Roku Developer Program

[bmn]

Hi, i'm having problems loading images, both on canvas component and using both getfile and asyncgetfile.

The canvas component doesnt show the images (sometimes) and the async/getfile finishes loading, but when i try to get the local file it doesn't exist

There is a very erratic behavior, and after some tests i think it has got to do with image size (px/kb) and simoultaneous loading.

I started a java tomcat to use as proxy and monitor the image urls to be loaded by the canvas component. At first i started returning big images (2000x200 px 3Mb) created on the fly, and these loaded fine, until i started changing the images fast, and i started getting a connection reset by peer (roku) in the server, that could be one of the problems.

any ideas?

thanks!

[RokuJoel]

I assume you are saving the files to tmp:/filename

so are you downloading multiple images to separate file names, or are you overwriting the image every time? You might want to grab a series, and then if you need to cleanup the tmp:/ area remove the oldest file.

The imageCanvas function is pretty slow to update, updates around 100 - 150 milliseconds. So Update, wait a bit, then update again.

For faster image rendering use roScreen instead of image canvas (of course this depends on what you are trying to accomplish).

- Joel

[bmn]

Thanks joel, i've been doing some more research on these images using firebug and loading them with js and html, and i got an http 302 status from the image and then it redirects to another url retrieveing the image.

How does roku handle http 302?

thanks!!

[bmn]

Joel, I tried using roScreen, but found no reference to it in the documentation, also i think it does not support the same methods roImageCanvas has...

ideas?

thanks!

[renojim]

roScreen is in the Brightscript reference.

-JT

[RokuJoel]

"bmn" wrote:
Thanks joel, i've been doing some more research on these images using firebug and loading them with js and html, and i got an http 302 status from the image and then it redirects to another url retrieveing the image.

How does roku handle http 302?

thanks!!

There's a resolveRedirect function in the MRSS template, see if that will work for you.

- Joel

[bmn]

Joel thanks for your reply! but i stil couldnt load...

ahttp=CreateObject("roUrlTransfer")
ahttp.EnableEncodings(true)

ahttp.AddHeader("user-agent", "Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1A543 Safari/419.3")
'ahttp.SetUrl(url)

port = CreateObject("roMessagePort")
ahttp.setPort(port)
result = invalid

done = false

while not done
ahttp.SetURL(url)
result = ahttp.AsyncGetToFile(filename)
if ahttp.AsyncHead()
while true
msg = wait(10000, ahttp.GetPort())

if msg <> invalid
h = msg.GetResponseHeaders()
PrintAA(h)
if ValidStr(h.location) <> ""
result = ValidStr(h.location)
else
done = true
end if
else
done = true
end if
exit while
end while
else
done = true
end if


end while
print "IMAGE LOADED TO FILE"
return result

the print image loaded to file appears, but when i check for the file it isnt there...

is the code i wrote correct? any more ideas?

thanks!!

[bmn]

Joel, shouldnt the Canvas SetLayer handle this images well? I mean shouldt the component handle the 302 message?

I'm really out of ideas here...

[bmn]

Joel got more crazy things now..

I started getting a 403 error now, not the 302 firefox received... so I changed the code to get the headers, i got to the target and then i should recall the thing again..

the problem is i am getting status 200 now, it just returns crazy values! could it be cache?

port = CreateObject("roMessagePort")
ahttp.setPort(port)
result = invalid
result = ahttp.AsyncGetToFile(filename)
while true
msg = wait(100, ahttp.GetPort())
if type(msg)="roUrlEvent"
print "status code"
print msg.GetResponseCode()
if msg.GetResponseCode() = 403 then
headers=msg.GetResponseHeadersArray()
for each h in headers
if h.Location <> invalid
url=h.Location
goto start
end if
next
exit while
end if
if msg.GetResponseCode() = 200 then
exit while
end if
end if
end while

[bmn]

I managed to get the Target header, which was returned in the 403 http error, this header contains the path to the image, i tried loading that image, and even though the http status is 200,the image is not shown...

Why could this happen?