From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Thierbach Subject: Re: Syncing to vblank for interlaced video modes Date: Mon, 15 Jun 2009 09:03:56 +0200 Message-ID: <20090615070356.GA4197@feanor> References: <20090614183442.GA13749@feanor> <3d374d00906141158h28a7d688re1133b656dcdb6c5@mail.gmail.com> <3d374d00906141556y44d5d493j330cc1ebf79e5968@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <3d374d00906141556y44d5d493j330cc1ebf79e5968-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nouveau-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Errors-To: nouveau-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org To: nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org List-Id: nouveau.vger.kernel.org On Sun, Jun 14, 2009 at 11:56:45PM +0100, Alistair Buxton wrote: > Stupid question: Given the presence of a register which indicates the > current field, why can't NVWaitVSync simply wait until the end of the > second field, by doing whatever it does twice iff it is called during > the first field? Because then you'd effectively halve the frame rate in interlaced modes, unless you somehow queue all the information for the second half-frame. > This method shouldn't require any patches in player software, since > by default they treat the two interlaced fields as a single frame, They do? I thought they they'd just treat every half-frame as a whole frame by scaling it up vertically. Which player actually does that? If you just combine two adjacent half-frames, you get the typical comb-style ragged edges on fast moving objects. Interlace *is* actually intended to give increased temporal resolution. With nearly the same spatial resolution, because the human brain compensates. If you treat two half-frames as one frame, you loose that. - Dirk