Brazil is notorious in Canada for slow visa processing, unless you happen to live in Toronto or (surprisingly) Winnipeg.
The deadlines for having a visa by Christmas have passed in some areas, and are still open in others.
If you live west of Manitoba, then it is very unlikely that you would get a visa before Christmas even if you applied today. The best bet right now is up to a month of processing.
If you live east of Ottawa then officially an application made today would be ready on or after Christmas day due to the new fifteen working days processing period.
If you live in Ottawa or the national capital region then an application made today would be ready in exatly ten working days.
If you live in Manitoba or Ontario (but not in Ottawa!), then your visa might actually get done before Christmas. Officially it is ten working days, but we are seeing some turn-arounds in as little as one week.
Click here for Brazilian visa forms.