If...	Then recording ends with...
The time limit in `vceRecord` is reached	CTA_REASON_TIMEOUT
No more space is available in the voice object, or recording in overwrite mode reached the end of the existing message	CTA_REASON_FINISHED
Silence is detected at the beginning of recording	CTA_REASON_NO_VOICE
Silence occurs after some energy is recorded	CTA_REASON_VOICE_END
Record is stopped at any time by calling `vceStop`	CTA_REASON_STOPPED
A touch tone digit is received and the corresponding bit in the DTMF abort parameter is set	CTA_REASON_DIGIT
The call is ended	CTA_REASON_RELEASED
Record is stopped because of a speech recognition event	CTA_REASON_RECOGNITION
You record to an object with an encoding that is not supported by the attached device service	CTAERR_FUNCTION_NOT_AVAIL

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5.5 Recording

There are two types of recording functions.

The message oriented function, vceRecordMessage, operates on a specific message number. This function creates a new message, replacing the existing message, if any.

The position-oriented function, vceRecord, operates on the current message in the specified context. Recording starts from the current position in the most recently accessed message.
There are no buffer-oriented record functions. Use the ADI functions adiRecordAsync or adiStartRecording if you need direct access to buffers. Refer to Chapter 7 for more information on the ADI Service: Playing/Recording. Refer to the ADI Service Function Reference Manual for more information on the ADI functions.
The vcerec demonstration program demonstrates copying messages from one voice file to another. Refer to Section 13.2.9, Voice File Record: vcerec for more information.

5.5.1 Recording Functions

Recording optionally starts with a beep tone. The recording functions have a time limit. Silence detected during recording can optionally abort the recording.
The following table lists when to use the record functions available in the CT Access Voice Message service. If you want to... Then use this function... Start recording at the current position in the current message vceRecord Record a message into a specified voice object vceRecordMessage

If you want to...	Then use this function...
Start recording at the current position in the current message	`vceRecord`
Record a message into a specified voice object	`vceRecordMessage`

5.5.2 Recording Completion Reasons

The following table lists the Voice Message service reason codes returned when record terminates. The reason is stated in the value field of the VCEEVN_RECORD_DONE_EVENT. Note: If record fails, the value field will contain an error code. If... Then recording ends with... The time limit in vceRecord is reached CTA_REASON_TIMEOUT No more space is available in the voice object, or recording in overwrite mode reached the end of the existing message CTA_REASON_FINISHED Silence is detected at the beginning of recording CTA_REASON_NO_VOICE Silence occurs after some energy is recorded CTA_REASON_VOICE_END Record is stopped at any time by calling vceStop CTA_REASON_STOPPED A touch tone digit is received and the corresponding bit in the DTMF abort parameter is set CTA_REASON_DIGIT The call is ended CTA_REASON_RELEASED Record is stopped because of a speech recognition event CTA_REASON_RECOGNITION You record to an object with an encoding that is not supported by the attached device service CTAERR_FUNCTION_NOT_AVAIL

5.5.3 Resizing Messages

When a message is replaced by vceRecordMessage, the new message might be larger or smaller than the previous one. The ability to resize a message depends on the object and the position of the message in the object. A message in a VOX file or a message that is located at the end of a flat (unformatted) file can grow without limit (until the disk is full). A file can physically shrink if the message at the end of the file is replaced with a smaller one (the shrinkage occurs when the file is closed). A message in a memory block is limited to the size of the memory specified with vceOpenMemory.

5.5.4 Parameters

The record functions take an optional pointer to a parameter structure. If you pass NULL, the parameters take default values. Refer to Section 3.5, Managing Parameters. Refer to Appendix D in the CT Access Function Reference Manual for more detailed information about the record parameters.
The parameters control the beep tone, silence detection, record gain (including optional Automatic Gain Control), and DTMF abort.
Automatic Gain Control (AGC) is an algorithm applied to incoming speech (recording) before compression and storage so that the amplitude of the stored speech is kept at a target level. Field Name Default Value Description DTMFabort 0xffff Abort on DTMF (bit mask). gain 0 dB The gain in dB applied to the signal before it is encoded. If Automatic Gain Control is enabled, this is the initial gain when recording starts. Valid range for AG boards is -54 to 24. novoicetime 5000 ms The maximum length of silence at the beginning of a recording before recording will be stopped with a reason of CTA_REASON_NO_VOICE. Use zero (0) to disable this timer. Valid range for AG boards is 0 - 65535. silencetime 3000 ms The maximum length of silence after audio energy has been detected before record will be stopped with a reason of CTA_REASON_VOICE_END. Use zero (0) to disable this timer. Valid range for AG boards is 0 - 65535. silenceampl -45dBm The maximum signal level, in dBm, that is considered to be silence. Valid range for AG boards is -51 to -15. beepfreq 1000 Hz The frequency of the record beep tone. Use zero (0) to disable the beep. Valid range for AG boards is 200 - 3600. beepampl -20 dBm The amplitude of the beep tone. Valid range for AG boards is -54 to 3. beeptime 200 ms The duration of the beep. 0 disables the beep. Valid range for AG boards is 0 - 65535. AGCenable 0 Flag to enable Automatic Gain Control. Note: When using AG boards, the parameters presented in the previous table override the corresponding fields in the ADI.RECORD category. ADI.RECORD contains additional fields which you can use to control Automatic Gain Control (AGC) characteristics.
Figures 43, 44, and 45 illustrate the three time windows that terminate the record function: Figure 43. Record Termination - No Voice Figure 44. Record Termination - Voice End Figure 45. Record Termination - Timeout

Field Name	Default Value	Description
DTMFabort	0xffff	Abort on DTMF (bit mask).
gain	0 dB	The gain in dB applied to the signal before it is encoded. If Automatic Gain Control is enabled, this is the initial gain when recording starts. Valid range for AG boards is -54 to 24.
novoicetime	5000 ms	The maximum length of silence at the beginning of a recording before recording will be stopped with a reason of CTA_REASON_NO_VOICE. Use zero (0) to disable this timer. Valid range for AG boards is 0 - 65535.
silencetime	3000 ms	The maximum length of silence after audio energy has been detected before record will be stopped with a reason of CTA_REASON_VOICE_END. Use zero (0) to disable this timer. Valid range for AG boards is 0 - 65535.
silenceampl	-45dBm	The maximum signal level, in dBm, that is considered to be silence. Valid range for AG boards is -51 to -15.
beepfreq	1000 Hz	The frequency of the record beep tone. Use zero (0) to disable the beep. Valid range for AG boards is 200 - 3600.
beepampl	-20 dBm	The amplitude of the beep tone. Valid range for AG boards is -54 to 3.
beeptime	200 ms	The duration of the beep. 0 disables the beep. Valid range for AG boards is 0 - 65535.
AGCenable	0	Flag to enable Automatic Gain Control.

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