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Rockbox mail archiveSubject: Re: Fast forward and reverseRe: Fast forward and reverse
From: <Matt.OReilly_at_wachovia.com>
Date: Tue, 28 May 2002 09:40:33 -0400 That sounds like a very good solution, and much simpler than what I had in mind. I think the next logical step then is to make sure we read enough data when rewinding. Currently it seems that the Archos only gets about 2 seconds of the already-played song to replay; this should be increased to a larger amount, IMO. That way repeated rewinds will not need separate disk reads to function. I leave it to you to determine the optimum amount of data to read from the disk should that be necessary. It seems to me that the entire 2mb should not be filled - I know for myself, trying to learn a guitar/bass riff, sometimes I go over the same space dozens (hundreds?) of times, so I wouldn't want to have to read the disk each time I went over that space. Oh, that reminds me... has anyone requested a 1/2x, 1/4x, etc., playback speed yet? I'd love to be able to play a song at 1/4 or 1/16 speed without pitch modulation. I don't know what's required for that, but it would be nice... Thx Matt Björn Stenberg <bjorn_at_haxx.se> To: rockbox_at_cool.haxx.se Sent by: cc: owner-rockbox_at_co Subject: Re: Fast forward and reverse ol.haxx.se 05/28/2002 09:23 AM Please respond to rockbox Matt.OReilly_at_wachovia.com wrote: > Perhaps a portion of the cache can be reserved for already-played > material? They have a 2mb cache, correct? I would speculate that > reserving 0.5mb would be more than enough for most people, about 30 > seconds for going backwards. The downside to this approach is that we will then have 30 seconds less buffer for normal playback, resulting in shorter battery life. I think the simplest method will probably suffice. Currently we keep one play and one read pointer in the mp3 buffer. That is, one pointer for where the playback is currently and one for where the end of read data is: Read pointer Play pointer | | ----------+-------------------------------+----------- Start End When rewinding, we will be able to reuse all data to the left of "play", all the way back to "read". This amount will vary depending on when the last disk read was performed. If done very recently, the play pointer will be very close to the read pointer: Read Play | | ----------+----+-------------------------------------- Start End In this case, we can only rewind a little before having to read data from disk. This way, we don't have to design a special system for rewinding. We just use what we already have, but still get a better result than the Archos firmware. -- BjörnReceived on 2002-05-28 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |