From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id AF88B468B6 for ; Fri, 23 Jun 2023 18:12:53 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 076A568C195; Fri, 23 Jun 2023 21:12:50 +0300 (EEST) Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 890EA68C045 for ; Fri, 23 Jun 2023 21:12:43 +0300 (EEST) X-GND-Sasl: michael@niedermayer.cc Received: by mail.gandi.net (Postfix) with ESMTPSA id A872BFF804 for ; Fri, 23 Jun 2023 18:12:42 +0000 (UTC) Date: Fri, 23 Jun 2023 20:12:41 +0200 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20230623181241.GN3250409@pb2> References: <20230618222805.4054410-1-michael@niedermayer.cc> <20230623111728.GM3250409@pb2> <59E3CAAC-DA7F-424B-ABC1-1E300EA83571@remlab.net> MIME-Version: 1.0 In-Reply-To: <59E3CAAC-DA7F-424B-ABC1-1E300EA83571@remlab.net> Subject: Re: [FFmpeg-devel] [PATCH v2] avformat: add Software Defined Radio support X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Type: multipart/mixed; boundary="===============4879696283926644564==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============4879696283926644564== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="citGix+cyBYE+lqp" Content-Disposition: inline --citGix+cyBYE+lqp Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi On Fri, Jun 23, 2023 at 06:37:18PM +0200, R=E9mi Denis-Courmont wrote: > Hi, >=20 > Le 23 juin 2023 13:17:28 GMT+02:00, Michael Niedermayer a =E9crit=A0: > >On Fri, Jun 23, 2023 at 10:34:10AM +0800, Kieran Kunhya wrote: > >> FFmpeg is not the place for SDR. SDR is as large and complex as the > >> entirety of multimedia. > >>=20 > >> What next, is FFmpeg going to implement TCP in userspace, Wifi, Ethern= et, > >> an entire 4G and 5G stack? > > > >https://en.wikipedia.org/wiki/Straw_man > > > >What my patch is doing is adding support for AM demodulation, the AM > >specific code is like 2 pages. The future plan for FM demodulation will > >not add alot of code either. DAB/DVB should also not be anything big > >(if that is implemented at all by anyone) >=20 > Literally every one of those layer-2 protocols has a lower-level API alre= ady on Linux, and typically they are, or would be, backends to libavdevice. >=20 > (Specifically AM and FM are supported by V4L radio+ALSA; DAB and DVB by L= inux-DVB. 4G and 5G are network devices.) 4 problems * FFmpeg is not "linux only". * No software i tried or was suggested to me used V4L or Linux-DVB. * iam not sure the RSP1A i have has linux drivers for these interfaces * What iam interrested in was working with the signals at a low level, why because i find it interresting and fun. Accessing AM/FM through some high level API is not something iam interrested in. This is also because any issues are likely unsolvable at that level. If probing didnt find a station, or demodulation doesnt work, a high level API likely wont allow doing anything about that. >=20 > So I can only agree with Kieran that these are *lower* layers, that don't= really look like they belong in FFmpeg. FFmpeg has been always very low level. We stoped at where the OS provides support that works, not at some academic "level". If every OS provides a gr= eat SDR API than i missed that, which is possible because that was never someth= ing i was interrested in. >=20 > >If the code grows beyond that it could be split out into a seperate > >library outside FFmpeg. >=20 > I think that the point is, that that code should be up-front in a separat= e FFmpeg-independent library. And it's not just a technical argument with l= ayering. It's also that it's too far outside what FFmpeg typically works wi= th, so it really should not be put under the purview of FFmpeg-devel. In ot= her words, it's also a social problem. >=20 > The flip side of that argument is that this may be of interest to other h= igher-level projects than FFmpeg, including projects that (rightfully) don'= t depend on FFmpeg, and that this may interest people who wouldn't contribu= te or participate in FFmpeg. The issue i have with this view is it comes from people who want nothing to do with this SDR work. I would see this argument very differntly if it would come from people who want to work on that external SDR library. I mean this is more a "go away" than a "lets work together on SDR (for FFmp= eg)" >=20 > >The size of all of SDR really has as much bearing on FFmpeg as the size > >of all of mathematics has on the use of mathematics in FFmpeg. >=20 > On an empirical basis, I'd argue that FFmpeg mathematics are so fine-tune= d to specific algorithmic use cases, that you will anyway end up writing cu= stom algorithms and optimisations here. And thus you won't be sharing much = code with (the rest of) FFmpeg down the line. Iam not sure iam drifting off topic maybe but I frequently use code from libavutil outside multimedia thx [...] --=20 Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB The misfortune of the wise is better than the prosperity of the fool. -- Epicurus --citGix+cyBYE+lqp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEIAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCZJXglQAKCRBhHseHBAsP q3a7AJ9VWmqDpxOyUPPJDO7DLG1xpHGAEQCfT5Cz1swmtDFho7b3fU4jXQ9Lwoo= =oiOO -----END PGP SIGNATURE----- --citGix+cyBYE+lqp-- --===============4879696283926644564== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe". --===============4879696283926644564==--