Customer application framework:play audio files

Overview

The CAF (customer application framework) API offers functions to play or record audio files:

On call legs (CTBCAFCallLeg):

• PlayStream()
• RecordStream()

On audio mixers (CTBCAFMixer):

• MixerPlayStream()
• MixerRecordStream()

It also offers callbacks, on the call flow and call behavior classes (based on CTBCAFCallFlow or CTBCAFCallBehavior) to notify the application when files have started playing/recording, and stopped playing/recording:

• OnStreamPlayingStarted()
• OnStreamPlayingDone()
• OnStreamRecordingStarted()
• OnStreamRecordingDone()
• OnMixerStreamPlayingStarted()
• OnMixerStreamPlayingDone()
• OnMixerStreamRecordingStarted()
• OnMixerStreamRecordingDone()

API parameters

PlayStream/MixerPlayStream

Class CTBCAFPlayAttributes is used to build play attributes. Available attributes are:

• AddPlayFilePath: Add a file to the list of files to play. Has some parameters:
  • File path (or URI)
  • Start/end offsets (optional)
  • Repeat count (optional) specific for this file in the sequence of files
• fAllowBargeInInterruption: Allow barge-in interruption (automatic stopping of playback upon detected DTMF)
• fPrepareForRecording: Prepare hardware resources for recording (pre-reserve recording resources)
• un32RepeatCount: Number of times to play the whole file sequence of files
• fNotifyStartOfNewFile: Asks for OnStreamPlayingStarted (or OnMixerStreamPlayingStarted) events for each file in the sequence of files (otherwise, one for the whole sequence)
• s8AudioGainDB: Gain (or loss) of audio level
• fAllowMixing: Allow this playing sequence to be mixed with another file sequence simultaneously playing to the same call leg (or mixer)
• un8PlayIndex: Sequence "index" (0 to 3) to assign to this playing sequence. Will replace a previous playing sequence using the same index, but will be mixed with simultaneously playing sequences with other indexes on the same call leg (or mixer).
• fPaused: Prepare the playback, but stay paused at start-up