Thanks to all that replied, in the end I used libcurl for what I was doing with the HTTP stuff, and got it to work real well in fact.

What I ended up doing was using the std string/char functions in the callback function, so that it would take out what it needed on the fly and write it to the memory chunk. Since in the callback its using those, it made things easier and have much better performance.

In the main Qt program, I used the QString, by appending the returned data chunk via QString::fromUtf8. I could then do with it what I wanted to.