Tuesday, 2014-04-29

*** tpb has joined #timvideos00:00
*** loadstar81 has quit IRC00:10
*** loadstar81 has joined #timvideos00:12
*** skay has quit IRC00:37
*** skay has joined #timvideos00:38
*** skay has joined #timvideos00:38
*** ChanServ sets mode: +v skay00:38
*** ChanServ sets mode: +o CarlFK00:42
*** ChanServ sets mode: +o shenki00:42
*** ChanServ sets mode: +v ldlework00:42
*** mithro sets mode: -o techman8300:44
*** mithro sets mode: -v techman8300:45
*** mithro sets mode: -v thaytan00:45
*** FeltonChris has joined #timvideos00:54
*** ChanServ sets mode: +v FeltonChris01:28
mithroHey FeltonChris!01:28
FeltonChrismithro: hey01:31
mithroHow are things? Did some HDMI2USB work over the weekend01:33
mithroFeltonChris: did your Atlys turn up?01:33
FeltonChrisnot yet, FedEx indicate it was supposed to arrive on sat. but it did not, check the tracking again today and no updates?01:35
CarlFKthe fpga class I told ended with "lets bang out a VGA signal .. pretty sure it was outputs to resistors to a 15pin vga connector01:38
mithroCarlFK: yeah, you can generate a VGA signal just using the pins on a digital chip01:39
mithroCapturing is much harder :)01:39
CarlFKdo we have a "send vga" project ?01:39
*** puck has quit IRC01:43
*** puck has joined #timvideos01:44
mithroit's call a video card :)02:16
mithroshenki: it turns out that my motherboard has an embedded arm chip running Linux on it :P02:44
Joelwmithro: Did you see the project where someone got Linux running on one of the ARM chips on their hard drive?02:44
mithroJoelw: yeah02:44
mithroWow, it has 64 megabytes of memory02:46
shenkimithro: the BMC?03:36
shenkiall servers have them these days03:36
shenkinot always running linux tho03:36
shenkimithro: did you see this? https://plus.google.com/111282580643669107165/posts/Uwh9W3XiZTQ03:37
mithroshenki: nope!03:38
*** mparuszewski has joined #timvideos03:43
*** mparuszewski has quit IRC03:50
*** Niharika has joined #timvideos04:28
*** sarwarc has quit IRC05:16
*** slomo has joined #timvideos06:23
*** slomo has joined #timvideos06:23
shenkimithro: ping07:19
mithroshenki: just going to bed, is it quick?07:19
shenkimithro: it can be. i want to set up a vpn on a mithis server07:20
shenkimithro: is that ok? if so, which one?07:20
shenkiconnecting to while travelling07:20
mithroNot really sure if any are that suitable07:27
mithrogerty would have been before I turned it off07:28
shenkiokay. i'll find somewhere else then07:32
*** rohitksingh has joined #timvideos07:34
*** sarwarc has joined #timvideos08:07
*** Niharika has quit IRC08:09
*** Niharika has joined #timvideos08:11
*** Niharika has quit IRC08:20
*** Niharika has joined #timvideos08:24
*** Niharika has left #timvideos09:08
*** Niharika has quit IRC09:09
*** rohitksingh has quit IRC09:09
*** FeltonChris has left #timvideos11:18
*** Niharika has joined #timvideos12:41
canciI experience an interesting graphical artifact in images I capture with hdmi2usb13:42
canciit is easily reproducible with this pattern http://nowhere.ws/dump/testpattern.png13:42
cancifor each color of r,g,b there is a sample in the image consisting of four quadrants.13:43
cancieach of those quadrants representing one possible possition of a colored pixel in a 2x2 part of otherwise black pixels13:44
cancithe artefact is that for each of the colors, one of the quadrants is distinctly more visible than the other three13:44
canciand which quadrant that is changes when the test pattern is moved around the screen13:45
canciI'll make a sample capture this evening, maybe somebody has an idea what might be the problem13:46
*** shenki has quit IRC13:52
*** shenki has joined #timvideos13:56
*** ChanServ sets mode: +v shenki13:56
*** mparuszewski has joined #timvideos14:03
canci(a result in real world data is visible e.g. here http://nowhere.ws/dump/stream.jpg - notice the strange coloring in the braces of the green text and the weird smushed font on the red text)14:06
CarlFKcanci: (forgive my ignorance here, I am not very into the details) isn't this expected given the high jpg compression?14:08
canciCarlFK: I don't think so, as it's 100%14:11
cancieven when I compress it to the same level with another encoder the outcome is not the same14:11
CarlFKk - never mind ;)14:12
canciIt /might/ be some issue with chroma subsampling, maybe the implementation tries to be more efficient there, skipping some optimizations a full blown encoder does14:12
*** mparuszewski has quit IRC14:32
*** sarwarc has quit IRC15:02
*** mparuszewski has joined #timvideos15:33
*** slomo has quit IRC17:16
mithrocanci: there are two modes, mjpeg and raw17:36
mithrocanci: I assume you are using mjpeg there17:36
mithrocanci: can you take a screenshot and look at what happens if you do jpeg compression of it?17:37
*** mparuszewski has quit IRC17:38
mithrocanci: I guess it means you have a working board now?17:39
*** Niharika has left #timvideos17:49
*** Niharika has quit IRC17:49
cancimithro: yea, it works when I flash it with the usb stick18:38
cancimithro: https://github.com/cfra/HDMI2USB/wiki/Digilent-Atlys-Board%3A-Loading-Firmware#usb-flash-drive-method18:39
tpbTitle: Digilent Atlys Board: Loading Firmware · cfra/HDMI2USB Wiki · GitHub (at github.com)18:39
mithroCan you try the libFPGALink method?18:39
cancimithro: I will probably try it eventually, but right now my focus is more about trying a few scenarios with hdmi2usb and figuring out whether I want to use gst-switch or use something more simplistic18:41
*** slomo has joined #timvideos18:41
*** slomo has joined #timvideos18:41
mithroThe HDMI2USB is the priority project at the moment18:42
cancimithro: btw, I think the "issue" is that the jpeg encoder does 4:2:2 subsampling18:42
canciand does the subsampling by just dropping every second pixel18:42
mithrogst-switch is on the back burner18:42
mithrocanci: that is quite probable18:43
canciUnless that has been tried and thrown out before, I'd have a look whether I can figure out how to average the pixels and check whether that improves the captured data18:44
CarlFKcanci: I would love to help out with gst-switch, but currently the install is more than I want to figure out.  If you will figure out how to install it, I'll try working with it18:45
CarlFKcanci: the current install is very travis-ci laden, which may sound like a good thing, and I expect anyone will do what I did and will later agree, or later tell me I am nuts.18:46
canciCarlFK: I (think I) have installed it yesterday following the .travis-setup.sh18:46
canciI'm not exactly sure what the target platform is, I was doing it on debian testing and the tools are too new for the version of gstreamer referenced in the install script18:47
canci(although that fixed quite easily by cherry-picking a later commit that adds support for bison >= 3.0)18:48
CarlFKthat sounds about as far as I got.18:48
CarlFKI have to run and get food - I'll be back in an hour or so.18:48
canciin the end I was able to build everything, however I was not really sure how to proceed from there, as in how to add inputs or process output18:50
CarlFKI forget if I was able to build.  but I want to hear someone actually got it working18:52
CarlFKI was holding out for someone producing a real talk, but that may never happen if no one is first ;)18:52
*** CarlFK has quit IRC18:52
mithrocanci: take a look at the python API18:53
mithrocanci: we need to create a good test suite18:53
*** mparuszewski has joined #timvideos19:46
*** mpar has joined #timvideos20:22
*** mparuszewski has quit IRC20:25
*** slomo has quit IRC20:27
*** CarlFK has joined #timvideos21:42
*** ChanServ sets mode: +v CarlFK21:42
canciso, this is the testimage actually used22:05
canciand this is a recording of a screen displaying that image http://nowhere.ws/dump/flicker.mjpeg.xz22:05
cancithe screen itself does not show this artefact, only the mjpeg recording22:06
canciother than that I also encountered these interesting effects :) http://nowhere.ws/dump/foo.png http://nowhere.ws/dump/foobar.png22:20
*** CarlFK has quit IRC23:04
*** CarlFK has joined #timvideos23:19
*** ChanServ sets mode: +v CarlFK23:19

Generated by irclog2html.py 2.12.1 by Marius Gedminas - find it at mg.pov.lt!