Michael Riepe schrieb: >> Every video bigger than 2500MB is opend with sequential mode and smaller >> without that option (=everything in cache). >> This functionality would improve the export on same disk by 100% :-) >> (btw, where can I find the open file command to deactivate the >> sequential mode?) >> > > Look at the posix_fadvise() calls in src/buffer.cpp. > > Thanks. First, I replaced POSIX_FADV_DONTNEED with POSIX_FADV_WILLNEED and did some performace checks: - Index generation takes quite the same time 1,1 GB in 17 seconds. - Exporting on same hard disk is now done in 21 seconds instead of 34 seconds! =>That's really good!
Now, I tried a 4,3 GB file. (may memory has "only" 3,3 GB) - Index generation takes now 103 seconds instead of 49 seconds. (that's what is called "thrashing") - Exporting takes 100% longer (288 sec instead of 148 seconds) => this is definitely not OK. (maybe thrashing is better with kernel 2.6.23. see the http://kernelnewbies.org/Linux_2_6_23#head-102af265937262a7a21766ae58fddc1a29a5d8d7 or direct link to the benchmark http://lwn.net/Articles/235181/ ) Second (here is the interesting part ;-) ) I tried the option POSIX_FADV_NORMAL. Now the system know itself and automatically(!) whether to hold the video (...WILLNEED) or the don't hold the video (...DONTNEED) in memory. => this ist the best parameter, because you get always the best perfomance! regards Dominik PS: forget the new entry in .qt/dvbcut.sf.netrc. Just replace it with POSIX_FADV_NORMAL. (Feel free to do some performance checks yourself :-) ) PPS: I hope this works under Windows as goog as under Linux... If not, keep the old ...DONTNEED for the windows port.) ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ DVBCUT-user mailing list DVBCUT-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dvbcut-user
