MCI problem help please...

[Nueng]

I want to make karaoke program that can control On-Off channel 1 or channel 2 In Mpeg of vcd files.
( The vocal karaoke feature cancels or restores lead vocals feature)

I am using this syntax:

Code: Select all

Buffer$=Space(128) 
mciSendString_("OPEN d:\temp\test.dat TYPE MPEGVIDEO ALIAS FILM",Buffer$,128,0)
mciSendString_("PLAY FILM",0,0,0)
...
...

; 2 follow line is problem
mciSendString_("setaudio FILM audio left on" , Buffer$,128,0)
mciSendString_("setaudio FILM audio right off" , Buffer$,128,0)

...
...

The code can run
But it cannot control On-Off of the vocal channel.
Could you send me the syntax, please....

[inc.]

Those VCDs are simple Stereo, means no discrete 5.1 Channels.
You wont filter out the Vocals by switching r/l on/off

[Nueng]

ok I try this ...

Code: Select all

; singer mode (Right Channel)
mciSendString_("setaudio FILM left off" , Buffer$,128,0)
mciSendString_("setaudio FILM right on" , Buffer$,128,0) 

; stereo mode (Both Channel)
mciSendString_("setaudio FILM left on" , Buffer$,128,0)
mciSendString_("setaudio FILM right on" , Buffer$,128,0) 

; karaoke mode (Left Channel)
mciSendString_("setaudio FILM left on" , Buffer$,128,0)
mciSendString_("setaudio FILM right off" , Buffer$,128,0) 

ok now when i change to karaoke mode I can hear music on Left speaker ...but music can't out to Right speaker (it's mute !!)

it's look like "volume balance" feature.... (-_-')

can you introduce me or show tactic "how to copy right channel to left channel" and "copy left channel to right channel"...


Thank you

ps .sorry I'm not strong English language...

[traumatic]

Sorry, I've got no solution to your problem, but AFAIK just copying the
data over isn't enough. You have to phase-reverse the signal as well
("phase cancellation").