[directmusic] Re: Creating, downloading and unloading segments with DirectMusic
- From: Abhijit Patait <abhijit_patait@xxxxxxxxx>
- To: directmusic@xxxxxxxxxxxxx
- Date: Fri, 2 Jul 2004 10:36:27 -0700 (PDT)
Hello Vytautas
I cannot comment on the problem of downloading too many segments (as I haven't
encountered this problem).
One thing I can suggest about Audiopaths is that you should manualy activate
and de-activate the audiopaths when they are used/unused. I read somewhere
(don't remember where) that even if you are not playing anything on an
audiopath, it still keeps sending silence frames to the synthesizer, and takes
up CPU resources. You can use the API IDirectMusicAudiopath8::Activate(...) to
de-activate the audiopath. You should see significant reduction in system
resource usage after de-activating the paths.
Abhijit
Vytautas Leonavicius <vytas@xxxxxxxxxxxxx> wrote:
Hello Group,
I'll be very thankful for any help, cause I really need it.
I am developing sound subsystem in our game. It uses DirectMusic API. I got
lots of troubles with DirectMusic, so I begin to suspect that the main problem
is in my wrong model of using DirectMusic. I addition to lack of information on
that's going on inside DM, I got stuck finally.
I started this way - I loaded all segments from files based on list of
filenames. Later, I downloaded them all onto performance. The problem was with
download - it failed if too many sounds were downloaded. Then I introduced some
kind of cache, that managed all segments, and unloaded least useful, while
downloading new ones. That worked. For some time.
Later, I faced another problem. Instead of creating all segment files at
startup, I created them on first use. After this modfication, I found that now
I am able to download much more segments than prior to that! So, looks like
IDirectMusicLoader and IDirectMusicSegment::Download, affect each other - the
less segments you load from file, the more segments downloaded onto performance
successfully and vice versa.
Another weird thing, is that both loader and segment downloading fail with same
return value. : DMUS_E_LOADER_FAILEDOPEN File open failed because the file does
not exist or is locked. From above, looks like CreateSegmentFromFile and
Download affect some shared memory or resource, however, return value is saying
nothing about memory etc.
So it looks like I am doing something wrong, cause while searching forums, I
found no topics with similar problems.
When should I create segments from wave files? Should I destroy/create them
again during runtime, and that's more important, how many of them could be
created at once, without being afraid of crash? When should I download and
unload them? Is DMUS_E_LOADER_FAILEDOPEN saying: "too many segments created,
release some then retry"?
Another problem is with audiopaths. I am using separate audiopath per each
sound with separate volume. And I noticed, that even if I don't use audiopaths,
just create them, they slow down application. I suppose I'll going to implement
some audiopath sharing between sounds, however, what is 'too many audiopaths"?
How many audiopaths are allowed without noticeable perfromance penalty?
Weird thing, I don't know how many segments are allowed to be created from file
at once, I don't know how many of them could be downloaded at once, and same
thing with audiopaths. In DM documentation no single word about all these
things...
Vytautas
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