JP3495759B2 - Playback device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus for reproducing sounds of a plurality of channels.

[0002]

As is well known, an analog voice signal is converted into a digital signal and recorded on a magnetic tape.
As a magnetic recording / reproducing apparatus for reproducing this, DAT, digital VTR, etc. are known. These magnetic recording / reproducing devices are capable of recording / reproducing 2 to 4 channels of audio signals.

Further, there is provided a so-called special reproduction function of reproducing at a tape speed different from that at the time of recording. And with regard to audio, for example, interpolation is performed using digital data obtained during fast-forward playback,
Alternatively, there is also known a magnetic recording / reproducing apparatus which makes it possible to hear a certain amount of recorded contents by performing a partial mute or the like, although the recording quality is low.

[0004]

However, in the above-mentioned conventional magnetic recording / reproducing apparatus, the missing of the digital data of each channel at the time of the special reproduction is different, and therefore, the interpolation and the mute are independently repeated. become.

For example, in the case of 2-channel stereo, if the L (left) channel and the R (right) channel have different interpolations or partial mutes, the sound localization near the center moves swiftly from side to side. There was a problem that it became difficult to hear.

In view of the above problems, it is an object of the present invention to make it easier to hear a plurality of channels of sound reproduced during special reproduction.

[0007]

One of the playback devices of the present invention is a playback device capable of playing back audio of a plurality of channels, and the playback speed is S times the normal speed (1 <S ≦ 5). In this case, whether or not to mix and output the plurality of channels of sound is selected according to the type of the plurality of channels of sound.

One of the reproducing apparatuses of the present invention is a reproducing apparatus capable of reproducing the sound of the first and second channels, and the kind of the sound of the first and second channels is stereo, In addition, the playback speed is S times the normal speed (1
When <S ≦ 5), the sound of the first and second channels is mixed and output.

One of the reproducing apparatuses of the present invention is a reproducing apparatus capable of reproducing the sound of the first and second channels, and the kind of the sound of the first and second channels is bilingual. When the reproduction speed is S times (1 <S ≦ 5) the normal speed, the sound of the first channel is output without being mixed with the sound of the second channel.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the reproducing apparatus of the present invention will be described below with reference to the drawings. FIG. 1 shows the present invention as a digital VTR.
It is a block diagram which shows the example implemented by. It should be noted that blocks relating to recording are omitted in FIG.

FIG. 2 is a diagram showing an example of a track pattern of data recorded on the magnetic tape 1. As shown in FIG. 2, image data for one frame is divided into 10 tracks and recorded in the video area. In the audio area, audio data corresponding to one frame time is recorded.

In this example, audio data corresponding to one frame time of two-channel stereo audio (L channel, R channel) is recorded on the L channel and the R channel by dividing into 5 tracks.

Next, the case of reproducing the audio data thus recorded will be described. In FIG. 1, reference numeral 1 is a magnetic tape, 2 is a head, and this head 2 is actually composed of a plurality of + azimuth heads and −azimuth heads, and traces a track on the magnetic tape 1 to obtain an electric signal. Has an effect. Reference numeral 3 denotes an amplifier, which is provided to amplify the signal output from the head 2.

Next, a demodulation circuit 4 includes a circuit for extracting a clock from the amplified signal, a circuit for converting the signal into a binarized signal by a comparator, a sync pattern detection circuit, and the like. Of the digital data output from the demodulation circuit 4 configured in this way, the data obtained from the video area shown in FIG. 2 is sent to the error correction decoding circuit 5, and the data is output from the video data and the error correction code. Error is detected and corrected.

The video reproduction processing circuit 6 provided at the next stage of the error correction decoding circuit 5 performs compression and shuffling for restoring the compression and shuffling of the image data performed at the time of recording. After the above process is performed, D / A conversion is performed and the reproduced image is output from the image output terminal 7.

On the other hand, of the data output from the demodulation circuit 4, the data obtained from the voice region shown in FIG. 2 is sent to the error correction decoding circuit 8 and the data error is detected from the voice data and the error correction code. Then, the correction is made.

The data corrected by the error correction decoding circuit 8 is then sent to the audio reproduction processing circuit 9. In the audio reproduction processing circuit 9, a deshuffle for returning the shuffling performed at the time of recording and a reproduction processing such as separation of the L channel and the R channel are performed.

The L-channel data is sent to the first D / A converter 10 and the R-channel data is sent to the second D / A converter 11 by time-axis processing so that the output signal becomes continuous. And converted into analog signals. Then, these first and second D / A
The outputs of the converters 10 and 11 are given to the L channel audio output terminal 14 and the R channel audio output terminal 15 via the switch circuit 13, and these output terminals 1
Audio signals are output from 4 and 15.

In the magnetic recording / reproducing apparatus configured as described above, the adding circuit 12 is provided in this embodiment. The adder circuit 12 adds the outputs of the first D / A converter 10 and the second D / A converter 11, and outputs k
A mixed sound doubled (0 <k ≦ 1) is produced.

Further, the magnetic recording / reproducing apparatus of this embodiment is provided with a system controller circuit 17 for controlling a capstan or a reel (not shown) in accordance with an instruction from the operation button 16 and for rewinding and fast-forwarding. It is configured to perform control such as.

When the operator gives an instruction for fast-forward reproduction with the operation button 16, the system controller circuit 17 gives an instruction to switch the switch circuit 13, and the mixed voice output from the adder circuit 12 is output to the voice output terminals 14 and 15. Output.

Generally, when the special reproduction is in the reverse direction or the tape speed becomes high, it becomes difficult to understand the content of the reproduced sound. Therefore, it is practical to mute the sound at a tape speed outside the predetermined range. is there. Table 1 shows the relationship between the tape speed S and the audio output due to the switching of the switch circuit 13.

[0023]

[Table 1]

Further, FIG. 3 shows a state in which the head scans a track on the magnetic tape 1 when fast-forward reproduction is performed at a speed of about 3 times, and the image area is omitted here.

In FIG. 3, L + and R + indicate tracks in which the L channel data and the R channel data are respectively recorded in + azimuth. In addition, L-, R-
Indicates the tracks recorded with −azimuth, and the data in the shaded area can be obtained by the azimuth effect.

As is apparent from FIG. 3, when scanning is performed about three times, data of scattered tracks are obtained, and more errors occur when the head deviates from the tracks.

In the voice reproduction processing circuit 9, data interpolation is performed from a portion where error-free data is obtained by average value interpolation or the like, and if data loss is long, pre-value hold interpolation processing is performed. Also, since the tape speed is about 3 times faster, the time axis can be shortened to about 1/3 compared to normal playback,
Alternatively, omitting about 2/3, the D / A converter 10, 1
The process of outputting to 1 is performed.

FIG. 4 shows audio waveforms output from the first and second D / A converters 10 and 11 during fast-forward reproduction, and there are some portions where the previous value is held. Figure 4
In, the mix is the output waveform of the adder circuit 12,
For example, when the speed is about 3 times, this signal is output to the audio output terminals 14 and 15.

By thus mixing and outputting the L channel and R channel sounds, the sound is localized at the center when the left and right speakers are monitored, and the localization does not change rapidly. Therefore, it becomes easy to hear.

By the way, in the voice of the digital VTR, not only stereo but also bilingual (bilingual) may be recorded. In general, information indicating stereo or bilingual is recorded in the audio area as additional audio information.

In FIG. 1, the additional information detection circuit 18 detects whether the recorded voice is stereo or bilingual. Then, the result is sent to the system controller 17 to control the audio output as shown in Table 2 below.

[0032]

[Table 2]

By carrying out such control, bilingual sound is not mixed at the time of fast-forward reproduction, and it is possible to prevent the inconvenience caused by mixing the sound of L channel and R channel.

In the above embodiment, an example in which the number of audio channels is two has been described, but there are three channels consisting of a left channel, a right channel, a center channel and a rear channel.
The present invention is effective even in the case of four channels of the -1 system.

In addition, in the above-described embodiment, the adder circuit 12
The switch circuit 13 and the switch circuit 13 are provided after the D / A converters 10 and 11 to switch to the mix by the analog signal. However, if they are provided before the D / A converters 10 and 11 and performed digitally, the same effect can be obtained. It goes without saying that you can get it.

[0036]

According to the inventions described in claims 1 to 3, even when the reproduction speed is S times (1 <S ≦ 5) of the normal speed, a voice that is easy to hear is output. be able to. Further, according to the inventions of claims 4 to 6, the type of audio of the first and second channels is stereo, and the reproduction speed is S times as high as the normal speed (1 <S
Even if ≦ 5), it is possible to output a voice that is easy to hear. Further, according to the inventions of claims 7 to 9, the types of the sounds of the first and second channels are bilingual, and the reproduction speed is S times the normal speed (1 <S ≦ 5. ), A voice that is easy to hear can be output. It is characterized by outputting.

[0037]

[Brief description of drawings]

FIG. 1 is a block diagram of a reproducing system of a digital VTR showing an embodiment of a reproducing apparatus of the present invention.

FIG. 2 is a diagram illustrating a track pattern on a magnetic tape.

FIG. 3 is a diagram for explaining a track pattern of a voice region and a locus of a head.

FIG. 4 is a waveform diagram showing a D / A output and a mixed audio output during fast-forward reproduction.

[Explanation of symbols]

1 magnetic tape 2 heads 3 amplifier 4 Demodulation circuit 5 Error correction decoding circuit 6 Video reproduction processing circuit 7 Video output terminal 8 Error correction decoding circuit 9 Audio reproduction processing circuit 10 First D / A converter 11 Second D / A converter 12 adder circuit 13 switch circuit 14 Audio output terminal 15 Audio output terminal 16 operation buttons 17 System controller 18 Additional information detection circuit

Claims (9)

(57) [Claims] 1. A playback device capable of playing back multiple channels of audio, and when the playback speed is S times (1 <S ≦ 5) the normal speed, the multiple channels of audio are mixed and output. A reproducing apparatus, characterized in that whether to perform or not is selected according to the types of audio of the plurality of channels. 2. The reproduction speed is S times the normal speed (1 <S ≦
The playback device according to claim 1, wherein when the speed is faster than 5), the audios of the plurality of channels are muted. 3. When the reproduction speed is slower than the normal speed,
The reproduction device according to claim 1, wherein the audio of the plurality of channels is muted. 4. A playback device capable of playing back audio of first and second channels, wherein the type of audio of the first and second channels is stereo, and the playback speed is normal speed. S times (1 <S
When ≦ 5), the playback device is characterized in that the sounds of the first and second channels are mixed and output. 5. The reproduction speed is S times the normal speed (1 <S ≦
The playback device according to claim 4, wherein when the speed is faster than 5), the audios of the first and second channels are muted. 6. When the reproduction speed is slower than the normal speed,
The reproduction apparatus according to claim 4, wherein the audio of the plurality of channels is muted. 7. A reproducing apparatus capable of reproducing sound of first and second channels, wherein the kind of sound of the first and second channels is bilingual, and the reproducing speed is a normal speed. S times (1
When <S ≦ 5), the reproducing apparatus is characterized in that the sound of the first channel is output without being mixed with the sound of the second channel. 8. The reproduction speed is S times the normal speed (1 <S ≦
The playback device according to claim 7, wherein when the speed is faster than 5), the audios of the first and second channels are muted. 9. When the reproduction speed is slower than the normal speed,
9. The reproducing apparatus according to claim 7, wherein the sounds of the plurality of channels are muted.