addressable led strip brightness control with arduino

i am using led controller t1000s with programs played from sd card , but is it possible to add something like arduino what is changing real time signal and then i can change brightness?

http://www.ebay.com/itm/T1000S-SD-Card-LED-Pixel-Controller-For-WS2812B-LPD8806-6803-WS2811-WS2801/262006266695?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D41402%26meid%3D97d73234bd9442de8d5b2e1db14984de%26pid%3D100005%26rk%3D6%26rkt%3D6%26sd%3D171215367574

but is it possible to add something like arduino what is changing real time signal and then i can change brightness?

Yes but you have to disconnect the data line from the t1000s and use the Arduino. You can still use the power supply inside the t1000s but you can't use any of its pattern functions, you have to do it all on the Arduino.

but is it possible that pattern functions are coming from t1000s and signal is going through arduino and arduino is changing signal so that brightness is changed

mortenx:
but is it possible that pattern functions are coming from t1000s and signal is going through arduino and arduino is changing signal so that brightness is changed

Well I would say not. The data is a very fast synchronous signal running at 800KHz, the chances of recording that and putting it into memory with only a 16MHz processor are very slim., it is one thing to generate such a signal and another to be able to catch it. The LEDs themselves manage because their is dedicated hardware doing it.