• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 98 subscribers
  • Views 347 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Writing application for VPBE | DM36x DVEVM

Alyona
Expert 1295 points

Hello everyone,

I have "VPFE User's Guide.pdf" and "VPBE User's Guide.pdf" - here are lots of information about working with modules VPFE & VPBE via theirs registers and bits.

Also I have an application that works correctly that was written as an example (I found it in DVSDK) and it deals with VPFE. But there are no registers mentioned  in the whole project at all. How does it work without setting registers of VPFE? And what should I work with to write an application for VPBE?

  • 0
    Guru 11260 points

    Hi,

    Which application are you talking about, Can you attach the app.

    Thx,

    --Prabhakar Lad

  • 0 in reply to Prabhakar Lad
    Expert 1295 points

    Sorry, forgot to mention,

    I'm talking about    capture_prev_rsz_onthe_fly_yuv     application (in dvsdk there are only sources, compiled application I found in the filesystem that was on the SD card that was shipped with the board: /usr/share/ti/linux-driver-examples/imp-prev-rsz).

    BTW sources of other applications from this path look similar.

    If I got it right only driver works with registers, but we - developers - work with the driver. But then another problem is arising - where to find clear explanation for drivers? 

  • 0 in reply to Alyona
    Guru 11260 points

    Hi,

    Here is the (LINK)source of that application. If can have a closer look at the application,

    The application is doing capture-prevview-resize in continious mode. Each of this devices

    are opened configured and enabled. For example for capture device,

    /dev/video0 is opened , the IOCTL is issued here VIDIOC_QUERYCAP, This IOCTL queries the

    capability of the capture device this request is handled by the device driver itself and the driver

    returns back with its capabilities. Similarly for previewer, Resizer the device is opened issued

    IOCTL to configure and finally when everything is setup we issue a STREAMON IOCTL which

    again lands to driver and starts capturing.

    Hope that helps..

    Probably you first need to understand the basics of driver writing and application for that driver.

    Thx,

    --Prabhakar Lad

  • 0 in reply to Prabhakar Lad
    Expert 1295 points

    I would understand it with great pleasure, but it is really difficult to do having only the sources. By the method of reversing engineering. Will continue digging for docs...