Prosody RTP processing: API: sm_vmptx_config_codec_gsmefr

Prototype Definition

int sm_vmptx_config_codec_gsmefr(struct sm_vmptx_codec_gsmefr_parms *codecp)

Parameters

*codecp

a structure of the following type:

typedef struct sm_vmptx_codec_gsmefr_parms {
	tSMVMPtxId vmptx;					/* in */
	tSM_INT payload_type;					/* in */
	enum kSMVMPTxVADMode VADMode;				/* in */
	tSM_INT frames_per_packet;				/* in */
} SM_VMPTX_CODEC_GSMEFR_PARMS;

Description

Configures a VMP[tx] to use GSM-EFR for encoding data.

Note that this function is for use with the lightweight gsm-efr module only. Where full AMR-NB support is also required, please use sm_vmptx_config_codec_amrnb() with parameter gsmefr=1 and the module amr-nb or amr-nb-all instead.

This requires the module gsm-efr to have been downloaded.

Fields

vmptx

The VMP[tx] to which to add this codec

payload_type

The payload type identifer to use with this codec (see IETF RFC 3550 section 13). Supplying a value of -1 will remove any payload type configuration from the codec preventing its use.

VADMode

The mode of operation for the voice activity detector. One of these values:

kSMVMPTxVADModeDisabled

Disable VAD - all data delivered to the VMP[tx] is encoded and sent

kSMVMPTxVADModeEnabled

Enable VAD - if the signal is inactive, no data is sent (DTX)

kSMVMPTxVADModeComfortNoise

Enable VAD with comfort noise generation - if the signal is inactive, comfort noise packets are sent. If the main codec does not define its own comfort noise, it must have been configured by sm_vmptx_config_codec_comfort_noise().

frames_per_packet

The number of frames to send per packet. This value is normally one, which encodes 20 milliseconds per packet, but larger values can be used, reducing the packet overhead at the expense of extra delay.

Returns

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

• ERR_SM_DEVERR - device error

This function is part of the Prosody RTP processing API.