GF_Err text_box_size(GF_Box *s)
{
	GF_TextSampleEntryBox *ptr = (GF_TextSampleEntryBox*)s;

	/*base + this + string length*/
	s->size += 51 + 1;
	if (ptr->textName)
		s->size += strlen(ptr->textName);
	return GF_OK;
}
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.