JP3438972B2 - Speech speed conversion adapter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speech speed conversion adapter, and more particularly, to a speaker for receiving a first audio signal and a time code reproduced from, for example, a video tape recorder and outputting the second audio to a speaker. The present invention relates to a speech speed conversion adapter for giving a signal. 2. Description of the Related Art As a conventional VTR (Video Tape Recorder), there is a VTR equipped with a speech speed conversion function. this is,
For example, when a tape on which news is recorded is played back in a fast-forward manner, the audio signal can be played back without changing the pitch, which is convenient for the viewer. [0003] On the other hand, in a VTR not equipped with a speech speed conversion function, the voice pitch changes during high-speed reproduction, making it difficult for the viewer to hear the voice. SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a speech rate conversion adapter capable of adding a speech rate conversion function to a VTR without a speech rate conversion function. [0004] Speech speed conversion according to the present invention
The adapter is connected to the first video played from the video tape recorder.
Receiving the audio signals and the time code, a speech speed conversion adapter providing a second audio signal to the monitor, the detection by the detecting means, and detecting means for detecting a minimum period of the pulses thus defined the time code <br/> based on the minimum period which is by converting the time axis of the first audio signal comprising a converting means for generating a second audio signal, conversion means, Thailand normal reproduction
The minimum period of the pulse specified by the
Division means for dividing by the minimum period detected by the stage, and division
Time axis that converts the time axis according to the result of division by the arithmetic means
Including conversion means . For example, at the time of fast forward reproduction, a first audio signal and a time code reproduced from a video tape are supplied to a speech speed conversion adapter, and a second audio signal subjected to predetermined processing based on the time code is monitored. Is output to That is, in the speech rate conversion adapter, for example, the microcomputer
For example, the pulse period of data "1" included in the reproduced time code is detected, and the pulse period is divided by the pulse period of data "1" during normal reproduction. Further, the microcomputer converts the number of periodic waveforms included in, for example, a predetermined block of the first audio signal according to the division result, and generates a second audio signal. The generated second audio signal is then provided to a monitor. As a result, a sound whose sound pitch does not change is output from the monitor. According to the present invention, it is possible to output an audio signal whose audio pitch does not change from that in normal reproduction, and
A speech speed conversion function can be added to the TR. The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings. Referring to FIG. 1, a system 10 according to this embodiment is shown.
Are the VTR 12, the television 14, and the speech speed conversion adapter 1.
6 inclusive. The video signal reproduced from the VTR 12 is directly supplied to the monitor 14, and a desired image is output from the display 14a. The audio signal and the time code output from the VTR 12 are supplied to a speech speed conversion adapter 16, and an audio signal subjected to predetermined processing according to the time code is supplied to the monitor 14 from the speech speed conversion adapter 16. As a result, a sound whose sound pitch does not change is output from the speaker 14b of the monitor 14. The time code given to the speech speed conversion adapter 16 is SMPTE (Society of Motion Picture a
nd Television Engineering), and has a format as shown in FIG. That is, frame information is recorded in bit numbers “0” to “15”, hour, minute and second information is recorded in bit numbers “16” to “63”, and bit numbers “64” to “79” are recorded. Is recorded with the synchronization bit word.
Among them, the bit numbers “66” to “7” of the synchronization bit word
The data in "7" is always "1", from which the pulse period of the data of "1" is detected to extend the time axis of the input audio signal. The waveform and data of the time code recorded on the VTR 12 are represented as shown in FIG.
That is, among the data constituting the time code, data whose level does not change during the reference clock time of 416.7 microseconds is “0”, and data whose level changes in the middle of the reference clock time is “1”. Note that this time code is reproduced at the period shown in FIG. 3A during normal reproduction, but at the time of fast-forward reproduction, the period is shortened according to the speed. That is, the speed of fast-forward playback is two times the speed of normal playback.
If it is twice, the period is halved. FIG. 4 shows the configuration of the speech speed conversion adapter 16. The voice signal given to the speech speed conversion adapter 16 is A
After being converted into a digital signal by the / D converter 16a, it is given to the microcomputer 16b. The microcomputer 16b expands the digital signal for each predetermined block based on the time code. The expanded digital signal is stored in buffer memory 1
6c, and the stored digital signal is converted into an analog signal by the D / A converter 16d. This analog signal is applied to the monitor 14, and a sound is output from the speaker 14b at the same sound pitch as during normal reproduction. Referring to FIG. 5 and FIG.
The processing operation of b will be described. FIG. 5 is a flowchart for calculating the expansion ratio r _S of the audio signal based on the time code, and FIG. 6 is a flowchart for expanding the audio signal based on the calculated expansion ratio r _S. It is. First, in step S1 of FIG. 5, the edge counter 16e
Is initialized, and 417 is written to the RAM 16f as minimum data. Next, when the rising edge of the time code is input in step S3, the count value of the free-run counter 16g is written in the register 16h in step S5, and then the value of the register 16i is subtracted from the value of the register 16h in step S7. RAM is used as the edge interval between rising edges.
Write to 16f. Thereafter, in step S9, the value of the register 16h is written to the register 16i. Subsequently, in step S11, it is determined whether or not edge interval <minimum data. If "NO", the edge counter 16f is incremented in step S13 and the process proceeds to step S17.
If “YES” in 1, in step S15, the minimum data in the RAM 16f is rewritten with the edge interval as the minimum data, and the process proceeds to step S17. In step S17, it is determined whether or not the count value of the edge counter 16e is 80. If "NO", the process returns to the step S3. If "YES", the process returns to the step S3.
In 19, 416.8, which is the pulse period of the data "1" included in the time code during normal reproduction, is divided by the minimum data, that is, the pulse period of the data "1" included in the time code reproduced this time. The result of the division is written to the RAM 16f as the expansion rate r _S. Then, the process returns to step S1. The reason why it is determined in step S17 whether or not the count value is 80 is as follows. That is, the data of "1" shown in FIG.
Assuming that data of “0” is 0.5 pulse, if all data included in the time code is “1”, 80 pulses are 80 bits for one frame, but actually include “0”. Therefore, 80 bits or less are equivalent to 80 bits for one frame. Therefore, if 80 consecutive pulses are measured, there is always a synchronization bit word that includes "1", and the minimum data can be obtained from the cycle of "1". In the process shown in FIG. 5, since the free-run counter 16g and the register 16i are not reset and initialized at first, the minimum data may be incorrect in the first frame. Is correctly detected, so there is no problem. However, when it is desired to accurately detect the minimum data from the beginning, in step S1, the free-run counter 16g and the register 16i
May be reset and initialized. Next, with reference to FIG. 6, a process for expanding the audio signal will be described. First, step S21
Calculates the pitch period T of the input waveform at
Using the pitch period T, the waveform length L _S based on Equation 1
Is calculated. L _S = T / (r _S -1) Next, in step S23, it is determined whether or not the elongation ratio r _S ≤2. If "YES", the speech waveform is converted according to FIG. The process proceeds to step S25 for processing, and if “NO”, the process proceeds to step S35 for processing the audio waveform according to FIG. In step S25, the time point P1 indicated by the current pointer and one pitch period T
The audio waveform F (audio waveform A + audio waveform B) and the waveform G (audio waveform B + audio waveform C) each having a length of 2T are cut out from the time point P4 after the delay. Subsequently, step S2
7, a weight (window function W5 = i / (2T-1) (i = 0, 1,
.., 2T-1)), and 1 to 0
To the linearly changing weight (window function W6 = 1−i / (2T
-1)) and add these two sound waveforms to generate a sound waveform H having a length of 2T. In step S29, on the input speech waveform of FIG. 7 (A), the pointer is moved from the point P1 to the "L _S" point P3 advanced by. In step S31, from time P2 to time P
Up to 3 length "L _S -T" input voice waveform speech waveform H of
And output as it is as an audio waveform. Step S
At 33, it is determined whether or not the decompression process is to be continued.
If "ES", the process returns to step S21, while "NO"
In the case of, it ends. If "NO" is determined in the step S23, the process proceeds to a step S35.
5 and step S37 are basically the same as step S27, respectively, and a duplicate description will be omitted. And
In step S39, as shown in FIGS. 8A and 8B, of the audio waveform H generated in step S37,
Only outputs the audio waveform portion of the head from the waveform length "T + L _S". In step S41, it returns the portion of the speech waveform of "T-L _S" of time P7 subsequent speech waveform H to the input side. Thereafter, in step S43, the pointer is moved to the time point P1.
After that, the process proceeds to Step S33 after moving to the time point P5. Thus, when r _S > 2, FIG.
On the input voice waveform of (A), by moving the pointer from the point P1 to the "L _S" only when advanced P5, and outputs only the portion of the speech waveform length from the beginning of the speech waveform H 'T + L _S " , the speech waveform of the remaining "T-L _S" for use again in the next process, and returned to the input side. This "TL
_The reason for returning the " _S " portion to the input side is that the decompression processing performed in FIG. 8A is performed with respect to the time point P5 and thereafter, so that the point P
This is to maintain continuity at 7. In this manner, the audio signal reproduced from the VTR 12 is expanded in accordance with the expansion rate r _{S in} accordance with the flow charts shown in FIGS.
6c and the D / A converter 16d. According to this embodiment, the VTR 1
By processing the voice signal output from the speaker 2 by the voice speed conversion adapter 16, it is possible to output voice from the speaker 14b whose voice pitch is the same as that at the time of normal reproduction. VTR
Can be provided with a speech speed conversion function. Also, the editing work is facilitated when editing a video tape on which video and audio are recorded.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is an illustrative view showing a format of an SMPTE time code; FIG. 3A is a waveform diagram showing a recording waveform of a time code, and FIG. 3B is an illustrative view showing time code data; FIG. 4 is a block diagram showing a part of the embodiment in FIG. 1; FIG. 5 is a flowchart showing a part of the operation of the embodiment in FIG. 1; FIG. 6 is a flowchart showing a part of the operation of the embodiment in FIG. 1; FIG. 7 is a waveform diagram showing time axis expansion of an audio signal. FIG. 8 is a waveform diagram showing time axis expansion of an audio signal. [Description of Signs] 10 ... System 12 ... VTR 14 ... Monitor 16 ... Speech speed conversion adapter 16b ... Microcomputer

Claims (1)

(57) [Claims] [Claim 1] The first reproduced from a video tape recorder
Receiving the audio signals and the time code, a speech speed conversion adapter providing a second audio signal to the monitor, detection means for detecting a minimum period <br/> of pulses thus defined to the time code, and said detecting means Detected by
Comprising a conversion means for generating the second audio signal by converting the time axis of the first audio signal based on the minimum period which is, the conversion means, the time code reproduced at normal speed
Therefore, the minimum period of the pulse defined by the detecting means is detected by the detecting means.
Division means for dividing by the issued minimum period, and the division
Time for converting the time axis according to the result of division by the means
A speech speed conversion adapter including axis conversion means .