JPH01248755A - Voice addition system - Google Patents

Abstract

PURPOSE:To reduce the cost of conference talking with high quality while taking the advantage of transmission due to code compression by generating and outputting an added voice signal subjected to coding compression from envelope information of the sum of frequency components and signal source information of plural voice signals subjected to code compression. CONSTITUTION:The conference talking among 3 points A-C is realized by using the point B as a relay point, the voice information at its one point is added to the voice information from the point A at the relay point B and the result is sent to the point C, and the voice information at its own point is added to the voice information from the point C. Then a transmission reception section at the points A, C is provided with coder (compression coders) 1a, 1c applying coding compression to the voice signal and sending the result of the point B and decoders (compression decoders) 2a, 2c decoding the compressed coding data sent from the point B and reproducing/outputting the voice signal respectively. Thus, the effective conference talking is applied in the state of keeping the quality of the voice signal sufficiently high while the advantage of the information transmission due to coding compression is utilized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an audio signal addition method when realizing a conference call by encoding and compressing audio signals and transmitting the encoded and compressed audio signals.

(Prior Art) Recently, technology for encoding and compressing audio signals and transmitting them with high efficiency has been attracting attention. In such an audio information transmission system using encoding and compression, when a conference call is to be held between three parties, conventionally, as shown in FIG. A COG (compression encoder, C0D) is used to encode and compress audio for each path, and a decoder (compression encoder, C0D) is used to restore compressed and encoded information to an audio signal. A compression decoder (DEC) is provided respectively. The conference call is realized by adding and outputting the decoded audio signals via the decoder at each receiving end.

In other words, a speech signal is captured as a signal passed through a coefficient filter (phonological information) consisting of a signal source consisting of a pulse train or white noise, and the above-mentioned compression encoding of speech basically involves the information of the signal source and the above-mentioned filter. This is done by expressing the audio signal using envelope information indicating coefficients. For this reason, it is not possible to directly add compression-encoded audio information (encoded data), and as described above, the compression-encoded audio information must be decoded via a decoder and then added. Conference calls are now possible.

However, in a conference call that is realized by applying such an addition method, buses (
When the number of conference points is n, the number of paths required is [n (n-1) +21]. Therefore, it is undeniable that the communication cost becomes considerably high.

Therefore, as shown in Figure 5, the meeting point (here B
) has a relay function, and point B has this relay function.
It has been considered to perform addition processing for conference calls. That is, the information that has been encoded and compressed and transmitted at relay point B is decoded, the voice information at the own point is added to this decoded voice information, and then this added voice information is encoded and compressed to the next stage. (the other conference point) to realize a conference call.

According to such a conference call system, there is no need to form paths between a plurality of conference points, so it is possible to suppress an increase in communication costs.

However, for the CORG (compression encoder) at the relay point, it is necessary to encode and compress the audio information that has been added, which increases the processing burden and makes it difficult to encode and compress audio information while ensuring quality. The problem arises that it becomes As a result, the encoding quality of the audio signal deteriorates, and the quality of the audio in the conference call inevitably deteriorates.

(Problem to be Solved by the Invention) Conventionally, when realizing a conference call between multiple points by encoding and compressing audio and transmitting it, the audio that is encoded and compressed and transmitted is After the information is once decoded, it is necessary to add the audio for the conference call, resulting in problems such as increased communication costs and deterioration of the quality of the audio.

The present invention was developed in consideration of these circumstances, and its purpose is to realize high-quality conference calls at low cost while taking advantage of the advantages of audio transmission through encoding and compression. The object of the present invention is to provide a possible audio addition method.

[Structure of the Invention] (Means for Solving the Problems) The audio addition method according to the present invention obtains frequency components of a plurality of encoded and compressed audio signals, and obtains envelope information of the sum of these frequency components. By generating and outputting an encoded and compressed addition audio signal from the signal source information of the encoded and compressed plurality of audio signals, the addition process for the plurality of audio signals can be performed while remaining in the encoded and compressed state. It is characterized by its realization.

(Operation) According to the present invention, by inputting a plurality of encoded and compressed audio signals and determining the envelope information of the summed value of the frequency components of the audio signals determined from the encoded data, the summed audio signal can be calculated. It is possible to effectively obtain the frequency components of the audio signal in the coded data that has been coded and compressed. By simultaneously adding the signal source information of the audio signal in the plurality of input encoded data, it is possible to effectively obtain the signal source information of the audio signal in the encoded data obtained by encoding and compressing the added audio signal. Therefore, by configuring encoded data according to the frequency components and signal source information obtained in this way, the encoded compressed data of the added audio signal can be generated without decoding each of the encoded and compressed audio information. It becomes possible to generate and output.

As a result, even when implementing a conference call by encoding and compressing audio signals and transmitting them, it is possible to perform the addition process of the audio signals necessary for the conference call at the level of the encoded and compressed data. It becomes possible to effectively solve problems such as cost problems and conference call quality problems.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of a conference call system constructed by applying a voice addition method according to an embodiment of the present invention, and FIG. 2 is a diagram showing the processing concept of this method.

Figure 1 shows a conference call between three points [A, B, and C], with point B as a relay point. At relay point B, the voice information from point A is combined with the voice information from the own point. is added and transmitted to point C, and the voice information at the own point is added to the voice information from point C and transmitted to point A.

The transmitting/receiving units at points A and C are cogs (compression encoders;
C0D) la, lc, and decoders (compression decoders; DEC) 2a, 2c that decode compressed encoded data transmitted from point B and reproduce and output audio signals.

On the other hand, the transmitter/receiver at the relay point B is connected to the point A,
Two decoders (compression decoders, DECs) 3b and 4b that decode compressed encoded data transmitted from C and reproduce and output audio signals, and these DECs 3
an adder 5b that adds and outputs the decoded audio signals by b and 4b;
It is equipped with Furthermore, this transmitting/receiving section includes a COG (compression encoder, C0D) 6b that encodes and compresses the input audio signal, and a compression code transmitted from the point A to the encoded compressed data obtained by this COD fib. A coded data adder 7b adds the encoded data and transmits it to the point C, and adds the compressed encoded data transmitted from the point C to the encoded compressed data obtained in the COD 6b, and adds the compressed encoded data transmitted from the point C to the encoded data adder 7b. An encoded data adder 8b for transmission to A is provided respectively.

Note that instead of providing the two DECs 3b and 4b and the adder 5b, an encoded data adder that adds compressed encoded data transmitted from the points A and C, respectively;
It is also possible to configure a transmitting/receiving section at relay point B by providing one DEC for decoding the output encoded data of this encoded data adder.

By the way, the encoded data adders 7b and 8b add the encoded data of a plurality of encoded and compressed audio signals as they are, and are equipped with the processing functions shown in FIG. Realized.

Assuming that encoding compression is realized by adopting the PARCOR method, the encoded data consists of audio information signal source information S(ω) and envelope information (RAI?COR coefficient and parameter) A(ω). ) is used to equivalently represent audio information. However, ω indicates the angular velocity.

The encoded data adder 7b applies the encoded data of audio information that has been subjected to such encoding compression.

8b is 2 which the encoded data indicates as shown in FIG.
The frequency components of the two audio information are expressed as Sl(ω)・Al(ω), S2(ω)・A2
(ω), and the sum of the frequency components is calculated as SL(ω)·At(ω)+S2(ω)·A2(ω) (processing C). In other words, the frequency components of two pieces of audio information as shown in Fig. 3(a) and (b) are added together,
Addition frequency components as shown in FIG. 3(C) are obtained.

Then, divide this added frequency component by the signal source information, SL(ω)・At(ω)+S2(ω)・A2(ω)SL
(ω) 182(ω) The envelope information is extracted (processing d).

Through the above processing, the envelope information A3(ω) shown in the encoded data when the added audio signal is encoded and compressed is obtained as the calculation result of the above processing d, as shown in FIG. 3(d). . Therefore, according to this envelope information, necessary parameters are calculated as the encoded data of the added audio signal (process e).

Also, regarding the signal source information of encoded data, AI(ω)
+A2(ω) is obtained by an addition process (process f).

If coded data is generated according to the signal source information and envelope information (k parameter) obtained in this way, the coded data will be equivalent to adding and combining the two audio signals described above and encoding and compressing them. Here, addition processing of audio information at the encoded data level is realized.

Note that although the addition process of two audio signals has been described here, it goes without saying that the addition process of three or more audio signals can be implemented in the same way.

Thus, according to the conference call system realized by applying this method described above, the encoded data is directly subjected to conference calculation processing (addition processing) without decoding the encoded and compressed audio information at each conference participating point. Since the encoded data that has undergone addition processing can be transmitted, there is no increase in the processing load on the compression encoder (Coorg), and the quality of the encoded data is sufficiently high for high-quality conferences. It becomes possible to make phone calls. Furthermore, even if the relay method described above is used to form a path for a conference call, deterioration in signal quality can be suppressed by the addition method of audio signals described above, so the advantage of the relay method is that it maintains the quality of the conference call. This has great practical effects, such as making it possible to reduce communication costs by making full use of the information as it is.

It should be noted that the present invention is not limited to the embodiments described above, and the encoding and compression method, the number of conference participants, etc. may be determined according to the specifications. It goes without saying that the present method can also be applied to a conference call conducted by forming a one-to-one path between conference participants as shown in FIG. In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] As explained above, according to the present invention, it is possible to realize an effective conference call while taking advantage of the advantages of information transmission through encoding compression and maintaining the quality of the audio signal at a sufficiently high level. This has great practical effects, such as making it possible to keep communication costs low.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a conference call system configured by applying a voice addition method according to an embodiment of the present invention, FIG. 2 is a diagram showing the concept of voice addition processing in this method, and FIG. 3 1 is a diagram showing frequency components of audio signals subjected to addition processing, and FIGS. 4 and 5 are diagrams each showing a schematic configuration of a conventional conference call system. A, B, C--conference point, IB, le, 8b-Coorg (compression encoder; COD), 2a, 2c,
3b, 4b--decoder (compression decoder, DEC)
, 5b...Adder, 7b, 8b...Encoded data adder, a, b...Frequency calculation process, c, f...Addition process, d...Envelope information calculation process, e. ...K parameter calculation process. Applicant's agent Patent attorney Takehiko Suzue No. 1vtJ Figure 4

Claims (1)

[Claims] When realizing a conference call by encoding and compressing an audio signal and transmitting the encoded and compressed audio signals, and adding the multiple audio signals transmitted after encoding and compressing, Each frequency component of the audio signal is determined, and an encoded and compressed summed audio signal is determined from envelope information of the summed value of these frequency components and signal source information of the encoded and compressed plurality of audio signals. Audio addition method.