JPH05314666A - Video tape recorder - Google Patents

Abstract

PURPOSE:To obtain an audio reproducing signal having a high quality by recording the same audio signal in plural voice channels, selecting the channel in which the number of errors is the smallest and outputting it at the time of reproduction. CONSTITUTION:In the case of recording the audio signal of two channels, the recording mode of the channel selected by a recording mode setting part 12 is recorded in the banks A1, A2 of a memory A by an input/output controller 6, and also, stored in the banks B1, B2 of a memory B, as well, and a correction code and B bank recording information are added by signal processors 7, 8, respectively. Subsequently, the signal is converted to a series signal by a converter 9, thereafter, recorded in the A and B areas of each track of a magnetic tape. At the time of reproduction, the signal is converted to a parallel signal by a converter 10 and subjected to deinterleave processing by the signal processors 7, 8, thereafter, based on the number of detected errors and additional information, the channel in which the number of errors is the smallest is selected by a controller 11 and read out of the memory A or B. In such a manner, the reproducing audio signal having a high quality can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video tape recorder (hereinafter referred to as VTR) for recording and reproducing a multi-channel PCM audio signal together with a video signal.

[0002]

2. Description of the Related Art Currently, A mode of satellite broadcasting or HDTV
In (High Definition Television), a so-called high definition television MUSE (multiple sampling encoding method) system, multi-channel PCM audio broadcasting is put into practical use, and high-quality audio can be obtained by receiving this broadcasting. In addition, it is possible to record and reproduce such excellent quality audio and HD-VTR (High Definition Audio).
Next-generation VTRs such as n-VTR) are envisioned and are being developed. In such a VTR, it is possible to record PCM audio signals of four or more channels instead of the conventional two channels. When using multiple channels in this type of VTR, it is needless to say that, for example, four channels are simultaneously used for recording, but normally only two channels are used, and the required audio is recorded later on the remaining two channels. In order to enable post-recording, it is considered to divide these channels into a plurality of independent recording areas.

[0003]

However, the above-mentioned V
In TR, it is considered that recording of two channels is usually sufficient for normal use. Therefore, the remaining two channels are unused and it is desired to effectively utilize the remaining channels. Therefore, an object of the present invention is to provide a VTR that can effectively use a multi-channel audio recording area.

[0004]

A video tape recorder of the present invention, for example, as shown in FIG. 1, is a video tape recorder for recording and reproducing a multi-channel PCM audio signal together with a video signal. Mode setting means 12, storage means A and B having storage areas corresponding to the number of channels, and error correction processing and the same PCM when recording PCM audio signals
The signal processing means 7 and 8 adds information corresponding to signal recording and detects error correction data and additional information during reproduction, and outputs from the signal processing means 7 and 8 during reproduction of a PCM audio signal. Control means 11 for outputting an instruction signal for selecting the PCM audio signal with the fewest errors based on the error correction data and the additional information, and input / output control for controlling the switching of the input / output of the PCM audio signal by the instruction of the control means 11. And means 6.

[0005]

When the audio signal is recorded on the plural audio channels of the magnetic tape, not only is the signal recorded only on the predetermined channel, but the same audio signal is recorded on the other channels, and the same audio signal is recorded. Additional information indicating that "the same audio signal has been recorded" is also recorded on all channels. By detecting and comparing error correction data and additional information at the time of recording at the time of reproduction, the most effective audio signal having no or few errors can be selected and reproduced. Therefore, even if the magnetic tape is damaged or deteriorated, the sound quality deterioration during reproduction can be reduced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the video tape recorder (VTR) of the present invention will be described below with reference to FIGS. Reference numeral 1 denotes a video recording signal processing device, which processes the video signal input from the input terminal Tv ₁ such as digital conversion and modulation and outputs it as a recording signal. S1 is a video or audio signal changeover switch, and the video and audio signals are recorded in respective areas of the track of the magnetic tape by the changeover of this switch. A recording amplifier 2 amplifies a video signal or an audio signal input via the video or audio signal changeover switch S1 and is connected to the recording head H _R of the rotary drum D. A reproducing amplifier 3 amplifies and outputs a video signal or an audio signal output from the reproducing head H ₀ of the rotary drum D. Reference numeral 4 denotes a video reproduction signal processing device which performs processing such as demodulation and analog conversion on a video signal input via the reproduction amplifier 3 and outputs the reproduction signal as a reproduction signal from the output terminal Tv _O. 5 is a frame memory,
A recording or reproduction video signal from the image recording signal processing device 1 and the image reproduction signal processing device 4 is written or read for one screen. The video or audio signal change-over switch S1 and the reproduction amplifier 3 described above are connected to a parallel-serial converter 9 and a serial-parallel converter 10, respectively, which will be described later. The video circuit described above can be configured by known means.

6 is, for example, a channel selector, A-D
And a DA converter, a serial-parallel converter, a memory controller, and the like. At the time of recording, the input / output control device 6 switches and inputs, for example, 4-channel audio signals, converts the signals into digital audio signals, and switches first and second bank changeover switches S2 and S3 described later. By doing so, control is performed so that the memories A and B are sequentially written. Further, at the time of reproduction, the input / output control device 6 sequentially reads the audio signals from the memories A and B by switching the first and second bank changeover switches S2 and S3 and converts them into analog signals from the output terminal T _A0 . Output. When the input audio signal is a digital signal, it is converted into a serial-parallel signal in the input / output control device 6 and stored in the memories A and B.

Each of the memory A and the memory B is composed of, for example, a RAM or the like, and its storage area is, for example, 2 channels each.
That is, memory banks A ₁ and A ₂ and memory bank B ₁
And B ₂ (hereinafter banks A ₁ , A ₂ or banks B ₁ , B ₂
Is called). At the time of recording and reproducing of the VTR, for example, the memory A writes or reads the audio signals of the first and second channels to and from the banks A ₁ and A ₂ , respectively, and the memory B writes to and reads from the banks B ₁ and B _2. In addition, the audio signals of the third and fourth channels are written or read, respectively. As described above, S2 and S3 are the first and second bank changeover switches, which switch the audio signal of the corresponding channel to the banks A ₁ and A ₂ of the memories A and B and the banks B ₁ and B _{2 respectively.} Write to or read from. S4 and S5 are third and fourth bank changeover switches, which are sequentially changed over during recording and reproducing of the VTR, and write audio signals to the banks A ₁ and A ₂ and the banks B ₁ and B ₂ of the memories A and B, respectively. Alternatively, read out.

Bank changeover switches S2 to S5
To write or read audio signals.
Bank A of Re A and B respectively₁And A₂And bank B
₁And B₂In contrast, they are designed to work alternately
It For example, via the first bank selector switch S2
Bank A of the first channel of Mori A₁To audio signal
No. is being written, the third bank switching switch
Switch S4 is bank A of the second channel of memory A₂of
Read out. Next, bank A of the first channel ₁of
When writing is completed, the first bank selector switch S2
Is the second channel bank A₂Switched to a van
Ku A₂The audio signal is written into the
Link selector switch S4 is in bank A₁Switched to
This bank A ₁Is read out. As well
The bank of memory B for the third and fourth channels
B₁And B₂When writing or reading the audio signal of
The second and fourth bank changeover switches S3 and S5
Each of them operates alternately.

Reference numerals 7 and 8 are first and second audio signal processing devices, which add an error correction code to the audio signals of the memories A and B at the time of recording, and interleave at the time of reading to rearrange the audio signals. Is performed, and processing such as error dispersion is performed. Furthermore, the first
When the audio signals to which the error correction code is added are read from the memories A and B, the second audio signal processing devices 7 and 8 use the audio control device 11, which will be described later, to output the same audio signal to a predetermined channel and other channels. When the instruction to record is given, information indicating that "the same audio signal has been recorded" is added to the audio signal of each of these channels.

At the time of reproduction, the first and second audio signal processing devices 7 and 8 perform processing reverse to that at the time of recording, for the audio signal interleaved at the time of recording,
That is, when performing error correction and writing to the memories A and B,
The original signal is rearranged (deinterleaved), and error correction data indicating a correction result and data indicating the presence / absence of additional information indicating “recorded the same audio signal” are output.

Reference numerals S6 and S7 denote a recording signal switch and a reproduction signal switch. During recording, the recording signal switch S6 is switched so that the audio signals from the memories A and B are transferred to the first and second audio signal processing devices 7 and 7, respectively. 8 is output, and during reproduction, the reproduction signal switch S7 is switched to output the audio signal to the first and second audio signal processing devices 7 and 8.

Reference numeral 9 denotes a parallel-serial converter which has a built-in digital modulator, for example, converts a parallel audio signal into a serial audio signal, digitally modulates it, and outputs it as a recording signal to the video or audio signal changeover switch S1. ..
Reference numeral 10 denotes a serial-parallel converter, for example, which has a built-in digital demodulator, digitally demodulates an audio signal transmitted through the reproduction amplifier 3 during reproduction, and converts a serial audio signal into a parallel audio signal to reproduce a signal. Output to switch S7.

Reference numeral 11 is an audio control device, for example, RA
It is composed of a CPU having M, ROM, etc.
It is connected to the audio signal processing devices 7 and 8 and the input / output control device 6 and controls the entire audio circuit. At the time of recording, the audio control device 11 inputs so as to record an audio signal in a channel other than a predetermined channel based on a recording mode of, for example, "recording of 2 channels" set by a recording mode setting unit 12 described below. Instruct the output control device 6. A program for performing such processing is stored in advance in the ROM. Further, at the time of reproduction, comparison and detection are performed based on the error correction data and additional information of the audio signals output from the first and second audio signal processing devices 7 and 8, and an instruction signal for selecting the most effective audio signal is input. Output to the output control device 6.

Reference numeral 12 denotes the above-mentioned recording mode setting section, which is connected to the audio control device 11 and is constituted by, for example, a plurality of operation keys and the like, and selects and inputs a required recording mode.

FIG. 2 is an example schematically showing the recording format of the magnetic tape. Reference numeral 21 is a magnetic tape, and 22 is a plurality of tracks recorded on the magnetic tape by the rotating drum D (FIG. 1). The track 22 is divided into a video area 23 and an audio area 24.

FIG. 3 shows a recording area of one track of the recording format shown in FIG. Truck 2
Although 2 is divided into the video area 23 and the audio area 24 as described above, the audio area 24 is further divided into, for example, two areas of audio A and audio B. Further, a guard (gap) is provided between the video area and the audio A, and between the audio A and the audio B to prevent an error in later recording (post-recording). The video signal described above is recorded in the video area 23, and the audio signals of the first and second channels and the audio B are recorded in the audio A area.
For example, the third and fourth channel audio signals are recorded in the area, respectively.

The above-mentioned additional information may be recorded in an index area provided in addition to the audio area of the magnetic tape shown in FIG. Although not shown, the index area is provided, for example, between the video area and the audio area of the recording format of FIG. Also in this case, guards are set on both sides of the index area.

Next, the operation of the embodiment shown in FIG. 1 will be described. When recording an audio signal, the recording mode setting unit 12 controls, for example, 2 of the first and second channels.
When the mode for recording only the channel is selected, the input / output control device 6 switches and inputs the audio signals of the two channels according to the instruction of the audio control device 11, converts the audio signals of the two channels into the audio signals of digital signals, and outputs the first and second audio signals. By switching the bank changeover switches S2 and S3, the memory A
While her husband recorded in the bank A ₁ and A ₂ of the people, also be sequentially stored in bank B ₁ and B ₂ of the third and fourth channel memory B. Therefore, the same audio signal is stored in all the channels of the memories A and B.
Regarding the stored audio signal, the audio signal of the memory A is transferred to the first audio signal processing device 7 by switching the third and fourth bank changeover switches S4 and S5.
Also, the audio signals of the memory B are output to the second audio signal processing device 8, respectively. When the input audio signal reaches a predetermined amount, the first and second audio signal processing devices 7 and 8 perform a process of adding an error correction code to the audio signals of the memories A and B, and when reading the audio signal, For example, information indicating that "the same audio signal is recorded in the audio A and B areas (Fig. 3)" is added, interleaved and output to the recording data switch S6. If the index area is provided on the magnetic tape, such additional information may be recorded in this area.

When the output of the audio signal of the memory A from the first audio signal processing device 7 is completed, the recording signal switch S6 is switched to the side of the second audio signal processing device 8 and the audio signal of the memory B is output. .. Since the audio signal output through the recording signal switch S6 is in a parallel state, it is converted into a serial audio signal by the parallel-serial converter 9 and modulated into a recording signal to be converted into a video or audio signal changeover switch S1.
Sent to. After amplified by the audio signal by switching the switch S1 recording amplifier 2, sequentially recorded on the audio A and B regions of each track of the magnetic tape via the recording head H _R (Figure 3).

Next, regarding the processing at the time of reproducing the audio signal,
Explain. Output from the reproduction amplifier 3, for example, the first
~ 4th channel audio signal is converted from serial to parallel
Sent to the demodulator 10 and demodulated and converted from serial to parallel data
And output to the reproduction signal switch S7. This switch
By switching S7, the audio signal becomes the first and second audio signals.
The error correction is sent to the audio signal processing devices 7 and 8.
Such as reordering (deinterleave) into positive and original signals
Processing is performed. After such processing, the audio signal is the third
And the fourth bank changeover switches S4 and S5
The first and second channel memories A and the third and third memories
Each bank A of 4 channel memory B ₁And A₂common
Bini Bank B₁And B₂Are sequentially written and stored in.

More specifically, in the first and second audio signal processing devices 7 and 8, after the audio signals are corrected and the original signals are rearranged, that is, deinterleaving is performed, for example, an error of an error number is detected. In addition to detecting the correction data, the additional information indicating that "the same audio signal is recorded in the audio A and B areas" recorded during recording is detected and output to the audio control device 11. The audio control device 11 compares the input error correction data and determines the presence / absence of additional information, and based on these results, selects a channel having no error or the least number of channels and instructs the input / output control device 6 to do so. Output a signal. In response to this instruction, the input / output control device 6 reads the audio signal of the channel selected from the audio signals stored in the memories A and B by switching the first or second bank changeover switch S2 or S3, and the terminal T _A0
Output more.

For example, when the audio signal is rewritten (post-recorded) only in the audio B area later, the additional information is not recorded in this area. An instruction signal for outputting a signal is output to the input / output control device 6. In response to this instruction signal, the input / output control device 6 reads out an audio signal having additional information from the audio signal stored in the memory A and outputs it.

In the case of using the index area, for example, when the audio signal is rewritten by post-recording, the information in the index area may be rewritten.

As described above, in the present invention, additional information indicating that the same audio signal has been recorded together with the same error-corrected audio signal is recorded on channels other than the required channel, and these error correction data are reproduced at the time of reproduction. And, based on the additional information, only the most effective audio signal is selected. Therefore, even if the magnetic tape is damaged or deteriorated, the deterioration of the sound quality can be reduced.

Although two memories are used in the above-mentioned embodiment, only one memory is used and two memories are used for recording.
The present invention can be realized by reading the data once.
Further, in a VTR which records / reproduces only two channels for an audio signal, the following is done. In this case, since the audio signal processing device described above has only one system, two memories are connected to the audio signal processing device to process the audio signal. If the audio signal processing device has sufficient processing time, two memories are used to store audio signals for two channels, and normally only one of the memories is used. In this case, when the result of the error correction processing by the processing of such an audio signal processing device is bad, the error correction processing is performed on the audio signal stored in the other memory, and the error signal is reduced by using this audio signal. A high quality audio signal can be obtained.

Further, although the case where the magnetic tape has two audio areas has been described above, the present invention can be applied to the case where the magnetic tape has three or more audio areas.
For example, if you have three audio areas, "1 out of 3 areas"
It is necessary to set and select in advance such as “record in area → record common audio signal in three areas” or “record in two areas out of three areas → record the same audio signal in only one area”. Even in the case of having an audio area, it can be easily realized by the present invention. In this case, for example,
It has three recording areas A, B and C, of which A and B
When recording only in two areas of,
The recording area A is given priority, and the same audio signal as that of the recording area A is always recorded. The recording area A or B is selected and the same audio signal as either area is recorded. By doing so, it is possible to select the audio signal with the fewest errors, as in the above-described embodiment. Further, the present invention is not limited to the above-described embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0028]

As described above, according to the present invention, when an audio signal is recorded by performing an error correction process, not only the audio signal is recorded on a predetermined channel among a plurality of channels but also another channel is recorded. The same audio signal is recorded on each channel, and additional information indicating that the same audio signal is recorded on each channel is also recorded at the same time. At the time of reproduction, the error correction data and the audio signal with the fewest errors based on this additional information are recorded. Since the selection is made, there is an advantage that a high quality audio signal can be reproduced and the deterioration of the sound quality due to the damage of the magnetic tape can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a video tape recorder of the present invention.

FIG. 2 is a schematic diagram showing a recording format of a magnetic tape in the embodiment of FIG.

FIG. 3 is a schematic diagram showing a recording area of one track in the recording format of the magnetic tape of FIG.

[Explanation of symbols]

 6 Input / output control device A, B memory 7, 8 First and second audio signal processing device 11 Audio control device 12 Recording mode setting unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 5/93 G 4227-5C

Claims (1)

[Claims] 1. A multi-channel P together with a video signal.
In a video tape recorder which records and reproduces a CM audio signal, a recording mode setting means for setting a recording mode, a storage means having a storage area corresponding to the number of channels, and an error correction at the time of recording for the PCM audio signal. Signal processing means for processing and adding information corresponding to the same recording of the PCM signal, and detecting error correction data and additional information at the time of reproduction, and output from the signal processing means at the time of reproduction of the PCM audio signal Control means for outputting an instruction signal for selecting the PCM audio signal with the least error based on the error correction data and the additional information, and control of input / output switching of the PCM audio signal by the instruction of the control means. Input / output control means for Recorder.