<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: collapse; font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 14px; line-height: 18px; "><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 1em; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 14px; vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; clear: both; word-wrap: break-word; background-position: initial initial; background-repeat: initial initial; ">How to properly startup speex echo cancellation?</p></span><span class="Apple-style-span" style="border-collapse: collapse; font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 14px; line-height: 18px; ">AEC is working fine, except when the algorithm gets its first frames to cancel echo. I hear a terrible feedback sound for a few seconds, before the AEC algorithm settles down and starts to work as expected.</span><span class="Apple-style-span" style="border-collapse: collapse; font-family: Arial, 'Liberation Sans', 'DejaVu Sans', sans-serif; font-size: 14px; line-height: 18px; "><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 1em; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 14px; vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; clear: both; word-wrap: break-word; background-position: initial initial; background-repeat: initial initial; ">I use the function <code style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 1px; padding-right: 5px; padding-bottom: 1px; padding-left: 5px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 14px; vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: rgb(238, 238, 238); font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif; background-position: initial initial; background-repeat: initial initial; ">speex_echo_cancellation()</code>.</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 1em; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 14px; vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; clear: both; word-wrap: break-word; background-position: initial initial; background-repeat: initial initial; ">At the very start of the application, there are recorded frames available, but not yet playback frames. In the latter case, I supply a 'silent' playback frame to the noise cancellation function (frame containing all zeros). Is this the right approach?</p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 1em; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; border-top-width: 0px; border-right-width: 0px; border-bottom-width: 0px; border-left-width: 0px; border-style: initial; border-color: initial; font-size: 14px; vertical-align: baseline; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: transparent; clear: both; word-wrap: break-word; background-position: initial initial; background-repeat: initial initial; ">So, when the AEC is first called (with frames containing sound - not silence), a terrible feedback is heard. Does anyone know how I can solve this problem?</p></span></body></html>