JP2007164944A - Audio device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform reproduction with constant sound volume by easily reducing a level difference in reproduced sound volume when an information recording medium such as a disk is replaced. <P>SOLUTION: An audio device has a sound recording level detection section 18 which detects the sound recording level of audio information reproduced from the information recording medium and a reproduced sound volume setting correction section 17 which corrects the reproduction sound volume level of the audio information according to the sound recording level detected by the sound recording level detection part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an audio device having a built-in disk playback device such as a DVD (Digital Video Disk) player or a DVD changer, and in particular, audio capable of correcting the playback volume and keeping it constant even when the recording level of the disk changes. It relates to the device.

  In general, in a DVD player, not only a DVD disc but also a CD (Compact Disc) can be played. The volume when playing a disc such as a CD or DVD is set by a user with a volume controller (volume). ing. By the way, there is a difference in the recording level between DVD and CD. Generally, CD has a high recording level, but because DVD has a high dynamic range, an average recording level is higher than that of CD. Many are low. Therefore, in the DVD player, when the disc is changed from DVD to CD, or when the disc is changed from CD to DVD (that is, when the disc is changed), playback is performed even if the volume setting value by the user is the same. The playback volume level (that is, output) may be different.

  In order to reduce the difference in volume level (difference in volume level) at the time of disc exchange as described above, the volume set by the volume setting device depends on whether the disc is a CD or a DVD when playing back on a DVD player. Some output levels are variable.

  On the other hand, in order to adjust the volume output from the speaker when playing a disc, the level of the signal level corresponding to the disc playback position of the audio signal recorded on the disc is measured in advance, and it corresponds to the disc playback position. The strength information is stored in the strength information storage unit, and the disc playback signal level is automatically set during disc playback by setting the current attenuation and amplification level based on the strength information corresponding to the current disc playback position. Some are adjusted (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 7-24067 (pages 7 to 9, FIGS. 1 to 8)

  Since the conventional audio apparatus is configured as described above, the recording level differs among DVDs. The volume level difference at the time of disk playback can be determined simply by determining whether the disk is a CD or a DVD. Cannot be corrected accurately. For example, in a DVD on which a movie is recorded / recorded, the average recording level throughout the entire DVD is set low in order to produce a dynamic feeling of a large acoustic scene such as an explosion. On the other hand, music DVDs such as live music have a higher recording level as a whole, and the recording level may differ greatly between DVDs if the genre is different.

  Similarly, CDs such as pop-type CDs are often recorded at high recording levels that are close to digital full scale as a whole, but CDs such as classics have a large dynamic range and are average. Often recorded at a lower recording level. Thus, even in the same type of disc, the recording level varies depending on the genre and the like, and there is a recording level difference between the discs.

  When playing a disc recorded at various recording levels in this way, even if the user sets the playback volume, the volume will change each time the disc is replaced, and the volume setting value must be changed each time. Not only is it very complicated for the user, but the volume may suddenly increase when the disk is replaced.

  Further, even if the signal level strength corresponding to the disc playback position is measured and stored in advance, and the attenuation amount and the amplification degree are set based on the strength information corresponding to the disc playback position at the time of disc playback, The level of the signal level must be measured in advance corresponding to the disk playback position. When such measurement is performed every time the disk is replaced, the user must wait for the disk playback during the measurement.

  The present invention has been made to solve the above-described problems, and provides an audio apparatus that can easily reproduce at a constant volume by reducing the level difference of the playback volume when a disk is replaced. The purpose is to do.

  An audio apparatus according to the present invention comprises a recording level detecting means for detecting a recording level of audio information recorded on an information recording medium, and a reproduction volume level of the audio information according to the recording level detected by the recording level detecting means. Playback volume level correcting means for correcting.

  According to the present invention, when audio information is reproduced from an information recording medium such as a disc, the recording level is detected, and the reproduction volume level of the audio information is corrected based on the detected recording level. Even when the information recording medium is exchanged, there is no need for the user to adjust the reproduction volume level, and the reproduction volume level difference can be easily reduced and reproduction can be performed at a constant volume. .

Embodiment 1 FIG.
FIG. 1 is a block diagram showing an example of an audio apparatus according to Embodiment 1 of the present invention. An illustrated audio apparatus 10 includes a CD / DVD deck 11, a digital signal reading unit (hereinafter simply referred to as a signal reading unit) 12, Disc type determination unit (type determination unit) 13, memory (storage unit) 14, playback volume setting unit (playback volume setting unit) 15, first playback volume setting correction unit (type volume level correction unit) 16, second A reproduction volume setting correction unit 17, a recording level detection unit (recording level detection means) 18, a correction amount setting unit 19, a control unit 20, a volume controller 21, a D / A converter 22, a power amplifier 23, and a speaker 24 are provided. Sound (audio) is reproduced from a disc (CD or DVD) set in the CD / DVD deck 11 and output from the speaker 24. Here, the correction amount setting unit 19 and the second reproduction volume setting correction unit 17 function as reproduction volume level correction means.

  When playing a disc, the playback volume level is adjusted according to the disc type (for example, the type of CD or DVD), the recording level of the disc, and the volume set by the user, as will be described later. Thus, the user can enjoy music and the like at a certain playback volume level.

Next, the operation will be described.
Now, when a disc (information recording medium: not shown) is set on the CD / DVD deck 11 and the disc is reproduced, the signal reading unit 12 performs, for example, TOC (Table of Contents) information (type) of the disc. Information) and music signals (audio information). The disc type discriminating unit 13 discriminates the disc type according to the TOC information. The signal reading unit 12 is supplied with a disc determination signal indicating a disc determination result from the disc type determination unit 13, and when the disc is a DVD, the signal reading unit 12 further performs a decoding process such as Dolby Digital. And the signal reading part 11 once memorize | stores a music signal in the memory 14 once.

  On the other hand, the user uses the volume controller (volume) 21 to set the volume volume. This volume volume is given to the control unit 20, and the control unit 20 sets a set volume level in the reproduction volume setting unit 15 according to the volume volume set by the user. The music signal read from the memory 14 has its volume level set to the set volume level set in the playback volume setting unit 15, and the playback volume level is corrected by the first and second playback volume setting correction units 16 and 17. It is corrected.

  When the first reproduction volume setting correction unit 16 corrects the reproduction volume level, a disk determination signal is given from the disk type determination unit 13, and the first reproduction volume setting correction unit 16 receives the disk type indicated by the disk determination signal. The set volume level is corrected based on the above to obtain a first corrected playback volume level. The recording level detection unit 18 accesses the memory 14 to detect the recording level of the music signal, that is, the recording level of the disc, obtains the volume correction amount according to the detected recording level detection signal, and determines the volume correction amount. 2 to the reproduction volume setting correction unit 17. The second playback volume setting correction unit 17 corrects the first corrected playback volume level based on the volume correction amount to obtain the second corrected playback volume level.

  In this way, the music signal whose playback volume level is corrected is converted into an analog music signal by the D / A converter 22, amplified by the power amplifier 23, and output from the speaker 24 as music.

  Next, operations of the first and second reproduction volume setting correction units 16 and 17 will be described. FIG. 2 is a diagram showing an example of the correction amount set in the first reproduction volume setting correction unit 16. In the example shown, when the reproduction medium (reproduction disc) is a CD, the correction amount is −5 dB. When the playback medium is a DVD, the correction amount is set to 0 dB (that is, a different correction amount is set according to the disc type). As described above, since the recording level of CD and DVD is often higher in CD and DVD, as shown in FIG. 2, correction for lowering the playback volume level at the time of playback of CD as compared with the playback of DVD is performed. I do. As a result, the volume level difference during CD / DVD replacement can be reduced. The correction amount shown in FIG. 2 is set when the disc type is discriminated before audio reproduction, and the correction amount is always kept constant during reproduction until the next disc replacement.

  FIG. 3 is a diagram showing an example of the correction amount set in the second reproduction volume setting correction unit 17, and in the example shown, the correction amount is set according to a predetermined average recording level for each time. . For example, when the average recording level is 0 to −10 dB (not including −10 dB), the correction amount = 0 dB is set, and when the average recording level is −10 to −15 dB (not including −15 dB), the correction amount is +5 dB. Is set. Similarly, when the average recording level is −15 to −20 dB (not including −20 dB), the correction amount = + 10 dB is set, and when the average recording level is −20 to −25 dB (not including −25 dB), the correction amount is set. = + 15 dB is set.

  When the average recording level is −25 to −30 dB (not including −30 dB), the correction amount = + 20 dB is set, and when the average recording level is −30 to −35 dB (not including −35 dB), the correction amount = + 25 dB. When the average recording level is −35 to −70 dB (not including −70 dB), the correction amount = + 30 dB is set, and when the average recording level is −70 dB or less, the correction amount = 0 dB is set.

  As described above, the music signal read by the signal reading unit 12 is temporarily stored in the memory 14 and the music signal read from the memory 14 is set to the set volume level by the reproduction volume setting unit 15. Using the time when the music signal is stored in the memory 14, the recording level detection unit 18 detects the average value of the recording level for each predetermined time and supplies the average recording level to the correction amount setting unit 19. give. In accordance with the average recording level, for example, the correction amount setting unit 19 searches a correction amount table shown in FIG. 3 to obtain a correction amount corresponding to the average recording level, and this correction amount is used as the second reproduction volume setting correction. Set in part 17. Then, the second reproduction volume setting correction unit 17 corrects the reproduction volume level of the music signal according to the set correction amount, and outputs the music signal.

  In this way, when the volume level of the music signal is corrected according to the average recording level, even if the disc is of the same type (even if the disc is of the same type), the playback volume level is changed according to the difference in the recording level. As a result, it is possible to reduce the reproduction volume level difference even when the same type of disc is replaced. Furthermore, even during disc playback, the playback volume level difference due to the recording level difference caused by the playback location can be reduced, and there is no trouble that the user frequently operates the volume controller 21, and the volume is always substantially constant. You can enjoy sound such as music.

  Here, two discs (Disc A and Disc B) having different recording levels were reproduced using the audio device 10. Assume that the recording levels of Disc A and Disc B change as indicated by A1 and B1 in FIG. 4, respectively. On the other hand, the correction amount setting unit 19 refers to the correction table shown in FIG. 3 according to the detected recording level (average value, for example, average value for 5 seconds) given from the recording level detection unit 18 and performs the second reproduction. A correction amount is set in the volume setting correction unit 17.

  FIG. 5 is a diagram showing changes in the correction amount set in the second reproduction volume setting correction unit 17 (curve A2 is a change in correction amount with respect to Disc A, and curve B2 is a change in correction amount with respect to Disc B). It can be seen that the correction amount shown in the correction table is set in the second reproduction volume setting correction unit 17 in accordance with the detected recording level.

  Due to the correction of the playback volume level by the second playback volume setting correction unit 17, the playback volume level of the music signal changes from the curve A1 to the curve A3 shown in FIG. When B is reproduced, the curve changes from a curve B1 to a curve B3 shown in FIG. Comparing the curve A3 and the curve B3, it can be seen that the reproduction volume level difference is reduced as a result of correcting the reproduction volume level. Further, it can be seen that even in the same type of disc, the playback volume level difference is reduced between playback locations with significantly different average recording levels. When changing the correction amount, for example, if it is changed at once from 5 dB to 10 dB, it is desirable to change it gradually (stepwise) because an uncomfortable feeling is generated at the change point.

  By the way, for example, in an in-vehicle audio device or a portable audio device, a memory (shock proof memory) that prevents sound skipping due to vibration or the like is used as the memory 14. Therefore, if data such as a music signal is stored using the shock proof memory and the recording level is detected using the data read from the shock proof memory, there is no need to newly add a memory or the like. Can be reduced.

  As described above, according to the first embodiment, the playback volume level is corrected according to the recording level of the disc, so that even if the disc is replaced, the user does not need to adjust the playback volume level. Thus, it is possible to easily reproduce at a constant volume by reducing the difference in reproduction volume level for each disk.

  According to the first embodiment, the reproduction signal read from the disk is temporarily stored in the memory, and the recording level of the reproduction signal stored in the memory is averaged over a predetermined time to obtain the recording level. Therefore, the playback is not interrupted when the disc is played, and the user does not feel bothered.

  According to the first embodiment, the disc type is discriminated in accordance with the TOC information in the disc, and the reproduction signal is corrected in accordance with the discrimination result, so that the disc type (for example, CD or DVD) is determined. ), An appropriate reproduction volume level can be corrected.

  According to the first embodiment, since the shock proof memory that prevents sound skipping due to vibration is used as the memory, the in-vehicle audio apparatus or the like that is previously provided with the shock proof memory has a new memory. There is no need, and the cost can be reduced.

It is a block diagram which shows an example of the audio apparatus by Embodiment 1 of this invention. It is a figure which shows the relationship between the correction amount set to the 1st reproduction volume setting correction | amendment part shown in FIG. 1, and reproduction | regeneration media. It is a figure which shows the relationship between the correction amount set to the 2nd reproduction | regeneration volume setting correction | amendment part shown in FIG. 1, and an average recording level. It is a figure which shows the time change of the recording level of a different disc. It is a figure which shows the change of a volume correction amount about the disk which has a recording level shown in FIG. It is a figure which shows the change of the reproduction | regeneration volume level before the volume level correction | amendment of the disc A, and after correction | amendment. It is a figure which shows the change of the reproduction | regeneration sound volume level before the sound volume level correction | amendment of the disk B, and after correction | amendment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Audio apparatus, 11 CD / DVD deck, 12 Signal reading part, 13 Disc classification determination part, 14 Memory, 15 Playback volume setting part, 16, 17 Playback volume setting correction part, 18 Recording level detection part, 19 Correction amount setting part , 20 control unit, 21 volume controller, 22 D / A converter, 23 power amplifier, 24 speaker.

Claims (5)

Information reading means for reading audio information from the information recording medium;
Recording level detection means for detecting the recording level of the audio information read by the information reading means;
An audio apparatus comprising: a playback volume level correcting unit that corrects a playback volume level of the audio information in accordance with the recording level detected by the recording level detecting unit. Comprising storage means for temporarily storing audio information read from the information recording medium;
2. The audio apparatus according to claim 1, wherein the recording level detecting means averages the recording levels of the audio information stored in the storage means over a predetermined time to obtain the recording level as an average value. . Reproduction volume setting means for outputting audio information stored in the storage means at a preset reproduction volume level,
3. The audio apparatus according to claim 2, wherein the reproduction volume level correcting means corrects the reproduction volume level for the audio information output from the reproduction volume setting means. Type discriminating means for discriminating the type of the information recording medium recorded in the information recording medium;
A type volume level correction unit that corrects the reproduction volume level of the audio information output from the reproduction volume setting unit according to the determination result by the type determination unit;
4. The audio apparatus according to claim 3, wherein the reproduction volume level correcting means corrects the audio information corrected by the type volume level correcting means. The audio device according to any one of claims 2 to 4, wherein a shock proof memory that prevents sound skipping due to vibration is used as the storage means.

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