Changes between Initial Version and Version 1 of APS

Timestamp:

Jul 24, 2008 2:02:33 PM (16 years ago)

Author:

nanang

Comment:

--

APS

@@ +1 @@
+= Enable Audio Proxy Server (APS) in PJSIP =
+
+== Introduction ==
+You can read about APS [http://wiki.forum.nokia.com/index.php/Audio_Proxy_Server here].
+The benefits of enabling APS in PJSIP are:
+ - '''Low latency'''. As mentioned somewhere that PCM frame size in some audio layer is about 4KB (4KB/2/8000Hz * 1000ms = 250ms), this seems to be the source of high latency audio in Symbian, while using APS it is possible to record/play ''encoded'' audio frames with latency only about 30ms! 
+ - '''Ability to switch audio-routing (to earpiece or loudspeaker)'''. Using standard API (CMdaAudioOutputStream) the audio is routed to loudspeaker which may not be prefered in a private conversation. While routing audio to earpiece can also avoid echo.
+
+== Requirements ==
+To build PJSIP with APS support, you will need:
+ 1. APS release 2.4.3 that is packaged in [http://wiki.forum.nokia.com/index.php/SDK_API_Plugin SDK API Plug-in], e.g:
+    - for [http://www.forum.nokia.com/info/sw.nokia.com/id/53439e01-f605-4491-96f4-62d003bd4c0c/S60_3rd_SDK_MR_API_Plug-In_Pack1.zip.html MR]
+    - for [http://www.forum.nokia.com/info/sw.nokia.com/id/4ff42a22-7099-4cc9-91bf-5e66166bd28d/S60_3rd_SDK_FP1_API_Plug-In_Pack.html FP1]
+    - not sure for FP2, is it included in the FP2 SDK?
+ 2. You may also need [http://www.forum.nokia.com/info/sw.nokia.com/id/48a93bd5-028a-4b3e-a0b1-148ff203b2b3/Extensions_plugin_S60_3rd_ed.exe.html Extensions plug-in for S60 3rd Edition SDK for Symbian OS, for C++, MR] to get '''sounddevice.h'''.
+
+
+== Building Steps ==
+Here are a few steps to build PJSIP with APS support:
+ 1. Edit '''bld.inf''' and '''application .mmp files''' (e.g: ''symbian_ua.mmp'', ''symbian_ua_gui.mmp'', ''symsndtest.mmp''), please make sure '''SND_USE_APS''' is set:
+{{{
+#define SND_USE_NULL    0
+#define SND_USE_APS     1
+}}}
+ 2. If you are using Carbide, please refresh the project first (right click '''bld.inf''' from the '''Symbian Project Navigator''' pane, and select '''Refresh'''). '''symbian_audio_aps.mmp''' should be there after the refresh done.
+ 3. Clean and rebuild the whole project, please note that WINSCW target doesn't seem to support APS.
+ 4. Make the installer (.sis file) for the application.
+
+
+== Installation ==
+ 1. Install APS Server '''apsserver2.sisx''' to device, the installer comes with the APS SDK package i.e in folder '''!InstallToDevice/AudioProxyServer243'''. You will need to do this only once for each device.
+ 2. Sign the application installer with APS support with '''Developer Certificate using Open Signed Offline/with Publisher ID'''. (APS requires '''MultimediaDD''' capability and this capability is among the restricted capabilities). Please see [http://www.symbiansigned.com Symbian Signed] for more detail.
+ 3. Install the application to the device.
+
+
+== Developing Application with APS Support ==
+There are some notes for developing application with APS support:
+ - Currently, frame time/PTIME supported by sound device with APS is only 20ms. For example if your application is using pjsua, you will need to specify something like this in pjsua config:
+{{{
+med_cfg.audio_frame_ptime = 20;
+}}}
+ - Specify application UID in a global variable named '''APP_UID''' whose base type '''TPtrC''', e.g:
+{{{
+TPtrC APP_UID = _L("2000521C");
+}}}
+
+
+== Limitation ==
+ - As mentioned before, sound device will only support 20ms frame time.
+ - Currently, this APS wrapper can only work in S60 3rd edition device that supports G.711, which perhaps (almost) all S60 3rd edition devices.