Backend buffer questions
#1
I've read through many posts, and I understand the buffer setting in the GUI was removed. Cool, no sweat.

I do have some questions about the inherent features of the buffer, however.

The cache setting in the network settings outlined in the WIKI:
http://wiki.xbmc.org/index.php?title=Adv...network.3E

Is the Cachemembuffersize within the advancedsettings.xml still a valid workflow, and will putting a larger number as a value improve the playback reliability off of a NAS or CPU over 802.11n? (see end post)

What is the default value of the buffer inside of XBMC, so I have a starting point to add on my values, if still applicable. (i.e. how much of the file is buffered when loaded - does XBMC attempt to buffer the entire file, or just 10MB at a time, etc?

Win XP SP3. XBMC 10.0.

Reason for question: XBMC constant re-buffering (randomly) of 720p or 1080i h.264 files played back from an 802.11n connected NAS via a CIF share. (I know many other factors go into NAS playback and wireless connectivity - I am heavily working on improving those those as well...but all things being equal....) (FWIW, the h.264 files range from 4.5-8GB, and vary in range from 90 min to 2.5 hours. Average is 1.5 Mbps. XBMC can play them just fine when local)

I am watching the buffer via the "o" key, and yes the "vq" and "aq" hit zero% prior to buffering.

I appreciate the time and hard work on development, gang.

~Michael
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#2
Polite bump, err, nudge!
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#3
The advancedsettings setting is still supported, but I'm not sure it does anything useful.

I had a quick scan through the code, and it looks to me as if a debug log should contain:

CFileCache::Open - opening <filename> using cache

if it uses a cache. See line 85 in https://github.com/xbmc/xbmc/blob/master...eCache.cpp if you're curious. I tried playing a few streams and that entry didn't appear in my debug log, so it looks as if that part of the code isn't being used.

JR
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#4
Thanks for the reply, JR.

I'll focus my efforts more heavily on improving the network XBMC sits on, rather than try and tweak my XBMC CPU.

Thanks!

~Michael
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#5
In any case the cache is unlikely to help with playback across a LAN. It's intended to deal with Internet streams that might pause for a few seconds. If your NAS cannot send data fast enough to keep up with the playback then all the cache will do is slightly increase the time between "Buffering" messages.

JR
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#6
Discussion on Cache calculation:

http://forum.xbmc.org/showthread.php?tid...ight=cache

Recent Trac on Cache:
http://trac.xbmc.org/ticket/10772
http://trac.xbmc.org/ticket/10779

Increasing cache size will not work when the internet stream doesn't support resume. XBMC will buffer to the maximum cache size and then will stop. Then it will try to resume from their which won't work for streams that don't support resume. Another issue is XBMC doesn't fill the cache at the beginining, it will only fill the cache if you pause it.

We should change the logic to have MINIMUM ( Value defined in advancedsettings ) and MAXIMUM ( Actual File Size ) cache size
The normal XBMC log IS NOT a debug log, to enable debug logging you must toggle it on under XBMC Settings - System or in advancedsettings.xml. Use XBMC Debug Log Addon to retrieve it.
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