Add support for live auxillary audio input and software mixing with scheduled content

Martin Konecny added a comment - 18/Feb/11 1:50 AM Paul, support for recording live shows is in this ticket: http://dev.sourcefabric.org/browse/CC-1630 We need to support liveshows first.

Martin Konecny added a comment - 22/Feb/11 3:30 AM "I noticed that some of the planned features (e.g. live mode mic, phone-in shows) depend on having an auxiliary audio input on the Airtime server. This is problematic in a remote situation without having some stream from the client, and a remote controlled software mixer on the server (i.e. enabling manual adjustment to prevent clipping). We don't want to end up with a design where only half the features work remotely, because I believe the remote support is Airtime's killer feature. It might be simpler to say that Airtime itself doesn't have an audio input, it only accepts streams for rebroadcasting. This would leave features like live mic input and phone integration to be done in the third-party desktop client (e.g. IDJC already has these features). There, the microphone, TBU (analogue phone interface), or Skype client would be connecting on the same desktop machine, so it would be a lot simpler, and more robust against network problems. Later on, we might consider having a software mixer on the Airtime server, so for example you can do Live Mode in the browser, and mix in a remote mic input using an N/ACIP stream. It's technically possible; there is a reference implementation for Windows available under GPL, based on pjsip: http://sourceforge.net/projects/aoip/ http://www.pjsip.org/ but maybe this is a little too complicated for the short term. Cheers! Daniel"

Martin Konecny added a comment - 22/Feb/11 3:33 AM Daniel is right that this is a big step. For now I would suggest that we support live-in only when microphone input at the server is available, and eventually move to allowing live remote streams.

Daniel James added a comment - 12/Apr/11 11:28 AM We now have auxiliary input in the show recording feature. This could be sent on to liquidsoap via an ALSA plugin which splits the soundcard line input into two virtual devices.

Todd Fisher Wallin added a comment - 31/Jul/12 7:13 PM - edited I would like to show a use case in an FM on-air station... It would be great to offer the use of an input.alsa source as an option for one of the two streaming sources. This functionality is already in liquidsoap. This would allow a station that uses many analog sources to feed them to the airtime computer and use it for their stream feed instead of having to use a second piece of hardware/software to generate a stream when using analog audio sources. For example, at WDRT we currently feed the studio mixer output to a digigram card in a gentoo box running liquidsoap to generate the streams for the icecast server and for our STL. If airtime had input.alsa options, we could use the airtime server to do this, thus eliminating the need to route airtime through the mixing console to get to the stream generating box. feed = input.alsa( bufferize=false, device="hw:1" ) is the way we grab input from the audio card in liquidsoap. We also do not want to encode a stream from the console and send it to the airtime server as that would produce a high bandwidth price on the lan and also add another level of latency. Todd

Martin Konecny added a comment - 07/Aug/12 1:43 AM Hi Todd, This is a great idea. Will try and fit this in somewhere in the near future.

Daniel James added a comment - 07/Aug/12 9:09 AM Ideally this should be integrated with the show recorder to prevent conflicts between ecasound and liquidsoap trying to open the hardware audio input at the same time. You would probably want to record a live show that you were streaming, for proof of broadcast and archival purposes.

Todd Fisher Wallin added a comment - 07/Aug/12 3:15 PM Since Liquidsoap is already doing most all of the backend audio processing, wouldn't it make sense to have it do the show recording as well? Or did I miss something that was in another ticket?

radioa6 added a comment - 30/Oct/12 9:10 AM To use Airtime in a production environment and use it to fully automate the dj station this feature is surely needed. The way we used to do it in one of the commercial radio stations i worked with is as follows : Plan a show with music and put in content blocks. These content blocks contain a switch to aux input so it can take live input or use a prerecorded content block. The content blocks also had the information for the dj to read aloud or misc info so they could easily click on it and it would pop up in our browser. See its as a simple document viewer. ( would be awesome if it supported multiple document filetypes and/or intregration with Superdesk )