<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><blockquote type="cite"><div><div style="background-color: rgb(255, 255, 255); font-family: arial, helvetica, sans-serif; font-size: 12pt; position: static; z-index: auto; "><div style="font-size: 16px; font-family: arial, helvetica, sans-serif; background-color: transparent; font-style: normal; "> In my RTSP server, I create a ServerMediaSession with ServerMediaSubsession for H.264 video stream. Somehow, I need to turn audio on later while streaming. I can add a ServerMediaSubsession into the ServerMediaSession, so the ServerMediaSession has 2 sub-sessions. But in this case, the player client is not aware of that the audio is on now. Per my understanding, the RTSP server shall notify the client by sending ANNOUNCE command with new SDP payload. So, is there anyway to let RTSP to do so?</div></div></div></blockquote><div><br></div></div>No, not with our software (or any other software that I'm aware of). The "ANNOUNCE" RTSP command has always been optional, and is barely implemented by anyone. Our library allows a RTSP client to send an "ANNOUNCE" command to the server, but we do not support a server sending an "ANNOUNCE" command to the client, nor do we have any way for the client to handle such a command.<div><br></div><div>Your best solution would be to create your "ServerMediaSession" initially with an audio "ServerMediaSubsession", even if the audio stream doesn't actually exist at first. Then later, if you wish, you can actually start streaming the audio, and clients should start playing it.</div><br><br><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; ">Ross Finlayson<br>Live Networks, Inc.<br><a href="http://www.live555.com/">http://www.live555.com/</a></span></span>
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