FOCUS Enhancements 3.2 - Manual (Page 176)

Troubleshooting
162
"Latent Images" or "Flashing" During Playback
1. Incorrect timecodes or improperly closed encoding session. If
the incorrect timecode is given for a particular file it is possible
to actually encode a frame or two of the trailer or header
information from the source. Often this "extra" frame is seen
only briefly and may appear as a "flash" on the screen. Review
the original source of the encoding and determine if the
timecodes are correct or if the encoding session was actually
closed on the proper frame.
2. Playing MPEG 1 and MPEG2 files back to back: The
resolution switch from MPEG 1 files (342X240) to MPEG2
files (720X480) causes a "latent image" or a "quadrant display"
of the last played file's image. The only way to perform
seamless playback when using a playlist of files is to insert an
encoded "black file" with blank audio track, between MPEG 1
and MPEG 2 files. The black MPEG file preceding the
playback file should be of the same standard. In other words,
prior to an MPEG 1 file the "black file"--again with a blank
audio track--should be MPEG 1 and vice versa.
Stuttering Files During Playback
Irregular playback can be caused by a number of conditions:
1. Mixed video only MPEG files with MPEG with video and
audio data: Confirm that all files are either video only, audio
only, or audio/video files. It is recommended to have a "blank"
audio track encoded with all MPEG files--even if no audio is
present on the source material. This will ensure compatibility,
if MPEGs with audio/video information are introduced at a
later date.
2. Dolby Digital files: Dolby Digital files can not be mixed with
any other type of file. Ensure that all of the file types are the
same.