Image Sequence Playback - PRG MBOX User Manual

Image Sequence Playback

Mbox v4.1 adds support for the playback of Image Sequences. Image sequences can be used in place of movies and
are made up of multiple still image files, numbered sequentially. To play an image sequence as if it's a movie, rather than
a still image, Mbox displays the still images one after the other, at a predetermined rate. There are both advantages and
disadvantages to image sequences.
+ Pro - images can use still image formats (PNG, TIFF) that are less lossy or lossless (i.e. uncompressed) and which
can have alpha channels.
+ Pro - with image sequences it's possible to make changes by only editing and re-rendering the affected
frames/images rather than the entire movie. Thereby reducing transfer time for the changes.
+ Pro - image sequences can be played back at any frame rate.
+ Con - a movie running at 30fps with require 1800 image files per minute of content, which means lots of files.
+ Con - some image formats (especially TIFF) have extremely large file sizes. PNG is relatively compact, but TIFF
requires about 8Mb for a single 1080p image.
+ Con - unlike movie files, image sequences can't have audio tracks.
Because it is very time-consuming to open, decompress, and display the actual source files in an image sequence,
these files are converted to a proprietary format in advance. The Mbox application converts the files automatically when
they are found, and if edits are made to individual images in the sequence, those images get converted and replace
the previous version automatically. The conversion process is quite fast and happens in the background, but it must
happen before the image sequence can be played. The conversion process is triggered by a media rescan in the Mbox
application.
MBOX® USER MANUAL
172