|
|
Atari coding BBS
| Re: .xm playback on Atari |
|---|
|
Posted by: evil
|
Mar,26.2011-18:16
|
It's basicly about bandwidth of the CPU->DSP transfer that is the problem.
Some small calculations on this:
* 32 stereo channels, 16 bit samples, max note frequency is probably very high, say we have two octaves higher than Protracker, then it's about 112 kHz. This makes it 32*4*112000 about 14 MB/sec to transfer to DSP. The hostport limit is around 3 MB/sec. That's worst case scenario of course which probably never happens :)
* Okay, if we scale the samples in CPU before transfer them to DSP, this lessens the burden on the DSP hostport, but rises the work for the CPU. If we replay at 49170 Hz this would then give 32*4*49170 which is about 6.2 MB/sec plus additional time for sample scaling. So we're still short on resources.
* Lower the replay frequency to 32780 Hz, then we get 32*4*32780 which is about 4 MB/sec. To go lower than 32780 isn't really worthwhile because it sounds too bad.
So all in all, no you can't do a full featured/full quality XM replay on the Falcon, it has too limited bandwidth to DSP and too weak CPU.
--
Anders Eriksson
ae@dhs.nu
|
[All messages in this thread] [Start new thread]
|
Topic
|
Posted by
|
Date
|
|
.xm playback on Atari
|
Simon Sunnyboy / Paradize
|
Mar,26.2011-12:13
|
|
Re: .xm playback on Atari
|
505
|
Mar,26.2011-13:16
|
|
Re: .xm playback on Atari
|
sqward
|
Mar,26.2011-18:05
|
|
Re: .xm playback on Atari
|
evil
|
Mar,26.2011-18:16
|
|
Re: .xm playback on Atari
|
sqward
|
Mar,26.2011-18:30
|
|
Re: .xm playback on Atari
|
evil
|
Mar,26.2011-20:15
|
|
Re: .xm playback on Atari
|
sqward
|
Mar,26.2011-20:46
|
|
Re: .xm playback on Atari
|
Arthur
|
Mar,27.2011-19:45
|
|
Re: .xm playback on Atari
|
Orion_
|
Sep,08.2011-11:59
|
|
Re: .xm playback on Atari
|
nativ
|
Sep,20.2011-13:10
|
What's the anti-troll code?
That's your personal code to be able to add comments and messages on the dhs.nu site.
Don't have a code or forgot it? Fix it here.
|
