KR20010016735A - Compact Disc for Compressed Audio Data and Compact Disc Player for Compressed Audio Data - Google Patents

Abstract

PURPOSE: A CD(compact disk) and a CD player for compressed music are provided to reproduce the CD containing compressed music while using tool unit of ordinary CD player. CONSTITUTION: To reproduce ordinary music data, data read from a head(6) is bypassed to a reproducer(8). To reproduce compressed music data, the data is stored in a buffer(12) for being reproduced into decompressed data by a decoder(16). Then, the data is reproduced in the reproducer. Herein, a specific amount of data is read from the a CD(4) for being stored in the buffer, because the storing speed in the buffer is faster than decoding speed of the compressed music. Therefore, small amount of buffer is used by not requiring to store entire data to be reproduced in the buffer.

Description

Compact Disc Players for Compressed Music and Compact Disc Players for Compressed Music Playback {Compact Disc for Compressed Audio Data and Compact Disc Player for Compressed Audio Data}

The present invention relates to a compact disc for compressed music {CD (Compact Disc)} and a CD player for playing compressed music, and more particularly to a CD capable of storing compressed music, and compressed music as well as a CD for general music. The present invention relates to a compressed music player combined CD player that can also play the recorded CD.

Generally, CD-DA (Compact Disc-Digital Audio) has been used for music CDs, but computer music has rapidly developed due to the popularization of computers and the spread of communication, and various types of audio data are used.

In particular, voice compression technology has been developed that compresses data after digitizing an analog voice signal, and various studies have been conducted to improve the compression rate while preventing degradation of sound quality. One is the Moving Picture Expert Group (MPEG) format. The MPEG format uses perceptual coding to remove audio or video signals that are unrecognizable by hearing, such as weak signals behind strong signals. Can be compressed. In particular, the recently used MPEG layer 3 is generally referred to as MP3, which has a sound quality and compression ratio high enough to hold about 14 hours of audio data on a single CD-ROM with almost the same sound quality as the original sound. to provide.

In order to play such compressed music, compressed music can be played by executing a software MP3 player such as WinAmp or WinPlay using a computer on which a sound card is installed.

However, there is a need to reproduce the above compressed music without using expensive equipment such as a computer. Especially, in the case of a portable device, the necessity of the compressed music is large. Recently, a player, such as an MP3 player, which professionally reproduces them has also appeared. The MP3 player receives the MP3 file, which is compressed and converted by a computer, through a communication or the like, and is reproduced as voice data by a decoder in the MP3 player. At this time, the MP3 player stores and plays the MP3 file received in a memory such as a flash memory to store the MP3 file.

However, such an MP3 player is limited to a small number of music files that can be played by using expensive flash memory such as a memory card as a medium for storing music files, and also has a problem in that a general music CD cannot be played.

On the other hand, the compressed format of the compressed music is AAC (Advanced Audio Coding; Alias of mp4), which is 30% higher than MP3 in addition to MP3, and ASF (Advanced Streaming) using streaming technology, which is characterized by a high compression ratio developed by Microsoft. Formats, LQT, Liquid Audio's music compression format, Vector Quntization Format (VQF), also known as Transform-domain Weighted INterleave Vector Quntization (NTV) from Japan, and AT & T's A2b with a compression ratio of 1/20. It is coming out one after another with the pros and cons of, and it is expected that new compression formats will continue to emerge in the future.

Since it is extremely inconvenient in terms of price and user's position to purchase each compressed format music player according to such various compressed formats, there is a need for a player that plays music recorded on a CD regardless of the compression format as well as the presence or absence of compression.

Accordingly, the present invention has been devised to solve the above problems, and it is possible to compress not only general music CDs but also by using the mechanism of the general music CD player without using a data-only device such as a CD-ROM driver. It is an object to provide a CD player capable of playing a CD on which music is recorded.

In order to achieve the above object, a CD player for playing compressed music according to the present invention includes a CD controller for controlling driving of an inserted CD, a head for reading data stored in the CD, and a type of data according to the type of read data. A separator for separating paths, a buffer for storing the read data if the read data is compressed data, a decoder for decoding the data of the buffer and converting the data into a general music format, and data read from the head or the decoder. A player for reproducing the decoded data, and a central controller for controlling the separator, the buffer, the CD controller, and the decoder.

Another object of the present invention is to provide a compressed music CD which is capable of reproducing compressed music by reading compressed format at the time of reproduction to decode the compressed music.

In order to achieve the above object, a compressed music CD according to the present invention includes a header information field in which information about a compressed format of compressed music is recorded and compressed music data at a specific position, and reads the compressed format at the time of reproduction, and compresses the compressed format accordingly. It is characterized by being able to play music.

1 is a schematic diagram of a compact disc (CD) player for playing compressed music according to the present invention.

2 is a schematic diagram of a CD for compressed music according to the present invention.

<Explanation of symbols for main parts of drawing>

2 ... CD Controller 4 ... CD

6 ... head 8 ... player

10 ... separator 12 ... buffer

14 ... central controller 16 ... decoder

Hereinafter, exemplary embodiments of a CD player for playing compressed music according to the present invention will be described in detail with reference to the accompanying drawings.

1 shows a schematic diagram of a CD player for playing compressed music according to an embodiment of the present invention.

The CD player for compressed music reproduction includes a CD controller (2) for controlling a CD (4) inserted in the player, a head (6) for reading data of the CD (4), and a path for reading the read data. Separator 10, a buffer 12 for storing the read data in the case of compressed music, a decoder 16 for decoding the data of the buffer 12 and converting the data into a general music format, and the data or decoder read out from the head 6 A player 8 for reproducing the data decoded at 16, and a central controller 14 for controlling the separator 10, the buffer 12, the CD controller 2, and the decoder 16.

The separator 10 changes the path for transmitting the read data depending on whether the inserted CD 4 is a general music CD or a compressed music CD. That is, when the inserted CD 4 is a general music CD, the read data is sent to the player 8 for playback. In the case of a compressed music CD, the read data is stored in the buffer 12.

At this time, it is necessary to determine whether the data read out from the head 6 is general music or compressed music. To this end, as shown in FIG. 2, the compressed music CD 4 separately installs the header information field 20 and the compressed music field 22 in which the presence or absence of compression and / or the compression format are recorded. In this case, the header information field 20 may be formed at any specific position of the CD 4, but is preferably formed inside the CD. On the other hand, since the CD for general music does not have header information on a compressed format, it can be determined that the data read out using the general music CD is general music. In FIG. 2, 24 is an insertion hole for CD rotation, and 26 is a transparent part for CD fixing.

As music data is recorded in various kinds of compression formats on the CD, information about the compression format is recorded in the header information field 20 of the CD. You can choose the type. At this time, the header information may be stored in the buffer 12 first, and then the central controller 14 may read and perform the same. The central controller 14 may use the compressed music format (general music is an uncompressed format) according to the header information. Can be seen), and the appropriate control is performed.

That is, in the case of general music data, the data read out from the head 6 is bypassed to the player 8, and in the case of compressed music data, it is stored in the buffer 12 once and then decompressed by the decoder 16. The data is reproduced by the player 8 for reproduction.

In the case of compressed music, the data recorded on the CD 4 is compressed at a high compression rate, so that the speed of storing the data of the CD 4 in the buffer 12 is considerably faster than the speed at which the compressed music is decoded and reproduced as sound. . Therefore, it is not necessary to continuously store the data of the CD 4 in the buffer 12, and read only a certain amount of data from the CD 4, store it in the buffer 12, decode and play the music, and play the music. When the data is further needed, the data can be read out and stored in the buffer accordingly. At this time, since the buffer 12 area in which the decoded data has been recorded can be reused and stored, all the data to be reproduced is stored in the buffer 12. Only a relatively small amount of buffer 12 can be used since there is no need to store in.

On the other hand, the central controller 14 transfers the data stored in the buffer 12 to the decoder 16 at an appropriate speed required for music reproduction. In order to transfer the data between the buffer 10 and the decoder 16, a method such as DMA (Direct Memory Access), in which the central controller 14 is not continuously involved, may be used. As the decoding proceeds, the central controller 14 transmits a player control signal to the CD controller 2 to read the data of the CD 4 into the buffer 12 to enable continuous music reproduction.

The buffer 12 preferably uses a first-in, first-out queue type memory. At this time, the capacity of the buffer 12 can be appropriately determined according to the decoding speed and the compression ratio of the decoder 16, and it is sufficient to use several megabytes of RAM. Therefore, the CD player for compressed music playback can be produced at a relatively low cost compared to the conventional MP3 player using a large amount of flash memory and expensive.

This compressed music player CD player can play not only general music CDs but also CDs 4 recorded in various compressed formats. For example, in addition to MP3, AAC (Advanced Audio Coding; Alias of mp4) with more than 30% better compression rate than MP3, Advanced Streaming Format (ASF) using Streaming technology featuring high compression rate developed by Microsoft, and Liquid Audio LQT, which is a compression format, Vector Quntization Format (VQF), also known as Transform-domain Weighted INterleave Vector Quntization (NTV) of Japan NTT, A2b of AT & T Co., which has a compression ratio of 1/20, and the like. In order to play CDs recorded by such various compression formats, it is sufficient to provide a decoder 16 corresponding to each compression format.

In addition, in order to play music of various compression formats with one player, a plurality of decoders corresponding to the compression format are installed in the player and decoded by the corresponding decoder 16 according to the compression format. Freely play CDs recorded in compressed music format.

The decoder 16 used in the compressed music player CD player according to the present invention may be implemented in hardware, software or firmware as necessary.

The storage method proposed by the present invention may vary somewhat depending on the compression format, but it is possible to store dozens of pieces of music on a single piece of current music CD, and the compressed music CD in which many of these songs are stored is compatible with the general music CD. This provides a new type of music storage format with remarkable storage efficiency compared to conventional music CDs.

As described above, the CD player for playing compressed music according to the present invention is a player composed of a mechanism part of a CD player for general music, and can play not only general music CD but also CD with compressed music recorded thereon. In addition, it is possible to play compressed music according to various compression formats as one player, which not only promotes user convenience, but also is economical and portable. In addition, the conventional MP3 player is expensive because it requires a large amount of memory, whereas the CD player for playing compressed music can play a much larger amount of music using a relatively small amount of memory.

On the other hand, the CD for compressed music according to the present invention can store dozens to hundreds of songs on a single CD, which has an effect of significantly increasing the storage efficiency compared to conventional general music CDs.

Claims (5)

CD controller 2 for controlling the operation of the inserted CD 4, a head 6 for reading data stored in the CD 4, and a separator for separating the path of data according to the type of read data. (10), a buffer 12 for storing the read data when the data is in a compressed format, a decoder 16 for decoding the data in the buffer 12 and converting the data into a general music format, and the head ( A player 8 which reproduces the data read out from 6 or the data decoded by the decoder 16, and controls the separator 10, the buffer 12, the CD controller 2, and the decoder 16; CD player for playing compressed music including a central controller (14). The CD player according to claim 1, wherein the buffer (12) stores header information relating to the presence or absence of compression and / or compression format. The CD controller (2), the separator (10), according to claim 1 or 2, wherein the central controller (14) reads the header information stored in the CD (4) to determine whether there is a compression and / or a compression format. And / or selectively play compressed or uncompressed music by controlling the decoder (16). The CD player according to claim 1 or 2, wherein the decoder (16) decodes the compressed music by being decoded by the decoder (16) corresponding to a compression format in which a plurality of decoders are installed and read. . Compressed music CD comprising a header information field in which information about the compressed format of compressed music is recorded at a specific position and compressed music data so that the compressed format can be read at the time of playback to decode and play the compressed music accordingly. .