JPH0470700A - Sound reproducing device - Google Patents

Abstract

PURPOSE:To eliminate a rasping noise outputted from a speaker when a large number of errors exist in data by passing the output of an error correction circuit as sound output data to the spear only when the number of error bits detected at an error detection circuit is less than the correctable number of bits. CONSTITUTION:The number (n) of error bits detected by the error detection circuit 1 is compared with the correctable number (p) of bits at a decision circuit 3. When it is decided as n>p as a comparison result, a noise elimination circuit 4 functions so as not to pass the output of the error correction circuit 2, and also, passes sound input data whose error is corrected at the error correction circuit 2. In such a way, output is prevented issued from the noise elimination circuit 4 even when a state where no corrective operation is performed by the error correction circuit 2 due to a large number of errors in the sound input data and only the noise is outputted occurs. Thereby, it is possible to prevent the rasping noise outputted from the speaker 14.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to an audio playback device that includes error control, and aims to realize an audio playback device that can remove noise that may be output from an error correction circuit, and detects errors in audio input data. an error detection circuit; an error correction circuit that corrects errors in the audio input data; a determination circuit that determines whether the number of erroneous focus detected by the error detection circuit is less than or equal to the correctable number of bits; It is comprised of a noise removal circuit that passes the output of the error correction circuit as audio output data to a speaker only when the number of error bits is equal to or less than the number of correctable bits.

[Industrial application field]

The present invention relates to an audio reproducing device, and more particularly to an audio reproducing device including error control.

When transmitting data, data errors occur with a certain probability in the transmission path system, so audio playback devices require some form of error control to detect and correct such data errors. There is.

[Conventional technology]

In a conventional audio reproduction device, as schematically shown in FIG. After detecting where and what kind of error has occurred and correcting it, the signal is decoded in a decoder 12, converted into an analog signal by a D/A converter I3, and an audio output is generated from a speaker 14.

[Problem to be solved by the invention]

Therefore, if an error occurs that exceeds the ability of the error correction circuit 11 to correct the error, it will not be possible to correct the error even if it is detected.

Therefore, the error correction circuit 1 cannot output the received signal in a normal form, and only noise is output, which causes the problem that the speaker 14 outputs a harsh sound. there were.

Therefore, the present invention is an audio reproduction bag that can remove noise that may be output from an error correction circuit! The purpose is to realize the following.

[Means to solve the problem]

In order to achieve the above object, the audio reproduction device according to the present invention includes an error detection circuit 1 for detecting errors in audio input data, and an error detection circuit 1 for correcting errors in the audio input data, as shown in principle in FIG. an error correction circuit 2 that determines whether or not the number of error bits detected by the error detection circuit l is less than or equal to the number of correctable bits; A noise removal circuit 4 is provided which allows the output of the error correction circuit 2 to pass through as audio output data to the speaker 14 only when the following conditions are satisfied.

[For production]

In the operation of the present invention shown in FIG. 1, the number n of error bits detected by the error detection circuit 1 is compared with the correctable focus number p in the determination circuit 3.

As a result, when the determination circuit 3 determines that the signal is nap, the noise removal circuit 4 works so as not to pass the output of the error correction circuit 2, and when n≦p, the noise is corrected by the error correction circuit 2. Pass input data through.

As a result, even if the error correction circuit 2 becomes unable to correct errors when there are many errors in the audio input data and only noise is output, the noise removal circuit 4 prevents the output from being output, thereby eliminating the harsh sound. The output from the speaker 14 is eliminated.

〔Example〕

FIG. 2 shows an embodiment of the audio reproduction device according to the present invention. In this embodiment, a generator polynomial circuit is used as the error correction circuit 1, and the determination circuit 3 is determined based on the number of error bits of the generator polynomial circuit 1. It is composed of a comparison circuit 31 that compares n with the number of correctable bits P, and a memory 32 that provides the number of correctable points p. It consists of a select circuit that selects output data (■) or ground level (■). Note that the decoding circuit 12, D/A converter 13, and speaker 14 connected to the output of the select circuit 4 are the same as in the case of FIG.

In the operation of the embodiment of the present invention having such a configuration, human voice data is input to the generator polynomial circuit, and its error pitch l-n is detected.

This error pin)n is stored in the memory 3 in the comparator circuit 31.
2 is compared with the number p of error correctable focuses stored in advance.

As a result, when n≦p, the output signal of the comparison circuit 31 becomes a logic "1" level.

In this state, there are many errors in the audio input data, and since error correction is not possible and noise is output from the error correction circuit 2, the select circuit 4 that receives the logic ``1'' level signal is at the ground level. Select (2) to prevent the output from the error correction circuit 2 from passing through.

As a result, even if there are many errors in the audio data, no noise is output from the speaker 14, resulting in a silent output state.

On the other hand, at nap time, the error in the audio input data can be corrected, so the output of the comparison circuit 31 is a logic "0".
The select circuit 4 switches to select the output signal ■ of the error correction circuit 2, and the decoding circuit 12
A normal audio signal is output from the speaker 14 via the D/A converter 13.

Note that when n≦p, the error correction operation itself of the error correction circuit 2 may be stopped by a logic "1" level signal (indicated by a dotted line) output from the comparison circuit 31.

〔Effect of the invention〕

As described above, according to the audio playback device according to the present invention, only when the number of erroneous focus detected by the error detection circuit is equal to or less than the number of bits that can be corrected, the output of the error correction circuit is converted into audio output data to the speaker. Since the configuration is configured such that the data is passed through as a result, it is possible to remove harsh noise that may be output from the speaker when there are many errors in the data.

[Brief explanation of drawings]

FIG. 1 is a principle block diagram of an audio reproducing device according to the present invention, FIG. 2 is a block diagram showing an embodiment of the audio reproducing device according to the present invention, and FIG. 3 is a block diagram showing a conventional example. It is. In FIG. 1, 1...error detection circuit, 2...error correction circuit, 3...judgment circuit, 4...noise removal circuit. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] An error detection circuit (1) that detects errors in voice input data; and an error correction circuit (2) that corrects errors in the voice input data.
and a determination circuit (1) that determines whether the number of error bits detected by the error detection circuit (1) is less than or equal to the number of correctable bits.
3), and only when the number of error bits is less than or equal to the number of correctable bits, the output of the error correction circuit (2) is sent to the speaker (14).
Noise removal circuit (4) to pass as audio output data to
), and an audio playback device comprising: