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Rockbox mail archiveSubject: Cutting recording (was): Re: Wishful thinkingCutting recording (was): Re: Wishful thinking
From: Martin Borus <martin_at_borus.de>
Date: Thu, 21 Nov 2002 15:25:02 +0100 rockbox_at_cool.haxx.se schrieb am 21.11.02 12:33:42: > James Ockwell wrote: > > Just wondering if we will be able to detect a silence and therefore be able > > to automatically separate tracks when recording through line in? > > Yes, that is certainly possible. > > However, the accuracy may be, let's say, non-optimal. :-) > > It is a little tricky if we want to split at frame boundaries, but > otherwise it should be pretty straightforward. Is this already up for discussion or should we wait until recording works kind-of flawless? If it is: In my opinion it is essential to perform the cut on the frame boundaries so that you can always correct a wrong cut later. To detect the cut point I'd suggest: - a minimum time for silence (example 0.5 seconds) - a max level for silence (example -35 db) - a minimum time since the last cut (example 120 seconds) These three selection rules are pretty straightforward. Another four optional pro features might make it really cool: - maximum time since last cut (example 900 seconds - cut afterwards) - max level gain (example 1 db) - max level gain time (example 60 second) - remove silence longer then (example 1.9 seconds) After a cut now there wouldn't be any cuts for 120 seconds at all. After that, if the sound stayed below -35db for longer then 0.5 seconds, the frame that has the first audio above -35db would be the first of a new file. If not cut has been make after 120 + 60 seconds the "max level gain" would hit. After each "max level gain time" the max level for silence would go up (making a cut more likely). No matter what happens, after 900 seconds there will be a cut. The "remove silence longer then" option would be used to make shure unwanted silence does not get recorded. Which this set of rules it should be possible to get a right cut point for most recording situations. What do you think? In my opinion this is something for a future version 2.1 rather than 2.0. I'd love to have it in the end though, because it would be really convenient to record streaming (satellite/radio) music and CDs this way. Martin ______________________________________________________________________________ Ab heute wird nichts mehr vergessen! Mit dem Organizer von WEB.DE FreeMail. http://freemail.web.de/features/?mc=021145 Received on 2002-11-21 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |