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Rockbox mail archiveSubject: Re: MP3Buffer?Re: MP3Buffer?
From: George Styles <george_at_ripnet.co.uk>
Date: Fri, 9 Aug 2002 11:45:26 +0100 Thanks :) g ----- Original Message ----- From: "Nielsen Linus (ext)" <Linus.Nielsen_at_elema.siemens.se> To: <rockbox_at_cool.haxx.se> Sent: Friday, August 09, 2002 11:41 AM Subject: RE: MP3Buffer? > > how big is the internal MP3 buffer in the MAS chip? i assume > > that it uses DMA to load in a new buffer from 'main' ram every > > time it runs out, but how often does it do this? > > The MAS documentation doesn't tell how large the buffer is. It requests data > in about 30-40ms intervals, if I remember correctly. > > > the reason I ask is that I want to try and implement a 'beep' > > when a remote control button is pressed. My idea is to overwrite > > the buffer in main ram with a 'beep' mp3 frame, and wait for it > > to be DMA'ed to the MAS chip. > > This shouldn't be very hard to accomplish. Just reinit the DMA controller > with your new buffer and wait. Two problems arise: > > 1) There may be a delay of at least 20-30 milliseconds > > 2) The playing track will probably be disrupted, because of the loss of > sync, and the lost bit reservoir. > > > Could we do something else to the MAS chip to feedback? like > > maybe set all bass/treble/loudness DSP settings to max for > > 1/10s to make it sound different for a bit? > > You could try. > > /Linus > Received on 2002-08-09 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |