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Content can originate from a variety of sources: a digital source, such as Windows Media files with .avi, .wmv, or .wav extensions; an analog source, such as television; or from film.
The National Television Standards Committee (NTSC) defines video as analog data that is interlaced and broadcast at 30 frames per second (fps). Interlaced video is displayed using a half-resolution image known as a field and uses two video fields to make a single frame of video. Each field of video contains alternating lines of an image: field one displays the odd numbered lines and field two displays the even numbered lines. Interlacing saves bandwidth when the video is transmitted over the airways or on cable, but when interlaced content is transferred to a digital format, the quality suffers. Any content encoded from sources such as digital video cameras, VHS tapes, 8mm film, and cable television could be affected by the quality degradation. You can use Windows Media Encoder to deinterlace the content, filtering the alternate fields into two frames to achieve a smoother result.
Deinterlacing is not supported for:
Film that is produced by high-end video cameras, such as those used by television or movie studios, is shot at 24 fps. When put onto another medium such as a digital video disc (DVD) or videotape, extra fields are added to achieve the standard 30 fps required by NTSC or 25 fps required by Phase Alternating Line (PAL). The method of adding frames is called 3:2 pulldown and is performed in a telecine room. You can use Windows Media Encoder to remove the added fields of video and encode the image at 24 fps, resulting in a smaller file size and higher-quality image. The process of removing the extra frames is called inverse telecine. Inverse telecine is not supported for:
Video optimization settings must be the same between source groups. If you have multiple source groups in your session configuration, make sure that each one uses the same video optimization setting. For example, if you have one source group that you want to deinterlace, you must deinterlace the other source groups as well. You must set the video optimization for each source group individually.