Re: [pygame] How to check sound format of mixer?

[Lenard Lindstrom <len-l@xxxxxxxxx>]

Marcus von Appen wrote:
> On, Tue Feb 19, 2008, Alistair Buxton wrote:
>
>   
> > > I'm an oblivious idiot :-). A buffer method's already available in the
> > > current SVN tree.  You can use pygame.Sound (your_buffer) safely, the
> > > buffer just has to match the mixer criteria.
> > >
> > > Due to the SDL_Mixer implementation however, the buffer will be copied,
> > > so a manipulation of the buffer object after creating the Sound will not
> > > have any impact on it.
> > >
> > >       
> > I'm looking at that code right now. It looks like it tries to copy it,
> > and if it can't, it raises an exception. But then there is a block of
> > code right after which would load it in place, but can not be reached
> > currently, because the previous code returns on error. Correct? So I'm
> > guessing this is already WIP by somebody :)
> >     
>
> The code should be fully functional. To which unreachable lines do you
> refer?
>
>   
Found it. The code never reaches the part that handles file objects, 
since mixer.c:881,882 return an error if the object has no buffer interface:

       if (PyObject_AsReadBuffer (file, &buf, &buflen) == -1)
           return -1;

The following changes to examples\sound.py confirm it.

file = open(os.path.join('data', 'secosmic_lo.wav'), 'rb')
try:
   sound = mixer.Sound(file)
finally:
   file.close()

Running the modified sound.py raises an exception:

Traceback (most recent call last):
 File "sound.py", line 21, in <module>
   sound = mixer.Sound(file)
TypeError: expected a readable buffer object


--
Lenard Lindstrom
<len-l@xxxxxxxxx>