From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m3DKnK3g017026 for ; Sun, 13 Apr 2008 16:49:20 -0400 Received: from hs-out-0708.google.com (hs-out-0708.google.com [64.233.178.240]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id m3DKn79F021381 for ; Sun, 13 Apr 2008 16:49:07 -0400 Received: by hs-out-0708.google.com with SMTP id x43so308675hsb.3 for ; Sun, 13 Apr 2008 13:49:07 -0700 (PDT) Message-ID: <175f5a0f0804131349id288b3jca581ba5efd3ba17@mail.gmail.com> Date: Sun, 13 Apr 2008 22:49:06 +0200 From: "H. Willstrand" To: "Markus Rechberger" In-Reply-To: <529381.57396.qm@web907.biz.mail.mud.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080413172207.4276a17f@areia> <529381.57396.qm@web907.biz.mail.mud.yahoo.com> Cc: Video , Mauro Carvalho Chehab Subject: Re: [ANNOUNCE] Videobuf improvements to allow its usage with USB drivers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: video4linux-list-bounces@redhat.com Errors-To: video4linux-list-bounces@redhat.com List-ID: On Sun, Apr 13, 2008 at 10:34 PM, Markus Rechberger wrote: > > --- Mauro Carvalho Chehab > schrieb: > > > > > On Sun, 13 Apr 2008 18:17:54 +0200 (CEST) > > Markus Rechberger wrote: > > > > > > Conclusion: > > > > > > > The time consumption to receive the stream where > > reduced from about 33.38 seconds to 0.05 seconds > > > > > > the question is moreover what made capture_example > > go > > > up to 100% CPU in the first try and to 0% in the > > > second one. > > > I'm not sure about the old implementation in the > > > original driver, although I'm just curious about > > the > > > details here. xawtv usually uses very little > > cputime > > > at all. > > > If I use > > > "$ time mplayer tv:// -tv driver=v4l2" it shows up > > > > > > > > real 0m40.972s > > > user 0m0.230s > > > sys 0m0.050s > > > > > > your benchmark is a bit unclear. > > > > The advantage of using capture_example for benchmark > > tests is that it is a very > > simple mmap loop, without multi-thread, and just > > discarding the return. With > > this, you're timing just the minimal requirements > > for receiving frames. > > > > A TV application will also need to use the video > > adapter to present images, and > > may do some other tasks, like running DSP algorithms > > for de-interlacing. It may > > also discard frames, if there's not enough CPU to > > work will all of them. So, > > you will never know how much of those times are due > > to V4L kernelspace part. > > > > On the tests I did here with TV applications, the > > amount of performance, > > reported by "top" also indicated that the previous > > approach were worse. > > > > For example, on the same centino machine @1.5 GHZ, > > mplayer with "-tv driver=v4l2" > > were ranging from 30% to 75% of CPU. With videobuf, > > the CPU consumption were > > close to 23%, without much variation. > > > > my eeePC shows up 0-5% CPU usage with mplayer > fullscreen without videobuf, seems more like > something's broken in your testapplication or > somewhere else? > Using the em28xx? My is about 40-70% CPU... Br H.Willstrand > mplayer uses the memory mapped interface for this. > > Also the command > "$ mplayer -benchmark tv:// -tv driver=v4l2" > > CPU Intel 620 Mhz > > Markus > > > > -- > video4linux-list mailing list > Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe > https://www.redhat.com/mailman/listinfo/video4linux-list > -- video4linux-list mailing list Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe https://www.redhat.com/mailman/listinfo/video4linux-list