data recording medium 7. Each block transmits / receives data via the data bus 8.

The video compression means 2 includes a video signal acquisition / separation means 11, an A / D converter 12, a video data compression means 13,
A frame interrupt signal generating means 14 is provided. The video signal capturing / separating means 11 captures an analog composite video signal S _V supplied from a video / audio recording / reproducing device such as a VTR,
The video signal V _A included in the composite video signal S _V is separated from the horizontal synchronizing signal H _O and the vertical synchronizing signal V _O, and the analog video signal V _A is sent to the A / D converter 12 and the horizontal synchronizing signal H _O. and supplies the vertical synchronizing signal V _O on the frame interrupt signal generating means 14. The A / D converter 12 uses the analog video signal V
_A is converted into a digital video signal V _D , and the video signal V _D is provided to the video data compression means 13.

The video data compression means 13 is composed of, for example, a time division multiplex (TDM) conversion means and an encoding means, and the A / D
The converted digital video signal V _D in frame units is subjected to time division multiplexing processing, and then video compression processing is performed using a predictive coding method, discrete cosine transform (DCT) or the like, and the compressed video signal D _V is controlled. Data bus 8 under the control of 4
The data is recorded on the compressed data recording medium 7 such as a hard disk via.

Further, the video data compression means 13 supplies the supervisory signal F _A to the frame interrupt signal generation means 14 based on the video signal D _V at the time when the compressed video signal D _V is generated when the compression is started. .

The frame interrupt signal generating means 14 is provided with a signal generating means and generates a frame interrupt signal F _O based on the horizontal synchronizing signal H _O and the vertical synchronizing signal V _O supplied from the video signal capturing / separating means 11. The video data is supplied to the video data compression means 13 and is controlled so that the compression processing is executed from the frame head of the digital video signal V _D.

The frame interrupt signal generating means 14 is provided with a signal monitoring means and a judging means, and the video data compressing means 13 is provided.
The start of the compression processing of the video signal V _{D in} the above is monitored, and only when the frame interrupt signal F _O and the monitoring signal F _A from the video data compression means 13 are present at the same time, the frame interrupt signal F _C is subjected to audio data compression. Means 16 are provided to control the start of compression of the digital audio signal S _D.

The audio compression means 3 comprises an A / D converter 15 and an audio data compression means 16, and takes in an analog audio signal S _A supplied from a video / audio recording / reproducing device such as a VTR, and A / D It is converted into a digital audio signal S _D via the converter 15 and supplied to the audio data compression means 16.

The audio data compression means 16 performs band division coding (SB-ADPCM) on the digital audio signal S _D ,
Audio compression processing is performed using modified discrete cosine transform (MDCT) or the like, and the compressed audio signal D _A is recorded on the compressed data recording medium 7 such as a hard disk via the data bus 8 under the control of the control means 4.

The control means 4 is provided with various arithmetic functions and processing functions based on a microprocessor, and includes a video compression means 2, an audio compression means 3, a user interface 5, a memory 6 and a compressed data recording medium 7 via a data bus 8. Performs operation control, sequence control, data processing, etc.

The user interface 5 provides the control means 4 with a command signal U _I for compressing the video / audio signal at an arbitrary time based on the input information K _S input by the user (for example, keyboard operation).

The memory 6 is composed of a memory such as a ROM and a RAM, and stores a command program for operation control and sequence control of the video / audio signal compression apparatus 1 and stores and updates a command signal U _I from a user. .

The compressed data recording medium 7 is composed of a recording medium such as a hard disk drive (HDD) and a hard disk, and is subjected to compression processing supplied from the video compression means 2 and the audio compression means 3 under the control of the control means 4. The synchronized synchronous video signal D _V and audio signal D _A are recorded and output for reproduction as required.

In the configuration of the video / audio signal compressing device 1, one or both of the video compressing means 2 and the audio compressing means 3 are constituted by independent video compressing means and audio compressing means, respectively. The signal generating means may be composed of a computer system including the control means 4.

As described above, since the video / audio signal compression apparatus according to the present invention is provided with the frame interrupt signal generating means for generating the frame interrupt signal based on the horizontal synchronizing signal and the vertical synchronizing signal, The frame interrupt signal output at the start of compression can be supplied to the audio compression means to control the start of compression of the audio signal, and the compression of the audio signal can be started simultaneously with the start of compression of the video signal.

Next, a video / audio signal compression method according to the present invention will be described with reference to FIG. When the power of the video / audio signal compression device 1 is turned on, the video compression means 2 and the audio compression means 3 are performed based on the reset operation of the power-on reset circuit (not shown) or the input information K _S from the reset key.
And the control means 4 is initialized (first step).

Subsequently, the analog composite video signal S _V and the analog audio signal S _A supplied from the video / audio recording / reproducing device such as a VTR are converted into digital video signals V _D by A / D converters 12 and 15, respectively. , Audio signal S _D. (Second step) At this point, the digitally converted video signal V
_D and the audio signal S _D are respectively the video data compression means 13,
Although the data is input to the audio data compression means 16, the compression processing is not performed and the audio data compression means 16 is put in a standby state so that the compression processing can be immediately performed when there is a compression command.

When the command signal U _I is generated based on the input information K _S from the user, the control means 4 sends the compression start command signals C _V and C _A to the video data compression means 13 and the audio data compression means 16, respectively. , Command to start compression of video and audio signals (third step).

In this state, the video data compression means 13 causes the frame interrupt signal generation means 16 to generate the frame interrupt signal F.
_{When O} is received and recognized, compression of the video signal is started from the beginning of the frame following the frame in which the frame interrupt signal F _O was recognized (fourth step).

On the other hand, the frame interrupt signal F _O output from the frame interrupt signal generation means 16 at the start of compression of the video signal.
And the compressed video signal D _V is monitored and the frame interrupt signal F _C is supplied from the frame interrupt signal generation unit 16 to the audio data compression unit 16 based on the monitor signal F _A output from the video data compression unit 13. Audio data compression means 16
Immediately starts compressing the audio signal (fifth step).

There is no time delay between the start of compression of the video signal and the start of compression of the audio signal (if any, it is extremely small).
Therefore, the video signal D _V and the audio signal D _A are generated in synchronization,
The synchronized video / audio compression signal (D _V / D _A ) can be recorded on the compressed data recording medium 7.

As described above, the video / audio signal compression method according to the present invention includes the first step of initializing the video compression means, the audio compression means and the control means, and the A / D conversion of the video signal and the audio signal. A second step to be executed, a third step to issue a command to start compression of a video signal and an audio signal, and a fourth step to start compression of a video signal from the beginning of the next frame after recognizing a frame interrupt signal, A fifth step of starting the compression of the audio signal based on the frame interrupt signal output at the start of the compression of the video signal, and performing the compression of the video signal and the audio signal in the order of these steps,
The video signal D _V and the audio signal D _A can be synchronized and compressed.

Particularly, since the step of starting the compression of the audio signal based on the frame interrupt signal output at the start of the compression of the video signal is provided, the compression of the audio signal is started in synchronization with the start of the compression of the video signal. be able to.

FIG. 2 is a time chart of the video / audio signal compression processing of the video / audio signal compression apparatus according to the present invention.
In FIG. 2, when the user gives a command to start the compression processing of video and audio at an arbitrary time t _O1 of frame 1, after recognizing the frame interrupt signal F _O at the start time of frame 2 (time t _O2 ), The compression processing of the video signal is started at t _O3 , but if the interrupt processing takes time and the start of the compression processing is not in time for the start of the frame 2, the video signal is processed from the start of the frame 3 (time t _O4 ). Start compression.

When the compression of the video signal is started from the beginning of the frame 3 (time t _O4 ), when the compression of the video signal is started, the frame interrupt signal F _O output at the start of the frame 3 and the video signal _A frame interrupt signal F _C is output based on the supervisory signal F _A that is output at the start of compression, and the compression of the audio signal is started at the same time as the compression of the video signal by using this frame interrupt signal F _C as a trigger. The video D _V and the audio signal D _A are output in synchronization.

FIG. 3 is an operation flow chart of the video / audio signal compression method and apparatus according to the present invention. Step P
In 1, the apparatus is initialized, and in step P2, the analog video signal and audio signal are A / D converted and converted into digital signals.

Next, in step P3, it is determined whether or not there is a command to start compression from the user. If there is a command, the process proceeds to step P4, and if there is no command, it is determined again whether or not there is a command. Subsequently, in step P4, it is determined whether or not the frame interrupt signal is recognized. If it is recognized, the process proceeds to step P5, and if it is not recognized, it is determined again whether or not the frame interrupt signal is recognized. .

In step P5, compression of the video signal is started from the beginning of a predetermined frame. In step P6, it is determined whether the video signal compression start and the frame interrupt signal recognition occur at the same time. If the simultaneous recognition occurs, the process proceeds to step P7. If the simultaneous recognition does not occur, step P5 is repeated again. . In step P7, the compression of the audio signal is started, and the synchronous compression of the video signal and the audio signal is established (step P8).

[0039]

As described above, the video / audio signal compression method according to the present invention comprises the step of starting the compression of the audio signal based on the frame interrupt signal output at the start of the compression of the video signal, Since the compression of the audio signal can be started at the same time when the compression of the video signal is started, the compression of the video and audio signals can be realized in synchronization.

Further, the video / audio signal compression apparatus according to the present invention comprises a frame interrupt signal generating means for generating a frame interrupt signal based on the horizontal synchronizing signal and the vertical synchronizing signal, and outputs it at the start of compression of the video signal. Since it is possible to control the start of compression of the audio signal by supplying the frame interrupt signal to the audio compression means, it is possible to start the compression of the audio signal at the same time as the start of the compression of the video signal, and a simple configuration and control Can synchronize the compression of video and audio signals.

Therefore, it is possible to provide a video / audio signal compression method and apparatus capable of performing compression processing by synchronizing an audio signal and a video signal with a simple configuration and control.

[Brief description of the drawings]

FIG. 1 is a block diagram of a main part of a video / audio signal compression device according to the present invention.

FIG. 2 is a time chart of video / audio signal compression processing of the video / audio signal compression apparatus according to the present invention.

FIG. 3 is an operation flowchart of a video / audio signal compression method and apparatus according to the present invention.

FIG. 4 is a video / audio signal compression processing time chart of a conventional video / audio signal compression device.

[Explanation of symbols]

1 ... Video / audio signal compression device, 2 ... Video compression means, 3 ...
Audio compression means, 4 ... Control means, 5 ... User interface, 6 ... Memory, 7 ... Compressed data recording medium, 8 ... Data bus, 11 ... Video signal acquisition / separation means, 12, 15 ... A
/ D converter, 13 ... video data compression means, 14 ... frame interrupt signal generation means, 16 ... audio data compression means, D _A
… Compressed audio signal, D _V … Compressed video signal, D _V / D
_A ... Video / audio compression signal, F _O , F _C ... Frame interrupt signal, F _A ... Monitoring signal, H _O ... Horizontal synchronization signal, K _S ... Input information, S _A ... Analog audio signal, S _D ... Digital audio Signal, S _V ... Analog composite video signal, V _A ... Analog video signal, V _D ... Digital video signal, V _O ... Vertical sync signal.

Claims (2)

[Claims] 1. A video compression unit for compressing a video signal, an audio compression unit for compressing an audio signal associated with the video signal, and a control unit for controlling the video compression unit and the audio compression unit. A video / audio signal compression method using a video / audio signal compression device for synchronizing a video signal and an audio signal at the start of compression, characterized in that the synchronization of the video signal and the audio signal is executed according to the following steps. Video / audio signal compression method. First step: Initialize the video compression means, the audio compression means, and the control means. Second step: A / D conversion of video signal and audio signal is executed. Third step: issue a command to start compression of the video and audio signals. Fourth step: After recognizing the frame interrupt signal, compression of the video signal is started from the beginning of the next frame. Fifth step: The compression of the audio signal is started based on the frame interrupt signal output when the compression of the video signal is started. 2. A video compression means for compressing a video signal, an audio compression means for compressing an audio signal associated with the video signal, and a control means for controlling the video compression means and the audio compression means. In the provided video / audio signal compression device, the video compression means includes frame interrupt signal generation means for generating a frame interrupt signal based on a horizontal synchronization signal and a vertical synchronization signal separated from the composite video signal. The video / audio signal compression apparatus, wherein a frame interrupt signal output at the start of compression is supplied to the audio compression means to control the compression start of the audio signal.