Re: [boost] media > audio project (gsoc or future boost)

Subject: Re: [boost] media > audio project (gsoc or future boost)
From: Brendon Costa (brendon.j.costa_at_[hidden])
Date: 2013-04-21 21:37:21

One thing I think you should certainly check into with using boost::asio,
(I don't know a lot about boost::asio except its usage), is the realtime
nature of the audio threads and whether that can be guaranteed with asio.

Quite often the audio callbacks fired from the various audio subsystems are
not "user" threads and have certain restrictions on their usage such as not
permitting memory allocations, usage of locks etc within the threads
without possible discontinuities in the audio stream. Basically the actual
code in these callbacks should be quite limited and maybe asio is not
suitable for dispatching these.

For example see: http://portaudio.com/docs/v19-doxydocs/api_overview.html (The
Callback I/O Method)

You can relax these restrictions by introducing extra buffering (and
latency), but for many applications increasing latency is not preferable or
even acceptable.

What is the scope of this idea? Are you planning just to wrap existing
cross platform API's previously mentioned? What sorts of features would you
provide?

On Monday, 22 April 2013, adrien courdavault wrote:

> I looked at the documentation on the web site and at ASIO.
>
> However I will probably have to ask a lot of questions about ASIO
> phylosophy. It clearly looks like it would be better if possible to extend
> ASIO to manage audio devices than creating a new lib. But this suppose that
> I progress on ASIO understanding. I think I will have to make a different
> post on this subject in the future.
>
> PS, if anyone has feedbacks on this reflection you are welcome.
>
>
> On 21 April 2013 10:29, adrien courdavault <adrien.courdavault_at_[hidden]<javascript:;>
> >wrote:
>
> > I will try to see in Trac if anything is related to this and how I could
> > perhaps make a basic.
> > Any help on both the procedure of writing a proposal or the audio_device
> > problem is really welcome to give me directions or advices.
> > I actually don't know what is the procedure for that kind of thing
> usually.
> >
> >
> > On 21 April 2013 04:11, Michael Marcin <mike.marcin_at_[hidden]<javascript:;>>
> wrote:
> >
> >> On 4/20/2013 5:07 PM, adrien courdavault wrote:
> >>
> >>> Is there an existing work started inside boost in this subject ? I
> would
> >>> be
> >>> happy to help on this issue.
> >>>
> >>> I have to study ASIO to see the design style, but I have already used
> >>> most
> >>> of existing audio device API and librairies that provides portable APIs
> >>> for
> >>> this.
> >>>
> >>>
> >> Not that I know of, seems like it would be a good addition.
> >>
> >>
> >>
> >>
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