Processing 1.0 - Processing Discourse - Using a dvcam as a web-cam in Linux

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Using a dvcam as a web-cam in Linux (Read 13158 times)

Patricio YaBB Newbies Offline Posts: 4	Re: Using a dvcam as a web-cam in Linux Reply #30 - Jan 5^th, 2010, 5:23am Wow! that works great! thanks you SO MUCH!

oddlog

Re: Using a dvcam as a web-cam in Linux
Reply #31 - Feb 9^th, 2010, 8:22pm

hello,
i'm having the same problem here using sony dv handycam.
i was carefuly reading this topic and everything worked in my case except this last thing

Quote:

pipe = new GSPipeline(this, "dv1394src port=0 ! video/x-dv ! dvdemux ! dvdec ! ffmpegcolorspace ! video/x-raw-rgb, width=720, height=480, bpp=32, depth=24);

i'm unable to perform that.
gst-launch gives "internal data flow error"
and without conversion i'm stuck with "buffer underflow exception" in processing.
i searched for numerous other examples but could not find single one that does conversion from yuv to rgb.
im using latest 0.6-pre0 gsvideo library and gstreamer from karmic repo

im just hoping you have some other ideas

Re: Using a dvcam as a web-cam in Linux
Reply #32 - Feb 10^th, 2010, 9:07am

As it has been suggested before, the first thing to test would be to try the pipeline from the command line with gst-launch, i.e.:

gst-launch-0.10 dv1394src port=0 ! video/x-dv ! dvdemux ! dvdec ! ffmpegcolorspace ! video/x-raw-rgb, width=720, height=480, bpp=32, depth=24 ! xvimagesink

Does this test shows the image from the camera? If the problem persists, then it means it is an issue with gstreamer and not with gsvideo itself.

oddlog

Re: Using a dvcam as a web-cam in Linux
Reply #33 - Feb 14^th, 2010, 2:15pm

i tried pipline and as soon as i add rgb as in video/x-raw-rgb anywhere in pipeline i ends with internal dataflow error.
without rgb conversion in pipeline it works fine, but then it does not work in processing

for capturing kino says:
>>> formats supported: 4
>>> 0x32595559 (YUY2) packed
>>> 0x32315659 (YV12) planar
>>> 0x59565955 (UYVY) packed
>>> 0x30323449 (I420) planar

i could try to compile gstreamer from git but i dont see how could that help

Re: Using a dvcam as a web-cam in Linux
Reply #34 - Feb 14^th, 2010, 3:58pm

the problem here is that processing requires frames in rgb format, and the camera only seems to provide in YUY2, YV12, UYVY and I420 formats.

After some online browsing, I have the impression that the colorspace conversions you need (YUY2->RGB, YV12->RGB, etc) are not implemented in gstreamer yet Sad

But maybe I'm wrong...

oddlog

Re: Using a dvcam as a web-cam in Linux
Reply #35 - Feb 14^th, 2010, 4:25pm

i found out that xvimage sink cannot display rgb for some reason (while ximagesink can)
example
Code:

gst-launch -v videotestsrc ! ffmpegcolorspace ! video/x-raw-rgb ! xvimagesink

gives "cannot negotiate format"
but in our case we have "internal dataflow error" with xvimagesink and ximagesink .. something between dv to rgb conversion.

then i found ARToolkit forum thread about some axis cam, where they say that it is not possible to display cam output with gst-launch but that it does not matter since artoolkit can process stream, and they use fakesink.

then i tried normal web cam with v4l2 and same "buffer underflow" error happend.. that when i got crazy...
after removing spaces between capsfilter parameters it suddenly worked..
Code:

"v4l2src ! ffmpegcolorspace ! video/x-raw-rgb,width=320,height=240,bpp=32,depth=24"

than i did same thing to dv1394src.. it WORKED!

now it works even with spaces beetwen parameters...
i can not explain it

so finaly this works.. tnx for replies
Code:

cam = new GSPipeline(this, "dv1394src ! video/x-dv ! dvdemux ! dvdec ! ffmpegcolorspace ! video/x-raw-rgb, width=720, height=480, bpp=32, depth=24");

ac Full Member Offline Posts: 237	Re: Using a dvcam as a web-cam in Linux Reply #36 - Feb 15^th, 2010, 12:11pm I'm glad to know you managed to make it work, although you are not sure exactly how A gstreamer mystery, I guess.

flashradio

Re: Using a dvcam as a web-cam in Linux
Reply #37 - May 5^th, 2010, 6:05am

Hello,

i will also use the gsvideo for a firewire cam on Windows XP.
USB works very fine. But, if i use the pipe with Firewire 1394, the i get the message:
Quote:

0:00:01.218750000 3968 17164B78 ERROR GST_PIPELINE grammar.tab.c:1975:_gst_parse_yyparse: no element "dv1394src"
0:00:01.218750000 3968 17164B78 ERROR GST_PIPELINE grammar.tab.c:2564:_gst_parse_launch: Unrecoverable syntax error while parsing pipeline dv1394src ! video/x-dv ! dvdemux ! dvdec ! ffmpegcolorspace ! video/x-raw-rgb, width=720, height=480, bpp=32, depth=24 ! fakesink name=VideoSink
processing.app.debug.RunnerException: GstException: no element "dv1394src"
at processing.app.Sketch.placeException(Unknown Source)
at processing.app.debug.Runner.findException(Unknown Source)
at processing.app.debug.Runner.reportException(Unknown Source)
at processing.app.debug.Runner.exception(Unknown Source)
at processing.app.debug.EventThread.exceptionEvent(Unknown Source)
at processing.app.debug.EventThread.handleEvent(Unknown Source)
at processing.app.debug.EventThread.run(Unknown Source)
Exception in thread "Animation Thread" org.gstreamer.GstException: no element "dv1394src"
at org.gstreamer.Pipeline.launch(Pipeline.java:128)
at codeanticode.gsvideo.GSPipeline.<init>(GSPipeline.java:93)
at Test.setup(Test.java:58)
at processing.core.PApplet.handleDraw(Unknown Source)
at processing.core.PApplet.run(Unknown Source)
at java.lang.Thread.run(Thread.java:619)

flashradio

Re: Using a dvcam as a web-cam in Linux
Reply #38 - May 5^th, 2010, 6:13am

and when i use the 1394 firewire cam over GSCapture, then i get following error:
Quote:

0:00:01.515625000 4640 17165320 ERROR dshowvideosrc gstdshowvideosrc.cpp:897:gst_dshowvideosrc_getcaps_from_streamcaps: Failed to retrieve IAMStreamConfig (error=0x80004002)
0:00:01.609375000 4640 17165320 ERROR dshowvideosrc gstdshowvideosrc.cpp:751:gst_dshowvideosrc_set_caps: Can't connect capture filter with fakesink filter (error=0x80070057)

ac Full Member Offline Posts: 237	Re: Using a dvcam as a web-cam in Linux Reply #39 - May 6^th, 2010, 10:18am Did you try the ksvideosrc element? Code: pipe = new GSPipeline(this, "ksvideosrc device-index=0 ! decodebin2 ! ffmpegcolorspace ! video/x-raw-rgb, bpp=32, depth=24"); I tested it with a fire-i camera, and works ok. I also recommend you to use the latest preview release (0.6-pre3).

flashradio

Re: Using a dvcam as a web-cam in Linux
Reply #40 - May 7^th, 2010, 4:54am

hi AC,

you are the man!!!

But i use this simple code:
i Code:

mport codeanticode.gsvideo.*;
GSPipeline pipe;
void setup() 
{
   size(720, 576);
   pipe = new GSPipeline(this, "ksvideosrc device-index=0 ! decodebin2 ! ffmpegcolorspace ! video/x-raw-rgb, bpp=32, depth=24");
}

void draw() 
{
    if (pipe.available() == true) 
    {
	  pipe.read();
	  image(pipe, 0, 0);
    }
}

and i get following errors:
Quote:

** (java.exe:3684): WARNING **: ks_video_format_to_structure returned NULL

I have deleoped a realtime echo video effect.
Windows XP (SP3), Processing, GSVIDEO, USB Microsoft HD Webcam:
http://www.flashalbum.info/#/1d770934d44de09b0d24f04fd01708ba/f213545e059a398626...

Now i will use for better quality a good mini-DV cam from sony over firewire. The Signal is 50 fps (half frames) interlaced.
I have programmed a deinterlacer for 25 fps fullframes progressiv.

ac Full Member Offline Posts: 237	Re: Using a dvcam as a web-cam in Linux Reply #41 - May 7^th, 2010, 9:27pm Very neat effect! You shouldn't worry too much about the message from gstreamer, it is just a warning. If the video capture works fine, then it is not very important

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