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winmill's avatar
winmill
Reel Rookie
5 years ago

CreateObject roBitmap execution time

I tracked down my app's response lag to the CreateObject("roBitmap") call. This call seems to have a wide range of execution times on devices I can test.

On most recent devices (e.g. 3930X), it takes 72ms. However, on a recent 55" TCL (55S525), this call takes 551ms. I tried a factory reset, but still see same results.

Here's the code that I've inserted into hello-world to test.

timer = CreateObject("roTimespan")
timer.Mark()
bitmap = CreateObject("roBitmap", {width: 146, height: 146, AlphaEnable: true})
bitmap.Finish()
print "Device roBitmap create: " + timer.TotalMilliseconds().ToStr() + "ms"


Why would this call take so long on a device?

 

Roku Developer Program

3 Replies

  • necrotek's avatar
    necrotek
    Roku Guru
    5 years ago

    Not sure why it would take so long and don't have a Roku tv to test... but why are you calling bitmap.Finish() if you have not drawn anything to the bitmap?  I do not use bitmap.finish() and have never had an issue.  If you are using a roScreen with double buffer I think it will do a finish before swapbuffers(). You will only have this "execution time" hit when creating. Draws are done quickly. 

    2nd possibility is that the new Roku tvs' and roku ultras do have new chips and draw2d drivers have not been implemented exactly the same as the older devices.  I have a new Roku ultra and have not encountered any issues with slow bitmap creation that I have noticed but there is a scaling issue with non HD roScreen. 

     

    • winmill's avatar
      winmill
      Reel Rookie
      5 years ago

      Thanks for the point on the bitmap.Finish(). Removing that takes 20ms from the execution time.

      The 55" TCL is still at 531ms for the CreateObject("roBitmap") call. The Roku model number is A105X, so it's an A000X device in the hardware specs table.

      I did get a chance to run this on a 40" TCL (an 8000X device). It ran in 79ms after removing the bitmap.Finish() call.

      The 55" TCL A000X device has good specs on the hardware table, but seems to take a long time to create a bitmap.

      • winmill's avatar
        winmill
        Reel Rookie
        5 years ago

        More diagnostics. This code snippet now runs in 3ms on the 55" TCL.

        'screen = CreateObject("roSGScreen")
screen = CreateObject("roScreen", true)
timer = CreateObject("roTimespan")
timer.Mark()
bitmap = CreateObject("roBitmap", {width: 146, height: 146, AlphaEnable: true})
bitmap.Finish()
print "Device roBitmap create: " + timer.TotalMilliseconds().ToStr() + "ms"

        If I change the comment lines and use the line with "roSGScreen" instead of "roScreen", then it takes 518ms.

        So, it seems that using SceneGraph increases CreateObject("roBitmap") from 3ms to 518ms.