220 26176 <062a23c8-fff7-4e83-bc20-2b3523538977@isocpp.org> article Path: news.gmane.org!not-for-mail From: alexander.zywicki@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Any interest to adding audio support to the std library? Date: Sat, 4 Jun 2016 07:12:05 -0700 (PDT) Lines: 126 Approved: news@gmane.org Message-ID: <062a23c8-fff7-4e83-bc20-2b3523538977@isocpp.org> References: <5751B06A.4080501@mail1.stofanet.dk> <5290948.va25uYNizX@tjmaciei-mobl1> <1580229.cHEgQxCuA1@tjmaciei-mobl1> <62b7649a-5de5-4330-9bac-708375d36e2c@isocpp.org> <4cfc7939-1ebf-415f-8ef4-d51e7cdadef5@isocpp.org> <239cb9ab-c5d5-4ce5-b876-b5220cc1e116@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_1238_500414784.1465049525647" X-Trace: ger.gmane.org 1465049529 6036 80.91.229.3 (4 Jun 2016 14:12:09 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 4 Jun 2016 14:12:09 +0000 (UTC) Cc: alexander.zywicki@gmail.com To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCS7TY6DTQOBBNWDZO5AKGQEFVBXL2A@isocpp.org Sat Jun 04 16:12:09 2016 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-vk0-f72.google.com ([209.85.213.72]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1b9CJ6-0008Jc-Gf for gclcip-std-proposals@m.gmane.org; Sat, 04 Jun 2016 16:12:08 +0200 Original-Received: by mail-vk0-f72.google.com with SMTP id f5sf25867085vkb.1 for ; Sat, 04 Jun 2016 07:12:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:x-original-sender:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=TeXZ2Regfu3wt89nqGEc6zFapt5cEWyDf5end5JoVmw=; b=b/p44tXW+IMZuUurT/oSSkXMh5PN7CkhoQbYZkU+hxEai7lmdq20AH+//toCu6xodu IihDzGS7sZzlLziLqIYfNimw8YMzoU+86cKKt8Ne/UzFnWW1y+3WnMkAErxXcHa2jCwA zhOfsB+mBgLO1BSLbOkdglhGSoDLBQwseva7Pen7grzUw0T0l9KgKQpWEUt9zRY7Sy6C Uo+QeRPy5pZt5Z3rWssKGpqAQsLB8dZSay60Myae5lYAas8es7VyC3MREU/d1bnHzmT/ Y10V7KWrW2vlQ+kedF46KToLH6SmibUOnmuJZ8tGfd7yP4doR6eL2a+IofNIaUWwnkDG gXow== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:x-original-sender:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=TeXZ2Regfu3wt89nqGEc6zFapt5cEWyDf5end5JoVmw=; b=tRTLDKQx8AkiH7JCmMwOYE+SS9sy2tcUm0KxsmmgLAjIHXz+adx6qmMkoUAyIvWuOM 4WIy12lI89AKo3bxoRME1eiZngfTlWS+Id6XUeXCJX9qqtaEGJYN9YE6XGyTWYmpIULs 3DNI7iMWQAi7QxAbOjnkcdkaONGrlpvEhd6SrzVUj2JBUB+Rx+1n2BUK1aA0pGbKfuq6 BWF7xhFAmdkZUoT10TGIPINhL9X5l60Was55oWjwlSuFtakB1vCwYOKXfccXI/aqBnCc iOjHq+rr2RmqC3cyOnwJh95peOfOpnL5cmApzo+sW0SRVVd2t6rxoF9YPBg1Pd+v48+B NuyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:x-original-sender:reply-to :precedence:mailing-list:list-id:x-spam-checked-in-group:list-post :list-help:list-archive:list-subscribe:list-unsubscribe; bh=TeXZ2Regfu3wt89nqGEc6zFapt5cEWyDf5end5JoVmw=; b=dRQ/6QyywJVRYiUpMUMkirOFtBg6JGZ6dDzD6d+1SJ90QfM+9Dk8eVuc2U1QgQp7Jb zjneQ0uP/ByYk4sXbfI6PBFwK97UaGFhB5ijcRFZjkr6wbIpKXKwMwR2NGk9NdaVYaOE 4pF6dsA3HBBLbrVqQsSTMK6HWaa9+EYII5kh3rxZBL4CDauAERbqislLa4MW77IF9jGM kTQqFt2il/5NP7MarYT4bmWXhuxt56EiAaQlSHHzaHBZ18Kyg4lVM+GpUrsuf4T0IniX wEbShVLzG2Vy/kLGNHTOsnuwi/mzFvWygTusn7df0Zo7Ec6234WkxfoBMya/XFrdGekZ xzMw== X-Gm-Message-State: ALyK8tJrqDpFWb64sv27zDX7ol45qVISrfRTcl+z/eIsdpMUD51bvObH+0ux9dNGFifC/w== X-Received: by 10.129.82.1 with SMTP id g1mr6250604ywb.28.1465049527495; Sat, 04 Jun 2016 07:12:07 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.107.39.4 with SMTP id n4ls621100ion.26.gmail; Sat, 04 Jun 2016 07:12:06 -0700 (PDT) X-Received: by 10.36.57.131 with SMTP id l125mr123184ita.7.1465049526632; Sat, 04 Jun 2016 07:12:06 -0700 (PDT) In-Reply-To: <239cb9ab-c5d5-4ce5-b876-b5220cc1e116@isocpp.org> X-Original-Sender: alexander.zywicki@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:26176 Archived-At: ------=_Part_1238_500414784.1465049525647 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable - hide quoted text - On Saturday, June 4, 2016 at 1:28:01 AM UTC-5, Ron wrote:=20 > Some thoughts...=20 >=20 >=20 > 'N' should be runtime for channels in a frame and for a frame buffer. Th= e buffer size might be negotiable with the device.=20 >=20 >=20 > I like a lot of that code in the original post, but I don't like the comp= arison to iostreams. Its really the '>>' operator that I don't like. When= you copy into your frame buffer, an '=3D' operator should be used since an= yone that sees an '=3D' operator knows its a copy. But really, you shouldn= 't need to move data around so much. If you stream from input to 'buff', t= hen process and then move from 'buff' to output then you are moving a lot o= f data unnecessarily.=20 >=20 >=20 > I think what should happen is this; The process chain is triggered when t= he output signals it is ready for data by calling the first linked process.= Starting at the output, each process kernel calls the previous until it r= eaches the input where the input device/file/etc copies the data to the cha= ins frame buffer. Each process then operates on that single buffer in turn= until finally returning to the output, thus altering the buffer instead of= moving data from place to place. I like to think of the processing chain = as starting from the output or destination. When the output is ready for d= ata it calls to a linked process for information, it calls to the next link= and so on until data begins to get processed. So a bottom up approach, wh= ere the input doesn't officially start until the output is ready. I know i= t is opposite of the way audio really flows through a system but it makes t= hings easier then moving data like a bucket brigade. It can also allow eas= ier parallel processing when there are multiple branches on a node. So if = you think of an audio mixer, where there are many inputs and a single outpu= t, the output calls to many channels/nodes at once so they can all be proce= ssed in parallel and mixed together after each of the processes end.=20 >=20 >=20 >=20 > Also, I'm not sure the word 'format' should be used to refer to files. I= know people like to say "file format" but then, what format is the audio d= ata in that is in the file format? Its just confusing, so I think 'contain= er' is a better word for files. Then that leaves the word format open for = use as a way of describing the data format of an audio frame buffer. So an= audio_format class would contain information on sample rate, channels, int= erleaving, channel routing and other information and a container class woul= d deal with files.=20 >=20 >=20 > I personally would rather have all audio with greater than 2 or 3 channel= s processed in Ambisonic-B format and then have the audio driver figure out= how to extract the channels for each speaker, but I know this won't fly wi= th everyone so we would need a class for channel routing information as wel= l.=20 >=20 >=20 > All I can think of at the moment..=20 >=20 >=20 >=20 >=20 >=20 >=20 > On Friday, June 3, 2016 at 9:08:45 PM UTC-7, alexande...@gmail.com wrote:= =20 > I agree, how do you feel about the concept i proposed in my original abou= t having std audio stream classes similar to std::fstream. The std::astream= /iastream/oastream would represent the default audio device on the system a= s determined by some method of polling the system. The user could either ch= oose to use them as is or manually select a different device?=20 >=20 > On Friday, June 3, 2016 at 10:51:12 PM UTC-5, Ron wrote:=20 > Well, it needs to start somewhere. I think having basic buffers using st= d::array or plain old arrays might do for now and get some basic audio reco= rding and playback into C++. It should be as simple as possible to get to = the interfaces on the machine and make them work. The data processing can = build onto it with more complex primitives, templates and classes. This wa= y there is at least something semi-usable with code we have today while the= rest of the building blocks are being worked on. Just a thought though.= =20 For the most part I agree with you, I think that using the << operator in t= he callback would be confusing and ahold be replaced with =3D to be more cl= ear, and that the callback parameters should be changed to be of type frame= _buffer to keeps things simple. But I think that using the << operator for = routing purposes still may be useful. Consider the situation where you woul= d like to have multiple types of inputs/outputs or connect to multiple devi= ces and need to specify which ones you are routing to and from. My intent t= here was to provide an interface that allowed you to specify that your prog= ram would take input from 0-N selected inputs and 0-N selected outputs if d= esired.=20 I think using a pull model for determining order of operations could work i= n most cases but it would be more complex if you desired a multi out situat= ion. The model that worked best in theory for me in that situation was to t= reat the signal flow as a graph and have each node in the graph keep track = of its completion for the buffer period, the outputs would ask their depend= ent nodes if they are done and if so take the result, in turn those nodes w= ould ask their dependent nodes or inputs about completion until the graph r= eaches all input or non dependent nodes. A friend of mine likened this to A= * path finding without weighting certain paths. Each node waits on its depe= ndents, which eventually will be a device input or a file. This all of cour= se assumes support of a graph model that allows for dynamic connection of I= /o, which I find to be desirable.=20 Do you think that multiple io should be supported?=20 Do you think that there needs to be some way of routing between the devices= and your program? --=20 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 e= mail 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/062a23c8-fff7-4e83-bc20-2b3523538977%40isocpp.or= g. ------=_Part_1238_500414784.1465049525647-- .