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 C180245BC6 for ; Sun, 25 Jun 2023 13:53:52 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 2015268C156; Sun, 25 Jun 2023 16:53:49 +0300 (EEST) Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [217.70.183.198]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id A98DD68BF2C for ; Sun, 25 Jun 2023 16:53:41 +0300 (EEST) X-GND-Sasl: michael@niedermayer.cc Received: by mail.gandi.net (Postfix) with ESMTPSA id AF2E2C0002 for ; Sun, 25 Jun 2023 13:53:40 +0000 (UTC) Date: Sun, 25 Jun 2023 15:53:39 +0200 From: Michael Niedermayer To: FFmpeg development discussions and patches Message-ID: <20230625135339.GA3250409@pb2> References: <20230618222805.4054410-1-michael@niedermayer.cc> <20230623111728.GM3250409@pb2> <59E3CAAC-DA7F-424B-ABC1-1E300EA83571@remlab.net> <20230623181241.GN3250409@pb2> MIME-Version: 1.0 In-Reply-To: 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="===============8588201253702825285==" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: --===============8588201253702825285== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="yh423QPMiEk4ZruG" Content-Disposition: inline --yh423QPMiEk4ZruG Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Jun 24, 2023 at 10:27:13PM +0200, R=E9mi Denis-Courmont wrote: >=20 >=20 > Le 23 juin 2023 20:12:41 GMT+02:00, Michael Niedermayer a =E9crit=A0: > >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, Eth= ernet, > >> >> 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 wi= ll > >> >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 a= lready on Linux, and typically they are, or would be, backends to libavdevi= ce. > >>=20 > >> (Specifically AM and FM are supported by V4L radio+ALSA; DAB and DVB b= y Linux-DVB. 4G and 5G are network devices.) > > > >4 problems > >* FFmpeg is not "linux only". >=20 > And then what? Whether you like it or not, radio signal processing sits o= n top of OS-specific APIs to access whatever bus or hardware. You can't mak= e this OS-independent whether it's in FFmpeg or elsewhere. >=20 > At best you can write or reuse platform abstraction layers (such as libus= b). Maybe. >=20 > In other words, whether this ends up in FFmpeg or not has absolutely no b= earing on this "problem" as you call it. >=20 > But it doesn't end here. Audio input on Linux is normally exposed with AL= SA modules (hw/plughw if the driver is in kernel, but it doesn't have to be= ), and other OSes have equivalent APIs. A sound (pun unintended) implementa= tion of AM or FM would actually be an ALSA module, and *maybe* also PA and = PW modules. (They don't have to be kernel mode drivers.) >=20 > ...Not an FFmpeg device or demux. This is interresting. I never tried but there should be a way to pipe ffmpeg output back into alsa to make it available as an alsa module This could actually be usefull as is with no sdr. but that tought i have he= re is 100% off topic >=20 > >* No software i tried or was suggested to me used V4L or Linux-DVB. >=20 > That would be because audio input is done with ALSA (in combination with = V4L for *hardware* radio tuning). >=20 > The point was that this is lower layer stuff that belongs in a lower leve= l library or module, rather than FFmpeg. I never *literally* said that you = should (or even could) use V4L or Linux-DVB here. Those APIs are rather for= the *hardware* equivalent of what you're doing in *software*. >=20 > So again, no "problem" here. ok, i misunderstood you somewhat here thx [...] --=20 Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Old school: Use the lowest level language in which you can solve the problem conveniently. New school: Use the highest level language in which the latest supercomputer can solve the problem without the user falling asleep waiting. --yh423QPMiEk4ZruG Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABEIAB0WIQSf8hKLFH72cwut8TNhHseHBAsPqwUCZJhG3wAKCRBhHseHBAsP qwyhAJ902tvfvb6+rQFy00N2I6Wos2axZgCeIcYM4ZyCxrAO5F1snRbSqfWofro= =VXV7 -----END PGP SIGNATURE----- --yh423QPMiEk4ZruG-- --===============8588201253702825285== 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". --===============8588201253702825285==--