[mythtv] Random blockiness that probably isn't CPU or PCI bus
bandwidth-related
Eric Anderson
rico99 at sbcglobal.net
Wed Jan 19 00:37:42 EST 2005
> I have not tried your latest version. When I tried to remove the
> "double buffering" when reading from the ringbuffer, I needed to
> greatly increase the ringbuffer to get it to work as well. I also
> never increased the internal buffer size in the HD-x000 driver --
> maybe that is why my results differed from yours. If I have time this
> weekend, I will try your latest version. I assume it applies to the
> latest CVS?
Actually, I'm not 100% up-to-date. But hdtvrecorder.cpp and
hdtvrecorder.h haven't changed
since I last updated. So it should still apply. If you have a chance to
try it out, that would be
cool.
BTW - With my version I don't get any buffer overruns at the end of a
recording. (I have the
reader thread close() the device so we don't have the case where the
main thread tells the
reader to stop reading, process remaining data, then close -- during
which time the device
driver hits an overrun.) I *do* still sometimes get a buffer overrun
when multiple recordings
start up. But it's normally a one-time thing.
I'm wondering if *any* buffer overrun poisons the device driver for
later. (Just a theory...)
Because with the CVS version, I pretty much always get a buffer overrun
at the end of
the recording. Like you said (below), maybe the 1.6 driver fixes some
stuff.
> Have you tried the v1.6 driver? It seems to work well for me --
> although it may be why I see an occasional overrun now, when I didn't
> a couple of weeks ago (I was using the 1.5 driver).
>
I haven't. But I think I reviewed diffs of the code from 1.4 to 1.5 to
1.6 and I didn't see anything related
to the CX8800 stuff. I am planning to try that out, though. Just
haven't gotten to it yet.
> Maybe increasing the internal buffer size in the HD3000 driver is
> causing a problem? Probably not. I have seen the corruption you are
> talking about, but not in several weeks. That is why I think it may
> be fixed in the 1.6 driver.
Good data point. Let me get back to you on that.
Thanks.
-Eric
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