220 26311 <2897526.WjqoZ8n3I9@lastique-pc> article Path: news.gmane.org!not-for-mail From: Andrey Semashev Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Any interest to adding audio support to the std library? 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[2a00:1450:4010:c07::232]) by mx.google.com with ESMTPS id q9si11679016lbp.130.2016.06.13.01.24.31 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 13 Jun 2016 01:24:31 -0700 (PDT) Received-SPF: pass (google.com: domain of andrey.semashev@gmail.com designates 2a00:1450:4010:c07::232 as permitted sender) client-ip=2a00:1450:4010:c07::232; Original-Received: by mail-lf0-x232.google.com with SMTP id j7so55983451lfg.1 for ; Mon, 13 Jun 2016 01:24:31 -0700 (PDT) X-Received: by 10.46.71.70 with SMTP id u67mr1050759lja.19.1465806271421; Mon, 13 Jun 2016 01:24:31 -0700 (PDT) Original-Received: from lastique-pc.localnet (broadband-90-154-68-136.nationalcablenetworks.ru. [90.154.68.136]) by smtp.googlemail.com with ESMTPSA id g28sm2676400ljg.24.2016.06.13.01.24.30 for (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 13 Jun 2016 01:24:30 -0700 (PDT) User-Agent: KMail/5.1.3 (Linux/4.4.0-24-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: <2943c5c2-2c46-4447-b8f6-7647fc34d52c@isocpp.org> X-Original-Sender: andrey.semashev@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com; spf=pass (google.com: domain of andrey.semashev@gmail.com designates 2a00:1450:4010:c07::232 as permitted sender) smtp.mailfrom=andrey.semashev@gmail.com; dmarc=pass (p=NONE dis=NONE) header.from=gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Spam-Checked-In-Group: std-proposals@isocpp.org X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:26311 Archived-At: This is a multi-part message in MIME format. --nextPart1596736.jOlD2Hf51T Content-Type: text/plain; charset=UTF-8 As I suggested earlier, I think the clock should be specified by the user (probably as a template parameter for the audio frame). On Monday, 13 June 2016 11:22:50 MSK alexander.zywicki@gmail.com wrote: > How do you all feel about this definition for a clock? > > #include > #include > > //define audio_clock as high_resolution clock if high_resolution clock > is_steady==true else use steady_clock > //conditional will result in a clock that is monotonic either way > //but can result in using a high_resolution_clock on certain platforms > using audio_clock = typename std::conditional high_resolution_clock::is_steady, > std::chrono:: > high_resolution_clock, > std::chrono::steady_clock>:: > type; > > On Sunday, June 12, 2016 at 4:09:44 PM UTC-5, alexande...@gmail.com wrote: > > In that case I would argue for the use of the "std::chrono::steady_clock" > > based on the fact that it is specified to be a monotonic clock. > > > > Or a clock defined in a similar manor that counts in samples. > > > > I also would imagine that our clock would need to have "is_steady" always > > be true? > > > > > > On Jun 11, 2016, at 4:09 AM, Andrey Semashev > > wrote: > > > > On Saturday, 11 June 2016 11:03:41 MSK alexander.zywicki@gmail.com wrote: > > > Or at least store a time point each time the stream is started using a > > > > clock > > > > > with a well defined epoch, so that we might be able to find the length > > > of > > > > > > time that the stream has been active and have meaningful measurements of > > > > > > time within the stream. > > > > There is no need to have the epoch bound to the beginning of the stream to > > calculate its duration. Or any particular epoch at all. All you need is > > the > > timestamp of its first and last frames. > > > > > > > > A fixed epoch becomes important when you try to synchronize multiple > > streams together. But even then it's not important what exactly is the > > epoch; what is important is that it has to be the same for all streams you > > are processing. -- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/2897526.WjqoZ8n3I9%40lastique-pc. --nextPart1596736.jOlD2Hf51T Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=UTF-8

As I sugges= ted earlier, I think the clock should be specified by the user (probably as= a template parameter for the audio frame).

&nb= sp;

On Monday, = 13 June 2016 11:22:50 MSK alexander.zywicki@gmail.com wrote:

> How do= you all feel about this definition for a clock?

>

> #inclu= de <chrono>

> #inclu= de <type_traits>

>

> //defi= ne audio_clock as high_resolution clock if high_resolution clock

> is_ste= ady=3D=3Dtrue else use steady_clock

> //cond= itional will result in a clock that is monotonic either way

> //but = can result in using a high_resolution_clock on certain platforms

> using = audio_clock =3D typename std::conditional<std::chrono::

> high_r= esolution_clock::is_steady,

> = std::chrono::

> high_r= esolution_clock,

> = std::chrono::steady_clock>::

> type;<= /p>

>

> On Sun= day, June 12, 2016 at 4:09:44 PM UTC-5, alexande...@gmail.com wrote:

> > I= n that case I would argue for the use of the "std::chrono::steady_cloc= k"

> > b= ased on the fact that it is specified to be a monotonic clock.

> > <= /p>

> > O= r a clock defined in a similar manor that counts in samples.

> > <= /p>

> > I= also would imagine that our clock would need to have "is_steady"= always

> > b= e true?

> > <= /p>

> > <= /p>

> > O= n Jun 11, 2016, at 4:09 AM, Andrey Semashev <andrey.semashev@gmail.com&g= t;

> > w= rote:

> > <= /p>

> > O= n Saturday, 11 June 2016 11:03:41 MSK alexander.zywicki@gmail.com wrote:

> > &= gt; Or at least store a time point each time the stream is started using a<= /p>

> > <= /p>

> > c= lock

> > <= /p>

> > &= gt; with a well defined epoch, so that we might be able to find the length<= /p>

> > &= gt; of

> > &= gt;

> > &= gt; time that the stream has been active and have meaningful measurements o= f

> > &= gt;

> > &= gt; time within the stream.

> > <= /p>

> > T= here is no need to have the epoch bound to the beginning of the stream to

> > c= alculate its duration. Or any particular epoch at all. All you need is

> > t= he

> > t= imestamp of its first and last frames.

> > <= /p>

> > <= /p>

> > <= /p>

> > A= fixed epoch becomes important when you try to synchronize multiple

> > s= treams together. But even then it's not important what exactly is the

> > e= poch; what is important is that it has to be the same for all streams you

> > a= re processing.

&nb= sp;

&nb= sp;

--
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