9035 Owner’s Manual
••••
(V 1.0.9)
Page 15 of 27
Window Horizontal Size
Specifies the size of the reference window in sample clocks. If an output video horizontal hsync pulse
falls outside of the reference window, the framesync will correct the output timing. A larger value will
allow the output timing to drift further from the reference before the frame sync corrects. If the
reference input has high jitter, you may need to set this to 3 or 4 sample clocks. The default setting is
two sample clocks.
Line and Field Latency
Specifies the smallest amount of latency allowed by the frame sync. This latency measurement is in
lines and fields of the output video. The frame sync will not output a field unless the specified number
of lines and fields are captured in the buffer. Minimum latency is three lines and zero fields in all video
modes. The maximum latency is format dependent. The operational latency of the frame sync is always
between the specified minimum latency and minimum latency plus one frame (not one field).
Some examples:
Ex 1: 525i Video and Reference are co-timed precisely, Field Latency = 0, line latency =3
Output video will be exactly one frame behind input video, because input video is not leading reference
by more than the line latency amount.
Ex 2: 720p Video and Reference are co-timed precisely, Field Latency = 2, line latency =3
Output video will be exactly three frames behind input video. One frame, because input video is not
leading reference by more than the line latency amount and two additional frames because field latency
is set to two (and 720p video has one field per frame)
Ex 3: 1080i Video and Reference are co-timed precisely, Field Latency = 1, line latency =3
Output video will be exactly two frames behind input video. One frame, because input video is not
leading reference by more than the line latency amount and one additional frame because field latency
is set to two (and 1080i video has two fields per frame)
Ex 4: 525i Video is asynchronous from a 1080i59.94 reference,
Field Latency = 0, line latency =3
Output video will track the reference precisely. Input to output video latency will slowly drift between
3 lines and one frame plus three lines as the video moves relative to the reference.
Audio Delay
Reports the amount of current audio delay. The audio delay always matches the video delay.
Reset Frame Sync
Resets the frame sync, clearing any buffered audio and video. You must reset the framesync after
manipulating the horizontal and vertical offset in order re-establish correct audio and video co-timing.
