releasenotes.txt

symbian上实用全工音频输出/输入的例子代码

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S60 Platform: Full-Duplex Audio Example v2.0  

    This example application plays and records audio simultaneously, reading
    from the microphone and writing to the earpiece/speaker, creating a local 
    audio feedback loop. Audio is processed in encoded format, using real-time 
    encoding/decoding support from audio hardware.
    
    The example supports Nokia抯 S60 2nd Edition, Feature Pack 2 and Feature 
    Pack 3 devices, as well as S60 3rd Edition devices.

Note  for VoIP developers:
For VoIP applications, this example is only suitable for S60 2nd Edition and for S60 2nd Edition FP2 and FP3 devices. 
VoIP applications on S60 3rd Edition and newer releases should use Audio Proxy Server (APS).There is a more suitable
example in the Audio Proxy Server v2.3 package. This SDK plug-in is available for download at: 

http://www.forum.nokia.com/info/sw.nokia.com/id/029f9e6e-b7cc-4c39-8104-72a58c2209ec/APS_v2_3_S60_3rd_S60_3rd_FP1.zip.html    
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PREREQUISITES

    Symbian OS key concepts
    Audio streaming on Symbian OS
    Multitasking and threads

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IMPORTANT FILES AND CLASSES

    inc\fullduplexenginebase.h
    
    src\fullduplexengine.cpp 
    src\inpustreamthread.cpp

    Symbian APIs:    CMMFDevSound, 
                     MDevSoundObserver
                 
    Example classes: CFullDuplexEngine,
                     CInputStreamThread                

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RUNNING THE EXAMPLE

    Running the example is simple. After starting the application, the status
    text should read "Init complete." Full-duplex streaming can be started and
    stopped from the Options menu. Status information and possible errors are
    displayed on screen.
    
    Supported codecs:
    
        - AMR-NB (default after initialization)
        - G.711
        - G.729
        - iLBC
        
    The codec to use can be selected from the Options->Codec menu. Note that some
    devices may only support AMR-NB encoding.
    
    Full-duplex operation is achieved by using two CMMFDevSound instances, one
    for input (record) and one for output (playback).
    
    The input stream runs in its own thread, while output streaming is 
    done in the main thread. DevSound objects write to/read from a single
    audio buffer, which is shared between the threads. 
    
    Two threads are used to synchronize the streams with semaphores.
    Multi-thread implementation is not a requirement for full-duplex streaming,
    however.
        
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KNOWN ISSUES

    Running other CPU-intensive tasks during streaming may cause skips in the
    audio or a delay between the input and output streams because the number of
    buffered frames increases. (Frame dropping should be implemented to
    control the latency.)
    
    Full-duplex operation is enabled by using custom preference / priority
    values. However, on S60 3rd Edition, using non-default values also requires
    MultimediaDD capability. Signing an application with MultimediaDD capability
    requires an ACS Publisher ID and support from the manufacturer. For more information,
    visit www.symbiansigned.com and www.forum.nokia.com/testing.
    
    Audio output routing cannot be controlled. On S60 2nd Edition devices, audio is 
    played routed to the earpiece by default. On S60 3rd Edition devices, audio is 
    routed to the speaker. There is no public API that could be used for 
    controlling this behavior.
    
    This example can only be run on target devices, because the emulators do not
    support full-duplex audio.

    As this example does not use APS, it is not suitable for VoIP applications in S60 3rd Edition and
    newer releases.  There is a more suitable example in the Audio Proxy Server v2.3 package. 
    This SDK plug in is available for download at: 
    http://www.forum.nokia.com/info/sw.nokia.com/id/029f9e6e-b7cc-4c39-8104-72a58c2209ec/APS_v2_3_S60_3rd_S60_3rd_FP1.zip.html
    
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BUILD & INSTALLATION INSTRUCTIONS

MOBILE DEVICE (S60 3rd Edition)
------------------------------

    Go to /FullDuplexEx/group
    bldmake bldfiles
    abld build gcce urel
    Go to /FullDuplexEx/sis
    Edit the fullduplexex_3rd_ed.pkg's paths to match those on your system.
    makesis fullduplexex_3rd_ed.pkg
    
    Sign the SIS package:
	- Signing an application with MultimediaDD capability requires an ACS Publisher
	ID and approval from the manufacturer. For more information, visit the following 
	Web sites:
	    www.symbiansigned.com
	    www.forum.nokia.com/testing

    Install the signed .sis file to a device.


MOBILE DEVICE (S60 2nd Edition)
-------------------------------

    Go to /FullDuplexEx/group
    bldmake bldfiles
    abld build thumb urel
    Go to /FullDuplexEx/sis
    Edit the fullduplexex_2nd_ed.pkg's paths to match those on your system.

    makesis fullduplexex_2nd_ed.pkg

    Install the .sis file to a device.
    
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COMPATIBILITY

  S60 2nd Edition, Feature Pack 2
  S60 2nd Edition, Feature Pack 3
  S60 3rd Edition
  S60 3rd Edition, Feature Pack 1
    
  Tested on Nokia 6630, Nokia N70, Nokia N80, and Nokia E60.
    
  Created / tested with:
  
  Series 60 2nd Edition SDK for Symbian OS, Supporting Feature Pack 3, for C++
    
  S60 3rd Edition SDK for Symbian OS, for C++, Maintenance Release
  + Extensions plug-in for S60 3rd Edition SDK for Symbian OS, for C++, MR
    
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VERSION HISTORY

    2.0	    Support added for S60 3rd Edition. Support added for G.711, G.729
            and iLBC codecs. Inter-thread communication now done with an active 
            object instead of exception handling.
	
    1.0	    First release (published in Forum Nokia PRO).

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