Topic: replace image on the fly

[dsfraser]

I have a setup that is using a video switcher that has an embedded web server and page for online control. I have managed to configure a Raspberry Pi (cheap and small) to be a reverse proxy to the switcher. So when you access the url of the Pi from outside it will serve the web page from the video switcher living on the private network, and allow you change the video feed. I should probably also mention I'm using the localhost tunneling program PageKite.

It all works rather well, and given my "I really don't know what I doing status" I was very pleased. Of course now they want to implement 2 or 3 more of these setups to remote locations.

The web page from the switcher is embedded in firmware and cannot be changed. So if I have 3 switches I would have 3 identical pages. It has the possibility to get confusing for the operators.

So what I would like to do is to brand the individual switches somehow, Site #1, Site #2 something to give the user a clue as to which one they are dealing with.

Is it possible to have the apache server on the Pi insert or replace an image, on the fly, when it serves the video switchers web page? There is a large 'top_bar.gif' on each page with the manufacturers name, and there is plenty of room to add text to it. So hopefully I could have a copy on the Pi and whenever it passed the switchers page it would substitute the changed 'top_bar.gif'.

I've been playing around with mod_rewrite but the best I've managed to do is block the embedded gif's from loading, it never seems to find the replacement ones on the Pi.

Some of the different things I've tried

RewriteEngine On
RewriteRule /images/(.*)\.gif$ /home/pi/$1\.gif

RewriteCond %{REQUEST_URI} images\top_bar.gif
RewriteRule .* /home/pi/top_bar.gif [L]

RewriteRule /images/top_bar.gif /home/pi/top_bar.gif

Anyway, I'm thankful for any pointers.

[mraddi]

I've created a directory "prx" within the apache's document-root and within this "prx"-directory a file ".htaccess" (maybe you need "AllowOverride All" within apache's "<Directory>"-section to allow this to work).

The .htaccess-file looks like this:

[dsfraser]

Thank-you very much!

With your pointers and help I was able to accomplish what I needed to do... it only took a week of banging my head on the desk, and in the end so simple.

I really only had to replace one gif so I was able to pare it down to:

RewriteEngine on
# LogLevel alert rewrite:trace3
RewriteRule "images/top_bar.gif" "/my_top_bar.gif" [L]

I guess the trick was placing my_top_bar.gif in the /var/www/html/ directory not in the user home, where it never seemed to get found.

Thanks again
dsfraser