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</o:shapelayout></xml><![endif]--></head><body lang=ZH-CN link=blue vlink=purple style='text-justify-trim:punctuation'><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Could anyone introduce how a message is handled by a filter sink and its master sink?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Take echo cancellation as example, I found <o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo2'><![if !supportLists]><span lang=EN-US><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US>The AEC filter sink’s message handler is called in its master ALSA sink’s IO thread.<o:p></o:p></span></p><p class=MsoListParagraph style='margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo2'><![if !supportLists]><span lang=EN-US><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US>It seems that the AEC virtual sink share its master’s message queue, right?<o:p></o:p></span></p><p class=MsoNormal style='margin-left:18.0pt'><span lang=EN-US>Because In module-echo-cancel’s pa__init(), I found the following code:<o:p></o:p></span></p><p class=MsoNormal style='text-indent:21.0pt'><span lang=EN-US>pa_sink_set_asyncmsgq(u->sink, sink_master->asyncmsgq);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Then how a message to filter/master sink is dispatched in one IO thread? Can a message is processed by the filter and then by the master?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Thanks & Best Regards<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Amanda<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></body></html>