4.2

In the preview area, choose Clear Poster Frame from the
Marker pop-up menu .
Add markers
A marker flags a specific timing location in a source file. You can
append a marker with editing notes or other descriptive
information. Additionally, when you output the source file to an
H.264, MPEG-2, or MPEG-4 video format, each marker forces the
creation of an . Added I-frames improve compression
quality, but can increase overall file size. Compressor can create
the following types of markers:
Chapter markers: Generate named index points and thumbnail
images for DVDs, QuickTime movies, or video podcasts. You
can also assign a URL to a chapter marker to have that URL
appear during playback of a podcast. Chapter markers are
also included in submissions to the iTunes Store as part of an
. Chapter markers appear orange in the
Compressor preview area.
Compression markers: Generate an I-frame, but do not
generate thumbnails, chapter-track entries, or other metadata.
Add them to a video if a section appears to have lower image
quality than the surrounding frames. Compression markers
appear blue in the Compressor preview area.
Edit/cut markers: Function identically to Compression markers.
They are commonly used by compression artists to force an I-
frame at an edit point to ensure higher image quality at that
moment in the video. Edit/cut markers appear red in the
I-frame
iTunes Store Package