🚀 go-pugleaf

Yes, you do indeed need to set the file format.  There is sample code to
do this in the "mpgparse" sample.  In this case it looks at the mpeg
audio header info and sets the paramaters of the mediatype.format to the
correct values.  If the format is not set correctly, then you cannot
connect to the renderer (since it won't know what frequency the file
is,etc.)

In your case, since you are reading a wav file you will have to find the
same type of info within the wav file so you can set the parameters. 
I'm sure there are plenty of places on the web where you can get the
spec for wav files.

Good luck,

Jim

wyx wrote:
> 
> hello,
> 
>     I want to write a direct show source filter which can read a wave
> file(.wav) and connect to a
>     audio renderer filter provided by direct show.
> 
>     However, I found that I need to specify the file media format (not
> media type) in order to
>     play the file using my filter.
> 
>     But I have look through those sample source filter codes, none of
> them need to specify the file format.
> 
>     Can anyone tell me at which point the sample source code (say,
> async) specify(get) the file format ?
> 
>     Or do I really need to specify the file format in order to connect
> my filter to another filter ?
>     At the beginning, I just specify the media type and media sub type.
> But it fails to connect to another
>     filter. After adding the code to specify the file format in the
> GetMediaType(), the filter works.
> 
>     So is there any method that can make a source filter without specify
> the file format ?
> 
>     Thank you very much !!
> 
> reagrds,
> yung