[fluid-dev] Re: Fast file renderer

[josh]

Quoting David Henningsson <address@hidden>:
> So we have three cases here:
>
> 1) Libsndfile < 1.0.18, no vorbis support
> 2) Libsndfile >= 1.0.18, compiled without vorbis support
> 3) Libsndfile >= 1.0.18, compiled with vorbis support
>
> We agree that 1 and 3 works currently, right?

Right.

> In case 2, I believe the SF_FORMAT_VORBIS is still present in sndfile.h
> so the code will still compile, right? Then whether sf_command(NULL,
> SFC_GET_FORMAT_MAJOR, ...) will return the oga file extension or not
> would be up to libsndfile, if it does, it's a bug in libsndfile. If it
> does not, ((info->format & SF_FORMAT_TYPEMASK) == SF_FORMAT_OGG) will
> never be true. So case 2 should also work.


That is true, it hadn't occurred to me that SF_FORMAT_VORBIS would  
still be available.


> > I think it might be best to just query libsndfile for the first   
> > supported audio format, for a given file type, if no audio format   
> > is specified and the default of 16 bit PCM fails.  That would solve  
> >  the Ogg/Vorbis issue and possibly work fine with future supported   
> > file types which have a specific audio format.
>
> If that is possible, that would be even better.


With sf_command you can query the available audio formats for a  
particular file type.  If they add support for other audio formats to  
Ogg though, that could become a problem, since you wouldn't be able to  
specify Vorbis explicitly in that case.

Another option would be to dynamically list all the available formats  
(by querying libsndfile for their descriptions) and for formats that  
we know of, provide a short abbreviation as we do now.  For  
unrecognized formats, it could just list something like fmt17 (using  
its assigned ID number).  Whenever "fmt" is encountered, whatever  
number follows would be used verbatim as the format ID, so that any  
format could be specified by its number (to provide backwards  
compatibility in future versions where we add a format abbreviation).

I think I might like that the best.  We could also make it to where -O  
help would list only valid audio formats for the given file type (if  
specified).

How does that sound?


> // David


Josh