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phunni

Member

From: Bristol, UK

Registered: 2003-08-13

Posts: 794

Alternatives to Vgrabbj

I recently here about wanting ot set up a stopmotion "studio" for my 7 year old daughter and I have decided that the simplest option for here is to use the Linux Stopmotion app.

My problem is what grabbing software to use to capture images from the camera.  The ones suggested by default are:

vgrabbj
vgrabbj as a daemon
uvccapture
videodog
dvgrab (firewire)

These all seem to either be outdated, for firewire or painfully slow.  Can anyone suggest a modern option (ideally available in the repos or aur) that can work with the Linux Stopmotion app?

Thanks in advance.

Awebb

Member

Registered: 2010-05-06

Posts: 6,688

Re: Alternatives to Vgrabbj

Which one is vgrabbj? Is it slow or outdated? What does outdated mean? Is it just old and unmaintained, or does it actually lack features?

Lone_Wolf

Administrator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 14,840

Re: Alternatives to Vgrabbj

It takes a v4l (not v4l2!)] device as input to put it into an jpeg, pnm, or png file.

No v4L2 support  and last commit was 2 years ago.  I'd say that qualifies as outdated.

edit

used bold in quote and edited post to clarify there are 2 things that combined make me feel it's outdated.

Last edited by Lone_Wolf (2015-11-14 15:28:42)

---

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Awebb

Member

Registered: 2010-05-06

Posts: 6,688

Re: Alternatives to Vgrabbj

Only if there are open issues or if the tool does not work anymore with recent hardware. If it works, why update it?

phunni

Member

From: Bristol, UK

Registered: 2003-08-13

Posts: 794

Re: Alternatives to Vgrabbj

It's outdated, but not too slow if used in daemon mode.  The problem is that, because it's so old, it's actually pretty difficult to build on arch because all the libraries have moved on so much and it simply won't compile

Edit: further information on it not compiling.  It fails with this error:

./vgrabbj.h:45:28: fatal error: linux/videodev.h No such file or directory

I'm led to believe from Googling that this is  a result of outdated libraries being required.

Last edited by phunni (2015-11-17 10:06:26)

phunni

Member

From: Bristol, UK

Registered: 2003-08-13

Posts: 794

Re: Alternatives to Vgrabbj

I'd like to give uvccapture a go, but it's not in the repos or AUR.  Will try compiling, but not holding my breath!

Awebb

Member

Registered: 2010-05-06

Posts: 6,688

Re: Alternatives to Vgrabbj

Okay, this is getting frustrating. All possible sources besides dvgrab don't really build or work for me. Even linuxstopmotion doesn't seem to be maintained, the last bug report is from 2011. The software itself works, our only problem is recording frames for the project, right?

Let's ignore the providers for a moment and try to make our own grabber. Let's have a look at the dvgrab grabber settings:

Pre-poll command: NONE
Start daemon: dvgrab --format jpeg --jpeg-overwrite --jpeg-temp dvtemp.jpeg --every 25 $IMAGEFILE &
Stop daemon: kill -9 $(pidof dvgrab)

I have found a tool called streamer (from the xawtv package in extra), that is capable of capturing frames from a video4linux device. The syntax can be simple, streamer -f jpeg -o outputfile.jpg records one jpeg frame. Now, your possibilities are without limits. You could write a script, that calls streamer every few seconds until it is killed. You could write a systemd user service, that calls a one shot streamer poll and is being controlled by a systemd timer.

EDIT: You can get as creative here as you want. You could start the daemon as (abstract) "while /tmp/capture_switch exists, loop through taking images and pauses" and the stop command would be killing the file.

I'd say $IMAGEFILE is being set by linuxstopmotion, so I guess you don't need to loop through filenames.

EDIT: Come to think of it, you don't even need a loop and timer logic. Just enter the grabber as the pre-poll, like "streamer -f jpeg -o $IMAGEFILE". Another important variable in linuxstopmotion seems to be $VIDEODEVICE.

I also checked streamer, it has two options, that allow you to specify a duration and a number of repetitions, but I'm not sure linuxstopmotion uses the same file numbering. As long as there are no performance problems, I'd stick with the pre-poll option.

Last edited by Awebb (2015-11-19 13:40:46)

phunni

Member

From: Bristol, UK

Registered: 2003-08-13

Posts: 794

Re: Alternatives to Vgrabbj

@Awebb - thanks for all of that.  It looks like you've been giving this quite some thought!  I had found streamer and thought it looked very promising, but I'm having what I assume is a hardware issue in that software which works on other machines won't work on the laptop I'm trying to set up.  I posted about that issue here

Awebb

Member

Registered: 2010-05-06

Posts: 6,688

Re: Alternatives to Vgrabbj

Try streamer. I'm getting the same error with most other tools.

phunni

Member

From: Bristol, UK

Registered: 2003-08-13

Posts: 794

Re: Alternatives to Vgrabbj

When I try streamer with the debug switch I get the following:

$ streamer -d -f jpeg -o test.jpg > streamer.out
checking writer files [multiple image files] ...
  video name=ppm ext=ppm: ext mismatch [need jpg]
  video name=pgm ext=pgm: ext mismatch [need jpg]
  video name=jpeg ext=jpeg: ext mismatch [need jpg]
checking writer raw [single file, raw video data] ...
  video name=rgb ext=raw: ext mismatch [need jpg]
  video name=gray ext=raw: ext mismatch [need jpg]
  video name=422 ext=raw: ext mismatch [need jpg]
  video name=422p ext=raw: ext mismatch [need jpg]
  video name=4mpeg ext=yuv: ext mismatch [need jpg]
  video name=4mpeg-o ext=yuv: ext mismatch [need jpg]
checking writer avi [Microsoft AVI (RIFF) format] ...
  video name=rgb15 ext=avi: ext mismatch [need jpg]
  video name=rgb24 ext=avi: ext mismatch [need jpg]
  video name=mjpeg ext=avi: ext mismatch [need jpg]
  video name=jpeg ext=avi: ext mismatch [need jpg]
no match found
neither audio nor video format specified/found

When I try and use dvgrab specifying v4l2 (with the -V switch ) and the input device (using the --input switch) it seems to wake up the camera (positive) and then just sit there with the message "waiting for DV..." and nothing else happens.  As far as I can tell it's not actually taking any pictures.
The encouraging thing about dvgrab, though, is that I get the exact same result from within linuxstopmotion - i.e. no picture, but the camera wakes up and there is no error message - although I do get the "waiting for DV..." message anyway.

The ioctl message still appears every now and again with dvgrab, but not instantly when I start dvgrab, which makes me hope it could work...

Incidentally, I have also tried qstopmotion, which seems to have seen a little bit more recent development.  I can get the picture aspect working using the v4l2 setting, which seems like real progress, but there doesn't seem to be a way to add audio in qstopmotion - which is definitely a deal breaker! After briefly Googling, there doesn't seem to be an obvious v4l2 cmd line command that I could plug into linuxstopmotion - I suspect, in fact, they're calling it from C code.

Edit: all attempts to google the problem with dvgrab are, so far, unhelpful as they refer to firewire cameras.

Last edited by phunni (2015-11-20 20:58:12)

phunni

Member

From: Bristol, UK

Registered: 2003-08-13

Posts: 794

Re: Alternatives to Vgrabbj

Turns out I can't even get audio to work properly with linuxstopmotion anyway - even if I could get images into it!

My daughter's birthday is on Monday and it now looks like I've failed and, in order to avoid letting her down, we're going to have to go and buy a low end windows laptop :-(

My house was Windows free...