If your HTiB doesn't have an aux analog input that you can connect to the headphone jack of the TV then you would need an ADC to convert the headphone out to digital.
http/www.amazon.com/SANOXY-Analog-Digital-Converter-Adapter/dp/B005F20756
Be careful to turn the TV volume way down since you don't want to overload the input of the converter. Turning it up won't increase the output of the converter.