problem with 5dpo
lazarus / 39-Graphics

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proxy3d · 2012-11-06 08:14

I'm trying to include in WebCamera Linux in VirtualBox. Install 5dpo.
The camera is compatible with Linux. Use Lazarus 1.0 .. 1
Use examples from 5dpo to run "/ dev/video0". I choose "Video Active",
I wrote "Could not start streaming".
What does this mean? In what could be the problem?

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User137 · 2012-11-06 10:06

Quote from: proxy3d on November 06, 2012, 09:14:07 amThe camera is
compatible with Linux.How do you determine that? Have you tried to use
the camera with other software first?

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proxy3d · 2012-11-06 10:20

written on the camera is compatible with Linux 2.6 and above. I
specifically chose a camera that works under Linux.

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BigChimp · 2012-11-06 10:32

So first try if you can get any output using Linux tools, e.g.
something like
cat /dev/video0 > /tmp/testvideo.mpg
then press ctrl-c after a while
(if it outputs mpeg, don't know how webcams output their video; could
be something else as well)
then
file /tmp/testvideo.mpg
and then try opening it with a media player.

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proxy3d · 2012-11-06 10:48

I use a Creative Labs VF0520 Live! Cam Sync. I tried Cheese for
testing. In the setting of Cheese - the correct name of the camera. No
video. How to enable video WebCamera in Linux?

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BigChimp · 2012-11-06 12:17

Look it up in the documentation of your distribution, as well as the
VirtualBox manual (because you will need to forward the USB port).

In general, it may be a better idea to troubleshoot/read documentation
a bit better, indicate what you have done, what exactly failed etc. I
have the sense that you're slapping everything together and expect it
to work. When it doesn't, you're looking for ready-made solutions on
the forum.
Of course, I might well be wrong, but that's the impression I get...

Good luck.

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proxy3d · 2012-11-06 12:46

all USB devices work well in VirtualBox (Flash drive, printer). The
problem with the webcam. I have read many documents before writing
here. I tried to change the permissions, installing additions to
Linux. There is a driver or a program that emulates WebCamera in
Linux? I need to test my components.

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Laksen · 2012-11-06 13:45

Looks like it's a problem with the USB driver in VirtualBox:
https://www.virtualbox.org/ticket/242

A solution could be to buy a very old USB camera, or stop using
VirtualBox

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proxy3d · 2012-11-06 13:55

Under VMWare has this problem?

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proxy3d · 2012-11-08 10:37

Convert VirtualBox virtual disk in VMWare (in disk manager in
VirtualBox - choose Copying in VDMX). In VMWare no problem with
WebCamera.

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proxy3d · 2012-11-08 13:31

What are the components in Lazarus that in Linux work with Web Camera
(5dpo not want to work)? I run the example from 5dpo, video is not
displayed in the window. Video from Web-Camera works in the program
"cheese" in Linux. In what could be the problem? What are the
components or more examples of working with Web-camera in Linux in any
programming language?

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proxy3d · 2012-11-08 14:11

What sets the property UseLibV4l?
Worked only format YUYV.
I've tried all formats, works only YUYV (black and white). I tried to
change UseLibV4l, same result. But the program "cheese" shows the
color image from the camera.
OS: Linux Mandriva, Lazarus 1.0.2

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proxy3d · 2012-11-09 07:42

Problem solved. Example 5dpo video resolution 320x240, the program
"cheese" 640x480. If the "cheese" I change to any other solution, the
program dies. If I put in 5dpo 640x480, it works.
The question is how to get Linux available video formats and
resolutions Web Camera?

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irfanbagus · 2012-11-20 23:46

to get supported frame size i do something like this (code not tested)
:

Code: [Select]var
  J: Integer;
  Size: v4l2_frmsizeenum;
  Handle: THandle;

...

J:= 0;
repeat
  Size.index:= J;
  Size.pixel_format:= V4L2_PIX_FMT_YUYV;
  if FpIOCtl(Handle,VIDIOC_ENUM_FRAMESIZES,@Size)=0 then
  begin
    Writeln(
      Size.stepwise.min_width, // this is width
        'x',
      Size.stepwise.max_width // this is height
       );
  end
  else
    break;
  Inc(J);
until False;

be careful with v4l2_frmsizeenum record definition in videodev2.pas.
it's incomplete (that's why my example use  min_width&max_width  to
get width&height). and a lot of webcam (or the driver) on linux only
support YUYV. you must convert it if you need rgb color.