Function ffav_sys::sws_getCachedContext

pub unsafe extern "C" fn sws_getCachedContext(
    context: *mut SwsContext, 
    srcW: c_int, 
    srcH: c_int, 
    srcFormat: AVPixelFormat, 
    dstW: c_int, 
    dstH: c_int, 
    dstFormat: AVPixelFormat, 
    flags: c_int, 
    srcFilter: *mut SwsFilter, 
    dstFilter: *mut SwsFilter, 
    param: *const f64
) -> *mut SwsContext

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.