Vela CineCast 2000-0422, Installation And User Manual

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132 CineCast Quad Pro Version 2.6 Installation and User Manual
MPEG PLAY Command (With Frame Counting)
Case 1 — Terminal Frame Count within the last 3.5MB of data.
This is the ideal case where the host system hits the End-of-File before the decoder
stops playback. After the last
MPEG WRITE
, the host sends a
RESET BUFFER
command and queues up the next playback (new data followed by a new
MPEG
PLAY
command). The decoder does not return any special SCSI Status.
Case 2 — Terminal Frame Count much smaller than file size.
In this case the decoder returns a SCSI Status Condition Met when the decoder
has two frames remaining in the playback. This is a non-fatal warning which in-
forms the host system that the terminal frame count will be reached in two frame
times. The host system should stop sending MPEG data to the decoder (enough
data resides in the decoder’s buffers to play out the remaining two frames).
After the host receives Condition Met, the host should queue up the next playback
(i.e.
RESET BUFFER
command, send new MPEG data, and send a new
MPEG PLAY
command). The amount of time the host has to set up the next playback is two
frames plus the amount of post-black set in the last
PLAY AUDIO
/
VIDEO
command.
Case 3 — The decoder runs out of data before frame count is reached.
This is a rare error condition which can occur if the frame count is set too large,
e.g., within six frames to the end of the file.
When this occurs, playback stops and the decoder will report:
This error will be reported on the next SCSI command issued, so it may occur
during an
MPEG WRITE
. It can also show up when the
RESET BUFFER
command is
sent instead of the start of the next video.
This error code can also be a result of data starvation during playback, when the
host is not sending data fast enough to keep up with the playback rate. This is a
fatal playback error, in which the decoder is informing the host system that play-
back has stopped. A
RESET BUFFER
command, new data, and a new
PLAY AUDIO
/
VIDEO
command are required before playback can start or resume.
SCSI Status Check Condition
Sense Data: Sense Key 03h (Medium Error)
Additional Sense Code and Qualifier 0005h (End-of-Data Detected)
Additional Sense Bytes 18 & 19 FF02h