When it does not like the con­tain­er, it does not have an entry for it. If it does not like the video in the con­tain­er, it dis­plays a black screen (or some big col­ored pix­els… depend­ing on the degree of dis­agree­ment with the video) but plays the audio. I always had the audio work­ing if the con­tain­er was OK, but I assume it will just play the video with­out audio if the audio is not OK.