Re: [rc-hackers] Play video files on Yarp port

[Erik B. <eri...@hi...>]

Dear Tobias and the rest of the list,

I've now a follow up on my earlier question regarding video playback. I've
used the opencv grabber as suggested and it's been working just fine. No
I'd like to playback several video files simultaneously with exact frame
sync. I've therefore created my own module that instantiates the
OpenCVGrabber and writes images to a port, rather than using the grabber
through yarpdev.

It turns out my custom frame streamer is significantly slower than
streaming images by instantiating the OpenCVGrabber using yarpdev --from
myconfig.ini. I've tried using both a standard Port and a
BufferedPort<ImageOf<PixelRgb>> and in both cases the port writing takes up
a lot of resources. I'm using a simple configuration where a single
HD-resolution video is streamed to a yarpview display.

I'm following the basic pattern in image_process_module example, with the
exception that I'm of course reading images directly from the grabber
rather than from a port.
http://www.yarp.it/os_2image_process_module_8cpp-example.html#a6, like
this:

MyRateThread::run() {
  ...
  grabber->getImage(outputImage);
  imagePortOut->write(outputImage);
}

outputImage is here declared as ImageOf<PixelRgb> and imagePortOut is a
standard yarp Port configured with background write. I've confirmed that it
is the port writing that takes time, the call to the grabber is of course
fast.

In the final setup, I intend to use four simultaneous (synced) video
streams that go to several target ports, some are yarpviews and some other
yarp modules. The streams eats up a lot of resources and I'm lousing
frames.

Any suggestions on how I should go about it are welcome.

Kind regards, Erik

tors 26 nov. 2015 kl 11:04 skrev Erik Billing <eri...@hi...>:

> Ah, I see - simple when you know it. Many thanx for the help!
>
> --
> *Erik Billing,*
> *Assoc. Senior Lecturer, *
> *University of Skövde*
> *www.his.se/erikb <http://www.his.se/erikb/>*
> *eri...@hi... <eri...@hi...>*
>
>
> tors 26 nov. 2015 kl 10:46 skrev Tobias Fischer <t.f...@im...
> >:
>
>> Hi,
>>
>> see this: http://www.yarp.it/yarpdev.html
>>
>> In short, you need to first enable CREATE_DEVICE_LIBRARY_MODULES in the
>> cmake options, and after configuring once also enable
>> ENABLE_yarpmod_opencv_grabber / ENABLE_yarpmod_ffmpeg_grabber or whatever
>> driver you need.
>>
>>
>> Best,
>> Tobias
>>
>>
>> On 26/11/15 07:51, Erik Billing wrote:
>>
>> Dear Tobias and Konstantinos,
>>
>> many thanx for the hint. I've tried to use both the ffmpeg and opencv
>> grabbers but they do not seem to be present on my system (running Win 7
>> with Yarp 2.3.63). I realize I can do  *yarpdev --list *and neither
>> ffmpeg nor opencv are present in the list. Maybe I'm missing something
>> fundamental, so I need to install these grabbers separately?
>>
>> Kind regards,
>> --
>> *Erik Billing,*
>> *Assoc. Senior Lecturer, *
>> *University of Skövde*
>> *www.his.se/erikb <http://www.his.se/erikb/>*
>> *eri...@hi... <eri...@hi...>*
>>
>>
>> fre 20 nov. 2015 kl 11:32 skrev Tobias Fischer <t.f...@im...
>> >:
>>
>>> Hi,
>>>
>>> there are at least two options:
>>> 1) ffmpeg_grabber and
>>> 2) opencv_grabber
>>>
>>> You can find examples for both here:
>>> <http://www.yarp.it/group__dev__examples.html>
>>> http://www.yarp.it/group__dev__examples.html
>>>
>>> And if you want to modify a driver, you can finds some hints here:
>>> http://wiki.icub.org/wiki/Modifying_a_YARP_Driver
>>>
>>> Best,
>>> Tobias
>>>
>>>
>>> On 20/11/15 08:36, Erik Billing wrote:
>>>
>>> Dear rc-hackers,
>>>
>>> I'm looking for a Yarp module able to read video files (avi, various
>>> encodings) and stream them on a yarp port. I've seen a lot of discussion on
>>> how to record from Yarp  bottles, and some of how to replay a recorded dump
>>> - but in my case files are not recorded using Yarp.
>>>
>>> Any suggestions welcome,
>>> --
>>> *Erik Billing,*
>>> *Assoc. Senior Lecturer, *
>>> *University of Skövde*
>>> *www.his.se/erikb <http://www.his.se/erikb/>*
>>> *eri...@hi... <eri...@hi...>*
>>>
>>>
>>>
>>> ------------------------------------------------------------------------------
>>>
>>>
>>>
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>>> Robotcub-hackers mailing lis...@li...https://lists.sourceforge.net/lists/listinfo/robotcub-hackers
>>>
>>>
>>