Advent Communications
209298 - DVE5000 Technical Operation Handbook - CL140042 Page 107 of
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APPENDIX E- DOLBY E NOTES
Things to remember about Dolby –
1. A Dolby E frame is the same length, and must be correctly timed and synchronous
with, the video frame.
2. Correct timing is the responsibility of the preceding Dolby encoder and associated
embedder, prior to the DVE5000. However the DVE5000 has the ability to correct
badly timed signals – described later.
3. Incorrectly timed Dolby will decode audibly, but may cause problems in post
production where the editing process cuts through a Dolby audio frame.
4. The correct timing, called “DE position” as measured using a DM100 Dolby analyser
(for example), is between TV lines 11 and 26 for NTSC and between line 7 and 31 for
PAL. Note that even for HD formats, line timing is referred to PAL/NTSC analogue
timing on a DM100 analyser.
Soon the line timing will be referred to in “uS” to avoid confusion. The DVE5000 uses
this notation, relative to the SMPTE RP168 reference point, so the correct values as
displayed are as shown in this table –
625 25 1080i 50 525 29.97 1080i 59.94
PAL SD PAL HD NTSC SD
NTSC HD
Potentially earliest valid DE position
TV line 7 11 11 16
uS * 390 390 450 450
Ideal DE line position ± 80uS
TV line ± 80uS 12 21 14 24
uS ± 80uS * 730 730 690 690
Potentially latest valid DE position
TV line 31 55 26 50
uS * 1950 1950 1460 1460
* - in relation to SMPTE RP168
reference point and approximate values
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