alexaClientSDK::audioEncoderInterfaces::AudioEncoderInterface Class Reference

Interface for encoding audio stream. More...

#include <AudioEncoderInterface.h>

Public Member Functions
virtual	~AudioEncoderInterface ()=default
	Virtual destructor. More...
virtual std::shared_ptr< avsCommon::avs::AudioInputStream >	startEncoding (const std::shared_ptr< avsCommon::avs::AudioInputStream > &inputStream, avsCommon::utils::AudioFormat inputFormat, avsCommon::avs::AudioInputStream::Index begin, avsCommon::avs::AudioInputStream::Reader::Reference reference)=0
	Start the new encoding session. More...
virtual void	stopEncoding (bool stopImmediately=false)=0
	Stop current encoding session. More...
virtual avsCommon::utils::AudioFormat::Encoding	getEncoding ()=0
	Get output encoding type. More...
virtual std::string	getAVSFormatName ()=0
	Get output format name for AVS service. More...

Detailed Description

Interface for encoding audio stream.

This class provides generic interface between audio stream encoder implementation and the application who wants to encode audio stream.

Encoder converts input audio stream into encoded format. Each encoder implementation is expected to support one output format which doesn't change over time.

Encoding operation starts with startEncoding() call and finished in one of the following cases:

• Encoder reaches end of input stream
• Encoder encounters an error
• Encoding operation is stopped using stopEncoding() operation

Encoder supports a single encoding session, but there can be more than one encoder in the system.

See also

AudioEncoderInterface::AudioStream

AudioEncoderInterface::AudioFormat

Constructor & Destructor Documentation

~AudioEncoderInterface()

virtual alexaClientSDK::audioEncoderInterfaces::AudioEncoderInterface::~AudioEncoderInterface ( )

virtualdefault

Virtual destructor.

Member Function Documentation

getAVSFormatName()

virtual std::string alexaClientSDK::audioEncoderInterfaces::AudioEncoderInterface::getAVSFormatName ( )

pure virtual

Get output format name for AVS service.

This method returns output format name for AVS service. The encoder may change the format depending on configuration when encoding starts with startEncoding() call, and the clients should use this method after it. The AVS format name doesn't change until the next call to startEncoding().

Returns

The string interpretation of the output format, that AVS cloud service can recognize.

See also

https://developer.amazon.com/en-US/docs/alexa/alexa-voice-service/speechrecognizer.html#recognize

getEncoding()

virtual avsCommon::utils::AudioFormat::Encoding alexaClientSDK::audioEncoderInterfaces::AudioEncoderInterface::getEncoding ( )

pure virtual

Get output encoding type.

Method returns output encoding type.

Returns

Output encoding supported by this encoder.

startEncoding()

virtual std::shared_ptr<avsCommon::avs::AudioInputStream> alexaClientSDK::audioEncoderInterfaces::AudioEncoderInterface::startEncoding ( const std::shared_ptr< avsCommon::avs::AudioInputStream > &  inputStream, avsCommon::utils::AudioFormat  inputFormat, avsCommon::avs::AudioInputStream::Index  begin, avsCommon::avs::AudioInputStream::Reader::Reference  reference  )

pure virtual

Start the new encoding session.

Method starts the new encoding session. Object can manage only single session at the same time, thus this call will fail if ongoing encoding session exists.

If the method succeeds, client may request to stop encoding with stopEncoding() call. The encoding session will continue until stopped, end of inputStream is reached, or encoder encounters an error.

When this method is called, encoder may change the format returned with getAVSFormatName() method based on input format.

Parameters

[in]	inputStream	The AudioStream to stream audio from. (i.e.input stream that has raw PCM frames.)
[in]	inputFormat	The AudioFormat to describe the audio format of the input stream.
[in]	begin	The index where encoding should begin.
[in]	reference	The reference for the index.

Returns

Stream for encoding output. Encoder creates a new stream for storing the encoding results. On error the result is nullptr.

stopEncoding()

virtual void alexaClientSDK::audioEncoderInterfaces::AudioEncoderInterface::stopEncoding ( bool  stopImmediately = false )

pure virtual

Stop current encoding session.

Method stops current encoding session if it exists. If there is an ongoing encoding session, the method returns after the session is terminated.

This method has an execution timeout, and even if stopImmediately is false, encoding will be aborted if it cannot be stopped gracefully.

Parameters

[in]

stopImmediately

Flag indicating that encoding should stop immediately. If this flag is set to false (the default), encoding will continue until any existing data in the buffer has been encoded. If this flag is set to true, existing data in the buffer which has not already been encoded will be discarded, and encoding will stop immediately.

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The documentation for this class was generated from the following file:

• /workplace/avs-device-sdk/core/AudioEncoder/AudioEncoderInterfaces/include/acsdk/AudioEncoderInterfaces/AudioEncoderInterface.h