Adobe 65021048 User Guide - Page 39

ADOBE PREMIERE PRO CS3 33 User Guide Special projects About 24p footage and projects Footage acquired from a camcorder or by film transfer, at roughly 24 non-interlaced (progressive) fps is called 24p footage. This footage emulates film in its picture quality and depiction of movement because the 24p frame rate is very close to that of motion-picture film, and each frame is built from progressive lines (not from interlaced halfframe fields). 24p formats have become popular among low-budget digital filmmakers because they lend a film look to its subjects. To create a 24p project in Adobe Premiere Pro, you select one of the 24p project preset that matches the format and frame aspect ratio of your footage. You can import files and capture footage as usual. Adobe Premiere Pro includes two alternate 24p pulldown schemes: Repeat Frame and Interlaced Frame. Both options convert 24p footage so that it plays back at 29.97 fps, but there are subtle visual and performance differences between them. You can select one of these options in Project Settings when starting a new project, or change it in an existing project. You can edit 24p footage in Adobe Premiere Pro. If you edit 24p footage in a project using one of the standard Adobe Premiere Pro DV-NTSC presets, Adobe Premiere Pro uses a 24p DV pulldown scheme to convert the footage to 23.976 fps interlaced video for playback to standard NTSC devices. You would use this method, for example, to export your movie to a standard NTSC format for mastering to tape or broadcasting. If you edit 24p footage in a project based on one of the DV-24p presets, Adobe Premiere Pro, by default, disables the 24p pulldown scheme, and enables a pull-up scheme for playback to standard NTSC devices. This allows you to export the movie to a file in a 24p format. You would use this method, for example, if you want to export your movie to a DVD for playback on DVD players and TV monitors that support 24p formats. When you are done editing, you can use the Adobe Media Encoder to export the 24p movie from Adobe Premiere Pro to Adobe Encore CS3. You can open it in Encore, author your DVD, then master and burn the project as a 24p MPEG-2 stream. The resulting DVD exhibits no interlacing artifacts on 480p-capable (progressive scan-capable) DVD players and televisions. Alternatively, you can export the Adobe Premiere Pro 24p project into a format, such as still-image sequences, appropriate for transfer to film. Note: Adobe Premiere Pro accepts 24p and 24Pa footage only from cameras using these schemes. About 3:2 and 24Pa pulldown When you transfer 24-fps film to 29.97-fps video, you use a process called 3:2 pulldown, in which the film frames are distributed across video fields in a repeating 3:2 pattern. The first frame of film is copied to fields 1 and 2 of the first frame of video, and also to field 1 of the second video frame. The second frame of film is then spread across the next two fields of video-field 2 of the second video frame and field 1 of the third frame of video. This 3:2 pattern is repeated until four frames of film are spread over five frames of video, and then the pattern is repeated. The 3:2 pulldown process results in whole frames (represented by a W) and split-field frames (represented by an S). The three whole video frames contain two fields from the same film frame. The remaining two split-field frames contain a video frame from two different film frames. The two split-field frames are always adjacent to each other. The phase of 3:2 pulldown refers to the point at which the two split-field frames fall within the first five frames of the footage. Phase occurs as a result of two conversions that happen during 3:2 pulldown: 24-fps film is redistributed through 30-fps video, so each of four frames of 24-fps film is spread out over five frames of 30 (29.97)-fps video. First, the film is slowed down 0.1% to match the speed difference between 29.97 fps and 30 fps. Next, each film frame is repeated in a special pattern and mated to fields of video. April 1, 2008