OpenEuphoria

Re: Win32Lib: PlaySound/setVisible solution

• Posted by Dan Moyer <DanMoyer at PRODIGY.NET> Nov 03, 1999
• 513 views

Brian,

Thanks for the code!  Using it & David's suggestion for making playSound a
function, I have unfortunately discovered that using playSound in async
mode AND setting the SND_NOSTOP flag to allow a series of wave files to be
played amount to the same thing as using playSound in sync mode.

I took your demo solution & simplified it, from a "play list" orientation
into just a "while" test loop of the SND_NOSTOP return (see below for
snippet), so I could just feed PlaySound a series of wave files & the while
loop would test to see if the preceding was finished & then when it was it
would play the next & so forth till it did all of them. (This would be
simpler to integrate into my application.)

  This worked just fine as far as making a sequence of wave files play in
nominally async mode, no hiccups at all that I could force;  BUT: now it
operates essentially like SYNC mode did, in that the program is
unresponsive to other events while that SEQUENCE of sounds is playing,
which throws away that wonderful interruptibility I liked so much with
ASYNC mode.  I think the flag SND_NOSTOP means MORE than just that the
playSound function returns false if the audio device is busy playing a
sound, it also means DON'T STOP PLAYING UNTIL YOU'RE FINISHED (duh!), &
that's exactly what SYNC mode does, I think.  That "nostop" name had been
bothering me in the back of my mind, now I see why.

Bottom line seems to be that there's not much point in me using ASYNC mode,
if in order to make multiple files play in sequence I end up with something
indistinguishable from SYNC mode.

Anyway, it was interesting, & I thank you for you effort.  Your comments
about your demo were crystal clear & really very helpful. Hope it wasn't a
total waste of time for you.  Here's snippets of what I made from your
demo, using David's simpler prototype suggestion for changing xPlaySound
procedure to a function (thanks David, I need examples I can cut'n'paste as
much as I need explanations <sigh>).

Dan Moyer

-- MAKE NEW PLAYSOUND TO FUNCTION AS FUNCTION:
global constant
zPlaySound = linkFunc( winmm, "PlaySoundA", {C_INT, C_INT, C_INT},
C_INT )  -- taken from David's prototype suggestion

--  PLAY A .WAV FILE if none is currently playing, or wait until finished
if one is playing
--  & then play it:
procedure playsound(sequence wave)
atom file
  file = allocate_string(wave)
-- just loop here while/if previous wave playing, then play the new one:
-- ("false" return means something is currently playing)
  while c_func(zPlaySound, {file, 0, or_all({SND_FILENAME, SND_ASYNC,
SND_NOSTOP}) })= False do
   end while
  free(file)
end procedure

--SAY SOME THINGS:
procedure DoTest_onClick ()
  playsound("1.wav")
  playsound("2.wav")
  playsound("3.wav")
  playsound("4.wav")
end procedure