[MS Smartphone]Several solutions for MIDI playback

王朝other·作者佚名  2006-01-09
窄屏简体版  字體: |||超大  

For MS Smartphone 2003 platform,it is really not an easy thing to deal with MIDI playback.Here are several solutions,but every way has its own problems.

1.Use SDK raw API.

Refer to http://homepages.inspire.net.nz/~gambit/Midi/

Problem:

-Rough playback quality.It is only a prototype.When I tested with that source code,the playback quality is so rough.I spent some time to modify that source code and failed to fix the problem.

BTW: The problem of B in that article is due to the code:

WaveHdr.lpData = (LPSTR)&MidiMessage; //If changed to (LPSTR)MidiMessage,

dynamic memory allocation should work.As we know,for array,&MidiMessage is equal to

MidiMessage,but for pointer it is different.

2.Port open midi source projects to Smartphone platform

I've found two open midi source projects which are very good.One is Timidity and the other is WildMidi. Many famous games such as Quake and Duke3D uses Timdity to play midi sound.

Problems:

-It will take some time.

-It will add much more footprint to your application installation package due to its usage of GUS patches.

3.Buy midi codec

Currently it seems some company sells midi codec for MS Windows Mobile Platform.

Problems:

-It will take some money.Usually those companies want a lot of money.So it is the least recommended.

4.Use existing library API

I spent some time to analysis the midi issue of the default player within Dopod565 itself. I found that the player uses a DLL library ----midilib2.dll which is in \Windows directory.The export information of midilib2.dll is attached later.

MIDI_GetDuration

MIDI_GetExtensionInfo

MIDI_GetInfo

MIDI_GetPosition

MIDI_GetStatus

MIDI_GetVendorID

MIDI_GetVolume

MIDI_GetWaveOut

MIDI_Load

MIDI_Pause

MIDI_Play

MIDI_Resume

MIDI_SetVolume

MIDI_Stop

MIDI_Unload

fp_MIDI_GetDuration

fp_MIDI_GetExtensionInfo

fp_MIDI_GetInfo

fp_MIDI_GetPosition

fp_MIDI_GetStatus

fp_MIDI_GetVendorID

fp_MIDI_GetVolume

fp_MIDI_GetWaveOut

fp_MIDI_Load

fp_MIDI_Pause

fp_MIDI_Play

fp_MIDI_Resume

fp_MIDI_SetVolume

fp_MIDI_Stop

fp_MIDI_Unload

The DLL file is not open to public for use.For DLL files,we could only get function name information,and we couldn't find function declarations including parameters and return type.

I think the best way to handle MIDI playback problem is to ask for handset provider's

technical support and ask them to open midi API(For Dopod565,the API of midilib2.dll).

 
 
 
免责声明:本文为网络用户发布,其观点仅代表作者个人观点,与本站无关,本站仅提供信息存储服务。文中陈述内容未经本站证实,其真实性、完整性、及时性本站不作任何保证或承诺,请读者仅作参考,并请自行核实相关内容。
 
 
© 2005- 王朝網路 版權所有 導航