|Oracle8i interMedia Audio, Image, and Video User's Guide and Reference
Some glossary entries are from the free online Dictionary of Computing located at: http://wombat.doc.ic.ac.uk/foldoc/index.html.
Advanced Authoring Format, a professional multimedia authoring format defined by Microsoft Corporation for the Windows operating system to succeed the AVI file format. AAF is an open, industry-developed format that enables the exchange of media among digital production tools and content creation applications.
The European and worldwide (not North America and Japan) standard for nonuniform quantising logarithmic compression. A-Law is used as the European telephony standard.
Surround sound audio.
Adaptive Differential Pulse Code Modulation. A compression technique that records only the difference between samples and adjusts the coding scale dynamically to accommodate large and small differences. ADPCM is simple to implement, but introduces much white noise.
Abstract data type. See also (object type).
Audio Interchange File Format. A file format developed by Apple Computer Inc. for storing high quality sampled audio and musical instrument information.
Audio Interchange File Format with Compression. A file format developed by Apple Computer, Inc., for storing high quality sampled audio and musical instrument information that uses compression.
Advanced Streaming Format. A multimedia streaming format defined by Microsoft Corporation for the Windows operating system to succeed the AVI file format. ASF is an open, industry-developed format specifically tuned for streaming media distribution.
Proportions of height versus width.
Components of object types that are built-in data types or other user-defined types that model the structure of the real world. See Oracle8i Concepts for more information.
Audio file format common to the UNIX platform, especially Sun and NeXT computing platforms.
Sound. Computers (and audio compact discs and digital audio tape) handle sound by storing a sequence of discrete samples. The continuous sound waveform from the original source is sampled tens of thousands of times a second. Each sample represents the intensity of the sound pressure wave at that instant. Apart from the sampling frequency, the other parameter is the digital encoding of each sample including the number of bits used. The encoding may be linear, logarithmic or mu-law. The source could be a piece of music, voice recording, or generated audio. See also mu-law or u-law.
A change to the properties of audio data, such as format, encoding type, number of channels, sampling rate, or sample size.
Audio Video Interleaved. A file container format defined by Microsoft Corporation. An AVI file typically includes both an audio and a video sequence. The audio and video data can be in several formats, such as Intel Indeo, Iterated Systems ClearVideo (fractal), or Motion JPEG. See also AAF and ASF for more information.
The difference between the highest and lowest frequencies of a transmission channel.
A large object whose value is composed of binary data that is stored outside the database in an operating system file. The file itself is not stored in the database, but a pointer to the file is stored in the database. Because they are outside of the database, BFILEs are read-only.
Bidirectionally predictive-coded frame. In MPEG video, a B-frame is encoded using data describing how its picture has changed from the picture in the closest two I-frames or P-frames, one in the past and one in the future.
Binary large object. Large objects are stored in the database tablespace in a way that optimizes space and provides efficient access. Only a pointer to the object is actually stored in the row.
A large object whose value is composed of single-byte fixed-width character data that corresponds to the database character set defined for the Oracle8 database.
COmpressor DECompressor. Software modules that perform compression and decompression of multimedia data. Some common audio codecs or encoding types are ADPCM, Mu-Law, Two's Compliment, AC-3, and others. Some common video codecs or encoding types are MPEG-1, MPEG-2, Intel Indeo, Iterated Systems ClearVideo (fractal), Radius Cinepak, Motion JPEG, and others. Some common image codecs are JPEG, Packbits, HUFFMAN3, and others.
The coding of data to save storage space or transmission time. Compressed data must be decompressed before it can be used.
The format of an encoded audio, image, or video file produced by a codec. The Oracle Video Server, for example, supports several compression formats including MPEG-1, MPEG-2, Intel Indeo, Iterated Systems ClearVideo (fractal), Radius Cinepak, and Motion JPEG.
The way in which an encoder multiplexes video and audio together. For example, the container formats supported by the Oracle Video Server include MPEG-1 system, MPEG-2 transport, Oracle Video Stream, and any container format that meets the Raw Key Frame requirements.
A description of the image data, such as the pixel or color format.
Selecting the portion of an image within a specified rectangle and removing everything outside of that rectangle. See also cutting.
Selecting the portion of an image within a specified rectangle to create a subimage. If the subimage is copied to a new image, the effect is a cut. If the subimage replaces the original, the effect is a crop.
A method that creates an empty instance of an object.
The time it takes to play the entire audio or video data object.
The particular codec algorithm used to encode the audio and video data. Some common audio codecs are ADPCM, Mu-Law, Two's Compliment, AC-3, and others. Some common video codecs are Indeo, MPEG, and others. For audio and video data, usually the encoding type is specific to the computer platform.
To move data from the Oracle database to external storage as files, such as to a local file system, or to an HTTP server.
The file format of the audio data, such as AIFF, AIFF-C, AU, WAV, MIDI, RealAudio, and SND. The file format of the video data, such as QuickTime, AVI, MPEG1, and Real Video. The file format of the image data such as (TIFF, JFIF). See Appendix A for supported audio file and compression formats. See Appendix B for supported image file and compression formats.
A specific data structure or organization; usually an industry standard such as AIFF-C for audio data or QuickTime, AVI, or MPEG1 for video data.
The number of frames displayed every second. Thirty frames/second is considered a good rate for the human eye. A lower frame rate requires less bandwidth but reduces the quality of the video data. A higher frame rate produces a smoother, higher quality video, but requires more processing power and a greater bandwidth.
The number of pixels per inch of frames in the video data. Frame resolution can be adjusted to fit bandwidth requirements. Reducing frame resolution reduces video quality.
The height and width in pixels of each frame in the video data. This information is useful in estimating bandwidth requirements and determining appropriate display size for a given display screen size.
A body of information that a browser sends along with a URL when requesting a Web page. It includes such information as the browser type and MIME types.
Intra-coded frames. In MPEG video, an I-frame is a frame coded as a still image, not using any past history.
To ensure good rate control performance, I-frames must occur at regular intervals throughout a video stream. For the US and Japan, there are usually 11 frames (B-frames and P-frames) between each pair of I-frames in a sequence such as: IBBPBBPBBPBBIBBPBBP.... This is based on a random access requirement that an I-frame (starting point) is needed at least once every 0.4 seconds or so. MPEG encoding software often enables you to configure the I-frame frequency.
Interface Definition Language.
A graphic picture. The source could be a photograph, drawing, or generated image.
Changing the properties of an image, such as through scaling, rotation, or compression.
To move data into an Oracle database from external storage, such as external file servers, media servers, HTTP servers, FTP servers, and so forth.
Joint Photographic Experts Group. The original name of the committee that designed the standard image compression algorithm. The filename extension is .jpg or .jpeg. JPEG is a static-image compression format.
Large object. LOBs are used to hold large amounts of raw, binary data. Oracle8i interMedia supports LOBs.
A BLOB attribute that can keep up to 4GB of image, audio, or video data stored within the Oracle database. All data within localData is protected by Oracle's security and transaction support.
A file system that allows local access where, for example, BFILES can be stored.
The location of image, audio, or video data within the Oracle database.
A data compression algorithm that retains all the information in the data, allowing it to be recovered perfectly by decompression.
A means for reducing the storage space required for an image. The decompressed image is bit-for-bit identical to the original.
Unix compress and GNU gzip perform lossless compression.
A data compression algorithm that actually reduces the amount of information in the data, rather than just the number of bits used to represent that information. The lost information is usually removed because it is subjectively less important to the quality of the data (usually an image or sound) or because it can be recovered reasonably by interpolation from the remaining data.
A means for reducing the storage space required for an image. The decompressed image is not bit-for-bit identical to the original. Some details are lost or changed, although this might not be noticeable to the naked eye.
MPEG and JPEG are examples of lossy compression techniques.
Components of an object type that are functions or procedures written in PL/SQL and stored in the database or written in a language like C and stored externally. Methods implement specific operations that an application can perform on the data. See Oracle8i Concepts for more information.
Multipurpose Internet Mail Extensions. See Multipurpose Internet Mail Extensions (MIME).
A file format defined by the Multipurpose Internet Mail Extensions standard. This unique identifier is used for different file types when conveyed across a MIME-based protocol such as MIME e-mail or HTTP.
A compression technique for moving images that applies JPEG still image compression to each frame of a moving picture sequence.
Play-back requires a machine capable of decompressing and displaying each JPEG image quickly enough to sustain the required frame rate of the picture sequence.
There is no standard for Moving JPEG as with JPEG, but there are JPEG compression chips which are designed to work at television frame rates and resolutions.
Moving Picture Expert's Group, an ISO body focused on developing compression formats for full-motion video and audio signals and the synchronization of these signals during playback.
The first version of the MPEG format, optimized for CD-ROM. It uses discrete cosine transform (DCT) and Huffman coding to remove spatially redundant data within a frame and block-based motion compensated prediction (MCP) to remove data which is temporally redundant between frames. Audio is compressed using subband encoding.
A variant of the MPEG video and audio compression algorithm and file format, optimized for broadcast quality video for digital storage media up to 4.0Mbits/second. The file extension is .MP2.
MPEG-2 has been approved as International Standard IS-13818.
A variant of the MPEG video and audio compression algorithm and file format. The file extension is .MP3. This variant no longer exists and has been merged into MPEG-2.
A variant of the MPEG video and audio compression algorithm and file format used for low bandwidth video telephony. The file extension is .MP4. The International Standards Organization (ISO) has adopted the QuickTime 3 file format to form the starting point for a unified digital media storage format for the MPEG-4 specification. See also QuickTime 3 for more information.
The North America and Japan standard for nonuniform quantising logarithmic compression.
An Internet specification describing file types. Servers and browsers read the MIME type in the file header and decide what to do with the file, such as displaying it with a viewer or playing it as an audio file. MIME is used by HTTP servers to describe the type of file being delivered.
Number of audio channels present in the formatted audio data; also known as the channel count. Number of channels may range from 1 for mono audio data to 6 for AC3 encoded surround sound audio data.
The number of frames in the video object.
A database having both object-oriented and relational characteristics. Objects can be defined and stored, and then retrieved using standard relational methods.
A data type that includes attributes of the data and methods (functions and procedures) for operating on the data.
Oracle Call Interface.
An object type is sometimes referred to as an abstract data type (ADT).
An HTTP server that enables you to create and deploy distributed, cross-platform, dynamic applications. It provides a framework that encompasses a modular distributed architecture, an open API that enables you to create portable applications, and different application models or paradigms. Oracle Web Application Server consists of three components: HTTP Daemons (UNIX) or Listeners, Web Request Broker (WRB), and options or server-side applications.
An interMedia-defined object type that is part of the demo program that encapsulates all the functionality required to store and manage audio annotation data.
A interMedia audio-defined object type that encapsulates all the functionality required to store and manage audio data.
A interMedia image-defined object type that encapsulates all the functionality required to store and manage image data.
A interMedia video-defined object type that encapsulates all the functionality required to store and manage video data.
A interMedia-defined object type that only knows about the source of data; it is a common object type for interMedia object types. The ORDSource object type is used to get multimedia data from sources such as BLOBs stored locally in the Oracle database, BFILES stored locally in external file systems, media servers, FTP servers, and HTTP servers.
Oracle Video Server. An Oracle product that provides an end-to-end software solution for networked client and server computers that store, manage, deliver, and display digital video and audio on demand. Client applications run a wide variety of consumer and corporate platforms. OVS is supported on a variety of server platforms and scales to serve many concurrent users.
Predictive-coded frames. In MPEG video, a P-frame is encoded using data describing how its picture has changed from the picture in a previous I-frame or P-frame.
A file container format defined by Apple Computer, Inc., for integrating full-motion video and digitized sound into application programs.
An industry standard file format defined by Apple Computer, Inc., to create and publish digital media for the Mac OS, Java, and Windows operating environments. The International Standards Organization (ISO) has adopted the QuickTime 3 file format to form the starting point for a unified digital media storage format for the MPEG-4 specification. This will allow the vast majority of existing hardware, software, and digital content to work seamlessly with this next generation version of MPEG. See also MPEG-4 for more information.
A set of rules to which the content of video container format can conform. Some video servers, such as the Oracle Video Server, can only play content in container formats that conform to the rules of RKF. The rules of RKF are:stateless - all the data for displaying the picture in a video frame is contained entirely in that frame, rather than in previous frames.contiguous - all the data for a frame is stored together in the video file and no other data is mixed with it.
An uncompressed image format with a simple, fixed-size header.
The rate in samples per second at which the audio data was recorded. The sampling rate ranges from 5500 (one fourth of the Mac sampling rate) to 48000 (Digital Audio Tape (DAT) sampling rate).
The number of samples of audio data present in the audio data, or, stated another way, the number of bits per sample. The number of bits per sample is either 8 (8-bit) or 16 (16-bit).
Changing the proportions of an image in one or both dimensions. To enlarge an image, scale by a factor greater than one. To shrink an image, scale by a factor between zero and one.
Sound. Audio file format in use on the UNIX platform, especially Sun and NeXT computing platforms.
A compact string representation of a location (URL) for use in identifying an abstract or physical resource. URI is one of many addressing schemes, or protocols, invented for the Internet for the purpose of accessing objects using an encoded address string.
A form of URI. A compact string representation of the location for a resource that is available on the Internet. It is also the text-string format clients use to encode requests to Oracle Application Server.
Streaming images. The source could be a video camera, a recording, or a generated animation. See also full-motion video.
Compression of sequences of images.
Waveform-audio. WAV is a standard file container format developed by Microsoft Corporation for storing digital audio files. Conversion tools are available to allow most other operating systems to play WAV files.