What is the test for warrantless entry by a police officer to a house in a residential street?

We held that the warrantless entry was justified by the exigent circumstance of a burglary in progress, noting that the defendants had conceded "that an officer may enter a dwelling without a warrant if he reasonably believes a burglary is being committed therein." (People v. Duncan, supra, 42 Cal.3d 91, 98, 227 Cal.Rptr. 654, 720 P.2d 2.) The officer reasonably believed that a burglary was in progress, because he had heard a police broadcast that a burglary either had occurred or was occurring and had spoken to a neighbor who had seen suspects outside the residence. Upon inspecting the residence, the officer "found an open window with a television and other articles beneath it." (Ibid.)