What is an ast_frame ?
A frame of data read used to communicate between between channels and applications. Frames are divided into frame types and subclasses.
- Frame types
- VOICE: Voice data, subclass is codec (AST_FORMAT_*)
- VIDEO: Video data, subclass is codec (AST_FORMAT_*)
- DTMF: A DTMF digit, subclass is the digit
- IMAGE: Image transport, mostly used in IAX
- TEXT: Text messages and character by character (real time text)
- TEXT_DATA: Text messages in an ast_msg_data structure
- HTML: URLs and web pages
- MODEM: Modulated data encodings, such as T.38 and V.150
- IAX: Private frame type for the IAX protocol
- CNG: Comfort noise frames
- CONTROL:A control frame, subclass defined as AST_CONTROL_
- NULL: Empty, useless frame
- Files
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Control Frames
Control frames send signalling information between channels and devices. They are prefixed with AST_CONTROL_, like AST_CONTROL_FRAME_HANGUP
- HANGUP The other end has hungup
- RING Local ring
- RINGING The other end is ringing
- ANSWER The other end has answered
- BUSY Remote end is busy
- TAKEOFFHOOK Make it go off hook (what's "it" ? )
- OFFHOOK Line is off hook
- CONGESTION Congestion (circuit is busy, not available)
- FLASH Other end sends flash hook
- WINK Other end sends wink
- OPTION Send low-level option
- RADIO_KEY Key radio (see app_rpt.c)
- RADIO_UNKEY Un-key radio (see app_rpt.c)
- PROGRESS Other end indicates call progress
- PROCEEDING Indicates proceeding
- HOLD Call is placed on hold
- UNHOLD Call is back from hold
- VIDUPDATE Video update requested
- SRCUPDATE The source of media has changed (RTP marker bit must change)
- SRCCHANGE Media source has changed (RTP marker bit and SSRC must change)
- CONNECTED_LINE Connected line has changed
- REDIRECTING Call redirecting information has changed.
