JP2006004515A - Disk reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk reproducing device capable of stabilizing the output of voice when compressed voice data are reproduced at a high speed. <P>SOLUTION: The start address and the start time code for each piece of music stored in a buffer memory 16 are taken into a CPU 20, and the number of sectors required for constituting one frame when the compressed data of each piece of the music are decoded is calculated. The number of the sectors to be thinned is made large when the number of the required sectors is large and the number of sectors to be thinned is made small when the number of the required sectors is small so that the number of the frames included in one or each of the plurality of effective sectors having consecutive addresses read from the buffer memory 16 is controlled so as to be constant. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a disk reproducing apparatus that reads and reproduces data recorded on a disk medium.

  In recent years, SuperAudioCD, in which audio data having a higher bandwidth than CDDA (Compact Disc Digital Audio), which is a reproduction-only music CD, is attracting attention. For example, multi-channel audio data is recorded along with 2-channel audio data on the SuperAudioCD. The 2-channel audio data may not be compressed, but the multi-channel audio data is compressed and recorded because the data amount is large. TOC (Table of Contents) information, which is header information of each, is recorded at the head of the 2-channel and multi-channel audio data. The TOC information includes a start address of each song (track), a start time code, and the like.

By the way, the conventional disk reproducing apparatus stores the audio data read from the disk in the buffer memory, and reads and reproduces the audio data stored in the buffer memory. When reproduction information is operated and input, audio data stored in a buffer memory is thinned out and reproduced. As a result, the number of disk accesses is reduced, disk control is simplified, power consumption is reduced, and playback responsiveness to operation inputs is improved (see, for example, Patent Documents 1 and 2).
JP-A-7-141777 JP 2000-339864 A

  However, in the conventional disc playback device that plays SuperAudioCD, since the audio data stored in the buffer memory remains compressed, if the audio data stored in the buffer memory is thinned out in units of sectors, the audio data stored in the buffer memory is compressed for each song (track). Since the rate is changed, there is a problem that in some songs, the extended voice is reproduced, and in other songs, the voice is reproduced every minute, which gives the user a sense of incongruity.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a disc reproducing apparatus capable of making the audio output constant when the compressed audio data is reproduced at high speed.

  In order to achieve the above object, a disc reproducing apparatus according to the present invention includes compressed data obtained by compressing plane data configured in units of frames at different compression rates for a plurality of tracks, and a start address and a start time code of each track. Reading means for reading out the header information and the compressed data in units of sectors from a disk on which header information is recorded, storage means for storing the header information and compressed data read by the reading means, and storage in the storage means System control means for reading the compressed data stored in the storage means on the basis of the header information recorded, and decoding and reproducing the read compressed data, the system control means during the playback of the disc Stored in the storage means when fast-forward or fast-reverse high-speed playback information is input A disc playback apparatus having first high-speed playback control means for intermittently reading out compressed data, wherein the first high-speed playback control means includes a start address and a start time of each track stored in the storage means. First calculation means for reading a code and calculating the number of sectors required to form one frame when the compressed data of each track is decoded based on the read start address and start time code of each track And the storage means based on the number of sectors calculated by the calculation means so that the number of frames included in each of a plurality of sectors having one or more addresses that are intermittently read from the storage means is constant. And a first setting means for thinning out the compressed data stored in the memory.

  According to the disk reproducing apparatus of the present invention, when high-speed reproduction information is input, 1 when the compressed data of each track is decoded based on the start address and start time code of each track stored in the storage means. The number of sectors required to form a frame is calculated by the first calculation means, and the first calculation is performed so that the number of frames of one or more sectors read continuously from the storage means is constant. Based on the number of sectors calculated by the means, the compressed data stored in the storage means is thinned out by the first setting means. Therefore, at the time of high-speed reproduction, compressed data including a certain number of frames can be intermittently read and the sound output can be made constant.

  In order to achieve the above object, when high-speed playback information is operated and input, one frame is formed when the compressed data of each track is decoded based on the start address and start time code of each song included in the header information. The disk reproducing apparatus of the present invention is configured to calculate the number of sectors necessary to perform the calculation, and to calculate the number of sectors to be thinned out for each song so that the number of frames included in a plurality of continuously read out sectors is constant. Configure.

FIG. 1 is a diagram illustrating a schematic configuration of a disk reproducing apparatus according to the first embodiment.
As shown in FIG. 1, the disc playback apparatus of the first embodiment is a player that plays a SuperAudio CD 10. In the SuperAudio CD 10, for example, audio data constituting music is divided and recorded for each song (track). Each song is compressed at a different compression rate. TOC information (Table of Contents), which is header information, is recorded at the head of audio data constituting music. The TOC information is composed of the beginning address of each song, the time code of each song, and the like. The header information and the audio data of each song are recorded on a sector basis of the SuperAudio CD. The audio data (plane data) before compression is configured in frame units of 13.3 msec (1/75 sec). When the compression rate is maximum, 7 frames are recorded in one sector, and when the compression rate is minimum, 1 frame is recorded in 16 sectors.

  As shown in FIG. 1, the disk reproducing apparatus of the first embodiment includes a pickup 11, an RF amplifier 12, a servo controller 13, an ECC (Error Correction Code) 14, a memory controller 15, a buffer memory 16, and a DSD (Digital Stream Digital) 17. A DAC (Digital Analog Converter) 19, an operation display unit 19, and a CPU 20.

  The pickup 11 reads out the audio signal recorded on the SuperAudio CD 10 in units of sectors. The RF amplifier 12 amplifies the audio signal read by the pickup 11. The servo controller 13 controls the rotation of the SuperAudio CD 10 and controls the focus, tracking, and feed of the pickup 11. The ECC 14 converts the audio signal amplified by the RF amplifier 12 into digital audio data, and performs error correction on the audio data. The memory controller 15 temporarily stores in the buffer memory 16 the audio data that has been subjected to error correction by the ECC 14. The buffer memory 16 is composed of, for example, a DRAM. The DSD 17 decodes the compressed audio data stored in the buffer memory 16. The DAC 18 converts the audio data decoded by the DSD 17 into an analog audio signal and outputs the analog audio signal. The operation display unit 19 inputs operation information such as playback, stop, and fast forward, and displays status information such as music and time. The CPU 20 is mutually connected to the RF amplifier 12, the servo controller 13, the ECC 14, the memory controller 15, the DSD 17, and the operation display unit 19, and controls the entire apparatus.

  When the SuperAudio CD 10 is played back, the audio signal recorded on the SuperAudio CD 10 is read by the pickup 11, amplified by the RF amplifier 12, converted into audio data by the ECC 14, temporarily stored in the buffer memory 16, and then stored in the DSD 17. Is converted into an audio signal by the DAC 18 and output. First, the TOC information of the SuperAudio CD 10 is stored in the buffer memory 16, necessary information included in the TOC information is taken into the CPU 20, and then the audio data of each song is sequentially stored. The audio data of each song is read from the buffer memory 16 and played back. Access to the SuperAudio CD 10 and the buffer memory 16 is performed in units of sectors of the SuperAudio CD 10.

FIG. 2 is a flowchart showing the high-speed playback operation of the disc playback apparatus.
When the fast-forward button on the operation display unit 19 is pressed, first, the CPU 20 reads the start address and start time code of each song stored in the buffer memory 16 (step S1), and constitutes one frame of each song. Therefore, the number of sectors necessary for the calculation is calculated (step S2), and the number of sectors to be thinned out for each song is calculated by the CPU 20 (step S3). Next, the CPU 20 calculates the address of the head sector for fast-forwarding of the buffer memory 16 (step S4), and the CPU 20 validates or invalidates subsequent sectors in the buffer memory 16 according to the number of sectors to be thinned out for each song. Is set (step S5). Next, the invalid sector is skipped from the head sector of the buffer memory 16 by the CPU 20, and only valid sectors are sequentially read out, and high speed reproduction is performed (step S6).

FIG. 3 is a diagram illustrating an example of compressed data. FIG. 4 is a diagram showing the relationship between the relative address and playback time of a certain song.
As shown in FIG. 3, it is assumed that the start address and start time code of the first song and the start address and start time code of the second song included in the TOC information stored in the buffer memory 16 are acquired by the CPU 20. .

  First, the start address (30000) of the first music is subtracted from the start address (40000) of the second music, and the number of sectors (10000) of the first music is calculated. Next, the start time code of the first song (00 minutes 00 seconds 00 frames) is subtracted from the start time code of the second song (00 minutes 20 seconds 00 frames), and the playback time of the first song (20 × 75 frames = 1500 frames) Is calculated. Next, the number of sectors (10000) of the first song is divided by the reproduction time (1500), and the number of sectors (6.6...) Necessary for constituting one frame is calculated.

  Next, the number of sectors to be thinned out is determined from the number of sectors. When the number of sectors required for constituting one frame is large, the compression rate is low, so the number of sectors to be thinned is large. When the number of sectors required for constituting one frame is small, the compression rate is high, so the number of sectors to be thinned out is small.

  Since the number of sectors required to constitute one frame is not necessarily an integer value, as shown in FIG. 4, the relative address (number of sectors) of the music is plotted on the horizontal axis and the relative time (number of frames) is plotted on the vertical axis. For the axis, a straight line graph in which the inclination means the compression rate is generated, and the address of the sector to be validated or invalidated may be calculated by linear interpolation.

FIG. 5 is a diagram illustrating an example of the reading operation of the disk device. FIG. 6 is a diagram showing an example of a read operation of a conventional disk device.
As shown in FIG. 6, in the conventional disk reproducing apparatus, when the number of frames with consecutive addresses fluctuates when being decoded and decoded every certain sector, a certain piece of music reproduces an extended sound, In this song, every minute sound is played, giving the user a sense of incongruity.

  As shown in FIG. 5, in the disk playback apparatus of the first embodiment, during high-speed playback, for example, the first song is set for every two sectors, the second song is set for every three sectors, and the third song is set for every five sectors. The effective sector is thinned out from the buffer memory 16 and read out. When decoded by the DSD 17, the audio data of 5 frames is decoded from all the effective sectors having consecutive addresses, and a certain audio is output by the DAC 18.

  As described above, according to the disk reproducing apparatus of the first embodiment, the number of sectors necessary for constituting one frame when the compressed data of each music is decoded is calculated during high-speed reproduction. When the required number of sectors is large, the number of sectors to be thinned is increased. When the required number of sectors is small, the number of sectors to be thinned is decreased, and one or a plurality of consecutive addresses read by thinning out from the buffer memory 16 are read. The number of frames included in each effective sector is controlled to be constant. Therefore, the sound output can be made constant.

  In the first embodiment, when high-speed playback is input during playback, the compressed data stored in the buffer memory 16 is thinned out. However, for example, high-speed playback is input before normal playback. In some cases, it is also possible to read out data from the SuperAudio CD 10 by thinning out sectors in each piece of music.

1 is a diagram illustrating a schematic configuration of a disk reproducing device according to Embodiment 1. FIG. It is a flowchart which shows the operation | movement of high-speed reproduction of a disc reproducing | regenerating apparatus. It is a figure which shows an example of compressed data. It is a figure which shows the relationship between the relative address and playback time of a certain music. It is a figure which shows an example of the read-out operation | movement of a disc apparatus. It is a figure which shows an example of the read-out operation | movement of the conventional disc apparatus.

Explanation of symbols

10 ... SuperAudioCD, 11 ... Pickup, 12 ... RF amplifier, 13 ... Servo controller, 14 ... ECC (Error Correction Code), 15 ... Memory controller, 16 ... Buffer memory, 17 ... DSD (Digital Stream Digital), 18 ... DAC (Digital Analog Converter), 19 ... Operation display section, 20 ... CPU.

Claims (3)

The header information and the compression from the disc on which the compressed data obtained by compressing the plane data configured in units of frames at different compression rates for each of the plurality of tracks and the header information including the start address and start time code of each track are recorded. Reading means for reading out data in sector units, storage means for storing header information and compressed data read by the reading means, and compression stored in the storage means based on header information stored in the storage means System control means for reading data and decoding and reading the read compressed data, the system control means, when fast-forward or fast-reverse high-speed playback information is input during playback of the disc, A first high-speed reproduction system that intermittently reads out the compressed data stored in the storage means. A disc reproducing apparatus having means,
The first high-speed playback control means includes
1 frame is formed when the start address and start time code of each track stored in the storage means are read and the compressed data of each track is decoded based on the read start address and start time code of each track First calculating means for calculating the number of sectors necessary for performing,
Store in the storage means based on the number of sectors calculated by the calculation means so that the number of frames included in each of a plurality of sectors having consecutive addresses or one address read intermittently from the storage means is constant. First setting means for thinning out the compressed data,
A disc player characterized by that. The system control means is configured to cause the reading means to intermittently read out the compressed data stored in the disk when fast-forward or fast-rewind high-speed playback information is input before playing the disk. Having high-speed playback control means,
The second high-speed playback control means includes
One frame is formed when the start address and start time code of each track stored in the storage means are read and the compressed data of each track is decoded based on the read start address and start time code of each track Second calculating means for calculating the number of sectors necessary to
A second method for thinning out the compressed data stored in the disk based on the number of sectors calculated by the calculation means so that the number of frames included in one or more sectors continuously read from the disk is constant. 2. The disk reproducing apparatus according to claim 1, further comprising: a setting unit. 2. The disc reproducing apparatus according to claim 1, wherein the disc is a Super Audio CD (Super Audio Compact Disc), and the header information is TOC (Table of Contents) information.

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