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<div><span style="font-size: 10.5pt;">Hello:</span></div>
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<p class="MsoNormal"><span style="font-size: 10.5pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size: 10.5pt; font-family: Calibri, sans-serif;">We noticed that opus reconstructed noise is pulsing with a 400ms pattern when dtx is enabled in silk mode. This is independent of the background noise level and is found
with speech + non-speech period test files as well as variable level noise<span style="color:#1F497D">-</span>only test files. This issue can be reproduced
<span style="color:#1F497D"> </span>with opus v1.1 using this command:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size: 10.5pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);">
</span><span style="font-size: 10.5pt; font-family: Calibri, sans-serif;">./opus_demo voip 16000 1 25000 –dtx input.bin output.bin<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size: 10.5pt; font-family: Calibri, sans-serif;"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size: 10.5pt; font-family: Calibri, sans-serif;">We have attached a .wav file with the first channel as the input reference noise signal and the second channel as the opus codec output using the opus_demo application.<span style="color:#1F497D"></span>It
does not look like this has been reported already. We would like your feedback.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; font-family: Calibri, sans-serif;"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size: 10.5pt; font-family: Calibri, sans-serif;">Thanks,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size: 10.5pt; font-family: Calibri, sans-serif;">Gonzalo Mariano and Pascal Huart<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; font-family: Calibri, sans-serif;">Cisco<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size: 10.5pt; font-family: Calibri, sans-serif; color: black;"><o:p> </o:p></span></p>
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