Table of Contents
Advertisement
Chapter 2 — Overview and Operation
Frame Reporting
Returns the frame number as derived from the GOP header time code. The firm-
ware converts time code (in HH:MM:SS:FF format) into a frame number. This is
useful for back-to-back no-black playback (i.e. stream concatenation) because this
field will reflect the actual frame number of the currently playing stream.
The frame count will account for Drop Frame in NTSC. The starting frame count
depends on the initial GOP time code contained in the MPEG stream. If the
stream starts at 00:00:00:00, the first frame number will be 0. For other starting
time codes, a frame number will be derived from the hour, minutes, seconds,
and frames. As an example, for an initial GOP time code of 01:00:00:00, the first
frame will have a frame number of
NTSC with Drop Frame (29.97 Hz):
1 hour x (29.97 frames/sec x 60 sec/min x 60 min/hr) = 107892 frames
PAL (25 Hz):
1 hour x (25 frames/sec x 60 sec/min x 60 min/hr) = 90000 frames.
Mode Page 30h provides a generalized frame count of the number of video
frames decoded.
The decoder reports three different time codes:
• LTC Output Time Code: Each channel has an LTC output. The VITC time
code will be the same as the LTC output.
• GOP Time Code: Time code found within the GOP header of an MPEG
stream.
• LTC Input Time Code: Reports the Master House LTC clock from the LTC
input of the CineCast Quad Pro.
Each Time Code group comprises these fields:
Valid
"1" indicates the time code is valid.
"0" indicates the time code is not valid or not present and should be ignored.
Hours
Time Code hours range 0-23 (5-bits).
Minutes
Time Code minutes range 0-59 (6-bits).
Seconds
Time Code seconds range 0-59 (6-bits).
Frames
Time Code frames range 0-29 (NTSC); 0-24 (PAL) (5-bits).
103
Mode Parameter Pages
Advertisement
Table of Contents
