From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Wed, 06 Feb 2013 15:00:24 +0000 Subject: Re: CDF meeting @FOSDEM report Message-Id: <51127008.7050808@ti.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="------------enigA28ED1DA762A810046D2ACDF" List-Id: References: <1990856.qS9uisuiVF@avalon> <51123A5F.9050604@ti.com> In-Reply-To: To: Alex Deucher Cc: Laurent Pinchart , linux-fbdev@vger.kernel.org, Sebastien Guiriec , dri-devel@lists.freedesktop.org, Jesse Barnes , Benjamin Gaignard , Sumit Semwal , Tom Gall , Kyungmin Park , linux-media@vger.kernel.org, Stephen Warren , Thierry Reding , Mark Zhang , linaro-mm-sig@lists.linaro.org, =?ISO-8859-1?Q?St=E9phane_Marchesin?= , Alexandre Courbot , Ragesh Radhakrishnan , Thomas Petazzoni , Sunil Joshi , Maxime Ripard , Vikas Sajjan --------------enigA28ED1DA762A810046D2ACDF Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2013-02-06 16:44, Alex Deucher wrote: > On Wed, Feb 6, 2013 at 6:11 AM, Tomi Valkeinen = wrote: >> What is an encoder? Something that takes a video signal in, and lets t= he >> CPU store the received data to memory? Isn't that a decoder? >> >> Or do you mean something that takes a video signal in, and outputs a >> video signal in another format? (transcoder?) >=20 > In KMS parlance, we have two objects a crtc and an encoder. A crtc > reads data from memory and produces a data stream with display timing. > The encoder then takes that datastream and timing from the crtc and > converts it some sort of physical signal (LVDS, TMDS, DP, etc.). It's Isn't the video stream between CRTC and encoder just as physical, it just happens to be inside the GPU? This is the case for OMAP, at least, where DISPC could be considered CRTC, and DSI/HDMI/etc could be considered encoder. The stream between DISPC and DSI/HDMI is plain parallel RGB signal. The video stream could as well be outside OMAP. > not always a perfect match to the hardware. For example a lot of GPUs > have a DVO encoder which feeds a secondary encoder like an sil164 DVO > to TMDS encoder. Right. I think mapping the DRM entities to CDF ones is one of the bigger question marks we have with CDF. While I'm no expert on DRM, I think we have the following options: 1. Force DRM's model to CDF, meaning one encoder. 2. Extend DRM to support multiple encoders in a chain. 3. Support multiple encoders in a chain in CDF, but somehow map them to a single encoder in DRM side. I really dislike the first option, as it would severely limit where CDF can be used, or would force you to write some kind of combined drivers, so that you can have one encoder driver running multiple encoder devices.= Tomi --------------enigA28ED1DA762A810046D2ACDF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with undefined - http://www.enigmail.net/ iQIcBAEBAgAGBQJREnAIAAoJEPo9qoy8lh71tHQP/jTAXINjpdJdFARlTztAuSXG EZQnQvKvdUEJz96N1avraDYZtTma96VonJFSucZ0NiSU/vfxV4qQv26A3Tqxb+Yr PhzWgH9L5mMgtYA8aKY/EBFG4qWKpkHHJVp63WyNdnExRBf2fHT5AuooQ9FigSPD EBczM0EdV/Cey5UJidv3URjYLgGgfuT2McVWflq5LQzE+6vAjPuDBpDcu7WAAjqV dj7Cg2fRFSICnrNoRLu08oOCNqqIfn8kFM2xbYCNSkkbMoY2pHgvVL/KspC7HvVw kHKDCactA1WZdAuA/DSqNJsbBUVgZiw5pJjHD8u1SvYOUoCZA3CaZm9vc4OHg9Gb yEo7YOPCWcwljI0RFwZrhCCJ9aINKklPx2LOiJ+eJ7zyp/3qPNmxxVTksfzdY8YR SfMcchw2yB8tTcZaH1xI+lR2QFrCk+R79fe/0fpjRLLbMcelR4JZNX1z+w8XLakH rJRPN2uXhs3+xNAGrnlfG8TMFm/HYIR5AZ4+T26nNLidFqBO7jFaGtLoGukOHqXw 8i4sangPD072Sjp2am7U2ud6FouWEClny1PlzKx2z/XbS4aOcoJHzZGPJBCDyGj+ uujdOzAeOIHnWQ+/6jLrj0OoHMLMHVNjdLhgxKi5fLtzaIN2Laf4+n8yonr6w8s2 zcOkoe7TUYrS0CYvoflC =6uuz -----END PGP SIGNATURE----- --------------enigA28ED1DA762A810046D2ACDF--