|Portable DVD player|
|Saturday, 16 September 2006|
DVD systems have become popular in recent years as home video entertainment systems. DVD systems may also be used to record, store and provide data, such as computer and computing systems, in larger quantities than have heretofore been practicable with other storage devices. The digital versatile disk (DVD) standards provide for many features that were not available in previous standard video technologies, such as VHS tape and laser disc. A DVD provides nine angle screens. Image data of the respective angles are formatted in disc by disc manufacturers. In this respect, there can be provided a vivid screen by playing data corresponding to a variety of angles for a film scene or a live concert scene while variously varying the angle. The DVD format can be used for video, data storage, audio applications, and interactive videos, games, etc. Moreover, the DVD format allows each of these applications a greater flexibility than they would otherwise have under conventional video or audio CD formats or CD-ROM. The storage and playback mechanism used in DVDs closely resembles the mechanism used in compact discs (CDs) and DVD players and software use the same laser technology as CD players. However, the information storage capacity of a typical DVD is much higher than a CD. Presently available DVDs have a variety of capacities which depend on the technology used to manufacture the discs. Single-layer technologies can be either single or double-sided with capacities of 4.7 gigabytes and 9.4 gigabytes, respectively. Dual layer technologies will soon be available which use single or double sided capacities that hold approximately 8.5 gigabytes per side. This high information storage capacity makes DVDs suitable for storing not only audio information, but also video information and large amounts of computer data as well. Two DVD applications have been developed, namely a DVD video player and a DVD-ROM driver. The DVD video player reproduces still picture data/motion picture data, audio signal from the DVD, and transfers the data and signals to a home television set, whereby the TV reproduces them. The DVD-ROM reproduces video/motion picture data, audio signal, or digital data from the DVD, and transfers them to a personal computer (PC), whereby the PC outputs them on a display and to a speaker.
A DVD player is a device for playing discs produced under the DVD Video standard. A digital video disk (DVD) device plays a DVD to produce a video signal for a video display. A popular use for the DVD device is to play movies. The user buys a movie DVD and inserts the DVD into the DVD device. The DVD device reads the DVD to produce a DVD signal. The DVD device converts the DVD signal into a video signal for a television connected to the DVD device. DVD players have many CD player features, such as the ability to play selections in any order desired and the ability to read information from any point on the disc. The audio data recorded in a DVD-Video has a much higher quality than that in a CD since the audio data of the DVD has a higher sampling frequency and larger numbers of quantization bits and channels than that of the CD. Thus, the DVD player reproduces high quality audio data in multiple channels. DVD players have an advantage over video cassette players in that DVD players can quickly and accurately access specific segments of data anywhere on the medium. A DVD may also store uncompressed linear pulse code modulated data streams which have sample rates between 48-90 kHz and are sampled at 16 or 24 bits. In video, the resolution offered by the DVD format is much closer to the source video, at 720 pixels per horizontal line, than the VHS standard of 320 pixels per horizontal line. A DVD player may be coupled to other devices, such as a display device, a video/audio recording device, audio equipment and communicate with these other devices via a data bus. Such communication occurs in accordance with a bus protocol. A bus protocol typically provides for communicating both control information and data. Examples of bus protocols include the consumer electronics bus (CEBus) and the IEEE 1394 high performance serial bus. DVD players are often directed to the consumer market for entertainment use in homes, e.g., for high-resolution, high-fidelity playback of movies or music. DVDs are finding a significant market as a preferred storage and playback system for a wide variety of multimedia.
A digital versatile disc (DVD) player is generally composed of three logical units, as defined in the DVD specification. The first logical unit is a DVD player application that presents an interface to the user and relays user commands to the second logical unit. The second logical unit a DVD navigator that reads and interprets the information on the DVD and controls which segments of video and audio are processed based on the user commands. The third logical unit is a DVD presentation layer that decompresses data read from the DVD and presents the corresponding audio, video and subpicture streams, as applicable, to one or more renderers. A DVD player is implanted via a graphical user interface (GUI) that is displayed to a user, and through which the user is able to selectively control playback, etc., of the DVD using a pointing selection input device. A system microcontroller which controls the DVD player reads playback control information from a disk and stores the information in a buffer memory. The system microcontroller subsequently reproduces the audio and video data on the disk, with reference to the stored playback control information as needed. In a DVD player, a data controller transfers the coded picture information to a video decoding portion when the picture location information of controller corresponds to the recording location of the picture from optical pick-up. The video decoding unit consists of an input buffer and a video decoder. Video decoder reproduces the buffered picture information, and the reproduced picture information is transmitted to a reproduction picture buffer. Reproduction picture buffer buffers the reproduced picture information, which is then fed to an output controller. Output controller converts the reproduced picture information into an analog picture signal that is then reproduced by output device as a picture. The output device may be a television set or other display devices. The decoded data on a DVD disc typically includes an audio stream, a main video image stream, and a sub-picture video image stream. The sub-picture typically overlays the main video image and may contain a variety of different types of information such as menus, sub-titles, and directives. The main video image and the sub-picture image are separately processed, then combined for simultaneous display on the screen. DVD players are provided with analog signal output ports for both images and sound and sometimes also provided with digital PCM audio output ports. DVD players mix the decoded subpicture information with the decoded video into a single analog video signal for transport to a television. The DVD players are connected to image reproduction systems functioning also as sound reproduction systems, such as televisions, by means of image signal transmission cables and a plurality of the audio signal transmission cables compatible with multiple audio channels.
In general, a DVD player reads, via a laser reader, a DVD disk to extract digital video and digital audio. The DVD player converts the digital video and audio into signals that are readily presentable on a television set, home theater, or a computer. A DVD player provides many functions include jumping to various chapters of the video content, viewing special scenes of the video content, hearing additional commentary of the video content, and viewing the video content from different angles. To select one of these options, the user activates the sub-pictures, via a remote control, and then selects the particular option via an on-screen cursor. The DVD device operates based on a configuration that is stored in ROM. The configuration may include parameters for a decoding algorithm that is used to convert the DVD signal into the video signal for the television. The configuration may include parameters for a user interface that is used to present menus and obtain user selections. The information on a DVD formatted disc is recorded as discrete packets of data, in accordance with the applicable video and audio data compression standards, wherein designated packets carry data associated with various data streams, such as alternative video angles, audio tracks, subpicture streams and navigation information. DVD players are compatible with VCD and CD, that is, can read VCD and CD including CD, CD-R, and CD-RW and DVD including DVD, DVD-R, DVD+RW, DVD-RW, and DVD-RAM. After the type of disc is recognized, the DVD-ROMs use an appropriate laser with a specific wavelength to read data from the disc. DVD players may provide a remote control unit (RCU) menu to use for selecting which angle to view. The RCU menu may include buttons on a physical unit and/or icons in a graphical menu displayed on a display screen. A video disc player reading a DVD formatted disc may be controlled to display certain packets of data and skip over others. A single disc may be authored to allow playback of multiple camera angles, story endings, scenes according to a ratings content, etc. DVD subpictures are used as the graphical user interface (GUI) for such features as providing the user the ability to select from one of several different videos on a disc. A digital video disk player can perform an interactive playback in which a user can communicate with the player during playback. On the other hand, a conventional video cassette recorder or compact disk player can only perform simple playback.
Mobile audio/video is an important form of entertainment and information today. Mobile A/V devices are often utilized in automobiles, at the gym, jogging and the like. People have come to rely on mobile devices for entertainment and information content. Portable electronic devices have decreased both in size and weight over the past few years and are becoming ever more popular with travelers. This demand for smaller size with ever-increasing capability results in the rapid popularization of portable electronic devices, such as laptop computers, personal digital assistants (PDA's), portable digital and video cameras, portable music players, portable electronic games, and cellular phones. Portable electronic devices being designed today require the ability to operate with multi-media features and provide the user with the same enjoyable experience as that experienced from conventional high quality desktop systems. Because DVD players must be operationally attached to a video display, such as a television or television monitor, they are virtually impossible to use anywhere space is limited. Thus, portable DVD players incorporated with display devices were developed. Portable DVD players include a battery for providing power to the disc drive as well as other electronic components of the system that are collateral to the disc drive. These collateral electronic components include data processing electronics used to process the data stored on the recording medium of the disc drive, voltage regulators, battery chargers and other electronic components. The display devices used in portable DVD palyers are generally liquid crystal displays (LCD) and organic light emitting diode (OLED) displays. An organic light-emitting diode dispaly uses organic luminous devices as the light source of the display. Compared with LCD screens, an OLED has advantages of simpler structures, self-emitting design, excellent operating temperature, high definition, high contrast, and a wide viewing angle. Hence, it is the preferred the display device for portable DVD players and other portable electronics such as mobile phones, personal digital assistant (PDA), hand-held videogames, digital cameras, portable DVD players, and automobile navigation devices.