Source Signal for Audiovisual Tests

ITU recommendations suggest that the duration of the source sequences should be about 10 seconds for audiovisual, and the length of 5 short different sentences for speech. The termination of the sequences should not cause an incomplete sentence or musical phrase. An initial and a final silent period or gray scene, not longer than 500 ms, can be used to make the sequence be more natural. For the case of pair presentations, the references should have the best possible quality without any impairments. For audiovisual applications, speech and video should be perfectly synchronized.