audiotestsrc Creates audio test signals of given frequency and volume @GST_AUDIO_TEST_SRC_WAVE_SINE: @GST_AUDIO_TEST_SRC_WAVE_SQUARE: @GST_AUDIO_TEST_SRC_WAVE_SAW: @GST_AUDIO_TEST_SRC_WAVE_TRIANGLE: @GST_AUDIO_TEST_SRC_WAVE_SILENCE: @GST_AUDIO_TEST_SRC_WAVE_WHITE_NOISE: @GST_AUDIO_TEST_SRC_WAVE_PINK_NOISE: @GST_AUDIO_TEST_SRC_WAVE_SINE_TAB: