JPH0750804A - Signal recorder and signal recording method - Google Patents

Abstract

PURPOSE:To synchronize a video signal and a sound signal even in the case of additional recording by controlling a time to start coding the video signal and the sound signal based on a time error obtained by subtracting A sound time stamp from a video signal time stamp in the recording unit for additional recording start. CONSTITUTION:A memory 12 reads and stores a time error Te (n) received via a switch 11 and adds the time error Te (n) and a storage unit time length Tt. Then a divider 14 divides an output of an adder 13 by a processing unit time length Tp. Then an integral number processing unit 15 processes an output of the divider into an integral number through rounding or the like. The processing unit time length Tp is multiplied with the output of the integral number processing unit 15 to obtain an actual recording time length Tr (n). Then a subtractor 17 subtracts the output Tr (n) of the multiplier 16 from an output of the adder 13 to provide the result to the memory 12 and a subtractor 18 as an output. The subtractor 18 subtracts a time error of the output of the subtractor 17 from a video signal time stamp TSV (n+1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal and an audio signal when a plurality of signals such as a video signal and an audio signal are coded and then composited and recorded on a medium or transmitted to a communication path and decoded. The present invention relates to a signal recording device and a signal recording method for synchronizing signals.

[0002]

2. Description of the Related Art Conventionally, a signal recording device using a time stamp as time information has been used.

The above-mentioned conventional signal recording apparatus will be described below with reference to the drawings. FIG. 9 shows a block diagram of a conventional signal recording device. In FIG. 9, 9
1 is a video signal encoder, 92 is an audio signal encoder, 93
Is a time stamp calculator, 94 is a video signal encoder 91
, A multiplexer for combining the outputs of the audio signal encoder 92 and the time stamp calculator 94, 95 a demultiplexer for re-dividing the signal combined by the multiplexer 94, 96 a time stamp comparator, 97 a video signal decoder , 98 are audio signal decoders.

The operation of the signal recording apparatus constructed as above will be described below.

First, the video signal encoder 91 encodes the video signal into a digital signal, and the audio signal encoder 92.
At, the voice signal is encoded into a digital signal. next,
In the time stamp calculator 93, in a predetermined recording unit n, the time TSv (n) at which the video signal encoder 91 starts encoding the video signal and the audio signal encoder 92 encodes the audio signal. The start time TSa (n) is calculated and output. The multiplexer 94 combines the outputs of the video signal encoder 91, the audio signal encoder 92, and the time stamp calculator 94, and records them on a medium or transmits them on a communication path.

The demultiplexer 95 receives a signal from the medium or the transmission line, subdivides it, outputs the encoded video signal to the video signal decoder 97, and decodes the encoded audio signal into an audio signal. The time stamp TSv (n) of the video signal and the time stamp TSa (n) of the audio signal, which are output to the digitizer 98, are added to the time stamp comparator 96.
Is output to. Then, the time stamp comparator 96 compares the time stamp TSv (n) of the video signal with the time stamp TSa (n) of the audio signal, and the video signal decoder 9
7 and the audio signal decoder 98 control the timing to start decoding. The video signal decoder 97 and the audio signal decoder 98 start decoding based on the decoding start signal from the time stamp comparator 96.

FIG. 10 shows a time correspondence relationship diagram of a conventional signal recording apparatus. In FIG. 10, a is a video coded input, b is a voice coded input, c is a multiplex stream, d is a video decoding output, and e is a voice decoding output.

The video frame frequency of the NTSC video signal is 30 × 1000/1001 Hz, while the sampling frequency of the audio signal is 48.0 kHz or 44.1 kHz.
Since Hz and the like are used, it is difficult to synchronize the video signal and the audio signal. Further, in order to reduce the correlation between the video frames and increase the compression rate in the video signal, encoding is performed in GOP (group of picture) units in which several frames (for example, 6 frames or 12 frames) are combined, and in the audio signal, the sample is sampled. In order to reduce the correlation between them and increase the compression rate, encoding is performed in units of hundreds of samples (for example, 384 samples) (this is called an audio frame), so it is more difficult to synchronize the video signal and audio signal. .

In FIG. 10, a video signal for each GOP unit (this is called a video segment) is associated with an audio segment consisting of an integer number of audio frames.

First, the video segment 1 of the video encoding input a is encoded with the recording unit n = 1. Next, the audio segment 1 which is the audio encoded input b whose start time is shifted from the video segment 1 by Te (1) is encoded. Then, the coded video segment 1 and the time stamp TSv (1) of the video segment 1 and the coded audio segment 1 and the time stamp TSa of the audio segment 1 are encoded.
(1) is combined and output as a multiplex stream. By repeating this processing while updating the recording unit n, the multiplex stream c is completed.

Next, the time stamp TSv (1) of the video segment 1 and the time stamp TSa (1) of the audio segment 1 are subdivided from the multiplex stream c, and the time error Te (1) is

[0012]

[Equation 7]

In the above, the recording unit n = 1 is obtained. Then, the video segment 1 re-divided from the multiplex stream c is decoded, and the audio segment 1 re-divided from the multiplex stream c is decoded at the time shifted by Te (1). By repeating this process while updating the recording unit n, a video decoding output and an audio decoding output can be obtained. The time relationship between the video signal and the audio signal is the same during encoding and during decoding.

When additional recording is performed in FIG. 10, a new video segment and audio segment are added after the video segment 3 and audio segment 3.

FIG. 11 is a time correspondence diagram when overwriting is performed in the conventional signal recording apparatus. Figure 11
, A is a video coded input, b is a voice coded input,
c is a multiplex stream, d is a multiplex stream in which audio segment 1'and audio segment 2'are overwritten, e is a video decoding output, and f is an audio decoding output. In FIG. 11, the audio segment 1 ′ and the audio segment 2 ′ are overwritten on the audio segment 1 and the audio segment 2 of the multiplex stream c to form the multiplex stream d.

FIG. 12 shows the time error of the audio signal with respect to the video signal of the conventional signal recording apparatus. Also, FIG.
3 shows the time error of the audio signal with respect to the video signal when the conventional signal recording device is overwritten. In contrast to FIG. 12, in FIG. 13, 0 GOP, 1 GOP, 2 GO
8 GOP, 9 GOP, 10 audio segments at position P
This is an example of overwriting at the GOP position.

[0017]

However, the above-mentioned structure has a problem that the video signal and the audio signal cannot be synchronized at the time of decoding when additional recording or overwriting is performed.

That is, as in the case of the video segment 3 of the video encoding input a and the audio segment 3 of the audio encoding input b in FIG. 10, there is a time error at the end point of the segment before additional recording, and therefore additional recording is performed. The start times at the time of decoding the video segment and the audio segment are not the same, and the timing is shifted.

In the case of overwriting, as shown in FIG. 11, since the audio segment 1'and the audio segment 2'are overwritten, the video segment 3 and the audio segment 3 are overwritten.
The time error of (1) is different from the timing before the video coding input a and the audio coding input b are overwritten, after the video coding output e and the audio coding output f are overwritten. This can be easily understood from FIGS. 12 and 13.

In view of the above problems, the present invention provides a signal recording apparatus and a signal recording method capable of synchronizing a video signal and an audio signal even if additional recording or overwriting is performed.

[0021]

To achieve this object, a signal recording apparatus of the present invention stores a time error Te (n) between a reference time at the start point of a recording unit n and an actual recording time. Means, adding means for adding the recording unit time length Tt to the time error Te (n) output from the storage means, dividing means for dividing the output of the adding means by the processing unit time length Tp, and the dividing means. Processing unit time length Tp in the output of the integerizing means
And the actual recording time length Tr in the recording unit n
The output unit Tr (n) of the multiplication unit is subtracted from the output of the multiplication unit and the output unit of the addition unit to obtain the next recording unit (n).
The subtraction means outputs the time error Te (n + 1) at the start point of (+1) to the storage means.

[0022]

With this structure, the adding unit adds the recording unit time length Tt to the contents of the storing unit, the dividing unit divides the output of the adding unit by the processing unit time length Tp, and the integerizing unit outputs the dividing unit. Is an integer. Further, the multiplication unit multiplies the output of the integer unit by the processing unit time length Tp,
The actual recording time length Tr (n) in the recording unit n is obtained, and the subtraction means outputs from the addition means to the output of the multiplication means T.
r (n) is subtracted to obtain the time error Te (n + 1) at the start point of the next recording unit (n + 1). Therefore,
When the additional recording is performed, the video signal and the audio signal can be synchronized with each other by controlling the time for starting the encoding of the video signal and the audio signal based on the time error Te (n + 1). Becomes

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the signal recording apparatus of the first invention. In FIG. 1, 11 is a switch, 12 is a memory, 13 is an adder, 14 is a divider, 15 is an integerizer, 16 is a multiplier, 1
Reference numeral 7 is a first subtractor, 18 is a second subtractor, and 19 is a third subtractor.

The operation of the signal recording apparatus configured as described above will be described below.

First, the third subtractor 19 subtracts the audio signal time stamp TSa (n) in the recording unit n from the video signal time stamp TSv (n) in the recording unit n to obtain the start point of the recording unit n. The time error Te (n) of the audio signal with respect to the video signal is obtained. Initially, the switch 11 is connected to the terminal B side, and the third subtractor 19
The time error Te (n) of the audio signal with respect to the video signal at the start point of the recording unit n, which is the output of 1. However, at the time of initial recording, the video signal time stamp TSv (0)
= 0 and the audio signal time stamp TSa (0) = 0, the time error Te (0) = 0. After this initial state, the switch 11 is connected to the terminal A side.

Next, the memory 12 reads and stores the time error Te (n) input via the switch 11. Then, the adder 13 adds the time error Te (n) stored in the memory 12 and the recording unit time length Tt. The recording unit time length Tt is, for example, a time length of 1 GOP unit when the audio signal is synchronized with the video signal. The divider 14 divides the output of the adder 13 by the processing unit time length Tp. The processing unit time length Tp is, for example, a voice frame length of a voice signal. And the integerizer 15
Outputs the output of the divider 14 to an integer value by rounding, rounding down, or rounding up. Multiplier 1
Reference numeral 6 multiplies the output of the integerizer 15 by the processing unit time length Tp to obtain the actual recording time length Tr (n). And the first
The subtractor 17 of the memory 12 subtracts the output Tr (n) of the multiplier 16 from the output of the adder 13 to obtain the time error Te (n + 1) at the start point of the next recording unit (n + 1) as the memory 12.
And to the second subtractor 18. Next, the second subtractor 18 outputs the video signal time stamp TS.
The time error Te (n + 1), which is the output of the first subtractor 17, is subtracted from v (n + 1) to obtain and output the audio signal time stamp TSa (n + 1).

As described above, according to the present embodiment, when additional recording is performed, the third subtractor 19 causes the video signal time stamp TSv in the recording unit (n + 1) at which additional recording is started.
(N + 1) to audio signal time stamp TSa (n +
Even when additional recording is performed, the video signal and the audio signal are synchronized by controlling the time when the encoding of the video signal and the audio signal is started based on the time error Te (n + 1) obtained by subtracting 1). Can be made.

In this embodiment, the case where the audio signal is synchronized with the video signal has been described, but the case where the video signal is synchronized with the audio signal can be similarly performed.

An embodiment of the signal recording method of the present invention will be described below with reference to the drawings.

FIG. 2 is a flow chart showing an embodiment of the signal recording method of the first invention. The operation of this signal recording method will be described below.

First, in step 201, it is determined whether the recording is initial recording or additional recording. If it is initial recording, the process proceeds to step 202, and if it is additional recording, the process proceeds to step 218. Next, when it is determined that the initial recording is performed in step 201, the recording unit n is set to the initial value 0 in step 202,
In step 203, the video signal time stamp TSv (0) in the recording unit 0 is set to the initial value 0, and in step 20
4, audio signal time stamp TSa in recording unit 0
(0) is set to the initial value 0. In step 205, the video signal time stamp TSv (0) is output, and step 2
The audio signal time stamp TSa (0) is output at 06,
In step 207, the time error Te in recording unit 0
(0) is set to the initial value 0.

On the other hand, if it is determined in step 201 that additional recording is to be performed, in step 218 the recording unit n for starting additional recording is set, in step 219 the video signal time stamp TSv (n) is read, and in step 220 the audio signal time is set. The stamp TSa (n) is read. Step 22
In step 1, the calculation of (Equation 7) is performed to obtain the time error Te (n) at the start point of the recording unit n, and in step 222, the coding start time of the audio signal is calculated as ((coding start time of video signal)- Te (n)).

Then, in step 208, the calculation of (Equation 8) is performed to obtain the actual recording time length Tr (n) of the audio signal. In this equation, the reference time is the video signal time stamp TSv (n).

[0035]

[Equation 8]

Next, in step 209, the video signal is encoded and output for the recording unit time length Tt, and in step 210, the audio signal is encoded for the actual recording time length Tr (n) obtained by (Equation 8). Output. And step 2
In (11), the calculation of (Equation 9) is performed, and the time error Te of the audio signal with respect to the video signal at the start point of the recording unit (n + 1) is Te.
Find (n + 1).

[0037]

[Equation 9]

Then, in step 212, the calculation of (Equation 10) is performed to obtain the video signal time stamp TSv (n + 1) at the start point of the recording unit (n + 1).

[0039]

[Equation 10]

Next, in step 213, the calculation of (Equation 11) is performed to obtain the audio signal time stamp TSa (n + 1) at the start point of the recording unit (n + 1).

[0041]

[Equation 11]

Then, in step 214, the video signal time stamp TSv (n + 1) is output, and in step 215, the audio signal time stamp TSa (n + 1) is output.
Next, in step 216, the recording unit n is updated. In step 217, it is determined whether or not the process is finished. If it is not finished, the process returns to step 208, and if finished, the process is finished.

As described above, according to the present embodiment, when additional recording is performed, the coding start time of the audio signal is set in step 222 based on the time error Te (n) obtained by the equation (7) in step 221. By controlling, the video signal and the audio signal can be synchronized even when the additional recording is performed.

Although the case where the audio signal is synchronized with the video signal has been described in the present embodiment, the case where the video signal is synchronized with the audio signal can be similarly performed.

An embodiment of the signal recording apparatus of the second invention will be described below with reference to the drawings.

FIG. 3 is a block diagram showing an embodiment of the signal recording apparatus of the second invention. In FIG. 3, 31 is an adder, 32 is a divider, 33 is an integerizer, 3
4 is a multiplier, 35 is a first subtractor, 36 is a second subtractor, and 37 is a zero section code output device.

The operation of the signal recording apparatus configured as described above will be described below.

When the overwriting ends in the recording unit n,
First, the adder 31 adds the time error Te (n) of the audio signal to the video signal at the start point of the recording unit n and the recording unit time length Tt. This recording unit time length Tt is, for example, 1 GO when synchronizing an audio signal with a video signal.
The time length is P units. Next, the divider 32 is the adder 31
Is divided by the processing unit time length Tp. The processing unit time length Tp is, for example, a voice frame length of a voice signal. The integerizer 33 converts the output of the divider 32 into an integer value by processing such as rounding, rounding down, and rounding up.

Next, the multiplier 34 multiplies the output of the integerizer 33 by the processing unit time length Tp to obtain the actual recording time length Tr.
(N) is calculated and output. The first subtractor 35 subtracts the output Tr (n) of the multiplier 34 from the output of the adder 31 and outputs it to the second subtractor 36. The second subtractor 36 subtracts the output of the first subtractor 35 from the time error Te (n + 1) at the start point of the unoverwritten recording unit (n + 1) to obtain the time length Tz of zero data. Ask. Then, the zero data code output device 37 outputs a zero data code based on the time length Tz of the zero data obtained by the second subtractor 36.

FIG. 4 is a time correspondence diagram when overwriting is performed in the signal recording apparatus of this embodiment. Figure 4
, A is a video coded input, b is a voice coded input,
c is a multiplex stream, d is a multiplex stream in which audio segment 1'and audio segment 2'are overwritten, e is a video decoding output, and f is an audio decoding output. In FIG. 4, a video segment, which is a video signal for each 1 GOP unit, is associated with an audio segment including an integer number of audio frames.

First, the video segment 1 of the video coding input a is coded. Next, with respect to the video segment 1, the audio segment 1 of the audio encoded input b whose start time is shifted by Te (1) is encoded. Then, the encoded video segment 1 and the time stamp TSv of the video segment 1 are encoded.
(1) and the encoded audio segment 1 and the time stamp TSa (1) of the audio segment 1 are combined and output as a multiplex stream. By repeating the above processing, the multiplex stream c is completed. Next, the audio segment 1 ′ and the audio segment 2 ′ are overwritten on the audio segment 1 and the audio segment 2 of the multiplex stream c to create a new multiplex stream d. However, a zero data code is inserted after the last audio segment 2'of overwriting so as not to break the synchronization relationship between the video signal and the audio signal thereafter. From multiplex stream d,
The time stamp TSv (1) of the video segment 1 and the time stamp TSa (1) of the audio segment 1 are subdivided, and the time error Te (1) is calculated by the processing unit n.
= 1.

Then, the video segment 1 subdivided from the multiplex stream d is decoded and Te (1)
The audio segment 1 subdivided from the multiplex stream d is decoded at the shifted time. By repeating this process, all video signals and audio signals are decoded. By overwriting the audio segment 1'and the audio segment 2 ', the time error between the video segment 2 and the audio segment 2'changes to Te (2)', but the time error after the overwriting is completed. (Te (3),
...) is the same before and after overwriting.

FIG. 5 shows the time error of the audio signal with respect to the video signal when the signal recording apparatus of this embodiment is overwritten. In contrast to FIG. 12, which is not overwritten, in FIG. 5, another audio segment with a sampling frequency of 44.1 kHz is overwritten on the positions of 8 GOP, 9 GOP, and 10 GOP of the original audio segment with a sampling frequency of 48 kHz. Is. As a result of overwriting, the time error Te (n) of 9 GOP and 10 GOP is different from that of FIG. 12, but the time error (Te (11), ...) After the overwriting is overwritten. There is no difference between before and after overwriting.

As described above, according to this embodiment, since the time error Te (n + 1) at the start point of the recording unit (n + 1) is stored, the video signal and the audio signal are synchronized even after the additional recording. be able to.

In this embodiment, the case where the audio signal is synchronized with the video signal has been described, but the case where the video signal is synchronized with the audio signal can be similarly performed.

An embodiment of the signal recording method of the second invention will be described below with reference to the drawings.

FIG. 6 is a flow chart showing an embodiment of the signal recording method of the second invention. The operation of this signal recording method will be described below.

In the case of overwriting, first step 60
A recording unit n for starting overwriting with 0 is set. next,
In step 601, the video time stamp TSv (n) is read, and in step 602 the audio time stamp TSa.
Read (n). Then, in step 603 (Equation 12)
Is calculated, and the time error T at the start point of the recording unit n is calculated.
e (n) is obtained, and in step 604, the encoding start time of the audio signal is calculated as ((encoding start time of video signal) −Te
(N)) is set.

[0059]

[Equation 12]

Next, in step 605, the calculation of (Equation 13) is performed to obtain the actual recording time length Tr (n) of the audio signal. In this equation, the reference time is the video signal time stamp TSv (n) in the recording unit n.

[0061]

[Equation 13]

Then, in step 606, the video signal is encoded for the recording unit time length Tt and output, and in step 607.
Actual recording time length Tr obtained by calculating the audio signal in (Equation 13)
Only (n) is encoded and output.

Next, in step 608, it is judged whether or not the overwriting is completed. If it is not completed, step 609 is executed.
Go to step 615, and if finished, go to step 615. If the overwriting is not completed, the calculation of (Equation 14) is performed in step 609, and the time error Te (n) of the audio signal with respect to the video signal at the start point of the recording unit (n + 1) is calculated.
+1).

[0064]

[Equation 14]

Then, in step 610, the calculation of (Equation 15) is performed to obtain the video signal time stamp TSv (n + 1) at the start point of the recording unit (n + 1).

[0066]

[Equation 15]

Next, in step 611, the operation of (Equation 16) is performed to obtain the audio signal time stamp TSa (n + 1) at the start point of the recording unit (n + 1).

[0068]

[Equation 16]

In step 612, the video signal time stamp TSv (n + 1) is output, and in step 613, the audio signal time stamp TSa (n + 1) is output. Next, in step 614, the recording unit n is updated, and the process returns to step 605.

On the other hand, if it is determined in step 608 that the overwriting is completed, it is determined in step 615 whether the recording unit (n + 1) has been recorded. If it has not been recorded, the process proceeds to step 621. And if it has been recorded,
In step 616, the video time stamp TSv (n + 1)
Is read, and the voice time stamp TS is read in step 617.
Read a (n + 1). Next, in step 618, the calculation of (Equation 17) is performed to obtain the time error Te (n + 1) at the start point of the recording unit (n + 1).

[0071]

[Equation 17]

Then, in step 619, the calculation of (Equation 18) is performed to obtain the time length Tz of the zero data.

[0073]

[Equation 18]

Next, in step 620, a zero data code having a time length Tz is output. On the other hand, if it is determined in step 615 that the recording unit (n + 1) has not been recorded,
In step 621, the calculation of (Equation 14) is performed to obtain the time error Te (n) of the audio signal with respect to the video signal at the start point of the recording unit (n + 1).

Then, in step 622, the calculation of (Equation 15) is performed to obtain the video signal time stamp TSv (n + 1) at the start point of the recording unit (n + 1).

Next, in step 623, the calculation of (Equation 19) is performed to obtain the audio signal time stamp TSa (n + 1) at the start point of the recording unit (n + 1).

[0077]

[Formula 19]

Then, in step 624, the video signal time stamp TSv (n + 1) is output, and in step 625, the audio signal time stamp TSa (n + 1) is output and the process ends.

As described above, according to the present embodiment, when the overwriting is completed in the recording unit n, the video time stamp TSv (n + 1) is read in step 616, and step 61 is executed.
At 7, read the audio time stamp TSa (n + 1),
In step 618, the calculation of (Equation 17) is performed to obtain the time error Te (n + 1) of the audio signal with respect to the video signal at the start point of the recording unit (n + 1), and in step 619, the calculation of (Equation 18) is performed and zero. By obtaining the time length Tz of the data and outputting the zero data code of the time length Tz in step 620, the time error Te (n + 1) at the start point of the recording unit (n + 1) is saved, so that overwriting was performed. Even after that, the video signal and the audio signal can be synchronized.

Although the case where the audio signal is synchronized with the video signal has been described in the present embodiment, the case where the video signal is synchronized with the audio signal can be similarly performed.

An embodiment of the signal recording apparatus of the third invention will be described below with reference to the drawings.

FIG. 7 is a block diagram showing an embodiment of the signal recording apparatus of the third invention. In FIG. 7, 71 is a first adder, 72 is a second adder, and 73.
Is a subtractor.

The operation of the signal recording apparatus having the above structure will be described below.

First, the adder 71 encodes the video signal time stamp TSv (n) at the start point of the recording unit n and the time length Tv (n) for encoding the video signal in the recording unit n.
And are added to output the video signal time stamp TSv (n + 1) at the start point of the recording unit (n + 1). Next, the adder 72 encodes the audio signal for the time length Tv (n) for encoding the video signal in the recording unit n and the time TSv (n) for starting the encoding of the video signal in the recording unit n. The time error Te (n) of the start time is added. Then, the subtractor 73 subtracts the time length Ta (n) for encoding the audio signal from the output of the adder 72,
The time error Te (n + 1) of the time at which the encoding of the audio signal is started with respect to the time at which the encoding of the video signal in the recording unit (n + 1) is started is output.

According to the structure of this embodiment, when a plurality of types of signals are recorded, at least one time information of the video signal time stamp TSv (n) is recorded.
Is recorded and other signals are video signal time stamps T
Since the time error Te (n) with Sv (n) is recorded,
It is not necessary to record the time stamps of all signals, and the recording efficiency is improved. Also, when synchronizing a plurality of types of signals during decoding, the video signal time stamp TS
With v (n + 1) as the reference time, the time error Te (n +
It suffices to start the decoding based on 1), and the time error Te (n +
Since it is not necessary to calculate 1), the amount of processing can be reduced.

In the present embodiment, the video signal time stamp TSv (n +) at the start point of the recording unit (n + 1).
The case of recording the time error Te (n + 1) of the time to start the encoding of the audio signal in the recording unit (n + 1) for 1) has been described, but the audio signal time stamp TSa (n + 1) at the starting point of the recording unit (n + 1) is described. The same can be applied to the case of recording the time error Te (n + 1) of the time to start the encoding of the video signal in the recording unit (n + 1) for (1).

An embodiment of the signal recording method of the third invention will be described below with reference to the drawings.

FIG. 8 is a flow chart showing an embodiment of the signal recording method of the third invention. The operation of this signal recording method will be described below.

First, in step 801, a recording unit n is set. Next, in step 802, the video time stamp TS
v (n) is read, and in step 803, a time error Te (n) between the time when the encoding of the video signal in the recording unit n is started and the time when the encoding of the audio signal in the recording unit n is started is obtained. Then, in step 804, the video signal is encoded and output for the time length Tv (n), and in step 805, the audio signal is encoded and output for the time length Ta (n). In step 806, the operation of (Equation 20) is performed to obtain the video signal time stamp TSv (n + 1) at the start point of the recording unit (n + 1).

[0090]

[Equation 20]

Next, in step 807, the calculation of (Equation 21) is performed, and the time error Te (n + 1) of the time at which the encoding of the audio signal is started with respect to the time at which the encoding of the video signal in the recording unit (n + 1) is started. Ask for.

[0092]

[Equation 21]

Then, in step 808, the video signal time stamp TSv (n + 1) is output, and in step 809, the time error Te (n + 1) is output. Next, step 8
The recording unit n is updated at 10. In step 811, it is determined whether or not the process is finished. If not, step 80
Return to 2 and end if finished.

As described above, according to the present embodiment, the calculation of (Equation 20) is performed in step 806 to obtain the recording unit (n + 1).
Signal time stamp TSv (n +
1) is calculated, and the calculation of (21) is performed in step 807 to calculate the time error Te (n + 1) of the time to start encoding the audio signal with respect to the time to start encoding the video signal in the recording unit (n + 1). When a plurality of types of signals are recorded by the determination, the video signal time stamp TSv (n) which is at least one of the time information is recorded, and the other signals are recorded as the video signal time stamp TS.
Since the time error Te (n) with respect to v (n) is recorded, it is not necessary to record the time stamps of all signals,
Recording efficiency is high. Also, when synchronizing a plurality of types of signals during decoding, the video signal time stamp TSv
Decoding may be started based on the time error Te (n + 1) with respect to (n + 1), and it is not necessary to calculate the time error for synchronizing from each time stamp, so that the processing amount can be reduced.

In this embodiment, the video signal time stamp TSv (n +) at the start point of the recording unit (n + 1).
1), and a time error Te (n +) of the time to start encoding the audio signal in the recording unit (n + 1) with respect to the time to start encoding the video signal in the recording unit n + 1.
1) is recorded, the audio signal time stamp TSa (n +) at the start point of the recording unit (n + 1) is described.
1) and the time error Te (n) of the time to start encoding the video signal in the recording unit (n + 1) with respect to the time to start encoding the audio signal in the recording unit (n + 1).
The same can be applied to the case of recording +1).

[0096]

As described above, according to the signal recording apparatus of the first invention, when the additional recording is performed, the third subtracter causes the video signal time stamp TSv in the recording unit (n + 1) to start the additional recording. Time error Te (n) obtained by subtracting the audio signal time stamp TSa (n + 1) from (n + 1)
By controlling the time for starting the encoding of the video signal and the audio signal based on +1), the video signal and the audio signal can be synchronized even when additional recording is performed.

In addition, in the signal recording method of the first aspect of the invention, when additional recording is performed, the coding start time of the audio signal is calculated in step 222 based on the time error Te (n) obtained by (equation 7) in step 221. By controlling, the video signal and the audio signal can be synchronized even when additional recording is performed.

According to the signal recording apparatus of the second invention, the time error Te at the start point of the recording unit (n + 1)
Since (n + 1) is stored, the video signal and the audio signal can be synchronized even after the additional recording.

Further, according to the signal recording method of the second invention, when the overwriting is completed in the recording unit n, step 61
At 6, the video time stamp TSv (n + 1) is read,
In step 617, the voice time stamp TSa (n + 1)
Is read, the time error Te (n + 1) of the audio signal with respect to the video signal at the start point of the recording unit (n + 1) is calculated in step 618, and the operation of (expression 18) is performed in step 619. By doing so, the time length Tz of the zero data is obtained, and the zero data code of the time length Tz is output in step 620, so that the time error Te (n + 1) at the start point of the recording unit (n + 1) is saved.
Even after overwriting, the video signal and the audio signal can be synchronized.

Furthermore, according to the signal recording apparatus of the third invention, when recording a plurality of types of signals, a video signal time stamp T which is at least one of the time information therein.
Since Sv (n) is recorded and the other signals are recorded with the time error Te (n) from the video signal time stamp TSv (n), it is not necessary to record the time stamps of all signals, and the recording efficiency is improved. Get higher Further, when synchronizing a plurality of types of signals at the time of decoding, the time error Te is set with the video signal time stamp TSv (n + 1) as the reference time.
It is sufficient to start decoding based on (n + 1), and the time error Te for synchronizing from each time stamp
Since it is not necessary to calculate (n + 1), the processing amount can be reduced.

Further, according to the signal recording method of the third aspect of the present invention, the arithmetic operation of (Equation 20) is performed in step 806 to obtain the video signal time stamp TSv (n + 1) at the start point of the recording unit (n + 1), and then step In step 807, the calculation of (21) is performed to obtain a time error Te (n + 1) between the time at which the encoding of the video signal in the recording unit (n + 1) is started and the time error Te (n + 1) at which the encoding of the audio signal is started. When recording the signal of, the video signal time stamp T, which is at least one time information in the signal, is recorded.
Since Sv (n) is recorded and the other signals are recorded with the time error Te (n) from the video signal time stamp TSv (n), it is not necessary to record the time stamps of all signals, and the recording efficiency is improved. Get higher Further, when synchronizing a plurality of types of signals at the time of decoding, a time error Te (n + 1) with respect to the video signal time stamp TSv (n + 1).
It is only necessary to start the decoding based on the above, and it is not necessary to calculate the time error for synchronizing from the respective time stamps, so the processing amount can be reduced.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a signal recording device in an embodiment of a signal recording device of the first invention.

FIG. 2 is a flowchart of a signal recording method in an embodiment of the signal recording method of the first invention.

FIG. 3 is a block configuration diagram of a signal recording device in an embodiment of the signal recording device of the second invention.

FIG. 4 is a time correspondence relationship diagram when overwriting is performed in the signal recording device of the second invention.

FIG. 5 is a diagram showing a time error of an audio signal with respect to a video signal when overwriting is performed by the signal recording device of the second invention.

FIG. 6 is a flowchart in an embodiment of the signal recording method of the second invention.

FIG. 7 is a block configuration diagram in an embodiment of a signal recording device of a third invention.

FIG. 8 is a flowchart in an embodiment of the signal recording method of the third invention.

FIG. 9 is a block diagram of a conventional signal recording device.

FIG. 10 is a time correspondence diagram of a conventional signal recording device.

FIG. 11 is a time correspondence relationship diagram when overwriting is performed in the conventional signal recording device.

FIG. 12 is a diagram showing a time error of an audio signal with respect to a video signal of a conventional signal recording device.

FIG. 13 is a diagram showing a time error of an audio signal with respect to a video signal when overwriting is performed in a conventional signal recording device.

[Explanation of symbols]

 11 Switch 12 Memory 13 Adder 14 Divider 15 Integerizer 16 Multiplier 17 First Subtractor 18 Second Subtractor 19 Third Subtractor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04L 5/00 H04N 7/24

Claims (6)

[Claims] 1. Storage means for storing a time error Te (n) between a reference time at a start point of a recording unit n and an actual recording time, and a time error Te (n) output from the storage means.
Of the recording unit time length Tt, a division means for dividing the output of the addition means by the processing unit time length Tp, an integerization means for converting the output of the division means into an integer, and an integerization means of the integerization means. Multiply means for obtaining the actual recording time length Tr (n) in the recording unit n by multiplying the output by the processing unit time length Tp, and subtracting the output Tr (n) of the multiplying means from the output of the adding means, the next recording A signal recording device comprising: a subtraction unit that outputs the time error Te (n + 1) at the starting point of the unit (n + 1) to the storage unit. 2. An actual recording time length Tr (n) in the recording unit n is defined as Te (n), where a time error between the reference time at the starting point of the recording unit n and the actual recording time is Te (n). Then, the time error Te (n + 1) at the start point of the recording unit (n + 1) is calculated as follows. A signal recording method characterized by being obtained by. 3. A time error Te (n) between the reference time and the actual recording time at the start point of the last recording unit n of overwriting.
Of the recording unit time length Tt, a division means for dividing the output of the addition means by the processing unit time length Tp, an integerization means for converting the output of the division means into an integer, and an integerization means of the integerization means. A multiplication unit that multiplies the output by the processing unit time length Tp, a first subtraction unit that subtracts the output of the multiplication unit from the output of the addition unit, and a recording unit (n
Second subtraction means for subtracting the output of the first subtraction means from the time error Te (n + 1) at the start point of (+1),
And a zero data code output means for outputting a zero data code having a length according to the output of the second subtraction means. 4. The actual recording time length Tr (n) in the last recording unit n to be overwritten is given by Time length Tz of zero data to be inserted after that
(≧ 0) is given by A signal recording method characterized by being obtained by. 5. When recording a plurality of types of signals, time information TSv (n) at the start point of a recording unit n of at least one of the signals, and recording of a signal for recording this time information TSv (n). Actual recording time length Tv in unit n
(N) is added to output the time information TSv (n + 1) at the start point of the recording unit (n + 1), and recording of the signal for recording the time information TSv (n) and other signals Time error Te of start time in unit n
(N) and the actual recording time length Tv (n) of the signal for recording the time information TSv (n), and the time information TSv from the output of the second adding means.
The actual recording time length Ta (n) in the recording unit n of the signal not recording (n) is subtracted, and the recording unit (n + 1) of the signal recording the time information TSv (n) and the other signals.
And a subtractor that outputs a time error Te (n + 1) of the start time in step S1. 6. When recording a plurality of types of signals, the time information TSv (n) at the start point of the recording unit n of at least one of the signals is recorded, and the other signals are the time information TSv (n). And a time error Te (n) is recorded, and a signal for recording the time information TSv (n) is recorded as a time length Tv (n).
Only, the signal for recording the time error Te (n) is encoded and recorded for the time length Ta (n), and the time information TSv (n + 1) in the recording unit (n + 1) is expressed by The time error Te (n + 1) in the recording unit (n + 1) is calculated by A signal recording method characterized in that the signal is obtained and recorded by the method.