[pjsip] quick question about volume and PJSUA-LIB

[Jim Gomes]

Hi Chris,

The min/max are macros from the stdlib.h or from minmax.h file.  If you are getting compile errors, you can try renaming them to the ANSI compliant names __max and __min.  You can either add #include <stdlib.h>  or add #include <minmax.h> at the top of the file, or here are the macro definitions:

#ifndef __cplusplus
#define max(a,b)    (((a) > (b)) ? (a) : (b))
#define min(a,b)    (((a) < (b)) ? (a) : (b))
#endif  /* __cplusplus */


You can add that to the top of the file as well.  Or, you can expand the macros out and hand code them inline like so:

    int newlevel = (255 < (int) level) ? 255 : (int) level;
    newlevel = (0 > newlevel) ? 0 : newlevel;

I may change my implementation to the hand-coded expansion, since C macro expansion can be somewhat inefficient.  Or I may create some special inline functions that would allow me to use the original implementation without the macro expansion side-effects.  If you are compiling as C++, you can add #include <xutility> at the top of the file and use the _cpp_min()/_cpp_max() template inline functions that have no macro expansion side-effects.  These inline template functions are also aliased to the _MIN and _MAX macros.  Refer to the xutility file in your compiler directories for more info.
Regards,
Jim Gomes

From: pjsip-bounces at lists.pjsip.org [mailto:pjsip-bounces at lists.pjsip.org] On Behalf Of C R McClenaghan
Sent: Friday, 06 March, 2009 5:35 PM
To: pjsip list
Subject: Re: [pjsip] quick question about volume and PJSUA-LIB

Hey Jim,

Thanks, I may need this. I was able to modify the pjsua sample application to accept first a conference port number and then a volume adjust. It had previously been hardcoded to port 0 - but, hey, its a sample program. Anyway it now defaults to 0 but you can specify other ports and a listing of active ports is provided ala the connect/disconnect dialog.

I'm going to insert your update and see how I like it. Can you tell which library contains min and max, I'm getting a load error on the build.

Thanks,

Chris

On Mar 6, 2009, at 4:52 PM, Jim Gomes wrote:


Hi Chris,

I was doing some work in this area last week for one of my own projects.  I had great difficulty with this part of the library as well.  I eventually patched it to the following to get it to work.

/*
 * Adjust the signal level to be transmitted from the bridge to the
 * specified port by making it louder or quieter.
 */
PJ_DEF(pj_status_t) pjsua_conf_adjust_tx_level(pjsua_conf_port_id slot,
                                         float level)
{
    int newlevel = max(0, min(255, (int) level));
    return pjmedia_conf_adjust_tx_level(pjsua_var.mconf, slot,
                                  newlevel - 128);
}

/*
 * Adjust the signal level to be received from the specified port (to
 * the bridge) by making it louder or quieter.
 */
PJ_DEF(pj_status_t) pjsua_conf_adjust_rx_level(pjsua_conf_port_id slot,
                                         float level)
{
    int newlevel = max(0, min(255, (int) level));
    return pjmedia_conf_adjust_rx_level(pjsua_var.mconf, slot,
                                  newlevel - 128);
}



With this implementation, the level parameter has a valid range of 0 to 255, with 0 being mute.  Feel free to patch your version of the code, because the existing implementation is broken.

Regards,
Jim Gomes

From: pjsip-bounces at lists.pjsip.org<mailto:pjsip-bounces at lists.pjsip.org> [mailto:pjsip-bounces at lists.pjsip.org] On Behalf Of C R McClenaghan
Sent: Friday, 06 March, 2009 2:42 PM
To: pjsip list
Subject: [pjsip] quick question about volume and PJSUA-LIB

All,

Here's the documentation from online:

pj_status_t<http://www.pjsip.org/pjlib/docs/html/group__PJ__BASIC.htm#gb43ba3167bd2a2ab4580509dbf79200e> pjsua_conf_adjust_rx_level

(

pjsua_conf_port_id<http://www.pjsip.org/pjsip/docs/html/group__PJSUA__LIB__BASE.htm#gf5d44947e4e62dc31dfde88884534385>

slot,


float

level




)


Adjust the signal level to be received from the specified port (to the bridge) by making it louder or quieter.

Parameters:

slot

The conference bridge slot number.


level

Signal level adjustment. Value 1.0 means no level adjustment, while value 0 means to mute the port.

Returns:
PJ_SUCCESS on success, or the appropriate error code.

So, what are the appropriate ranges for the value of level? Are they 0 to 1? Are the values absolutes or relative to current volume? I'm playing with pjsua application and not sure I can tell. I'd like to see how fine grain the control can be.

Thanks,

Chris
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