Prosody RTP processing: API: sm_vmptx_config_codec_speex

Prototype Definition

int sm_vmptx_config_codec_speex(struct sm_vmptx_codec_speex_parms *codecp)

Parameters

*codecp
a structure of the following type: 
typedef struct sm_vmptx_codec_speex_parms {
	tSMVMPtxId vmptx;					/* in */
	tSM_INT payload_type;					/* in */
	enum kSMSpeexMode bandwidth;				/* in */
	enum kSMVMPTxVADMode VADMode;				/* in */
	tSM_INT frames_per_packet;				/* in */
} SM_VMPTX_CODEC_SPEEX_PARMS;

Description

Configures a VMP[tx] to use Speex for encoding data, as defined in IETF RFC 5574. However, neither variable bit-rate coding (VBR) nor discontinuous transmission (DTX) are supported.

This requires the module speex_vmp 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.
bandwidth
Ignored. kSMSpeexNarrowbandMode is always used since it is the only value supported by current firmware. One of these values:
kSMSpeexNarrowbandMode
Narrowband (8 kHz sampling rate) mode
kSMSpeexWidebandMode
Wideband (16 kHz sampling rate) mode
kSMSpeexUltrawidebandMode
Ultrawideband (32 kHz sampling rate) mode
VADMode
Currently ignored. Neither VAD nor CNG processing is implemented. 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 could be used, to reduce the packet overhead at the expense of extra delay. This field is currently ignored. Packets are always transmitted with one 20ms frame per packet.

Returns

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

This function is part of the Prosody RTP processing API.