32 mb limit: hardware or software one?

marce · Jan 18, 2005, 02:57 AM

Hi i have heard several times about the 32 mb limit using soundfont (i mean that you cant play more than 32 mb of samples at time).
Is this limit a hardware one (that means it can be solved) or is a thing that kxdrivers solves?

Thanks your answers.

Lex Nahumury · Jan 18, 2005, 04:45 AM

>>Is this limit a hardware one (that means it can be solved)

Yes and no. The hardware can addres only 32mb.
However via a software (paging) trick it is possible to playback larger sample data.
( CL drivers do that on their 10k2 based audigy cards.)

>> or is a thing that kxdrivers solves?

No, not at the moment.

/LeMury

marce · Jan 18, 2005, 05:07 AM

Thanks very much your answer.

**Eugene Gavrilov** · Jan 19, 2005, 07:12 PM

not exactly. simple 'paging' won't solve this issue, since new paging will need to reset page cache which will cause distortion. it seems that CL drivers use data copying. that is, they copy new soundfont data into pre-allocated buffers (say, 4kB each)... however, I cannot be 100%-sure.

E.

marce · Jan 20, 2005, 01:56 AM

Thanks again the info. About what do Audigy to solve this hardware limit, here is the info i have (is from the creative site, that made it maybe not the more trust, but the guy that wrote it is Ethan Winner that is a repectfull guy):

Quote:

The Sound Blaster Live! can play only 32 MB of Wave file data at one time, and that is further limited when using large SoundFonts. If you have loaded one or more SoundFonts that occupy, say, 60 MB of memory, the Sound Blaster Live! can play only the Wave data that lies within a contiguous 32 MB block. If you play an instrument that happens to lie near the beginning of SoundFont memory and then play a different patch near the end of the memory block, a "hole" develops and some instruments or notes will no longer play. The Audigy solves this by allowing a contiguous 4 GB "memory window" that the MIDI synthesizer can access all at once

How much is sure about this info, i really dont know.

Lex Nahumury · Jan 20, 2005, 07:40 AM

Quote:

Originally Posted by Eugene Gavrilov

not exactly. simple 'paging' won't solve this issue..

Yep, sorry, wrong terminology. Should be "copying".
Anyway; so far I haven't found any linux implementation of this 'trick'.
That is; afaik linux/alsa soundfont implementation also limits at 32mb.

/LeMury

droc2003 · Feb 8, 2005, 05:17 PM

I used to have the 32MB limitation with my SBLive and Creative drivers. I also had the 'holes' problem. Then I found this patch on the Internet, it involved adding the following registry key:

REGEDIT4

[HKEY_LOCAL_MACHINE\Software\Creative Tech\Devcon\0003]
"MaxPatchMemory"="133169152"

Now, I can play soundfonts up to around 128MB (although no individual sample within the soundfont exceeds 32MB) on my SBLive using Creative drivers, and no audible note dropouts, period.

I have inquired previously as to what this reg key does, but nobody has come up with a suitable explanation, all I know is, it works. That's why I'm still using Creative drivers on one of my machines. I would suspect that MaxPatchMemory could be raised higher, I haven't tried it yet.

Can the kxDriver play large soundfonts (>32MB) without dropouts?

Lex Nahumury · Feb 8, 2005, 09:31 PM

Quote:

Can the kxDriver play large soundfonts (>32MB) without dropouts?

No, but neither can CL drivers on an SBLive. (audigy I&II drivers can via a driver trick)
Those reg patches just allow you to load large sf (>32mb) in memory.
However, still only 32mb of sample data can be adressed at a time.

/LeMury

**Eugene Gavrilov** · Feb 9, 2005, 02:56 AM

I'm currently about to start implementing large (>32Mb) sample support (sf2-based). I cannot provide you with any release dates -- and even say if this feature is ever implemented. there will be an option to enable/disable this feature (for fast/slow PCs)

/E

Jan 18, 2005, 02:57 AM	#1
marce DriverHeaven Newbie Join Date: Jan 2005 Posts: 11 Rep Power: 0	32 mb limit: hardware or software one? Hi i have heard several times about the 32 mb limit using soundfont (i mean that you cant play more than 32 mb of samples at time). Is this limit a hardware one (that means it can be solved) or is a thing that kxdrivers solves? Thanks your answers.

Jan 18, 2005, 04:45 AM	#2
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	>>Is this limit a hardware one (that means it can be solved) Yes and no. The hardware can addres only 32mb. However via a software (paging) trick it is possible to playback larger sample data. ( CL drivers do that on their 10k2 based audigy cards.) >> or is a thing that kxdrivers solves? No, not at the moment. /LeMury

Jan 18, 2005, 05:07 AM	Thread Starter #3
marce DriverHeaven Newbie Join Date: Jan 2005 Posts: 11 Rep Power: 0	Thanks very much your answer.

Jan 19, 2005, 07:12 PM	#4
Eugene Gavrilov kX Project Lead Programmer and Coordinator Join Date: Dec 2002 Posts: 3,119 Rep Power: 75	not exactly. simple 'paging' won't solve this issue, since new paging will need to reset page cache which will cause distortion. it seems that CL drivers use data copying. that is, they copy new soundfont data into pre-allocated buffers (say, 4kB each)... however, I cannot be 100%-sure. E.

Feb 8, 2005, 05:17 PM	#7
droc2003 DriverHeaven Newbie Join Date: Mar 2003 Posts: 5 Rep Power: 0	I used to have the 32MB limitation with my SBLive and Creative drivers. I also had the 'holes' problem. Then I found this patch on the Internet, it involved adding the following registry key: REGEDIT4 [HKEY_LOCAL_MACHINE\Software\Creative Tech\Devcon\0003] "MaxPatchMemory"="133169152" Now, I can play soundfonts up to around 128MB (although no individual sample within the soundfont exceeds 32MB) on my SBLive using Creative drivers, and no audible note dropouts, period. I have inquired previously as to what this reg key does, but nobody has come up with a suitable explanation, all I know is, it works. That's why I'm still using Creative drivers on one of my machines. I would suspect that MaxPatchMemory could be raised higher, I haven't tried it yet. Can the kxDriver play large soundfonts (>32MB) without dropouts?

Feb 9, 2005, 02:56 AM	#9
Eugene Gavrilov kX Project Lead Programmer and Coordinator Join Date: Dec 2002 Posts: 3,119 Rep Power: 75	I'm currently about to start implementing large (>32Mb) sample support (sf2-based). I cannot provide you with any release dates -- and even say if this feature is ever implemented. there will be an option to enable/disable this feature (for fast/slow PCs) /E