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Subject: Re: Menus don't speak during paused playback

Re: Menus don't speak during paused playback

From: pondlife <pondlife_at_ntlworld.com>
Date: Sat, 24 Mar 2007 17:30:41 -0000

Hi Mike,

> 1) Somewhat smaller file buffer (more mem used for storing 32bit samples -
> what with really low mem SWCODEC like iFP?)

Why 32-bit samples? Processing efficency? Wouldn't an option to use 16-bit
be helpful? I tend to use my DAP to play 128k MP3s in a car, not as an
audiophile - thus preferring battery life over s/n ratio.

> 2) Limiting crossfading times (a channel must hold the length of a
crossfade
> since only one codec is active at a time).

How limited would this be? The current (7 second?) window is quite useful.
Maybe each channel could have multiple buffered blocks, and crossfades could
somehow be prepared in advance (i.e. latency is allowed to increase during
crossfades). I'm thinking of the decode and PCM playback as being largely
independent, with a new set of channel buffers between them, if that makes
any sense!

> 3) Possibly a bit more CPU intense though can't say for sure.
> Perhaps optimization elsewhere would offset this.

This is likely to be true, although the code could be that much simpler that
it makes little difference. There is considerable expense in the current
codec switching anyway.

> 4) If samplerate switching is employed, 1-3 become even more important.
> Agreement on the proper behavior regarding crossfading 2 or more tracks of
> different samplerates. Some discussion has taken place and maybe all
logical
> consequences addressed already since it seems to lead to two options: no
> crossfade in this case or don't switch rates.

I vote for no crossfade in this case.... KISS above all else.

> Think I should dedicate any pages to discussion of these concerns? Will
> anyone actually participate in deciding what they will and won't accept as
> compromises? I'd at least like basically voting on "I'd rather make the
> tradoffs to have the flexibility and instant response" or "Forget it, I'd
> rather just have the memory (and cycle?) savings of the current system."

Set up a wiki page - start with this conversation and point devs to it (ML
and IRC).

-- 
Steve B
Received on 2007-03-24

Page was last modified "Jan 10 2012" The Rockbox Crew
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