KR100762561B1 - Apparatus and method for signal processing of digital video recording system - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a signal processing apparatus and a method for controlling a path of an analog signal input to a system according to a system operation mode.

A signal processing apparatus of a digital video recording system according to the present invention comprises: a first analog signal decoder which receives a received analog signal and converts it into a digital video and audio signal; A second analog signal decoder which receives the received analog signal and converts it into a digital video and audio signal for recording and outputs the analog signal to the analog signal encoder; An analog signal encoder for compressing the digital video and audio signals output to the second analog signal decoder; A digital signal storage unit for storing the compressed digital video and audio signals; And a controller configured to selectively output one of an output signal of the first analog signal decoder unit or a recording signal stored in the digital signal storage unit according to the time shift operation.

Digital broadcasting, analog signal, recording, storage

Description

Apparatus and method for signal processing of digital video recording system

1 is a block diagram showing an analog signal processing apparatus of a digital video recording system according to the present invention.

2A, 2B, and 2C are diagrams each illustrating an analog broadcast signal processing path in FIG. 1;

3 is a flowchart illustrating an analog signal processing method of a digital video recording system according to a first embodiment of the present invention.

4 is a flowchart illustrating an analog signal processing method of a digital video recording system according to a second embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

110 ... analog signal input 120,150 ... analog signal decoder

130 ... signal selector 150 ... signal output

160 ... Analog Signal Encoder 170 ... Digital Signal Storage

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an analog signal processing apparatus and method for controlling a path of an analog signal input to a system according to a system operation mode.

As the spread of digital television expands, products for recording broadcasts have been released. These products are generally defined as personal video recorders (PVRs) and digital video recorders (DVRs). It has a function. For convenience of description, a product such as a PVR or a DVR will be described as a digital video recording system.

The digital video recording system includes a storage device such as a high-capacity hard disk drive (HDD), and stores (records) the received broadcast in the storage device so that the user can view the previous video at any time when the user wants to watch the previous video again. You can watch.

Due to the advantages of a digital video recording system, which is a recording device using such a storage device, it is being used as a device to replace a VCR in a time shifter, a TIVO, and the like, and the demand thereof is increasing.

In addition, even if digital broadcasting starts, the digital video recording system should be able to continuously perform service on interfaces between systems based on existing analog broadcasting or analog systems such as VCR and DVD.

Such a digital video recording system provides a time shift function. For this purpose, when an analog input signal is input, the system is compressed and stored in a predetermined format (eg, MPEG2) in the system, and then restored and output or displayed again. do.

However, the existing digital video recording system has the following problems. First, in a situation where a function such as time shift is operated in a digital video recording system, a user is always outputting while recording a video signal by encoding it, not the original analog video, even if the current broadcast is played. You will see an encoded video, and you will always see a video that is one to two seconds behind the original video due to the time delay required for that encoding.

In addition, even if the user does not operate the digital video recording system, the digital recording is always performed after the output, so that you always see the encoded video, not the original video, the point of view of the broadcast is delayed even when considering from the user's point of view Is generated.

It is a first object of the present invention to provide a signal processing apparatus and method for a digital video recording system which enables the selective control of an output path of an analog signal in a digital video recording system.

A second object of the present invention is to allow the signal to be bypassed or to perform bypass and recording, recording and output operations according to the operation mode of the digital video recording system.

According to an aspect of the present invention, there is provided a signal processing apparatus of a digital video recording system comprising: a first analog signal decoder configured to receive a received analog signal and convert the digital video and audio signals into output signals; A second analog signal decoder which receives the received analog signal and converts it into a digital video and audio signal for recording and outputs the analog signal to the analog signal encoder; An analog signal encoder for compressing the digital video and audio signals output to the second analog signal decoder; A digital signal storage unit for storing the compressed digital video and audio signals; And a controller configured to selectively output one of an output signal of the first analog signal decoder unit or a recording signal stored in the digital signal storage unit according to the time shift operation.

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Preferably, the control unit outputs a signal of the first analog signal decoder if the system does not operate or outputs a received broadcast signal, and outputs a signal of the digital signal storage unit if the recorded broadcast signal is output. .

Preferably, the control unit further includes a digital signal output of the selected first analog signal decoder unit and a signal processing output unit which releases and outputs the digital signal compressed by the analog signal encoder unit.

In addition, the signal processing method of the digital video recording system according to another embodiment of the present invention, converting the input signal into a digital video and audio signal; Outputting the converted digital video and audio signals when the system is not operating or is in a viewing mode of an input signal; Outputting the converted digital video and audio signals while compressing and storing the digital video and audio signals in a viewing and recording mode of an input signal; Outputting the compressed and stored digital signal when the output is a recorded signal; And controlling to operate in one of the output paths of the digital signal in each step according to whether the system is operating or recording.

Hereinafter, with reference to the accompanying drawings as follows.

1 is a block diagram showing a signal processing apparatus of a digital video recording system according to the present invention.

Referring to FIG. 1, an analog signal input unit 110 for receiving an analog signal, an analog decoder 120 for converting the input analog signal into a digital video and audio signal, and the analog signal decoder 120 A signal selector 130 for selectively outputting an output signal or a signal stored in a digital signal storage unit, a signal processing output unit 140 for outputting an output of the signal selector 130 to a playback device or an output device; In order to store the output of the analog signal decoder 120, an analog signal encoder 150 for encoding in a predetermined format (eg, MPEG2), and for storing the signal encoded by the analog signal encoder 150 The digital signal storage unit 160 and a control unit 170 for controlling the signal selection unit 130 according to the user's key signal.

Here, the analog signal decoder 120 converts an input analog signal into a digital image and an audio signal, and outputs the first analog signal decoder 121 to output the signal to the signal selector 130. And a second analog signal decoder 122 which converts the voice into an analog signal encoder 150 and outputs the same.

A signal processing apparatus and method of a digital video recording system according to an exemplary embodiment of the present invention configured as described above will be described with reference to the accompanying drawings.

First, the digital video recording system allows a user to record an analog or digital broadcast signal such as a broadcast program required, and then watch or manage a program as necessary.

Such a digital video recording system may be configured in / outside the television system or in a set top box, or separately configured to interface with the television system or set top box, selectively recording or / or outputting an input signal. .

To this end, the digital video recording system includes an analog signal input unit 110, an analog signal decoder unit 120, a signal selector unit 130, a signal processing output unit 140, an analog signal encoder unit 150, and a digital signal storage unit ( 160 and the controller 170, and operate in the direct output mode, the output and recording mode of the analog signal, the recorded signal output mode while recording, depending on whether the system is operating or recording.

The analog signal input unit 110 receives an analog signal from an input source. Here, the input source is an analog broadcast signal or a signal input through an external input connection from an external device (DVD, VCR, VTR, PC, etc.).

The analog signal decoder 120 includes a plurality of analog signal decoders 121 and 122, and converts an input signal into a digital video and audio signal and outputs it as a path for direct output and / or a path for recording. The analog signal decoder 120 decodes the input analog signal and outputs it in the form of a digital audio and video signal (eg, YCbCr).

In this case, the analog signal decoder 120 receives analog broadcast signals such as NTSC (National Television System Committee-US method) / PAL (Western Europe other than France) / SECAM (France, Middle East, etc.) and receives YPbPr or RGB format. An analog video signal may be provided. In the case of the analog signal decoder 120 having an A / D converter, a digital video may be provided in YCbCr or RGB format. In addition, when the analog video signal is input from the outside, in the case of the analog signal decoder without an A / D converter, the digital video may be processed by using an A / D converter separately.

The first analog decoder 121 of the analog decoder 120 converts the input analog signal a into a digital video and audio signal and outputs the converted signal to the signal selector 130. The second analog signal decoder 122 The input analog signal b is converted into a digital video and audio signal and output to the analog signal encoder 150.

Here, the analog signal decoder 120 does not branch (a, b) the signal at the front end of the input, but has an analog signal decoder and a branch (not shown) in the decoder to convert the digitally converted signal. You can branch off.

The signal selector 130 selects and outputs a signal output from the first analog signal decoder 121 and a signal stored in the digital signal storage unit 160 under the control of the controller 170. Here, the controller 170 selectively controls the signal output of the signal selector 130 according to whether the function of the digital video recording system (that is, the recording function) is used. For example, when the recording function is not used, the output of the first analog signal decoder 121 is selected and output. When the recording function is used, one signal is selected depending on whether the time shift is used. .

The analog signal encoder 150 encodes (compresses) the signal decoded by the second analog signal decoder 122 in an MPEG2 manner and stores the signal decoded in the digital signal storage unit 160. In this case, the analog signal encoder 160 is an MPEG encoder which compresses the digital video and audio signals output by the second analog decoder 122 in an MPEG2 manner and stores (records) the digital signal in the digital signal storage unit 160. Will generate The digital signal storage unit 160 is a storage medium such as a hard disk drive, and the stored signal is a broadcast signal in the form of a bit stream.

The signal stored in the digital signal storage unit 160 is output to the signal selector 130 under the control of the controller 170. In this case, the signal selector 130 outputs one of the video signal decoded by the first analog signal decoder 121 and the signal output from the digital signal storage unit 160, and the output signal is a signal. It is displayed on the display unit through the processing output unit 140 or output to another reproduction device or system.

Here, the signal processing output unit 140 is a signal that is compressed when stored in the digital signal storage unit 160, and further includes a decoder unit corresponding to the output signal of the analog signal encoder unit, the signal compressed in the MPEG2 method Uncompress the output.

In such a digital video recording system, the recording function is turned on / off according to a user's request or whether recording is performed, and the path of the input analog signal is controlled based on the on / off of the recording function. For example, when the recording function is not performed, the digital signal storage unit 160 does not need to be unnecessarily passed through. When the recording function is operated, it is determined whether the recording function is simple recording or playback while recording like a time shift. That is, in the case of simple recording, the playback path and the recording path are independently controlled, and in the case of playing while recording, the recording and playback path are provided together.

A detailed description of each operation mode is as follows.

FIG. 2A shows the video path P1 when the function of the digital video recording system is not operated. As shown in FIG. 2A, the analog signal a input to the analog signal input unit 110 is decoded by the first analog signal decoder 121, and the decoded signal is decoded by the signal selector 130. After the selection, the signal is output through the signal processing output unit 140. That is, since the system does not need to use the recording function at this time, by directly outputting the signal in a bypass form, it is possible to solve the signal delay problem when the signal is compressed and output.

As shown in FIG. 2A, when a signal is directly output from the first analog signal decoder through the signal selector and the signal processing output unit, the operation of the second analog signal decoder is turned off by the controller to operate the analog signal encoder. It can also be prevented.

2B illustrates a case in which some functions of the digital video recording system are operated. As shown therein, the analog signal input to the analog signal input unit 110 is branched into branches a and b, and then input to the first and second analog signal decoders 121 and 122, respectively, and then decoded. The signal decoded by the signal decoder 121 is selected by the signal selector 130 and output through the signal processing output unit 140 (P1). The signal decoded by the second analog signal decoder 122 is encoded by the analog signal encoder unit 150 in the MPEG2 manner and stored in the digital signal storage unit 160 (P2). At this time, even if the analog broadcast signal is compressed and recorded, the video signal at the present reproduction time can view a signal that is not a delayed signal.

At this time, when recording is performed together with the reproduction of the broadcast program, the channel to be reproduced and the channel to be recorded may be different. That is, the broadcast signal of the first channel output from the analog signal input unit 110 may be decoded and output to the signal selector 130, and the broadcast signal of the second channel may be encoded and stored in the digital signal storage unit 160. have.

In addition, when the digital video recording system as shown in FIG. 2 (b) operates, if the user wants to watch the video signal again or watch the recorded program again, the operation as shown in FIG. 2 (c) is performed. As shown in FIG. 2C, a signal input to the analog signal input unit 110 is recorded in the digital signal storage unit 160 through the second analog signal decoder 122 and the analog signal encoder unit 150. After that (P2), the recorded signal is selected by the signal selector 130 and output through the signal processing output unit 140 (P3). The time shift function may be implemented by using the signal stored in the digital signal storage unit 160. Alternatively, in the case of simply watching the previous video signal or the broadcast program again, the operation mode may be operated.

In this case, the controller 170 may operate only the analog signal decoder 122 to record the signal in the digital signal storage unit 160 and control the recorded signal to be output through the signal selector.

3 is a flowchart showing an operation state of the digital video recording system according to the present invention.

When an analog signal is received by the digital video recording system (S101), it is checked whether the received signal is recorded (S103). In the recording mode of the received signal, the received analog signal is decoded by an analog signal decoder (S109), the decoded signal is output to a signal selector, and the decoded signal is encoded in an MPEG2 scheme to store a digital signal. Recording to the unit (S111).

However, if the reception signal is not recorded, the analog signal is decoded into a digital signal (S105), and the decoded signal is output to the output unit through the signal selector (107).

This operation can check the path of the analog signal to be input, and can prevent the output through the unnecessary recording path. That is, even when the digital video recording system does not record, the digital video recording system can be output to the signal processing output unit directly through the signal selection unit without passing through the analog signal encoder unit or the digital signal storage unit.

4 is a view showing another operating state of the digital video recording system according to the present invention.

Referring to FIG. 4, when an analog signal is received in the digital video recording system (S101), the output path of the received signal is checked (S123). The output path can be checked according to a user's key input signal. The path is determined by simply watching a broadcast, recording with a broadcast, or watching a recorded program while recording.

At this time, if the identified path is a path outputted while recording (S125), the received signal is decoded into a digital signal (S125), the digital signal is encoded in the MPEG2 scheme and stored in the digital signal storage unit (HDD) ( S127 and S129, and outputs the stored signal to the output unit through the signal selector (S131).

If it is not output while recording, the received signal is decoded into a digital signal (YCbCr) (S133) and output to the output unit through the signal selector (S135). At this time, since the tuning operation is completed in the tuner and a signal is input to the analog signal input unit and a signal is output to the signal processing output unit, the speed shown on the screen is improved than before. It also responds immediately when the channel switches, so there is no problem of delays due to channel speed switching.

The present invention controls each path according to whether a recording function or a time shift function is used for a signal input to a digital video recording system, thereby outputting a bypass form for a signal that does not need to pass through the digital signal storage unit. This allows you to watch the current broadcast, not the delayed signal. In addition, it is also possible to solve the problem of deterioration / distortion of image quality generated from an uncompressed signal output.

So far, the present invention has been described with reference to the preferred embodiments, and those skilled in the art to which the present invention pertains to the detailed description of the present invention and other forms of embodiments within the essential technical scope of the present invention. Could be implemented. Here, the essential technical scope of the present invention is shown in the claims, and all differences within the equivalent range will be construed as being included in the present invention.

According to the signal processing apparatus and method in the digital video recording system according to the present invention, the output signal is unnecessarily compressed when not in the recording mode, thereby solving the problem of delayed output due to signal compression, and degrading / distorting image quality. It is effective to prevent.

In addition, even when passing through the digital video recording system, by outputting a signal corresponding to the original analog signal, it is possible to match the speed when switching the broadcast channel to the same as the channel switching speed of the general analog broadcast.

Claims (6)

A first analog signal decoder which receives the received analog signal and converts the analog signal into a digital video and audio signal; A second analog signal decoder which receives the received analog signal and converts it into a digital video and audio signal for recording and outputs the analog signal to the analog signal encoder; An analog signal encoder for compressing the digital video and audio signals output to the second analog signal decoder; A digital signal storage unit for storing the compressed digital video and audio signals; And And a controller for selectively outputting any one of an output signal of the first analog signal decoder unit or a recording signal stored in the digital signal storage unit according to a time shift operation. . delete delete The method of claim 1, The controller outputs a signal of the first analog signal decoder if the system does not operate or outputs a received broadcast signal, and outputs a signal of the digital signal storage unit when the recorded broadcast signal is output. Signal processing unit of the system. The method of claim 1, And a signal processing output unit for releasing and outputting the digital signal output from the selected first analog signal decoder unit and the digital signal compressed by the analog signal encoder unit under the control of the controller. Signal processing device. Converting an input signal into a digital video and audio signal; Outputting the converted digital video and audio signals when the system is not in operation or is in a viewing mode of an input signal; Outputting the converted digital video and audio signals while compressing and storing the digital video and audio signals in a viewing and recording mode of an input signal; Outputting the compressed and stored digital signal when the output is a recorded signal; And controlling to operate in one of the output paths of the digital signal in each step depending on whether the system is operating or recording.

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