Prosody speech processing: API: sm_conf_prim_add

Prototype Definition

int sm_conf_prim_add(struct sm_conf_prim_add_parms *confp)

Parameters

a structure of the following type:

typedef struct sm_conf_prim_add_parms {
	tSMChannelId channel;					/* in */
	tSMChannelId participant;				/* in */
	tSM_INT id;						/* out */
	/* Only in Prosody version 2 (TiNG) */
	float factor;						/* in */
	/* End of part only in Prosody version 2 (TiNG) */
} SM_CONF_PRIM_ADD_PARMS;

Description

Adds a new conference participant to the set of input channels whose conferenced sum is currently being output on output channel channel. All channels in a conference must have been allocated on a single Prosody processor module.

The participant must be a channel which has been attached to conferencing with sm_conf_prim_attach() unless the conference type is kSMConfTypeStandard in which case the channel input is implicitly attached if necessary.

On return id will be set to a value between 0 and 63, this value being an identifier for this conference participant. This identifier may be used to determine if this participant is currently active in the conference (see sm_conf_prim_info()), and in the call for the participant to leave the conference (see sm_conf_prim_leave()).

Note that a particular participant input channel is assigned the same id for every conference it is added into (or cloned into) while attached. If a channel is detached and attached again, it may be allocated a different id value.

Only on Prosody version 2 (TiNG): This requires the module inchan to have been downloaded.

Only on Prosody version 2 (TiNG): If the participant has any kind of tone detection enabled through a call to sm_listen_for() then tones detected will be suppressed from entering the conference. This means that as soon as the detector discovers that a tone is present, this participant will be temporarily suspended from the conference and restored when the tone detector determines that the tone has finished. Note, however, that this may permit a very short initial burst of tone to be audible in the conference as, to keep the transmission latency low, the detector cannot rewind back to the start of a tone. Any such short burst of tone will be shorter than the tone detector's minimum tone criterion.

Fields

channel: The channel on which the conference output has been started to which a new participant is to be added.
participant: The input channel which is to be added to the conference output channel.
id: An identifier which identifies this participant.
factor (Only in Prosody version 2 (TiNG)): If this module is configured for kSMConfTypeIndividualVolume, this field contains a multiplication factor and the signal from the input channel is multiplied by this value before being added to the conference output. Note that this is a factor and not in dB. To specify a gain in dB, use factor = pow(10, dB / 20). If the module is configured for standard conferencing, this field must be zero and the input signal is not modified before being added into the conference output.

Returns

0 if call completed successfully, otherwise a standard error such as:

ERR_SM_DEVERR - device error
ERR_SM_BAD_PARAMETER - illegal agc value
ERR_SM_WRONG_CHANNEL_STATE - if no conference started on channel

This function is part of the Prosody speech processing API.