Rockbox Technical Forums

Support and General Use => Audio Playback, Database and Playlists => Topic started by: perfectdrug on August 20, 2005, 01:42:04 PM

Title: antiskip-buffer
Post by: perfectdrug on August 20, 2005, 01:42:04 PM
can anyone tell what it is ?
can´t find an explanation
Title: Re: antiskip-buffer
Post by: psycho_maniac on August 20, 2005, 02:29:26 PM
have you ever heard of anit-skip in a cd player? its basically that. it reads data for so many (seconds?) and so if you bumped your player it wont skip but if it gets bumped for over how many seconds you have it set it will skip. i

m not sure if this is the technical answer but its what i think it is and if not im pretty close. if not ill just get ripped on. one question i have is why did they automatically set the antiskip buffer on iriver? it really dosnt need it at least i dont think so. never had it skip. man o man do i wihs archos had this when i had one. i would mow the lawn and it would skip like crazy, but with my iriver it never skips.
Title: Re: antiskip-buffer
Post by: perfectdrug on August 20, 2005, 03:15:36 PM
ok thanks
the antiskip-buffer was cause of my problem
i set it to 5 sek and everything was really slow
now have i configured it to 5 min and all works quite fine...
Title: Re: antiskip-buffer
Post by: wrecker on August 27, 2005, 05:59:42 AM
I've just updated the Anti-Skip Buffer section in the Wiki Manual.

Hopefully this will clarify things for you.

Link: WikiManual - Anti-Skip Buffer section (http://www.rockbox.org/twiki/bin/view/Main/ManualMainMenu#Anti_Skip_Buffer)
Title: Re: antiskip-buffer
Post by: oayz on October 20, 2005, 06:09:17 PM
In regards of anti-skip useing more power. If there no skips it just reads ahead and prefills the buffer. No extra power here. In case of skip of cause it will read more data again and again and does consume more. Assuming skips don't have offen extra power is probably negligible.

Any comments?
Title: Re: antiskip-buffer
Post by: the_winch on October 20, 2005, 10:31:34 PM
I don't know for sure but I think the anti-skip time is the minimal amount rockbox will keep in the buffer. If it's set for 5 minutes as soon as you have less than 5 minutes of data it tries to read more.

In that case setting it really high will reduce battery. If the anti-skip needs 75% of the buffer it will fill it to 100% wait until it falls to 75% and fill it again. That will require more drive starts/stops that if the anti-skip needs 25% of the buffer. With the anti-skip at 25% it can fill 75% of the buffer at a time reducing drive starts/stops.

I think the wiki description is perhaps a bit confusing when you are thinking about iriver with its large buffer. I'm not really sure iriver even needs a configurable setting.
Title: Re: antiskip-buffer
Post by: Lear on October 21, 2005, 06:39:48 AM
I don't know for sure but I think the anti-skip time is the minimal amount rockbox will keep in the buffer. If it's set for 5 minutes as soon as you have less than 5 minutes of data it tries to read more.

In that case setting it really high will reduce battery. If the anti-skip needs 75% of the buffer it will fill it to 100% wait until it falls to 75% and fill it again. That will require more drive starts/stops that if the anti-skip needs 25% of the buffer. With the anti-skip at 25% it can fill 75% of the buffer at a time reducing drive starts/stops.

That is correct.

Quote
I think the wiki description is perhaps a bit confusing when you are thinking about iriver with its large buffer. I'm not really sure iriver even needs a configurable setting.

Having the option can be good, because it depends much on how you use your player (or where you keep it during use). E.g., I have it set to 5 (or was it 15?) seconds and that works fine for me, while for some, a couple of minutes might be needed. Basically, it needs to be large enough for the drive to spin up and start reading before running out of data to play.

Hm.. I think I updated the Wiki section on the anti-skip buffer, but that was before the crash...
Title: Re: antiskip-buffer
Post by: oayz on October 21, 2005, 04:39:40 PM
Thanks for an explanation. It does make sense, but I've just timed drive access on my v2 playing 128/CBR. No matter how anti-skip is set (0 to 7) it always takes 90 seconds. If this is true I don't think power consumption changes.

I'm running Rockbox 2.5 flashed