[directmusic] Re: questions about direct music producer
- From: "Jason Booth" <jason@xxxxxxxxxxxxxxxx>
- To: <directmusic@xxxxxxxxxxxxx>
- Date: Tue, 22 Oct 2002 16:19:58 -0400
I can't answer all of these, but I'm sure some other people on
the list will fill in the rest:
> My questions are pretty low-level, so pardon me if they're answered
elsewhere, but here goes:
>=20
> 1.) How many audio voices can DMP handle before it clips? In fact, a
lowdown on how EXACTLY DMP handles mixing would be pretty good.
It seems to depend on your output quality, and the number of
band changes your making at one time. In Asheron's Call 2, we're pushing
about 64 3d sounds, and anywhere from 10-90 voices of music. The 3d
audio is mixed at 44.1k, and the music is mixed at 22k. I generally
found that running at 44.1k was too expensive for the number of voices
we wanted to push, and DMP started to crackle a lot. We are, however,
pushing a lot more voices than most games do.
> 3.) How large can .WAV files be if they are triggered by segments?
Can I load a .wav file that is 3 or 4 or 10 minutes long, or are there
problems with doing that?
I believe Direct Music automatically streams wavs bigger than 5
seconds, although this can be turned off. I'm currently doing a
prototype that uses a lot of streaming wav files, and haven't had any
major problems yet.
> 4.) How big as far as disk space goes can DLS collections be?
You want to keep them small because of band patching. Basically,
every time you call a band within a band track, the DLS files are
refreshed. If your refreshing a lot of large DLS banks, you will get
hitches. Instead, use lots of Pchannels, and place each instrument in a
single DLS file. It's better for organization anyway, as having one very
large DLS bank is confusing.
> 5.) Is there any way to add FX plug-ins to audiopaths that aren't
already there? Can I add a graphic EQ plug-in (third party or not) to
the list of effects that are possible, or would that require me to
actually code a graphic eq?
I don't know of any 3rd party effects, although I believe it's
possible to add your own. One of my current gripes with Direct Music in
general is the relationship between audio paths and effects. We're using
Direct Music for all our sound effects as well as music, and it's
obvious the effects/ audiopath stuff was really designed with music in
mind. Currently, if you place a compressor on a 3d audiopath, it
compresses the sound before the objects is positioned, instead of
operating on the output of the audiopath. This makes a run-time
compressor exactly the same as compressing your source data. You also
cannot pipe one audio path to another audio path of a different style:
For instance, I wanted to pipe all my 3d audio paths to a final mix
path, and put a compressor on that mix path much like you would on the
2mix of a mixing board. However, if you do this, you loose all 3d volume
information in the process.
I believe this is because they want to use the hardware to do 3d
positional audio, but that makes the effects fairly useless for those
types of things.
> 6.) What are some specific implementation problems that we should
avoid?
You really need to get to know the system, from both a code and
composition side. Your composer needs to be aware of how direct music
works from a technical standpoint, expecially if you plan on pushing a
lot of data through the system. The system has a lot of potential
approaches within it, which makes it very flexable, but also increases
the learning curve substancially.=20
7.) Can I use DMP to keep my house clean (vacuum, do the dishes, etc???)
No, but it might pull your hair out for the first few months ;)
Don't worry though, the results are worth it in the end..
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