Check if context can be reused, otherwise reallocate a new one.
If context is NULL, just calls sws_getContext() to get a new
context. Otherwise, checks if the parameters are the ones already
saved in context. If that is the case, returns the current
context. Otherwise, frees context and gets a new context with
the new parameters.
Be warned that srcFilter and dstFilter are not checked, they
are assumed to remain the same.
Check if context can be reused, otherwise reallocate a new one.
If context is NULL, just calls sws_getContext() to get a new context. Otherwise, checks if the parameters are the ones already saved in context. If that is the case, returns the current context. Otherwise, frees context and gets a new context with the new parameters.
Be warned that srcFilter and dstFilter are not checked, they are assumed to remain the same.