Vocabulary and Terms of DVD Video
The following terms may appear at many sites that deal with DVD or video. At this point in time, this short list of terms is not presented in alphabetical order.
- Resolution: The size of the video, as measured in pixels (a digital measurement).
- Bit-rate: The amount of data per second. This alone determines the filesize of a video file. NOTE: Actually, there are a couple more mitigating factors that can affect the file size, such as the discreet cosine and GOP length, but for the purpose of introduction, this is the only factor that affects filesize. Resolution does not determine filesize. However, bit-rate must increase with resolution, in order to allocate enough data to maintain high quality video or audio.
- VCD, SVCD, CVD, XVCD: Various methods of storing low or medium resolution MPEG files onto CD media, for the purpose of playing on VCD or VCD-capable DVD players. Not all DVD players will play all CD formatted video, and in fact, some cannot play any CD video. Often referred to as “the poor man’s DVD”. Not a high quality format, therefore not suggested.
- Macroblocks: When not enough bit-rate is being fed to an MPEG file, meaning there is an insufficient resolution-to-data ratio, the outcome is blocks on screen. MPEG is a compression system that divides an image into square zones, and when there is not enough bit-rate, these zone boundaries become visible.
- NLE: Abbreviation for “non-linear editor”, often in reference to high-dollar professional and semi-professional software like Adobe Premiere, Sony Vegas Video, or Avid. Non-linear means the video can be edited at random outside of real time (which is how editing was often done on tapes).
- Dropped frames: When the flow of data is interrupted during capture, and data is lost in the process. Video and/or audio frames are missing from the captured file, resulting in undesirable side effects like audio/video being out of sync, jerking in the image, or large missing gaps of time.