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Raspberry Pi with OpenCV

gtrplyer16

All,

 

          In my electronics club in college we are using the Raspberry Pi Camera with OpenCV trying to use the video to store to a location and view the video that was recorded on a laptop that is connected via Ethernet cable. When we go to compile and run the program that does this we are getting and error that it won't open the output video. It should be an AVI video and going through PuTTy it should be able to play that video but it's not. We tried using V4L2 driver for the camera which is 264 video format. Is there anyway we can convert it that it will play through PuTTy or is there other drivers out there that would actually record in AVI format?

  • 0

    Hi Tyler,

     

    I didn't completely understand the issue, but PuTTY only provides a text interface, and trying to launch any graphics or video programs remotely using PuTTY won't work.

    The solution is to transfer the video file (using SFTP for example) to your laptop, and then double-click it to play it. The latter is guesswork if it will play, I don't have an

    RPI camera nor tried this, but definitely PuTTY won't allow you to play video and the usual way would be to transfer the file across.

    I hope this helps!

  • 0 in reply to shabaz

    I just checked it looks like we are trying to open it with pscp. It works with still pictures however not video.

  • 0 in reply to gtrplyer16

    I see, PSCP is the file transfer method, so that should transfer any file across (picture or video or anything else). So, presuming you have transferred the file,  it sounds like the file itself is the issue or is not recognised by the laptop. Or it could be a file naming issue.

    What happens if you double-click, what exactly is the error message you see?

  • 0 in reply to shabaz

    Nothing is saving to click on. On PuTTy while remote accessing the Pi we run the program and on the Pi terminal we it set to reply "Can't open the output video" if something went wrong so nothing is being transferred to the laptop. At least nothing that we can see. So it's like it is recording the video then can't save or transfer it and then gets deleted or lost.

  • 0 in reply to gtrplyer16

    Can you copy and paste the text you type into PuTTY and the response you see?

    It could be that the program you're running is not intended to record, or has some command line switch to disable trying to bring up (say) an X-window. You can't bring up a window because PuTTY can't do that - the underlying protocol cannot do this. So you need to execute the program with the switches to only dump to file. It sounds like the program is not doing this.

    In general it is far easier to debug if we can see the specific text that was typed and the response.

  • 0 in reply to shabaz

    I am not currently able to show you the text that is coming up, but the other club member will be in around 2:30 PM (it is currently 11:00 AM here) and will communicate with you. Thank you!

  • 0

    As Shabaz as stated the Putty interface is  a text interface how ever it does allow for port forwarding in particular X forwarding.

    You can configure X-Forwarding and use the Xserver on Windows such as that supplied free with Cygwin  this will allow you to run a program on the RPI and display on the PC.

     

    Better still would to use SAMBA to export a directory with the video contents in and  mount this on the Windows PC. You can then just click on the file in Windows explorer and use what ever player you like ....VLC is a good one!

    John A

  • 0 in reply to Problemchild

    You can also consider running a streaming server such as ICEcast  to stream your generated media!

  • 0 in reply to Problemchild

    This is Zach, the other club member.  We are writing C++ code to try to take the input from the camera and output it to a video stream.  We are using the VideoWriter class for the output and it fails the isOpened check.  The input video reports errors trying to get the FOURCC property and the FRAME RATE.  The FOURCC property is set to -1, do you know what the appropriate value is to output avi?  Do we need to install a codec for open cv to ouput avi?

  • 0 in reply to gtrplyer16

    This is a different issue to the one originally described. So this is code you've written and are trying to debug.

    Did you really mean a stream (over the network), or did you mean a file? The vagueness in this thread is making things hard to understand.

     

    A google search reveals the raspberrypi.org site had someone ask a similar question here: http://www.raspberrypi.org/forums/viewtopic.php?f=67&t=85326 and no-one answered.

    Not being familiar with OpenCV, do you have to use it for writing the images to a video, or can you use a different library for that portion? In which case something like avconv if you've got screenshots captured to files or something? Is this to post-process, or to be live network stream? Like using RTSP?

    If not live, surely some code already exists to capture video to a file?

    Sorry for the equally vague questions/answers, but this now sounds like a question that needs camera and OpenCV knowledge - and I have neither.