Doh, HTML cause vger to drop it. Resending. On Fri, Apr 25, 2014 at 8:47 AM, Steven Toth <stoth@xxxxxxxxxxxxxx> wrote: > On Fri, Apr 25, 2014 at 8:19 AM, Steve Cookson <it@xxxxxxxxxx> wrote: >> >> Hi Guys, >> > > Hello again. > >> >> (I'm copying Ezequial on this because of the work he has done on the >> stk1160). >> >> My colleague (a Doctor) had this to say on the medical images I posted >> earlier (see below): >> >> > The impactVCB-e image is redder and less clear. The dvc100 and easycap >> > seem similar to me and both of them are not as good as the original one. >> >> So I have to ask how is it that the cheap little EasyCap is performing at >> the same level as the Dazzle DVC100 and better than the ImpactVCB-e? >> > > Its usually either because the Linux engineers simply aren't focused on > improving quality for the last 'mile', or that the ADC/Video digitizer > differers between products. 'Redder' isn't usually a differentiation between > video digitizer silicon, its miss-configuration - for example. > > >> >> It seems to me that the more complex and expensive DVC100 and ImpactVCB-e >> should perform well and that the EasyCap should be the runner up. >> > > Not necessarily, but I can understand why you may think that. The reality is > - you are measuring the work of individuals who we're not paid to create > these Linux drivers. They work well enough for their needs, they scratched > their own itch, then they moved on, more than likely this is the case. So, > you are seeing a mixture of different silicon, different attention to > detail, different default values and different levels of commitment in the > driver developers. > >> If the DVC100 and ImpactVCB-e had had the same love and attention that >> Ezequial has shown the EasyCap would they outperform it? >> > > Hard to say. With my experience working for Hauppauge, directly in their > engineering team, having worked on literally hundreds of products, lots of > different video digitizer, they're all fairly close quality wise in general, > with good signals, with the right drivers. > > What makes a good video digitizer stand out from a poor one, it how it > performs in very poor signal conditions. > > >> >> The ImpactVCB-e is easier to use internally and the Dazzle is external. >> Does the fact that the ImpactVCB-e has a PCI-e connector help it at all? >> > > > Invariably not. > > >> >> Otherwise I should just focus on EasyCap for my raw SD capture and move >> on. >> > > You need to make that judgement call. If you are building a business around > medical imaging and have no engineering capability to improve drivers, go > with what your gut says and what's available to you today. You shouldn't > rely on the good will of Linux engineers to fix your business requirements > in their spare time, in the coming weeks or months. > > Or, hire a consultant to improve the drivers for you and the rest of the > Linux community. This what everyone else does. > > - Steve > >> >> Thanks, >> >> Steve >> >> >> On 23/04/14 16:22, Steve Cookson wrote: >>> >>> Hi Guys, >>> >>> I would be interested in your views of the comparisons of these images. >>> The still is the image of a duodenum taken during an endoscopy and recorded >>> to a DVD player (via an s-video or composite cable). Although the endoscope >>> is an HD endoscope, the DVD recorder isn't and the resulting video is >>> 720x480i59.94. >>> >>> Here are further details of the video:- >>> >>> Format : MPEG Video v2 >>> Format profile : Main@Main >>> Format settings, BVOP : Yes, Matrix : Custom, GOP : M=3, N=15 >>> Bit rate mode : Variable >>> Bit rate : 4 566 Kbps >>> Maximum bit rate : 10 000 Kbps >>> Width : 720 pixels >>> Height : 480 pixels >>> Display aspect ratio : 4:3 >>> Frame rate : 29.970 fps >>> Standard : NTSC >>> Color space : YUV >>> Chroma subsampling : 4:2:0 >>> Bit depth : 8 bits >>> Scan type : Interlaced >>> Scan order : Top Field First >>> Compression mode : Lossy >>> Bits/(Pixel*Frame) : 0.441 >>> >>> The video was played through Dragon Player and the video signal has >>> exited through a mini-VGA port defined as 640x480 and passed through a >>> VGA->S-Video converter to an s-video cable. >>> >>> The cable has in turn been connected in turn to a Dazzle DVC100, an >>> EasyCap stk1160 and a Hauppauge ImapctVCB-e. >>> >>> Each setting (eg brightness and contrast etc) has as near as possible to >>> mid-range and a screengrab taken. >>> >>> The results are shown here: >>> >>> Original: >>> http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMrgmD6gSf74Ih4l5k2TGxc >>> >>> Dazzle DVC100: >>> http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMaOf4QTsIefYh4l5k2TGxc >>> >>> ImpactVCB-e: >>> http://tinypic.com/usermedia.php?uo=fNkd6hpTbcM7i72IqGujuIh4l5k2TGxc >>> >>> STK1160: >>> http://tinypic.com/usermedia.php?uo=fNkd6hpTbcPO7kmQk/IS94h4l5k2TGxc >>> >>> I would be grateful for your views on the quality of the images. >>> >>> Is one of materially higher quality than the others, or can I adjust the >>> settings to improve the quality of one of them more. >>> >>> It seems to me that the Hauppauge is marginally better than the others. >>> What do you think? >>> >>> Can I improve the test? >>> >>> Regards >>> >>> Steve. >>> >>> >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-media" in >>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >> > > > > -- > Steven Toth - Kernel Labs > http://www.kernellabs.com > -- Steven Toth - Kernel Labs http://www.kernellabs.com +1.646.355.8490 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
