bjm at lvcm
Apr 6, 2004, 10:23 PM
Post #9 of 12
(3018 views)
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David Engel wrote:
> On Tue, Apr 06, 2004 at 05:39:25PM -0700, Bruce Markey wrote:
>
>>independently. If you had 3 seconds of preroll and set 1 minute
>>of Start Early time for a show listed as starting on the hour,
>>the recorder would start at :58:57.
>
>
> Close. To give an encoder link time to stop/finish any current
> recording, new recordings actually start 2 seconds late, so the time
> would be :58:59.
:-) I knew that when I wrote it and didn't word it correctly.
The loop plans to kickoff the encoder after :58:57 has been
reached but the first frame written in the file is probably
after :58:59. The is the very essence of why we want preroll.
However, I agree with the conclusion but not the reasoning. In
this example, it clearly is not a back to back situation. If
there had been another show scheduled to end at :59:00, the
new recording would have started at :59:19 (after an hour show
on a remote slave over 802.11g).
The first show would stop recording at :59:00. The console
would report "backend still changing state, waiting.." and
for the next 17 seconds, the slave backend would send about
3600 INSERT statements to the database. One per keyframe. After
all have been sent over the net, the console reports, "changing
state finished, starting now" and about two seconds later,
presto, new recording starts 19 seconds late. This delay is
not caused by the scheduler run which we know runs in a few
hundredths of a second or anything about time fields in the
'record' table.
-- bjm
172 Query INSERT INTO recordedmarkup (chanid, starttime, mark, type, offset) values ( '1018', '20040406163000', 0, 7, "1808")
172 Query INSERT INTO recordedmarkup (chanid, starttime, mark, type, offset) values ( '1018', '20040406163000', 1, 7, "957794")
172 Query INSERT INTO recordedmarkup (chanid, starttime, mark, type, offset) values ( '1018', '20040406163000', 2, 7, "1610440")
172 Query INSERT INTO recordedmarkup (chanid, starttime, mark, type, offset) values ( '1018', '20040406163000', 3, 7, "2340303")
172 Query INSERT INTO recordedmarkup (chanid, starttime, mark, type, offset) values ( '1018', '20040406163000', 4, 7, "3013325")
172 Query INSERT INTO recordedmarkup (chanid, starttime, mark, type, offset) values ( '1018', '20040406163000', 5, 7, "3729921")
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