Datasheet

HH
VS1053B OGG VORBIS ENCODER VSMPG
2.5 Vox and Pause Operation
Vox / Pause allows the user to temporarily pause recording either based on audio con-
tent or direct user control. (For Ogg Vorbis Encoder Profiles that support Vox / Pause
operation, see Chapter 2.2.1.)
Vox control allows the unit to record only when someone is actually speaking. An audio
buffer makes it so that recording resumes slightly “before” the moment when speech is
detected, so in typical cases no syllables are lost at the beginning of a sentence.
Pause override allows the user to set and clear pause mode at will. This allows the user
to create a system where pause mode may be activated with a pause switch, like in a
traditional tape recorder.
buffer
Sample
Pause
logic
Pause override
input
Line/Mic Samples Samples Bitstream
Samples
A/D Encoder
Vox level
detector
Figure 4: Vox / Pause logic.
Figure 4 presents the pause logic. Input samples are fed to the Vox detector through a
high-pass filter. If pause hasn’t been overridden by the user, the Vox detector level is
used to control pause mode.
Note: It is not recommended to use Vox with a streaming system. When pause is
activated either by the user or by Vox, the sample counter (Chapter 5.1) stops and no
Ogg frames, not even empty ones, are output by the Encoder.
Rev. 1.70c 2012-11-16
Page 22(39)