Access Time: The time it takes for the disk pointer (read/write device) to move to the correct position on the hard drive, also referring to the time it takes for the hard drive to rotate to the correct position. This is an important criterion for measuring the performance of hard drives.

Alpha Channel: In computer graphics, each pixel contains three color information channels - red, green, and blue. In a 24 bit graphics, each channel contains 8 bits of color depth. If the graphics card has a 32-bit bus, the additional 8-bit signal is used to store invisible transparency signals for processing purposes, which is the Alpha channel. White alpha pixels are used to define opaque color pixels, black alpha pixels are used to define transparent pixels, and the gray scale between black and white is used to define semi transparent pixels.

Non natural signal: Simply put, it refers to the random appearance of free pixels in the picture. There are many reasons that may cause non natural signals, including excessively high compression ratios.

Aspect Ratio: In movies and television, the aspect ratio of a screen refers to the ratio of its width to its height. The aspect ratio of most desktop computers and regular TV systems is 4:3.

AVI: Abbreviation for Audio/Video Interleave. AVI is a specified video file format under Windows and is also the most widely used video file format in PC systems. Along with QUICKTIME and MPEG, it is known as one of the three mainstream video technologies in computers. Simply put, AVI works in a way that interlaces video and audio in a continuous manner.

Component Video Signal: Divides the screen into three separate signal channels (RGB): red, green, and blue (with additional brightness signal). The generated image quality is relatively high and is generally used in broadcast level video equipment.

Composite Video: Mixing color signals, brightness signals, and synchronization signals into one signal channel, widely used in home video devices.

Compression: Compression is an important concept in making digital movies. Both video and audio can be compressed through a computer during the digitization process. When sound and images are compressed, they can be processed more efficiently by the CPU and reduce the hard disk space occupied by video and audio files. Compression is also a key factor in the dissemination of videos on the network, and the file size must be compressed to the extent allowed by bandwidth before it can be downloaded by users.

Compression Ratio: The ratio of the original size of an image file to the size of the compressed image file. The algorithm for signal codec compression/decompression. That is, the compression standard used for compression and decompression (such as JPEG or Cinepak). General encoding includes converting analog video signals to compressed video files (such as MPEG) or converting analog sound signals to digital sound (such as RealAudio).

CPU: Central Processing Unit. Simply put, it is the "brain" of a computer, which is the most important microprocessor chip that works in conjunction with the motherboard and system memory.

Digitization: The process of converting analog signals into digital signals.

Dropout: A problem caused by metal magnetic particles falling off a magnetic tape, usually due to prolonged storage time or accidental operation. Signal loss can cause issues such as screen noise, ghosting, and lack of synchronization.

Offline Editing List (EDL): Abbreviation for Edit Decision List. A list generated by a computer that records all entry and exit points and their effects. Offline editing tables can be created using software like Premiere on inexpensive non-linear workstations or even home computers, and then controlled for final editing on advanced linear editing systems.

Fast and Wide Drive Array: An external (or internal) storage device consisting of several hard drives connected together to work simultaneously, thereby increasing throughput and access time. This is the most reliable method (although not the cheapest) for editing videos at full resolution and frame rate on a computer.

Frame rate (FPS): The number of frames per second. NTSC system is 30FPS, PAL system is 25FPS.

Key Frame: In some compression schemes, some frames are designated as keyframes. Since most of the content between two frames is often not significantly different, it is possible to compare subsequent frames with keyframes and save the parts that have truly changed. This can save space.

Longitudinal Time Code (LTC): The abbreviation for Longitudinal Time Code. A type of SMPTE time code, also known as relative time code, recorded on the magnetic track of a magnetic tape. Compared to Vertical Interval Time Code (VITC).

Luminance: refers to the level of brightness in a video image.

MPEG: The abbreviation for Moving Pictures Experts Group. MPEG is a compression standard for motion pictures and sound. The data flow of MPEG-1 standard video/audio streams is 150 kilobits per second, which is the same as the transmission rate of single speed CD-ROM. It works by setting keyframes and only changing different areas of the adjacent frame image.

Network User Bus (NuBus): The NuBus is the standard interface for the internal expansion slot of a Macintosh computer (specifically for video and audio expansion cards). New Mac computers are now using Intel's Super PCI standard, so you can only see the slots for the network user bus on older Mac models. If you plan to purchase a video or audio expansion card and have an old-fashioned Mac computer, please confirm what kind of slot your computer has first. The network user bus was designed by Texas Instruments.

NTSC stands for National Television Standards Committee. It is a television standard commonly used in Central and North America and Japan, which is only relative to the PAL standard in Europe and SECAM in France. His vertical resolution is 525 lines and the frame rate is 30 (29.97) FPS.

PAL: Short for Phase Alteration Line, it is a television standard commonly used in most countries in China and Europe. It has a higher vertical resolution (625 lines), but the frame rate is relatively slower than NTSC (25FPS).

PCI: stands for Peripheral Component Interconnect, which is an excellent built-in expansion interface used in Pentium computer systems (now also used by Apple's PowerPC).

QuickTime: Developed by Apple Computer Company, QuickTime has gradually become the standard video technology commonly used on Mac and PC computers. The files replayed in QuickTime are represented by the. mov suffix.

RGB: See component video signal.

SCSI stands for Small Computer System Interface. SCSI allows you to connect multiple expansion devices on your computer in a chain like manner through this interface.

SECAM: Abbreviation for Systeme Electronic Pour Couleur Avec Memoire. It is a television system adopted by France, Russia, and some Eastern European and African countries. It has the same vertical resolution and frame rate as the PAL standard, but the color of the SECAM standard is modulated by an FM signal.

SMPTE Time Code: Abbreviation for the Society of Motion Picture and Television Engineers, also known as Standard Time Code. This standard assigns a value to each frame of the video, allowing it to be used as an in and out point during editing.

Throughput: The nominal speed at which a hard disk continuously transfers data.

Time Code: See SMPTE Time Code.

Vector scope: also known as an oscilloscope, an instrument that displays the color tone and saturation level of a video image in a graphical manner, and can be used to adjust color matching.

Video Board: an internal expansion card used to digitize video and audio signals.

Video for Windows: Window Video Format (VFW) is a video technology included in the Windows 95 operating system. Their files are represented by the. avi suffix.

Virtual Memory: A memory management system used as a temporary swap area between memory and hard disk.

Vertical Interval Time Code (VITC): Abbreviation for Vertical Interval Time Code, a type of SMPTE time code. Recorded between every two frames, so it can be read out when the device stays at a certain frame.

WAV: WAV is the standard audio file format for Windows operating systems. WAV files are represented by the suffix. wav.

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