V4L2 driver for Ubuntu

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davidpark

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V4L2 driver for Ubuntu

PostWed Nov 28, 2012 1:50 pm

Hello Blackmagic Team,
I've bought an Intensity Pro and worked with VLC of ubuntu 12.04 64bit system.
But Intensity Pro doesn't work with Web Conference System's Camera such as Bigbluebutton that use flash player in Fire Fox or Chrome.
Let me know how to make your driver into V4L2 driver because Adobe flash player support to V4L2 driver.

Thanks.
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Reuben

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Re: V4L2 driver for Ubuntu

PostWed Dec 12, 2012 4:03 pm

Blackmagic's driver is not a V4L(2) driver. So it will not work with anything requiring V4L(2).

Perhaps in the future they may consider creating a V4L2 wrapper of some sort for their driver, but currently no such interface exists.
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ser

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Re: V4L2 driver for Ubuntu

PostSat Jun 01, 2013 6:37 am

I am extremely disappointed it is not possible to chat via skype using this card :(

Really, really disappointed.
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ser

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Re: V4L2 driver for Ubuntu

PostSun Feb 09, 2014 6:45 pm

Any progress on this? Because my card sits in the PC and a thick layer of dust is covering it.
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Alexander Sbitnev

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Re: V4L2 driver for Ubuntu

PostTue Feb 11, 2014 1:27 pm

There is possible solution for video.
I just create gstreamer <-> v4l2 bridge and got video under v4l2 oriented program.
All you need is v4l2loopback module installed.
Here is command line for v4l2 export:
gst-launch-0.10 decklinksrc mode=18 connection=1 ! videoscale ! video/x-raw-yuv,width=1280,height=720 ! v4l2sink device=/dev/video1 sync=false
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KiriKiri

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Re: V4L2 driver for Ubuntu

PostWed May 28, 2014 3:30 pm

shuras wrote:There is possible solution for video.
I just create gstreamer <-> v4l2 bridge and got video under v4l2 oriented program.
All you need is v4l2loopback module installed.
Here is command line for v4l2 export:
gst-launch-0.10 decklinksrc mode=18 connection=1 ! videoscale ! video/x-raw-yuv,width=1280,height=720 ! v4l2sink device=/dev/video1 sync=false




Could you please proved more details of your solution?
Thanks!
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Andrew Hawkins

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Re: V4L2 driver for Ubuntu

PostSun Jul 20, 2014 10:29 am

I also ran that command, and it outputs this:

Code: Select all
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock


But I can't find the stream in any V4L2 applications. I think I have all the relevant software installed.

I'm also really disappointed that this card doesn't support V4L out of the box, I want to be able to stream to Google Hangouts on Air, and it seems like a really obvious thing to have.
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Andrew Hawkins

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Re: V4L2 driver for Ubuntu

PostSun Jul 20, 2014 3:30 pm

After a lot of fiddling around, I found that this command did the trick perfectly:

Code: Select all
gst-launch-0.10 decklinksrc mode=11 connection=1 ! v4l2sink device=/dev/video1 sync=false


This is for a Canon iVis HF M31 camcorder, which outputs to 1080 59.97i, hence 'mode=11.' It shows up in Google Hangouts as 'WebcamStudio virtual video device' likely because I have WebcamStudio installed, but I don't know if that's necessary to have.
Last edited by Andrew Hawkins on Thu Jul 24, 2014 6:07 pm, edited 1 time in total.
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Andrew Hawkins

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Re: V4L2 driver for Ubuntu

PostThu Jul 24, 2014 2:02 pm

A bit of follow-up:

'v4l2sink device=/dev/video1' may not always work. Depending on what software you're using or what video devices you have on your machine, you may have to run the command:

Code: Select all
sudo modprobe v4l2loopback

...and then try video2, 3, 4, etc. until you find one that works. If you get:

Code: Select all
Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Setting pipeline to PLAYING ...
New clock: GstSystemClock

...then you know it's working.

There isn't a lot of documentation on the Blackmagic Gstreamer plugin that I can find by Googling, but if you type:

Code: Select all
gst-inspect decklinksrc

...you'll get a list of different modes to use, as well as different commands. As stated earlier, mode 11 is 1080 59.97i, which I believe is what most HD camcorders output. If you're feeding from a PS3 for example, it may be different.

For my purposes, I use a USB mixer for audio, so I don't need it from the camcorder. But according to another post, it's possible to use ALSA snd-aloop to pull audio from the Intensity Pro and route it to a virtual audio device. I'll post more if I ever get around to setting that up.

Feel free to contact me with questions, and I'll do what I can to help.
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Kieran Kunhya

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Re: V4L2 driver for Ubuntu

PostFri Jul 25, 2014 12:15 am

V4L2 is currently not a good idea for professional capture devices because video and audio sit on separate file descriptors. It's never possible to open both of them at the same time so you're always out of sync.
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Andrew Hawkins

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Re: V4L2 driver for Ubuntu

PostSat Jul 26, 2014 4:44 pm

Noticeably so?

I don't doubt that V4L(2) isn't ideal, but until the Gtalk plugin or Skype start using the Blackmagic API, or Wirecast is ported to Linux, then those of us who want to use the card for live webcasting don't have any other option.
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Alexander Sbitnev

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Re: V4L2 driver for Ubuntu

PostTue Jul 29, 2014 10:21 am

Andrew Hawkins wrote:After a lot of fiddling around, I found that this command did the trick perfectly:

Code: Select all
gst-launch-0.10 decklinksrc mode=11 connection=1 ! v4l2sink device=/dev/video1 sync=false


This is for a Canon iVis HF M31 camcorder, which outputs to 1080 59.97i, hence 'mode=11.' It shows up in Google Hangouts as 'WebcamStudio virtual video device' likely because I have WebcamStudio installed, but I don't know if that's necessary to have.

I am glad you also find your way. It is not easy to find working params for each keys. Gstreamer aren't quite supportive in case of wrong options. If you put wrong video mode it just silently doesn't do anything.
I can only can suggest what in case of problems both gst 0.1 and 1.0 should be tried and for brave one there is also debug available like next cmds:
GST_DEBUG="*:5" gst-launch-0.10 -v decklinksrc mode=10 connection=3 ! fpsdisplaysink sync=false
GST_DEBUG="decklinksrc:5" gst-launch-0.10 -v decklinksrc mode=10 connection=3 ! fpsdisplaysink sync=false

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