Class unavclWaveMixer

Unit

unaVC_wave

Declaration

type unavclWaveMixer = class(unavclInOutWavePipe)

Description

Mixes two or more PCM audio streams. No ACM codecs are used by this component.

Usage: If components has no provider component with formatProvider=true, specify PCM stream parameters before activating: set pcm_SamplesPerSec, pcm_BitsPerSample and pcm_NumChannels to specify the audio format parameters.

Set realTime to true if you wish the mixing to be made in real time manner. This component will mix as many streams as it has providers. Provider is any VC component, which has consumer property set to mixer component. Alternatively you can use addStream() and removeStream() method to add and remove streams (see Example B below).

Example A: c_mixer_client and c_mixer_server components are used in vcNetTalk demo to mix PCM streams coming from live recording device and WAVe file stored on disk.

Example B: mixer is used in vcPulseGen demo to mix unlimited number of sine waves. Refer to demo sources for details.

Hierarchy

• tComponent
• unavclInOutPipe
• unavclInOutWavePipe
• unavclWaveMixer

Overview

Methods

	function doAddProvider(provider: unavclInOutPipe): bool; override;
	function doWrite(data: pointer; len: uint; provider: pointer = nil): uint; override;
	procedure AfterConstruction(); override;
	procedure BeforeDestruction(); override;
	procedure createNewDevice(); override;
	procedure doRemoveProvider(provider: unavclInOutPipe); override;
	procedure doSetAddSilence(value: boolean); override;

Properties

	property addSilence;
	property calcVolume;
	property enableDataProcessing;
	property minActiveTime;
	property minVolumeLevel;
	property mixer: unaWaveMixerDevice read getMixer;
	property onThreshold;
	property realTime;
	property silenceDetectionMode;

Description

Methods

	function doAddProvider(provider: unavclInOutPipe): bool; override;

	function doWrite(data: pointer; len: uint; provider: pointer = nil): uint; override;
Writes data into mixer.

	procedure AfterConstruction(); override;

	procedure BeforeDestruction(); override;

	procedure createNewDevice(); override;
Creates PCM wave mixer device.

	procedure doRemoveProvider(provider: unavclInOutPipe); override;

	procedure doSetAddSilence(value: boolean); override;

Properties

	property addSilence;

	property calcVolume;

	property enableDataProcessing;
Specifies whether the component would perform any data mixing.

	property minActiveTime;

	property minVolumeLevel;

	property mixer: unaWaveMixerDevice read getMixer;
Returns PCM wave mixer device class instance.

	property onThreshold;

	property realTime;

	property silenceDetectionMode;

(c) 2012 Lake of Soft