JP2005031569A - Speech reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correctly decode a compressed and encoded speech stream even when auxiliary information on the theme, singer's name, etc., of a song is included in addition to music data as main information. <P>SOLUTION: In addition to a signal input part 1 which receives an input signal 5, a synchronizing signal detection part 2 which detects a synchronizing signal from the input signal 5 and decides whether the input signal 5 can be decoded from an appearance pattern of the detected synchronizing signal, and a signal processing part 3 which decodes the input signal 5 and supplies an output signal 6 when the synchronizing signal detection part 2 decides that the input signal can be decoded, provided is a host controller 4 which analyzes the input signal 5 and controls the start position and size of data transfer from the signal input part 1 to the synchronizing signal detection part 2 so that the auxiliary information in the input signal 5 is skipped and only the music data part is transferred to the synchronizing signal detection part 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an audio reproduction device for decoding a compression-encoded audio stream.

  With the recent progress of multimedia technology, devices capable of handling a plurality of media such as digitized video, audio and data, such as DVD players and tuners for digital TV broadcasting, have begun to spread. Moreover, the input content data to be handled by these multimedia devices is diversified. Accordingly, there is a need for an audio playback device having a multi-playback function that can decode any audio stream that has been compression-encoded according to various standards such as MPEG-1 / 2/3, DolbyAC-3, and DTS.

  In order to realize a multi-playback function in an audio playback apparatus, it is important to be able to determine which standard is an audio stream that has been compression-encoded according to which standard. For this determination, it is effective to use a synchronization signal in the audio stream.

According to a certain prior art, a synchronization signal detection unit for detecting a synchronization signal having a specific bit arrangement from an input signal is provided, and by using an appearance pattern of the synchronization signal, an audio stream of a PCM recording system and a DTS A stream is identified. Further, it is determined whether or not the input signal can be decoded from the appearance pattern (frequency of appearance intervals) of the synchronization signal (see Patent Document 1).
JP 2001-176199 A

  For example, in the case of MP3, in addition to song data which is main information essential for audio reproduction, auxiliary information such as a song title name and singer name is included in the audio stream. Therefore, even if the input signal is supplied to the synchronization signal detection unit in the above prior art by shifting it from the head by a predetermined position instead of from the head, if the auxiliary information located at the head of the input signal is long, it is not necessarily essential. An input signal that can be decoded is not always determined to be decodable. This is because the auxiliary information supplied to the synchronization signal detection unit prevents the determination in the synchronization signal detection unit.

  An object of the present invention is to provide an audio reproducing apparatus capable of correctly decoding an audio stream including auxiliary information.

  In order to achieve the above object, according to the present invention, only the music data portion, which is the main information in the input signal, is always supplied to the synchronization signal detector.

  More specifically, the present invention relates to a signal input for receiving an input signal including main information essential for audio reproduction and additional auxiliary information in an audio reproduction apparatus for decoding a compression-encoded audio stream. A synchronization signal detecting unit that detects a synchronization signal from main information in the input signal and determines whether the input signal can be decoded from an appearance pattern of the detected synchronization signal, and a synchronization signal detecting unit Analyzing the input signal so that the auxiliary signal in the input signal is not supplied to the synchronization signal detecting unit, and a signal processing unit for decoding the input signal when it is determined that decoding is possible And a host controller that controls data transfer of the input signal to the synchronization signal detector according to the result of the analysis.

  According to the present invention, only the music data portion, which is the main information in the input signal, is always supplied to the synchronization signal detection unit, so that the audio stream including the auxiliary information can be correctly decoded.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of the configuration of an audio playback apparatus according to the present invention. In FIG. 1, 1 is a signal input unit, 2 is a synchronization signal detection unit, 3 is a signal processing unit, 4 is a host controller, 5 is an input signal, and 6 is an output signal. The input signal 5 may be any audio stream that has been compression-encoded according to various standards. In addition to song data, which is main information essential for audio reproduction, auxiliary information such as the song title name and singer name is included in the audio signal. May be included in the stream. The signal input unit 1 receives an input signal 5 from a DVD disk, personal computer or the like (not shown). The synchronization signal detection unit 2 detects a synchronization signal from the main information in the input signal 5, and determines whether or not the input signal 5 can be decoded from the detected appearance pattern of the synchronization signal. The signal processing unit 3 performs a decoding process on the input signal 5 when the synchronization signal detection unit 2 determines that decoding is possible. An output signal 6 obtained from the signal processing unit 3 is supplied to a speaker through an external amplifier (not shown). The host controller 4 analyzes the input signal 5 so that the auxiliary information in the input signal 5 is not supplied to the synchronization signal detection unit 2, and the input signal to the synchronization signal detection unit 2 according to the result of the analysis 5 data transfer is controlled. More specifically, the host controller 4 gives a transfer control signal to the synchronization signal detection unit 2 so as to control the data transfer start position and data transfer size from the signal input unit 1 to the synchronization signal detection unit 2. As a result, the frequency of appearance of the synchronization signal in the input signal 5 given to the synchronization signal detection unit 2 is also controlled by the host controller 4. In the following description, it is assumed that the signal processing unit 3 can decode at least the DTS stream and the MP3 stream.

  FIG. 2 shows an example of the input signal 5 that does not include auxiliary information. For example, a DTS stream corresponds to this. In this case, since the input signal 5 is composed only of the synchronization signal and the music piece data, no matter what position in the input signal 5 the host controller 4 allows to start the data transfer to the synchronization signal detector 2, Only the music data portion in the signal 5 is supplied to the synchronization signal detector 2. Therefore, the synchronization signal detector 2 determines that the input signal 5 can be decoded, and the correct output signal 6 is obtained from the signal processor 3.

  FIG. 3 shows an example of the input signal 5 including auxiliary information at the beginning and the end. For example, in the case of an MP3 stream, the auxiliary information corresponds to what is called an ID3 tag, and indicates information such as a song title name and a singer name. When the input signal 5 as shown in FIG. 3 is given, the host controller 4 analyzes the input signal 5 so that the auxiliary information is skipped even if the first auxiliary information in the input signal 5 is long. Data transfer from the input unit 1 to the synchronization signal detection unit 2 is controlled. Since ID3v1 determines that the last 128 bytes of the input signal 5 are auxiliary information, the host controller 4 prevents the auxiliary information of the last 128 bytes from being supplied to the synchronization signal detection unit 2 as well. The data transfer start position and data transfer size from the signal input unit 1 to the synchronization signal detection unit 2 are controlled. Therefore, the synchronization signal detection unit 2 can determine that the input signal 5 can be decoded from the music data portion without being disturbed by the auxiliary information, and the correct output signal 6 can be obtained from the signal processing unit 3.

  The host controller 4 controls the number of data transfers from the signal input unit 1 to the synchronization signal detection unit 2 so that the possibility that the determination by the synchronization signal detection unit 2 is repeatedly performed and a correct determination result is obtained is increased. It is good. In this case, different portions in the input signal 5 are repeatedly supplied to the synchronization signal detection unit 2.

  As described above, the audio reproduction device according to the present invention has an effect of correctly decoding an audio stream including auxiliary information, and is useful as an audio reproduction device for decoding a compression-encoded audio stream. It is.

It is a block diagram which shows the structural example of the audio | voice reproduction apparatus which concerns on this invention. It is a figure which shows the example of the input signal which does not contain auxiliary information. It is a figure which shows the example of the input signal containing auxiliary information.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Signal input part 2 Synchronization signal detection part 3 Signal processing part 4 Host controller 5 Input signal 6 Output signal

Claims (4)

An audio reproduction device for decoding a compression-encoded audio stream,
A signal input unit for receiving an input signal including main information essential for sound reproduction and additional auxiliary information;
A synchronization signal detection unit that detects a synchronization signal from main information in the input signal and determines whether the input signal can be decoded from an appearance pattern of the detected synchronization signal;
A signal processing unit that performs a decoding process on the input signal when the synchronization signal detection unit determines that decoding is possible;
The input signal is analyzed so that auxiliary information in the input signal is not supplied to the synchronization signal detection unit, and data transfer of the input signal to the synchronization signal detection unit is controlled according to the analysis result And a host controller. The sound reproducing device according to claim 1,
The audio reproduction apparatus according to claim 1, wherein the host controller controls so that only the music data portion which is main information in the input signal is transferred to the synchronization signal detection unit. The sound reproducing device according to claim 1,
The audio reproduction apparatus according to claim 1, wherein the host controller controls a data transfer start position and a data transfer size to the synchronization signal detection unit. The sound reproducing device according to claim 1,
The audio reproduction device according to claim 1, wherein the host controller controls the number of times of data transfer to the synchronization signal detection unit so that the determination by the synchronization signal detection unit is repeatedly performed and a correct determination result is obtained.

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