Patent Application
20130021885
This application claims the benefit under U.S.C. §119(a) of Korean Patent Application No. 10-2011-0072574, filed on Jul. 21, 2011, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein in its entirety by reference for all purposes.
1. Field
The following description relates to an optical disc drive which is compatible with a plurality of hosts for reproducing digital content and a method of driving the optical disc drive.
2. Description of the Related Art
Optical disc drives are devices for storing and reproducing information. Examples of optical discs include compact discs (CDs), digital versatile discs (DVDs), blu-ray discs (BDs), and the like. Most DVD storage devices are compatible with CDs that have low capacity. In addition, optical medium storage devices compatible with CDs, DVDs, and BDs have recently been suggested.
Examples of information display devices include general-purpose devices such as computers and television (TV) sets. TV sets are image display devices that may be used to watch various pieces of information in real time. Recently, TV sets have been manufactured to allow peripheral devices to be connected thereto so that various pieces of content stored in the peripheral devices may be displayed using the TV set. TV sets, also referred to as hosts, have a limited connectivity range and compatibility problems with various types of media. For example, such hosts may reproduce digital content such as videos or music by themselves, however, most hosts do not include reproduction software for reproducing music from CDs, that is, reproducing audio of compact disc-digital audios (CD-DAs), and thus, may not reproduce digital content of the CDs.
In a general aspect, there is provided an optical disc drive comprising an information processing unit that processes information related to an optical medium, and an interface that connects the information processing unit to an external host. The information processing unit comprises a virtual file generator that generates content in a format that may be reproduced by a host, wherein the format is different from a format of content of the optical medium. The interface may use a universal serial bus (USB) protocol.
The optical disc drive may further comprise a virtual file generator that generates a virtual wave file using content in a raw data format of a compact disc-digital audio (CD-DA).
The optical disc drive may further comprise an interface comprising a file system converter that converts information of a file system in a native format of the optical medium into information of a file system supported by the host. The interface may also convert a native command set of the optical disc drive to a command set supported by the host. The interface may use a wireless protocol. The file system supported by the host may be a file allocation table (FAT) file system.
The optical disc drive may further comprise an optical medium that includes a native file system, which may be a compact disc-digital audio (CD-DA) file system, a file allocation table (FAT) file system, a compact disc file system (CDFS), or a universal disc format (UDF) file system.
In another general aspect, there is provided a method of driving an optical disc drive. The method comprises generating virtual digital content in a format that is different from a specific format of an optical disc mounted in the optical disc drive using digital content, and transmitting the virtual digital content to a host in response to a request of a host to which the optical disc drive is connected.
The method of driving an optical disc drive may further comprise generating virtual digital content in a wave format from content in a compact disc-digital audio (CD-DA) format. A virtual file system may be generated using content information of the optical disc. Further, the virtual file system may be an allocation table (FAT) file system.
The method of driving an optical disc drive may additionally comprise converting information of a file system in a native format of an optical medium mounted in the optical disc drive to information of a file system supported by the host, and transmitting the information of the file system supported by the host in response to a request of the host. In this aspect, a native command set of the optical disc drive may be converted to a command set supported by the host. Further, the file system supported by the host may be a file allocation table (FAT) file system. The optical disc may comprise one of a file allocation table (FAT) format, a compact disc file system (CDFS) format, a universal disc format (UDF), and a compact disc-digital audio (CD-DA) format.
Also, the optical disc drive may exchange information with the host by using a universal serial bus (USB) protocol.
In another general aspect, there is provided an optical disc drive that is connected to a host. The optical disc drive comprises a converter configured to convert data comprising a compact disc-digital audio (CD-DA) format into a virtual file system, and an interface configured to transmit the virtual file system to the host.
Other features and aspects may be apparent from the following detailed description, the drawings, and the claims.
Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience.
The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or system described herein. Accordingly, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be suggested to those of ordinary skill in the art. Also, descriptions of well-known functions and construction may be omitted for increased clarity and conciseness.
Typically, a digital content reproduction device such as a TV set does not have the ability to reproduce audio content in a compact disc-digital audio (CD-DA) format. The following relates to an optical disc drive that may provide digital content, for example CD-DA content, to a digital content reproduction device in a format that may be reproduced by the digital content reproduction device. For example, the providing of the digital content may include generating a virtual file system that is supported by the digital content reproduction device.
An audio CD in a CD-DA format, as defined by the Red Book, a standard for CD-DA specifications, includes three regions, that is, a lead-in region, a program region, and a lead-out region. An address of each track is stored in a table of content (TOC) of the lead-in region. Beginning and closing addresses of audio tracks and the audio tracks on which data is actually recorded are located in the program region.
As described herein, an optical disc drive may generate a virtual file, for example, a wave file, and a virtual file system, for example, a file allocation table (FAT) system based on information about the TOC and provide the virtual file and the virtual file system to a reproducer. In addition, the optical disc drive may be compatible with various other discs as well as an audio disc in a CD-DA format.
Optical media as described herein includes all types of general media on which information is physically recorded. Examples of the optical media include CDs, digital versatile discs (DVDs) (e.g., DVD-Rs, DVD-RWs, DVD+Rs, DVD+RWs, and DVD-RAMS), blu-ray discs (BDs), and the like, which each have their native file systems. The optical media may support file systems such as a compact disc file system (CDFS), a universal disc format (UDF) file system, and/or a file allocation table (FAT) file system. The optical media may also support audio that provides raw audio data having a track shape. In an example, the optical media may be mounted in optical disc drives, which may have interfaces connected to external hosts. For example, external hosts may include digital content reproduction devices such as television (TV) sets, set-top boxes, or DivX players. Although the optical media are independent devices, because native functions of the optical media may be performed by the optical disc drives, the optical media may be considered as elements of the optical disc drives.
Referring to
Information may be exchanged between interfaces of the optical disc drive 10 and the host 20 via the inter-cable 30, and the interfaces may each include a 1.0, 1.1, 2.0, or 3.0 version universal serial bus (USB) port. That is, a USB cable may be used as the inter-cable 30, and thus the optical disc drive 10 and the host 20 may exchange information by using a USB protocol. As another example, the interfaces may communicate wirelessly without using the inter-cable 30. Examples of wireless include BLUETOOTH®, an ad hoc method, a wireless optical connection method using infrared light, and the like.
The host 20 to which a slave may be connected may support a limited range of file systems. A typical file system is a FAT file system, which is applied to various types of memory cards such as CompactFlash (CF), Secure Digital (SD), MultiMediaCard (MMC), and Memory Stick, as well as hard disc drives (HDDs). Although there are various file systems, the host 20 may not support all of the file systems and may support one or more widely used file systems. Content to be reproduced may be obtained from the slave. However, a host 20 which supports only a FAT file system may not receive content from an optical medium storage device including a CDFS/UDF file system.
The following relates to a method and device, which may connect an optical disc drive to a host 20 that supports a limited range of file systems, such as a TV set, a set-top box, and a Divx player. The optical disc drive may convert a native file system of the optical disc drive into a file system supported by the host, and send the converted file system to the host. For example, the host 20 may reproduce raw audio content by establishing a virtual file and a virtual file system supported by the host 20 using track information from a CD-DA in which no file system exists. While a TV set is described as an example of a digital content reproduction device, the description herein is not limited thereto. Other examples of a digital content reproduction device include a digital photo frame, and the like.
Referring to
The optical pickup 12 may include an optical system including one or more of an objective lens, a laser diode (LD), a photodetector, and a mechanical system for mechanically supporting the optical system and performing focusing and tracking. The information processing unit 13 may include an encoder/decoder. In this example, the information processing unit 13 is connected to the interface 15 for connecting the optical disc drive 10 to a host 20, and the servo unit 14 is connected to the mechanical system. The information processing unit 13, the servo unit 14, and the interface 15 may be controlled by the central controller 16. In various examples, the information processing unit 13 may include a virtual file generator 13a for generating content in a format so a host 20 may reproduce content of a CD-DA format obtained from a CD.
Referring to
The host 20 may recognize that the optical disc drive 10 is a receivable device, and may receive information of a recognizable file system from the optical disc drive 10. As described herein, a receivable device is a device which a host 20, such as the TV set, a set-top box, or a DivX player, may recognize and access. In an example, receivable device may be used when the host 20 and the receivable device connected to the host 20 use a compatible command set and a compatible file system. A device that may not be accessed by the host 20 is defined as an unknown device and may not exchange information with the host 20.
While the optical disc drive 10 is connected to the host 20, the optical disc drive 10 may transmit information in response to a request of the host 20. However, if the optical disc drive 10 is not compatible with the host 20, the optical disc drive 10 may transmit a code regarding information about a command set mainly used by a block device such as a hard disc drive (HDD), which is a widely compatible and similar medium, by using a converter, which may be embedded in the interface 15. For example, if a CD-DA is used, the optical disc drive 10 may generate a virtual file system that may be recognized by the host 20 and may enable the host 20 to reproduce digital content of the CD-DA using the virtual file system.
According to an example of the USB specification, the optical disc drive 10 may have a device class code 08h in an interface descriptor and belongs to a mass storage device, and may have a subclass code 02h, and thus, may use an MMC-5 (AT attachment packet interface (ATAPI)) command set. However, if a device having a subclass code 02h using an MMC command set, that is, the optical disc drive 10 is a device that is not supported by the host 20, the optical disc drive 10 may not be used. Accordingly, by transmitting a subclass code 06h using a most common SBC (small computer system interface (SCSI) block command to the host 20, the host 20 may recognize the optical disc drive 10 as a usable device. However, if the device having the subclass code 02h is a device that is not supported by the host 20, the subclass code 02h may be transmitted as it is to the host 20. The optical disc drive may be a device having a peripheral device code 05h using an MMC command set. If a host 20 does not support such an MMC command set, the peripheral device code 05 may be converted to code 00h corresponding to a device using a receivable command set, for example, a most common SBC command set. In an example, a most common SBC command set may be a direct-access block device, such as a magnetic disc drive.
In this example, it is assumed that the optical disc drive 10 is recognized by the host 20 as a usable device. Accordingly, if the host 20 requests directory entry information, the optical disc drive 10 may convert information of a file system having a native format of the optical medium 11 to information of a file system having a format which may be recognized by the host 20. The optical disc drive 10 may transmit the converted information of the file system to the host 20. That is, although the optical disc drive 10 has information of a file system not recognizable by the host 20, for example a CD-DA or CDFS/UDF/FAT format, the optical disc drive 10 may convert the information of the file system into information of a file system that is recognizable by the host, for example, a FAT format, in response to a request of the host 20. The optical disc drive 10 may transmit the information of the file system having, for example, the FAT format to the host 20. In various examples, the conversion may be performed using a converter, which may be embedded in the interface 15. Examples of the FAT format include a FAT16 format of 16 bits, a FAT32 format of 32 bits, and the like.
Accordingly, the host 20 may recognize file information, which may include an address of content stored in the optical medium 11, and thus, the host 20 may access and reproduce specific content.
As described herein, a general host may not reproduce digital content that is in a CD-DA format. Accordingly, in various examples herein, the host 20 may access content in the CD-DA format using the aforesaid method, but may not reproduce the content in the CD-DA format. In general, a host 20 that may reproduce digital content may include a decoder for processing a WAV file or an MP3 file except a CD-DA format. In an example, an optical disc drive 10 may convert a CD-DA format into a format which may be processed by a host 20 for reproducing content and may provide the format to the host 20 via an interface 15.
In conventional art, a CD for providing content in a CD-DA format does not include a file system. The optical disc drive 10 may generate a virtual file system using, for example, table of content (TOC) information obtained from the CD. As an example, a CD may include up to 99 tracks, and each of the 99 tracks may include 2-channel 16-bit audio data modulated using linear pulse code modulation (PCM) at a sampling frequency of 44.1 khz. Such data in a CD-DA format may be converted to data in another format. For example, the virtual file generator 13a may generate a virtual wave file, as shown in
Referring to
Referring to
Additionally, a device type may be converted to a device type using a command set supported by the host 20. Referring to
Further, in operation 808, it may be determined whether an optical medium or an optical disc may be loaded on a disc tray. If it is determined in operation 808 that the optical medium or the optical disc is loaded on the disc tray, the method may proceed to an operation to determine whether there may be a next file system. If it is determined in operation 808 that the optical medium or the optical disc is not loaded on the disc tray, the method may end.
Also, in operation 809, it may be determined whether the optical disc is a disc of, for example, a FAT format. For example, a DVD-RAM may be formatted by using a UDF or FAT file system. If the DVD-RAM is formatted by using a FAT file system, the method may proceed to operation 814. In operation 814, since the FAT format may be supported by the host 20, the method may end. If the DVD-RAM is not formatted by using a FAT file system, the method may proceed to operation 810. In operation 810, it may be determined whether the optical disc is a disc of, for example, a CDFS format. If the optical disc is a disc of a CDFS format, the method may proceed to operation 811. In operation 811, a CDFS of the optical disc drive may be converted to a FAT file system to operate in response to a request of the host 20. If the optical disc is not a disc in a CDFS format, the method may proceed to operation 812. In operation 812, it may be determined whether the optical disc is, for example, a disc in a UDF format. If the optical disc is a disc in a UDF format, the method may proceed to operation 813. In operation 813, a UDF file system may be converted to a FAT file system in response to a request of the host 20.
In operation 814, it may be determined whether the optical disc is, for example, a disc in a CD-DA format. If it is determined in operation 814 that the optical disc is a disc of a CD-DA format, the method may proceed to operation 815. In operation 815, track information may be acquired from a TOC, and a virtual FAT file system may be generated. If it is determined in operation 814 that the optical disc is not a disc in a CD-DA format, the method may proceed to operation 804. In operation 804, a PC mode may be performed.
The host 20 may have information of a FAT file system such as directory entry or FAT from the optical disc drive 10, and thus, may upload and reproduce digital content from the optical disc drive. In an example, if a host 20 may not reproduce a CD-DA format, but rather, may reproduce a wave file, the host 20 may reproduce digital content in a CD-DA format from a CD. The method described herein may be used when access to an optical disc drive 10 may not be allowed, and when access to an optical disc drive 10 may be allowed, but an optical disc in a specific format may not be supported. That is, when a host 20 is not compatible with content of an optical disc drive 10 or a specific optical disc, the method may generate device information and a file system compatible with the host 20. In another example, the method may provide digital content that may be reproduced by the host 20 to the host 20 when a host 20 may not reproduce content of a CD and may reproduce content in another format.
Program instructions to perform a method described herein, or one or more operations thereof, may be recorded, stored, or fixed in one or more computer-readable storage media. The program instructions may be implemented by a computer. For example, the computer may cause a processor to execute the program instructions. The media may include, alone or in combination with the program instructions, data files, data structures, and the like. Examples of computer-readable storage media include magnetic media, such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM disks and DVDs; magneto-optical media, such as optical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like. Examples of program instructions include machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The program instructions, that is, software, may be distributed over network coupled computer systems so that the software is stored and executed in a distributed fashion. For example, the software and data may be stored by one or more computer readable storage mediums. Also, functional programs, codes, and code segments for accomplishing the example embodiments disclosed herein can be easily construed by programmers skilled in the art to which the embodiments pertain based on and using the flow diagrams and block diagrams of the figures and their corresponding descriptions as provided herein. Also, the described unit to perform an operation or a method may be hardware, software, or some combination of hardware and software. For example, the unit may be a software package running on a computer or the computer on which that software is running.
A number of examples have been described above. Nevertheless, it will be understood by those of ordinary skill in the art that various changes in form and details may be made. For example, suitable results may be achieved if the described techniques are performed in a different order or if components in a described system, architecture, device, or circuit are combined in a different manner or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2011-0072574 | Jul 2011 | KR | national |
