JP2003195893A - Device and method for speech reproduction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extremely excellent speech reproducing device which can reproduce a plurality of necessary speech streams at the same time and is nearly free of a rise in cost. <P>SOLUTION: When the plurality of speech streams are reproduced from a recording medium 1 where the plurality of speech streams are recorded, a selecting circuit 5 selects at least two of the plurality of speech streams. A speech decoding circuit 6 decodes the selected two streams at the same time. The decoded speech streams are reproduced as speeches A and B by a speaker. Thus, the speech decoding circuit 6 which decodes the plurality of speech streams at the same time is provided to enable the reproduction of a plurality of speeches by a common reproducing device, and then a plurality of persons can enjoy in, for example, Japanese and English. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio reproducing apparatus and an audio reproducing method for a recording medium or a broadcast medium in which a plurality of audio streams are recorded.

[0002]

2. Description of the Related Art At present, particularly in a DVD capable of recording moving image data, audio data, and sub-picture data representing subtitles and the like in an amount corresponding to a movie for about 2 hours on an optical disc having the same diameter as a CD. Up to eight types of audio streams can be recorded.

As a reproducing apparatus capable of simultaneously outputting a plurality of images or a plurality of sounds, for example, Japanese Patent Application Laid-Open No. 11-1779.
No. 10 publication is known. In order to output a plurality of images or a plurality of sounds at the same time by using the reproducing apparatus shown here, a plurality of decoding circuits are required, resulting in an increase in price.

By the way, a plurality of audio streams recorded on a DVD have various numbers of channels, languages and the like. However, only one audio stream is selected. For this reason, it is not a problem when watching it alone, but when multiple people with different dialects or languages want to hear at the same time in their respective dialects or languages, or even people with the same dialect or language do so in other dialects or foreign languages. If some people want it,
One voice decoding was not possible with one voice reproducing device.

[0005]

SUMMARY OF THE INVENTION In the above-described conventional audio reproducing apparatus, when a plurality of people having different dialects or languages want to listen in their respective dialects or languages at the same time, or even a person having the same dialect or language has another dialect or language. It was inconvenient for some people who wanted to listen in a foreign language.

SUMMARY OF THE INVENTION An object of the present invention is to provide an audio reproducing apparatus and an audio reproducing method which can reproduce a plurality of required audio streams at the same time, suppress the cost increase, and are excellent.

[0007]

In order to solve the above-mentioned problems, in the audio reproducing apparatus of the present invention, a recording medium on which a plurality of audio streams are recorded or a broadcast in which a plurality of audio streams are simultaneously transmitted is provided. A reproducing unit, which selects at least two streams from the plurality of audio streams during reproduction, a decoding unit which simultaneously decodes at least two streams selected by the selecting unit, and a decoding unit which decodes the streams. And an output unit for outputting the plurality of audio streams that have been generated.

Further, in the audio reproducing method of the present invention, when reproducing a recording medium in which a plurality of audio streams are recorded or a broadcast in which a plurality of audio streams are simultaneously transmitted, the plurality of audio streams are reproduced from the plurality of audio streams at the time of reproduction. It is characterized in that at least two streams are selected, at least two streams selected by the selecting means are simultaneously decoded, and a plurality of audio streams decoded by the decoding means are output.

According to the above means, a plurality of audio streams can be simultaneously reproduced by a common reproducing apparatus by simultaneously decoding a plurality of audio streams, so that, for example, a plurality of people can simultaneously enjoy Japanese and a foreign language. You can

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a circuit configuration diagram for explaining a first embodiment of the present invention.

The data recorded on the recording medium 1 is read by an optical pickup or the like (not shown). The read data is demodulated in the demodulation circuit 2, subjected to signal processing such as error correction in the signal processing circuit 3, and then supplied to the separation circuit 4.
The output data of the signal processing circuit 3 includes video, sub-video, audio, etc. The separation circuit 4 extracts an audio stream from the output data of the signal processing circuit 3 and outputs it to the audio stream selection circuit 5.

The audio stream here is audio data, and is a bit stream of audio compression code in the MPEG and DVD standards. The audio data has a sampling frequency, the number of quantization bits, and the number of channels. The number of channels is 2/0: L, R → stereo 3/0: L, C, R → multi-channel (front 3ch) 2/1: L, R, S (Surround) → multi-channel (front 2ch , rear 1ch) 3/1: L, C, R, S → multi-channel (front 3ch, rear 1ch) 2/2: L, R, Ls, Rs → multi-channel (front 2ch, rear 2ch) 3 / 2: There are L, C, R, Ls, Rs → multi-channel (front 3ch, rear 2ch). LFE (Low Frequency Effects) can be turned on / off independently of each channel mode. When this LFE is ON, for example, 5.1ch. 1 minute is LFE.

Since a DVD can have up to eight audio streams, dual mono is prohibited. Further, the number of dual mono is one as the number of audio streams, and each audio stream is set to any one of the above number of channels.

The audio stream selection circuit 5 is a separation circuit 4
From the plurality of audio streams output from, the two audio streams designated by the user by the stream number or the like are selected and sent to the audio decoding circuit 6.

Referring again to FIG. 1, the two audio streams selected by the audio stream selection circuit 5 are supplied to the audio decoding circuit 6 to be decoded into original digital audio data, and 1
One digital audio data is supplied to the output buffer 7, and the other digital audio data is supplied to the output buffer 11. A more specific configuration example of the voice decoding circuit 6 will be described with reference to FIG.

In FIG. 2, the audio stream selection circuit 5
The two audio streams selected in step 1 are supplied to the discriminating circuit 31, where the stream number is discriminated, and the stream with one number corresponding to the number is sent to the input buffer 32 and the other number is given. The attached stream is supplied to the input buffer 33. Input buffer 32,
Each audio stream stored in 33 is sent to the decoding unit 35 via the input selection switch 34, where it is decoded into the original digital audio data and stored in the input buffer 32 via the output selection switch 36. The decoded original digital audio data of the stream is output to the output buffer 7,
The decoded original digital audio data of the stream stored in the input buffer 33 is output to the output buffer 11.

In this way, a plurality of audio streams can be decoded serially at high speed, and the stream can be discriminated by the stream number, so that a plurality of audio streams can be simultaneously decoded.

Then, of the two digital audio data output from the audio decoding circuit 6, one digital audio data is converted into an analog audio signal by the D / A converter 8 via the output buffer 7 and amplified. After being amplified in circuit 9,
The sound A is reproduced by being supplied to a speaker (not shown) through the output terminal 10.

Of the two digital audio data output from the audio decoding circuit 6, the other digital audio data is converted into an analog audio signal by the D / A converter 12 via the output buffer 11. After being amplified by the amplifier circuit 13, it is supplied to a speaker (not shown) via the output terminal 14 to reproduce the sound B. The audio A and the audio B selected in this way can be reproduced simultaneously.

The audio stream selection circuit 5 can also perform reproduction by selecting one audio stream. Also,
Although two audio streams are selected in FIG. 1, three audio streams are selected.
One or more may be selected. In this case, the path from the voice decoding circuit 6 to the output terminal requires three lines or more.

According to this embodiment, since two or more audio streams are reproduced at the same time, when a plurality of people with different dialects or languages want to listen in their respective dialects or languages at the same time, or in the same dialect or language, Even if some people want to hear in other dialects or foreign languages, they can listen at the same time. For example, people with different languages can enjoy each other's languages at the same time, such as on an airplane or in a movie theater.

FIG. 3 is a block diagram for explaining the second embodiment of the present invention. The same components as those in FIG. 1 are designated by the same reference numerals, and the different components will be mainly described here.

The analog audio signal output from the D / A converter 8 is supplied to the amplifier circuit 9 and the selection circuit 15. The analog audio signal supplied to the amplifier circuit 9 is the amplifier circuit 9
After being amplified by, it is supplied to a speaker (not shown) via the line output terminal 10 to reproduce the audio A.

On the other hand, another analog audio signal output from the D / A converter 12 is supplied to the selection circuit 15.
In this selection circuit 15, the analog audio signal which is the output of the D / A converter 8 and the other which is the output of the D / A converter 12
The user selects one of the four analog audio signals and supplies the selected audio signal to the amplifier circuit 16. The analog audio signal selected by the selection circuit 15 is amplified by the amplification circuit 16 and then supplied to headphones (not shown) through the headphone terminal 17, where the audio B is reproduced, and the selected audio signal is selected. The voice A is reproduced through the speaker and the selected voice B is reproduced through the headphones at the same time.

The selecting circuit 15 automatically selects the D / A converter 1 when two streams are selected by the audio stream selecting circuit 5 in addition to the selection by the user.
The analog audio signal which is the output of 2 may be selected.

According to this embodiment, two audio streams can be played back at the same time by the speaker on one side and the headphones on the other side. Therefore, for example, when watching a DVD movie or the like in a family, oneself listens to English in the headphones and the other to the family. You can watch in Japanese from the speaker.

FIG. 4 is a block diagram for explaining the third embodiment of the present invention. In this embodiment, a multi-channel output is assumed. The same components as those in each of the above-described embodiments will be described with the same reference numerals.

That is, as the digital audio data output from the audio decoding circuit 6 to the output buffer 7, when the audio stream is multi-channel and multi-channel output is desired, the stereo L and R components and the surround Ls, Rs component and C (C
enter) and the LFE component are output respectively. From the output buffer 7, the L and R components are transferred to the D / A converter 8 and Ls and Rs.
The components are sent to the selection circuit 18, and the C and LFE components are sent to the D / A converter 22, respectively.

When the audio stream has two channels and when the audio stream is downmixed even in multi-channels and is output in stereo, the two channels are sent to the D / A converter 8.

The L and R components sent to the D / A converter 8 are
After converting to an analog voice signal and amplifying it with the amplifier circuit 9,
It is supplied to a speaker (not shown) via the output terminal 10,
Playback of voice A or L, R. Further, the C and LFE components sent to the D / A converter 22 are converted into analog audio signals, amplified by the amplifier circuit 23, and then called an unillustrated center speaker and sub woofer via the output terminal 24. It is supplied to the speaker for heavy bass, and C and LFE are reproduced.

On the other hand, the digital audio data output from the output buffer 11 is supplied to the selection circuit 18. In the selection circuit 18, L of the digital audio data from the output buffer 7
The s and Rs components and another digital audio data from the output buffer 11 are selected, and the Ls and Rs components are selected by the output of the output buffer 11 when the two audio streams are reproduced at the same time in the case of multi-channel reproduction. Certain digital audio data is selected and sent to the D / A converter 19. The Ls and Rs components or another digital audio data sent to the D / A converter 19 is converted into an analog audio signal, amplified by an amplifier circuit 20, and then supplied to a speaker (not shown) via an output terminal 21. The audio B or Ls, Rs is reproduced here.

FIG. 5 shows an operation flow from the audio stream selection circuit 5 in FIG. 4, which will be described with reference to FIG. First, when playing multi-channel,
1 which is multi-channel in the audio stream selection circuit 5
One audio stream is selected (STEP 1). One selected multi-channel stream is sent to the audio decoding circuit 6 and stored in the input buffer 32 inside this circuit 6 (STEP 3). The multi-channel audio stream stored in the input buffer 32 passes through the stream selection (STEP 4) and the stream identification flag fl.
After g1 is added (STEP5), it is sent to the decoding unit 35, where it is decoded into the original digital audio data (S).
TEP6). Flg1 is included in this decoded audio data.
Since the flag is attached, the identification flag judgment (ST
It is supplied to the output buffer 7 via EP7) (S
TEP8). Since the audio data stored in the output buffer 7 is multi-channel, the channels are distributed via STEP 9 (STEP 10). STEP10
2ch (L / R, Ls / Rs, C /
The LFE component is converted into an analog audio signal in STEP 11, amplified in STEP 12 and then output to each output terminal.

On the other hand, when reproducing two voices simultaneously, the two voice streams are selected by the voice stream selection circuit 5 and supplied to the voice decoding circuit 6 (STEP 1).
The two audio streams are identified in the circuit 6 (STEP 2), the stream number is discriminated here, and a stream (stream 1) having one number corresponding to the number is input buffer 32.
To the stream with the other number (stre
am2) is supplied to the input buffer 33 (STEP
3). The two stored audio streams are stream
1 → stream2 → stream1 → stream2
Decoding is performed in order as → .. However, after selecting a stream in STEP 4, a flag is added according to the stream in STEP 5. That is, flg1 is added to stream1 and flg2 is added to stream2.
The audio stream with this flag added is decoded by the decoding unit 35.
And is decoded into the original digital audio data (STEP 6). This decrypted audio data has f
Since the flag is lg1 or flg2,
The audio data A to which flg1 is added is sent to the output buffer 7 through the identification flag judgment (STEP 7)
The audio data B with g2 is supplied to the output buffer 11 (STEP 8). The audio data A stored in the output buffer 7 is converted into an analog audio signal in STEP 11 via STEP 9, amplified in STEP 12, and then output to the output terminal to reproduce the audio A. On the other hand, the audio data A stored in the output buffer 11 is S
Converted to analog voice signal by TEP11, STEP
After being amplified at 12, it is output to the output terminal and the voice B is reproduced.

According to this embodiment, in the apparatus capable of multi-channel reproduction, it is possible to reproduce two audio streams simultaneously by providing the selection circuit 18 and using the existing circuit and the output terminal. .

In this embodiment, two audio streams are selected, but three audio streams may be selected. In this case, the output terminal 24 outputs the voices C and C, LF.
Also serves as E component.

The present invention is not limited to the above-described embodiments, but various modifications can be made without departing from the spirit of the invention. For example, in the embodiments, a package medium called a recording medium has been described, but a broadcast medium or the like may be used.

[0038]

As described above, according to the present invention, by providing the function of simultaneously decoding a plurality of audio streams, it becomes possible to reproduce a plurality of audios simultaneously by a common reproducing apparatus.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a first embodiment of the present invention.

FIG. 2 is a block diagram for explaining the speech decoding circuit in FIG.

FIG. 3 is a block diagram for explaining a second embodiment of the present invention.

FIG. 4 is a block diagram for explaining a third embodiment of the present invention.

5 is a flowchart for explaining the operation of FIG.

[Explanation of symbols]

1 ... Recording medium 2 ... Demodulation circuit 3 ... Signal processing circuit 4 ... Separation circuit 5 ... Audio stream selection circuit 6 ... Voice decoding circuit 7, 11 ... Output buffer 8, 12, 19.22 ... D / A converter 9, 13, 16, 20, 23 ... Amplifier circuit 10, 14, 21, 24 ... Output terminals 15, 18 ... Selection circuit 17 ... Headphone jack 31 ... Discrimination circuit 32, 33 ... Input buffer 34 ... Input selection switch 35 ... Decoding section 37 ... Output selection switch

Continued front page    F-term (reference) 5C053 FA24 GB11 GB37 JA01 JA12                       LA06                 5D044 AB05 BC03 CC06 DE14 DE49                       FG18 GK04 GK12                 5D045 DA20                 5K068 AA15 BA02 BA06 BC02 CB21

Claims (6)

[Claims] 1. A recording medium in which a plurality of audio streams are recorded, or an audio reproducing apparatus for reproducing a broadcast in which a plurality of audio streams are simultaneously transmitted, and at least two streams are selected from the plurality of audio streams during reproduction. Audio comprising: a selecting means for performing the decoding, a decoding means for simultaneously decoding at least two streams selected by the selecting means, and an output means for outputting a plurality of audio streams decoded by the decoding means. Playback device. 2. The decoding means is provided with a discriminating means for discriminating the stream numbers of the plurality of audio streams and an input buffer for at least two streams discriminated by the discriminating means, and switching the plurality of input buffers. And a means for supplying the audio data decoded by the decoding means to a plurality of output buffers according to the switching of the supplying means. The audio reproduction device described. 3. The output means is provided with a headphone terminal,
The decoded audio can be distributed to the line output terminal and the headphone terminal at the same time.
The audio reproduction device described. 4. An audio reproducing apparatus according to claim 1, wherein said output means is adapted to simultaneously distribute each stream to a multi-channel output terminal when reproducing each stream in two channels. 5. An audio reproducing method for reproducing a recording medium in which a plurality of audio streams are recorded or a broadcast in which a plurality of audio streams are simultaneously transmitted, wherein at least two streams are selected from the plurality of audio streams during reproduction. Then, at least two streams selected by the selecting means are simultaneously decoded, and a plurality of audio streams decoded by the decoding means are output. 6. When reproducing a plurality of audio streams at the same time, a desired plurality of audio streams are selected by the selecting means, the selected audio streams are identified, the stream numbers are determined, and the respective stream numbers are determined. Decoding the digital audio data by the decoding means in the state where different flags are added to the digital audio data, distributing the decoded audio data to a reproduction system based on the different flags, and reproducing the plurality of audio streams. The audio reproduction method according to claim 5, wherein