Changes between Version 1 and Version 2 of MeasuringSoundLatency
- Timestamp:
- Jul 28, 2008 11:20:19 AM (16 years ago)
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MeasuringSoundLatency
v1 v2 8 8 * [http://www.pjsip.org/pjsua.htm pjsua] 9 9 * a computer with microphone and loudspeaker (not headset) 10 * {{{tock8.wav}}} WAV file (see the attachment on the bottom of this page)10 * [file:tock8.wav] WAV file attached. 11 11 * a WAV waveform display/analyzer to visually see the latency (such as Cool Edit on Windows) 12 * or {{{latency.c}}} file (see the attachment on the bottom of this page) if you don't have WAV waveform analyzer program.12 * or {{{latency.c}}} file if you don't have WAV waveform analyzer program. This file is included in PJSIP version 0.9.5 and later in {{{pjsip-apps/src/samples}}} directory, or if you use older PJSIP you can find the [file:latency.c] file attached. 13 13 14 14 == Setup == … … 62 62 Here's what the recorded signal ({{{rec1.wav}}}) looks like in my WAV analyzer: 63 63 64 [[Image(rec1.png)]] 64 65 65 66 The highlighted area in above picture shows one recording of both original signal and the echo. … … 67 68 If we zoom-in the highlighted area, it will look like this: 68 69 70 [[Image(rec1-zoom.png)]] 71 69 72 And to find out the latency, just measure the interval between original signal and echoed signal: 73 74 [[Image(rec1-latency.png)]] 70 75 71 76 In this test, I found out that the latency is approximately 171 milliseconds.