Changes between Version 17 and Version 18 of Nokia_APS_VAS_Direct


Ignore:
Timestamp:
Mar 13, 2009 1:40:40 PM (10 years ago)
Author:
nanang
Comment:

Minor fixes: replaces G.722 with GSM, rearranging phrases/words in few places.

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  • Nokia_APS_VAS_Direct

    v17 v18  
    1919Due to these benefits, the ability to use these codecs in PJSIP applications is very desirable. 
    2020 
    21 Note that non-APS codecs can still be used as usual, e.g: GSM, Speex/8000, and G.722. 
     21Note that non-APS codecs can still be used as usual, e.g: GSM, Speex/8000. 
    2222 
    2323[[BR]] 
     
    3131=== What APS-Direct is really === 
    3232 
    33 To use APS-Direct means that you're opening the sound device in codec (i.e. non-PCM) mode. You '''still have the choice''', at run-time, to open the sound device in PCM mode, if you wish, for example to make use of the PCM features in PJMEDIA such as the tone generator, or if you want to use the software codecs such as Speex or G.722 in PJMEDIA. Note that if you use PJSUA-LIB then the management of closing/re-opening the sound device using the correct codec will be done by PJSUA-LIB automatically. 
     33To use APS-Direct means that you're opening the sound device in codec (i.e. non-PCM) mode. You '''still have the choice''', at run-time, to open the sound device in PCM mode, if you wish, for example to make use of the PCM features in PJMEDIA such as the tone generator, or if you want to use the software codecs such as Speex or GSM in PJMEDIA. Note that if you use PJSUA-LIB then the management of closing/re-opening the sound device using the correct codec will be done by PJSUA-LIB automatically. 
    3434 
    3535To use APS-Direct also means that you are restricted to use the [#switchboard audio switchboard] at compile time (audio switchboard will be explained later). This means that you loose the capability of mixing audio with PJSUA-LIB, as well as several other restrictions on your audio routing arrangements. Among other things, you can't have two calls active and connected to the audio device at the same time. You can have more than one calls, but only one can be active (we recommend to put the other call on hold in this case). 
    3636 
    37 The sound device can only handle one format at a time. For example, if it is currently opened with G.729 format, you can't reconnect it to different media ports (such as stream or other pjmedia_port). You must first close it, then re-open it using the correct format. Note that if you are using PJSUA-LIB, this will be handled automatically (i.e. PJSUA-LIB will close/reopen the sound device with the correct format depending on what is connected to port zero in the [#switchboard audio switchboard]). But still you are limited to only able to connect one media port to the sound device at the same time (e.g. you cannot hear the call and play ringback tone to the sound device simultaneously). 
     37The sound device can only handle one format at a time. For example, if it is currently opened with G.729 format, you can't reconnect it to any media ports working with different format (e.g: stream or other pjmedia_port set to work with PCM). You must first close it, then re-open it using the same format as target port's format. Note that if you are using PJSUA-LIB, this will be handled automatically (i.e. PJSUA-LIB will close/reopen the sound device with the correct format depending on what is connected to port zero of the [#switchboard audio switchboard]). But still you are limited to only able to connect one media port to the sound device at the same time (e.g. you cannot hear the call and play ringback tone to the sound device simultaneously). 
    3838 
    3939 
     
    4444 - similarly when passthrough codec is selected in the stream, the stream will emit and take encoded audio frames (rather than PCM frames), hence it needs APS-Direct on the other side. 
    4545 
    46 One important thing to note: '''you may still use software codecs such as Speex and G.722 even when your application is compiled with APS-Direct support'''. When one of these software codecs is selected to be used by the stream, the stream will work as usual (i.e. emitting and taking PCM audio frames), so the audio device '''must''' be opened in normal/PCM mode (i.e. non-APS-Direct mode). If you are using PJSUA-LIB, then again this will be handled automatically. 
     46One important thing to note: '''you may still use software codecs such as Speex and GSM even when your application is compiled with APS-Direct support'''. When one of these software codecs is selected to be used by the stream, the stream will work as usual (i.e. emitting and taking PCM audio frames), so the audio device '''must''' be opened in normal/PCM mode (i.e. non-APS-Direct mode). If you are using PJSUA-LIB, then again this will be handled automatically. 
    4747 
    4848 
     
    5959#define PJMEDIA_CONF_USE_SWITCH_BOARD   1 
    6060 }}} 
    61  1. Selectively enable/disable which PCM codecs to be supported, for example to disable all PCM codecs: 
     61 1. Selectively enable/disable which software codecs to be supported, for example to disable all software codecs: 
    6262 {{{ 
    6363#define PJMEDIA_HAS_G711_CODEC          0 
     
    128128 }}} 
    129129 
    130 We also need to support passing around non-PCM frames in PJMEDIA. We added support for new frame type (the {{{enum pjmedia_frame_type}}}): '''{{{PJMEDIA_FRAME_TYPE_EXTENDED}}}'''. When the frame's type is set to this type, the {{{pjmedia_frame}}} structure may be typecasted to '''{{{pjmedia_frame_ext}}}''' struct (new): 
     130We also need to support passing around non-PCM frames in PJMEDIA. We added support for new frame type (the {{{enum pjmedia_frame_type}}}): '''{{{PJMEDIA_FRAME_TYPE_EXTENDED}}}'''. When the frame's type is set to this type, the {{{pjmedia_frame}}} structure can be typecasted to '''{{{pjmedia_frame_ext}}}''' struct (new): 
    131131 
    132132 {{{ 
     
    169169Understandably some conference bridge features will not be available: 
    170170 - audio mixing feature (no conferencing feature), 
    171  - audio level adjustment and query, 
     171 - audio level adjustment and query (only when the port is using non-PCM format), 
    172172 - passive ports. 
    173173