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| -rw-r--r-- | apps/OboeTester/docs/Usage.md | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/apps/OboeTester/docs/Usage.md b/apps/OboeTester/docs/Usage.md index 90d1c99c..98a6266a 100644 --- a/apps/OboeTester/docs/Usage.md +++ b/apps/OboeTester/docs/Usage.md @@ -25,15 +25,19 @@ The latency is estimated based on the timestamp information. Experiment with changing the buffer size to see if there are glitches when the size is high or low. Experiment with changing the "Workload". -Watch the frame counters and the #XRuns. +Watch the "% CPU" and the #XRuns. The audio is expected to glitch when the workload is high because there is too much work and the audio task misses its delivery deadlines. -The extra workload is generated by calculating a random number in a loop and then adding the result to the output at an inaudible level. This technique prevents the compiler optimizer from skipping the work. The workload fader is in arbitrary units that determines the number of loops. +The extra workload is generated by calculating a number of classic synthesizer voices with two oscillators, two envelopes and a resonant filter. You can see the affect of the changing workload in the "% cpu" report in the status area. The extra workload will always cause glitching when you get close to 100% CPU load. If the workload is causing glitching at a low % CPU load then there may be a problem with the callback timing. +A variety of output signals can be played including frequency sweeps and white noise. +The default output sound is a sine wave on each channel. The base frequency is 330 Hz +and increases by a ratio of 4:3 (a perfect fourth) for each channel. + Instructions for using TEST OUTPUT for 4 or more chanels is in [Wiki/OboeTester_MultiChannelOutput](https://github.com/google/oboe/wiki/OboeTester_MultiChannelOutput). @@ -44,14 +48,14 @@ Test input streams. Displays current volume as VU bars. ### Tap to Tone Latency Measure touch screen latency plus audio output latency. -Open, Start, then tap on the screen with your fingertip. +Press START then tap on the screen with your fingertip. The app will listen for the sound of your fingernail tapping the screen and the resulting beep, and then measure the time between them. If you use headphones then you can eliminate the latency caused by speaker protection. If you use USB-MIDI input then you can eliminate the latency due to the touch screen, which is around 15-30 msec. MIDI latency is generally under 1 msec. -This test works well for measuring the latency of Bluetooth headsets. +This test works well for measuring the output latency of Bluetooth headsets. More instructions in the [Wiki/OboeTester_TapToTone](https://github.com/google/oboe/wiki/OboeTester_TapToTone). |