SunVTS 3.0 Test Reference Manual

audiotest Subtests

Table 4-1 audiotest Subtests



Record/Play Test 

This test plays and records one second of data. It does not check data. This test is run on all audio implementations. 

Crystal Test 

The crystal test measures the accuracy of the crystal that generates the sample rate clock. It does this by playing a one-second signal and then measuring the actual time required to play the signal. This measurement is performed for each of the eight standard sample rates. This test is available for dbri(7) and audiocs(7) audio implementations

Loopback Tests 

This test verifies the functionality and signal quality of the audio ports. The test simultaneously plays and records a known signal. The recorded signal is analyzed for loop gain and signal-to-noise ratio plus distortion. This is repeated at various sample rates, encodings, precisions and channels. The audio ports that are supported depend on the audio implementation under test. The audiocs(7) implementation supports loopbacks from/to headphone, line-out, microphone, and line-in ports. The dbri(7)/speakerbox implementation supports fewer ports. The audioamd(7)implementation does not support loopback tests. Most tests require a stereo loopback cable.

NOTE: The microphone loopback tests require special hardware and are used by manufacturing centers and special test facilities. Do not invoke the microphone loopback tests unless you have the required hardware. 

Controls Test 

This test verifies the three control buttons on the Sun Speakerbox. The Controls test plays music while the user is prompted to press the Volume Down, Volume Up, and Mute buttons in a specific order. If no button is pressed in 30 seconds the test fails. This test is only supported on the dbri(7)/speakerbox implementation.

Audio Test 

 This test plays a 30-second music file out of the speaker or headphone. The full benefit of this test is only realized if the user listens to the output. Badly distorted audio, or not audible music indicates a problem. This test is supported on all audio implementations.