Difference between revisions of "Glossary of terms"

Revision as of 22:30, 31 January 2008

These are some terms that you'll see in the Knowledge Base:

• AAC: An advanced audio codec. Used in MP4 movies on SDA.
• AviSynth: A scripting tool for editing video.
• Capture: To record with a capture card.
• Codec: A way to compress video or audio. If video was uncompressed, it would be far too massive too transmit over the Internet; thus, it is compressed with a codec. To be played back, it must be decoded with the same codec.
• D1, D4, etc: Video dimensions. D1 (high resolution) in NTSC is 720x480 (DVD) or 640x480 (video file); PAL D1 is 720x576 (DVD) or 704x576 (video file). D4 (low resolution) in NTSC is 320x240; PAL is 352x288. D2 and D3 are only relevant to DVD output and are not discussed on this site.
• Deinterlace: Movies on SDA use progressive scan, but most video captured from TV equipment is interlaced. Deinterlacing is the process to turn interlaced video into progressive video. If the whole video can be made by only discarding parts of the video (LQ/MQ), the process is quick. Otherwise (HQ/IQ) the video must be analysed to recreate the missing parts of the picture, which is very slow.
• DivX: An older video codec. Used in AVI movies. Also see "XviD".
• Encode: To compress with a codec.
• F1, F2, F3: Video framerates. The number is the denominator of a fraction whose numerator is always 1. Thus, F1 is full framerate, F2 is half framerate, and F3 is third framerate. F1, F2 and F3 in NTSC are 59.94, 29.97 and 19.98 FPS, respectively, while in PAL they are 50, 25 and 50/3 (~16.666667) FPS, respectively.
• Field: An interlaced frame contains half the picture for each of two consecutive frames of video. Each normal frame's share of the interlaced frame is called a field. If the frame has 480 rows of pixels, the first field will be rows 1,3,5,...,479 and the second field will be rows 2,4,6,...,480. To separate fields means to take each set of fields and put them in their own individual frames.
• Finalize: A process done on DVD recorders that allows discs to be used on other equipment. Once you have finalized a disc, you cannot put anything else on it. The exception in DVD-RW, which you must format in order to write to once it has been finalized. Finalization must be done on the DVD recorder that recorded the disc.
• Frame: Rather than using true motion, videos use frames, where slightly different images are shown rapidly to create the illusion of motion. Each image is called a frame.
• Framerate: The rate at which frames are displayed. This is written as "x fps," where x is the number of frames displayed each second.
• H.264: An advanced video codec. Used in MP4 movies on SDA.
• HQ: High quality. 2Mib/s video, 128Kb/s audio.
• IQ: Insane quality. 5Mb/s video, up to 320Kb/s audio.
• Interlaced: When a video signal comes one field at a time, it is said to be interlaced. Interlacing is used in TV video to halve the amount of bandwidth used in the video signal, while only slightly harming the viewing experience. Also see "Field".
• LQ: Low quality. 128Kb/s video, 64Kb/s audio.
• MeGUI: A tool used to encode video and audio.
• MQ: Medium quality (same as normal quality). 512Kb/s video, 64Kb/s audio.
• MP3: An audio codec. Used in AVI movies on SDA.
• Nate: The person who handles capturing and encoding runs for SDA, as well as many other very important tasks.
• ND, NDA: Nero Digital Audio, the implementation of AAC used by SDA on Windows.
• NMF: New Master File. Refers to an intermediate source video file in the encoding process, usually one saved after deinterlacing (to avoid slow deinterlacing during each pass for each quality of output).
• NQ: Normal quality (same as medium quality).
• Progressive Scan: When a video signal comes whole frames at once, it is said to be progressive scan.
• Transcode: To convert from one file format to another. Similar to "Encode", except the source is usually already encoded.
• VirtualDub: A tool used to encode video and audio.
• VirtualDub Mod: A modification to VirtualDub that is superior in some aspects but inferior in others.
• x264: The implementation of H.264 used by SDA.
• XQ: X-TREME quality.
• Xvid: DivX spelled backwards. Xvid is open source and generally produces better quality video than DivX while remaining 100% compatible. Used in AVI movies on SDA.