1. What is media? media is the carrier of information representation and transmission. 2. media category: Sensory media, indicating media, performance media, storage media, and transmission media 3. definition and features of Multimedia Technology: multimedia technology is a computer interactive integrated sound processing, text, and graphic information technology, with integration, real-time and interactive. 4. multimedia standards: Microsoft proposed international digital image compression standards jointly developed by the mpc5. ISO and ITU: JPEG, MPEG, H.26x 6. audio compression standards: g.728, g.721, g.7227. Digitalization: Sampling-> quantization-> encoding 8. multimedia Technology Applications: Education and training, consulting and demonstration, entertainment and games, management information system (MIS), video conferencing system, computer support for collaborative work, video service system 9. data redundancy in multimedia data: space redundancy, time redundancy, information entropy redundancy, structure redundancy, knowledge redundancy, and visual redundancy. (Expansion required) 10. Color Space:
RGB color space, rgb8: 8: 8,
His color space: H (hue, tone), S (saturation, saturation), I (intensity, light intensity)
YUV color space: Y indicates the Brightness Signal, U and V indicate the color difference signal, and the sampling time is.
Yiq color space:
CMYK color space 11. Digital image formats: TIF, PCX, GIF, TGA, BMP, dvi12. Data Compression Technology:
(1) perform classification based on whether the decoded data is exactly the same as the original data:
A. reversible coding (distortion-free coding): Huffman coding, arithmetic coding, and travel Length Encoding
B. Irreversible coding (Distortion encoding): the compression ratio can be several to hundreds of times. Commonly used transform encoding and prediction Encoding
(2) Based on the compression principle:
A. prediction coding: the error source in the DPCM system is the quantizer at the sending end.
B. transform encoding: prediction encoding is mainly carried out in the time domain, transform encoding is based on the characteristics of concentrated energy in the frequency domain, in the frequency domain (Transform Domain) (K-L transformation, optimal transformation method)
C. quantization and vector quantization coding (the optimal quantizer is the max quantizer)
D. Information Entropy Encoding
E. subband Encoding
F. Model encoding 13. The following describes the steps for compressing the code based on DCT distortion:
(1) discrete cosine transformation
(2) Quantitative Processing
(3) DC coefficient encoding and AC coefficient travel Encoding
(4) entropy coding 14. Huffman encoding quantification: in variable-length coding, short code is assigned to the source symbol with a high probability, and long code is assigned to the source symbol with a low probability. If the length of the code word is strictly in the reverse order of the probability of occurrence of the symbol, the average length of the code result must be smaller than any other arrangement. 15. basic Principle of arithmetic coding: the information of the encoding is expressed as an interval (interval) between the numbers 0 and 1. The longer the information, the smaller the encoding interval, indicates that the more binary bits required for this interval. 16. features of arithmetic coding:. the probability model does not need to be defined in advance. The adaptive mode has unique advantages. B. when the probability of the source symbol is close to that of the source, arithmetic encoding is recommended. In this case, the efficiency is higher than that of Huffman encoding. 17. features: High compression rate (Low Bit Rate), lossless compression, progressive transmission, and regional compression of interest 18. the MPEG-1 standard is named "motion images and sound encoding for digital storage media at around Mbps" 19. the MPEG-2 standard name is "motion image and its companion sound information General encoding" 20. the MPEG-4 standard name is "very low rate audio-visual encoding" 21. two basic technologies are used in the MPEG Coding Algorithm, namely block-Based Motion Compensation Technology to reduce time redundancy and adct technology to reduce space redundancy based on DCT. there are three types of images in MPEG: intra picture, predicted picture, and bidirectional picture)
Prediction Method: Intra-frame prediction, Forward prediction, backward prediction, two-way prediction 23. what is the purpose of Dynamic Compensation Technology? It is mainly used to eliminate the time redundancy of P and B images and improve the compression efficiency.
Principle: block-Based Motion Compensation Technology is to find the best matching block that meets certain conditions in the reference frame. After finding the matching block, there are two ways to deal with this problem: one is to use matching blocks to replace the predicted blocks; the other is to use adct to encode the predicted errors, add the prediction error to the matching block. 24. Significant characteristics of MPEG-4: Content-based encoding, more emphasis on the media system interaction, interoperability and flexibility. 25. The standardized ituh.261 solution is titled "64 Kbps video and audio service video encoding method", also known as the p × 64 Kbps video encoding standard. The p × 64 Kbps video encoding and compression algorithm adopts a hybrid encoding method, that is, a mixture of DCT-based transform encoding method and DPCM prediction coding method with motion prediction. 26. Basic parameters of speech include pitch, resonance peak, speech spectrum, and sound intensity. The speech generation mechanism model consists of three parts: sound source, resonance mechanism (also called sound channel), and radiation mechanism. The source corresponding to the speech generation mechanism model is described by the pitch period parameter, the channel is described by the resonance peak parameter, and the radiation mechanism is described by the speech spectrum and sound intensity. 27. Main Features of multimedia information: 1. There are multiple forms of multimedia information. 2. Large multimedia information 28. Category of the disc: 1. CD-ROM read-only disc. 2. worm writes the disc multiple times at a time. 3. rewritalbe rewritable disc 29. How the disc works:
Read Principle: The information on the read-only disc is recorded in the form of pits and convex areas along the information track in the spiral shape of the disc, the plus and minus hops at the concave-convex border represent "1", and the two edges represent the numbers "0"
Principle of re-writing a CD:
(1). Magnetic-optic erase Principle
The magnetization of the irradiation unit area is opposite to that of other untreated units, resulting in an information storage status "1", which is equivalent to the storage unit "0"
(2). Principle of phase change Erasure
The two types of stability are high reflectivity crystalline and low reflectivity amorphous (glass state ). The writing process changes the information points of the recording media from crystalline to amorphous. The wiping process is the inverse process of the writing process. 30. CD specifications and standards:
1. CD-da. 2. CD-Rom. 3. CD-V (video ). 4. CD files can be recorded. 5. CD-I. 6. CD-ROM Xa. 7. Photo-CD. 8. video cd31. CD-ROM data transfer rate: 150kb/s called a single speed, speed kb/s, 4 speed 600kb/s, 6 speed 900kb/s32. CD-ROM specifications and formats: the CD-ROM Yellow Book standards largely inherit the contents of the Redbook, but the CD-ROM has its own data format. From the physical structure, the CD-ROM is also the optical track is divided into long sectors, using minute, second, sector data addressing method, using constant line rate servo mode. It differs from CD-DA primarily in the format of data in each sector. 33. DVD: MPEG-1 video quality has the quality of home video recorder, its technology has contributed to the VCD industry, MPEG-2 video quality is broadcast-level quality, because of the adoption of MPEG-2 standard video data size is very large, to solve its storage problems, digital video disc was developed and the standardized solution was completed in 1995. The size of the DVD disk is the same as that of the CD, and the maximum capacity of the dual-sided disk can reach 17 GB. Single-sided single-layer DVD disk can store 133 GB of data, store minutes of MPEG-2 video. Its resolution is the same as that of the current TV and comes with Dolby AC-3/MPEG-2 audio quality sound and subtitles for different voices. 34. Audio Card: audio card or audio card is a computer plug-in used to process audio signals. It is an important component for a general computer to upgrade to the PC. 35. video cards: video capture cards, video compression cards, video decompression cards, and video transfer cards. 36. Video Capture card function: video capture card continuously converts video signals into digital video data stored by computers. 37. Image digitalization
The spatial distribution and brightness (color) Distribution of image information are continuous, and the continuous information must be discretized. The process of discretization is the process of digital processing, it should include the discretization of spatial locations and the discretization of brightness level 38. image scanner: the photoelectric conversion component is CCD (electrical coupler) 39. the touch screen shall consist of three parts: sensor, control part, and drive part. 40. The touch screen can be divided into infrared touch screen, resistive touch screen, capacitive touch screen, surface acoustic wave technology and base vector pressure measurement touch screen according to its working principle. 41. The basic hardware structure of multimedia PCs can be summarized as: 1. A powerful and fast central processor (CPU ). 2. large storage space. 3. High-Resolution Display Interfaces and devices. 4. Sound processing interfaces and devices. 5. interfaces and devices that can process images. 6. configuration of storing a large amount of data. 42. The CD-I system is a family interactive multimedia system. 43. The VCD player consists of three core components: a CD drive or a CD loader. MPEG decoder. Microcontroller 44. DVD Playback System: 1. DVD disk reading mechanism. 2. DVD-DSP. 3. Digital Sound/video decoder. 4. microprocessor. 45. Significance and features of multimedia Workstation:
Workstation is a very powerful small computer system on the market. It is generally characterized by a UNIX operating system with GUI interfaces and strong graphic image processing functions. The multimedia workstation is designed to process discrete and continuous media information at the same time. 46. multimedia application software development process in Russia: 1. Define the intended audience and understand user needs. 2. Select the development method. 3. Prepare media data. 4. Complete system integration. 47. Audio Data:
The types of audio processed by computers usually include waveform audio and MIDI audio (p120) 48. a MIDI audio file is a string of time sequence commands that record the behavior of music, such as a piano key or a stepping board. However, Midi has a serious disadvantage, and it is not suitable for compiling audio for oral narration. 49. Image Data
Images are generally divided into static objects (usually called images) and active videos. A static image usually uses a bit ing matrix to represent the color data of each pixel. (P124) 50. A video is illuminated by light on an object and reflected on a camera or camera lens. This reflected light forms an electronic signal. These signals can be synthesized in three colors, namely, RGB. 51. Video standards:
NTSC: USA
Pal: China, UK
SECAM: France, Russia 52. What is graphics: computer graphics is a discipline that studies how to use computers to represent, generate, process, and display graphics. 53. Computer Animation uses computers to generate a series of continuous screen technologies that can be played in real time. 54. Computer Animation research content: 1. motion control method. 2. Animation Description Model and animation language. 3. The generation technology of the intermediate image. 4. Object Modeling Technology in 3D animation. 5. animation rendering technology 55. multimedia development and creation environment have the following functions: 1. provide multimedia programming environment. 2. hypermedia and multimedia data management functions. 3. Supports multimedia data input and output. 4. Application connection function. 5. Multimedia Data production function. 6. friendly user interface. 56. Features and categories of multimedia editing tools and typical tools
(1). multimedia editing tools based on cards or pages.
(2). multimedia editing tools based on graphic symbols and events.
(3). Time-based multimedia editing tools.
(4) traditional programming language-based compilation tools. 57. storage environment of multimedia data: 1. Replaceable hard disk. 2. tape backup media. 3. CD file media. 4. disk array. 58. multimedia data transmission environment: 3 transmission methods 1. Manual Transmission Using replaceable media. 2. Use a serial port for point-to-point transmission. 3. Use a network system to transmit data between computers. 59. Multimedia Data Management software environment: 1. file management system. 2. Create a specific logical directory. 3. Traditional character, numeric database management system. 4. multimedia database management system. 5. Hypertext and hypermedia 60. The impact of multimedia data on databases is reflected in the following aspects:
(1). Large data volumes and large differences between media sets affect the organization and storage methods in the database.
(2) Increasing media types makes data processing more difficult.
(3) The query result is a unified display of comprehensive multimedia information.
(4). mdbms should increase the ability to process long transactions.
(5). mdbms should provide strong version management capabilities. 61. The organizational structure of mdbms is generally divided into three types: centralized, master-slave, and collaborative. 62. The expanded relational data model not only supports formatting data, but also supports non-formatting data. 63. Basic object-oriented concepts:
(1). object. (2). attributes. (3). method. (4). Object Class. (5). subclass and parent class. (6). Message. (7). Inheritance. (8). Polymorphism
64.
(Important) object-oriented database model (unfinished p179
)65. Features of Content-Based Retrieval Technology
(1). Extract information clues from media content, analyze the media directly, and extract features. (2) There are a variety of feature extraction methods. (3) human-computer interaction. (4) Content-based retrieval uses a similar matching technique. 66. Content-based retrieval system implementation method:
(1). Based on traditional database retrieval methods. (2) Based on the signal processing theory, feature extraction and pattern recognition are adopted. 67. MPEG-7, its formal name is "multimedia content description interface" 68. concepts related to MPEG-7:
Data
Features
Description
Description Value
Description Mode
Description
Encoding description
(Core of the MPEG-7) Description Definition Language: a language that allows the generation of a new description pattern to describe sub-, allows the extension and modification of existing description mechanisms. (P190) 69. Text features: Linear and sequential. 70. Hyper Text features: there is no fixed order. 71. hypertext is a network composed of information nodes and links that represent the correlations between information nodes. 72. hypermedia = multimedia + hypertext 73. hypertext system structure model:
Ham model: divided into three layers
(1). database layer: provides storage, shared data, and network access functions.
(2 ). hyper Text abstraction layer: This layer is between the database layer and the user interface layer. This layer determines the basic features of Hyper Text system nodes and links, and records the links between nodes, the structure information about nodes and links is saved.
(3). the user interface layer, also known as performance, once formed an important manifestation of the particularity of the hypertext system. Including how to display the ham layer information (node and chain) by using commands.
Dexter model: also divided into three layers
(1). storage layer: Describe the network relationship between Members
(2). Member internal layer: describes the content and structure of each member in hypertext.
(3). runtime layer: describes the mechanisms that support user and text interaction.
(4). performance specification: the interface between the storage layer and the runtime layer of the model is called the performance specification.
(5). anchoring mechanism: the interface between the storage layer and members is called the anchoring mechanism. 74. The chain can be divided into the following types:
(1). Basic structure chain
(2). Organization chain
(3). inference chain 75. literature model Overview: Literature is a combination of articles or texts
General Structure of documents: the structure of documents includes content organization and layout.
Basic task of document model:
(1). It can represent the hierarchical content of multimedia documents.
(2) The layout of multimedia documents.
(3). It can represent the time layout of multimedia documents.
(4) The content can correspond to the layout. (P203) 76. Document model: ODA model and hytime model 77. HTML language: hypertext markup language 78. XML language: extensible markup language. Three elements: Document definition, XSL, and xlink. XML provides a data definition mechanism. Currently, two methods are available: DTD and schema79. common dynamic web page technologies include ASP, PHP, and jsp80. web systems use HTTP hypertext systems, the basic structure is a client/server model 81. network server site image features: in order to increase the response speed, reduce the network burden, and enhance the system robustness. 82. Proxy server features: cache hotspot access information near the client. 83. Advantages of Web Cache Design: Web Cache can significantly improve the service performance of the web system, reduce bandwidth consumption, reduce user access latency, and reduce the workload of remote web servers. Strengthen the robustness of Web Services. 84. disadvantages of Web Cache Design: lack of suitable cache proxy updates, proxy is always the bottleneck of system services, reducing the click rate of remote servers. 85. cache system architecture:
(1). Hierarchical Cache structure. (2) distributed cache structure. (3). Hybrid cache structure 86. Common cache Methods: pre-installed technology, dynamic replacement, and partial cache 87. cache replacement policies: (1) traditional replacement policies and their direct expansion. (2). Key-based replacement policies. (3). Cost-based replacement policies. 88. The data model is an abstract description of the objects to be studied in the real world that computers in the computer data world can accept. (1). Provide a computer-acceptable Information Representation and processing method (2). Be able to point out data structures. 89. Modeling of spatial-temporal relationships in multimedia data is a key issue in multimedia systems. 90. Multi-media system performance models are implemented in different layers. Descriptive definition:
(1) multimedia is the synthesis and reproduction of multimedia data.
(2) multimedia synthesis mainly includes space and time synthesis.
(3). Space synthesis is a description of the Spatial Characteristics and positional relationships between a series of media objects that coexist in the same domain.
(4). Time synthesis is a description of the time sequence relationship between a series of media objects in a certain time domain concurrency (including sequence and Parallelism.
(5) multimedia synchronization refers to the mechanism by which processes are used to coordinate the time sequence relationship, that is, the description of the time synthesis method.
91.
The Data Model Hierarchy of multimedia systems consists of three layers: application layer, information metadata layer, and Data Metadata layer.
(1). From the perspective of performance:
(2) How does the system arrange the user's performance (including the interaction capability )? This is an upper-layer synchronization problem, which is mainly solved by the script description.
(3) What is the time-space arrangement of each element in the Information element? This is an intermediate synchronization problem, that is, space-time synthesis.
(4) the specific implementation of the computer corresponds to the synchronization at the lowest layer, which is completed within the system.
| Information metadata Layer |
| Hierarchical Structure of Data Models in Multimedia Systems |
92. Formal Description: it is a method that accurately defines and describes the basic characteristics (attributes and structures) of information systems using mathematical or math-like concepts. 93. Formal Description of hypertext: Set Theory and first-order logic 94. Multimedia metadata:
From the top-down point of view: Information sub-blocks of information systems are composed of certain semantics.
From the bottom-up point of view: one or more media data elements are hyper-data elements that are synthesized after certain addition and packaging. 95. Information element size: public requirements of various multimedia applications, that is, the characteristics that information elements must meet. 96. Synthesis of information elements: Synthesis of information elements refers to the synthesis of Time and Space between multiple data elements, that is, the description of the relationship between time and space. Different models have different Descriptive methods. 97. The mheg standard uses an object-oriented method to analyze the design model. MH objects are divided into the following types:
(1). Output Content Object
(2). General Input object
(3). er object
(4). Basic Object
(5). Merging object
(6). Conditions and actions 98. The performance is to make all kinds of media information warfare a user activity and the synthesis and reproduction of multimedia data. 99. Arrange the synthesis performance of multiple media in chronological order and spatial relationship, that is, the problem of multimedia synchronization. 100. Three basic synchronous Representation Methods:
(1). Hierarchical Synchronization
(2). Timeline-based synchronization
(3). Synchronization Based on reference points 101. Influence of multimedia on Communication
(1). Multimedia Data Volume
(2). Real-time multimedia
(3) multimedia time and space constraints
(4). Multimedia Interactivity
(5). Distributed Processing and collaborative work 102. Implementation of multimedia communication:
Voice + video-> Multimedia Communication
Network + video-> Multimedia Communication
Cable TV + switching function-> multimedia communication 103. Key Technologies of multimedia communication:
Sound, video, animation, and other transmission technologies
Data compression and decompression Technology
Solve the problem of real-time multimedia synchronization
Solve protocol and standardization issues 104. the telephone number used to transmit static images on a simulated communication network is called the videophone 105. A video phone that transmits dynamic or quasi-dynamic images on a simulated communication network or a digital network is called a TV phone. It consists of four parts:
(1). Speech Processing
(2). Image Input
(3). image output
(4 ). image Signal Processing part 106. video Conferencing System: An audio-visual session-based telecommunications conference service that provides two-way real-time transmission of speech and motion-colored images between a group of users located in two or more locations. 107. Types of video conferencing systems:
(1). High-end meeting room type
(2). desktop conferencing system
(3). Videophone 108. Three Modes of video display conversion control:
(1). Voice activation mode
(2) Chairman's Control Model
(3 ). lecture mode 109. computer Networks are the product of the combination of computer technology and communication technology. They closely link information transmission and processing, and become an important symbol and basis of the Information Society. 110. Various methods and features supported by the Network for multimedia communication:
Telephone Exchange Network: in essence, a telephone network is used to simulate voice communication. By using a modem, binary data can be modulated into analog signals and transmitted in the telephone network.
Ethernet: The range and speed of Ethernet are limited, which cannot fully meet the requirements of real-time multimedia communication and multimedia type conversion. However, the transmission Effect of static multimedia is acceptable. However, Ethernet does not support QoS, which is a defect for multimedia communication.
Group Exchange Network:
FDDI: advantage: FDDI is a high-speed LAN that provides connection and transmission services, with fixed distribution of communication channel bandwidth. Disadvantages: because it is dedicated to data transmission, multimedia data features are not taken into account, different protocols cannot be selected for different media, and bandwidth cannot be dynamically allocated, So multimedia communication support has certain limitations.
ISDN: narrowband ISDN with 2 BNS can provide standard interfaces for telecom networks and support multiple communication services. However, the service content is limited and the bandwidth is not high, which is difficult to meet the requirements of complex multimedia communication.
111.
Service quality of multimedia communication networks (see section p262
)112. Basic Features of Distributed Multimedia Systems: (which are distributed and which are not)
Multimedia Integration
Resource Dispersion
Real-time operation Interaction
System transparency
113. Hierarchical Structure of Distributed Multimedia Systems
| Multimedia Presentation Layer |
| Multimedia Transport Layer |
| Multimedia Interface Layer |
114. Internet provides two types of services:
The reliable connection-oriented service uses the TCP protocol and does not require high latency of information packets.
Non-reliable connection-free services, using UDP protocol, do not guarantee no packet loss, nor guarantee that the latency meets the needs. 115. Multimedia Networks should solve the following problems: Increase network bandwidth, reduce latency, and reduce jitter.
Solution:
(1). Expand the link bandwidth
(2). Improved Internet Protocol 116. What is multicast and the scope of multicast addresses and implementation conditions
Multicast or multicasting refers to the transmission of information from a single point on the Internet to multiple specified points on the Internet (members in the same working group. Class D (224.0.0.0 ~ 239.00000000255) the multicast address. To support multicast, both the sending and receiving ends and their network facilities must have multicast functions. For local IP multicast, the environment required by the host node is: IP Multicast can be supported in the TCP/IP protocol stack; the software supports Internet Group Management Protocol (IGMP ), in this way, you can apply to participate in or Accept multicast. You must have the IP multicast application software. (P273) 117. Multicast Route Selection protocol:
(1) Distance Vector Multicast Routing Protocol
(2). the Shortest Path priority routing protocol for Multicast
(3) protocol-Independent Multicast Routing Protocol
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