AdoreStreamer Class Reference

This class handles the received audio buffers. More...

#include <adorestreamer.h>

Inheritance diagram for AdoreStreamer:

Public Member Functions
	AdoreStreamer ()
	~AdoreStreamer ()
void	SetEngine (GstEngine *engine)
	Pass the GStreamer Engine object to the class and get a BufferConsumer hook. More...
void	ConsumeBuffer (GstBuffer *buffer, int pipeline_id)
void	StartProbing ()
	tell ConsumeBuffer() to start collecting audio buffers for later fingerprinting More...
void	StopProbing ()
	stops collecting buffers and erases existing audio data from the fingerprinting buffer More...
QString &	GetLastFingerprint ()
	public read-only access to the private fingerprint_ member variable. More...
QString &	GetFingerprintingAlgorithm ()
	public read-only access to the private fingerprinting_algorithm_ member variable. More...
QString &	GetFingerprintingAlgorithmVersion ()
	public read-only access to the private fingerprinting_algorithm_version_ member variable. More...
void	ResetLastFingerprint ()
	erases a previously created fingerprint. More...

Private Member Functions
void	MonoMix (const short *source_buffer, int source_numsamples, int source_numberofchannels, int source_samplingrate, short *target_buffer, int target_buffer_size)
void	GetFingerprint (QString &fingerprint)
QString	ChromaPrint (short *data, int size)
QString	EchoPrint (short *data, int size)

Private Attributes
GstEngine *	engine_
	the GStreamer engine object, necessary to peek into the audio stream More...
QBuffer	buffer_
	fingerprinting buffer to collect audio buffers for some seconds before creating a fingerprint More...
bool	probing_
	controls the collection. More...
QTime	probing_start_time
	used to measure when MINIMUM_PROBING_DURATION has been reached and then create a fingerprint More...
int	samplerate_
	computed in ConsumeBuffer() and stored to determine whether the rate has changed and the audio buffer collection needs a restart. More...
QString	fingerprint_
	ascii (base64) representation of the result created by GetFingerprint(). More...
QString	fingerprinting_algorithm_
	either 'echoprint' or 'chromapint', depending on the #define uncommented in the cpp file. This is set in the constructor. More...
QString	fingerprinting_algorithm_version_
	current version of the fingerprinting algorithm. This is set in the constructor. More...

Detailed Description

This class handles the received audio buffers.

It computes the sample rate, converts the stereo stream to mono, and draws a fingerprint from the probed audio data.

Constructor & Destructor Documentation

AdoreStreamer::AdoreStreamer

(

)

AdoreStreamer::~AdoreStreamer

(

)

Member Function Documentation

QString AdoreStreamer::ChromaPrint ( short *  data, int  size  )

private

Creates a ChromaPrint audio fingerprint as used by MusicBrainz. The parameter size holds the number of shorts in data.

void AdoreStreamer::ConsumeBuffer	(	GstBuffer *	buffer,
		int	pipeline_id
	)

Callback for receiving audio buffers. This member function collects audio data for MINIMUM_PROBING_DURATION seconds after StartProbing() was initiated, then GetFingerprint() is being called.

See Also

StartProbing()

SetEngine() for hooking

~AdoreStreamer() for unhooking

QString AdoreStreamer::EchoPrint ( short *  data, int  size  )

private

Creates a EchoPrint audio fingerprint as used by EchoNest/last.fm. The parameter size holds the number of shorts in data. Note that the short int samples in the mono buffer have to be converted to floats before passing to the fingerprinting algorithm.

void AdoreStreamer::GetFingerprint ( QString &  fingerprint )

private

After enough audio data has been collected in buffer_ a fingerprint is being created from a mono downmix. Currently, EchoPrint and ChromaPrint are implemented. Just uncomment the corresponding #define at the start of the cpp file.

See Also

ChromaPrint()

EchoPrint()

QString& AdoreStreamer::GetFingerprintingAlgorithm ( )

inline

public read-only access to the private fingerprinting_algorithm_ member variable.

QString& AdoreStreamer::GetFingerprintingAlgorithmVersion ( )

inline

public read-only access to the private fingerprinting_algorithm_version_ member variable.

QString& AdoreStreamer::GetLastFingerprint ( )

inline

public read-only access to the private fingerprint_ member variable.

void AdoreStreamer::MonoMix ( const short *  source_buffer, int  source_numsamples, int  source_numberofchannels, int  source_samplingrate, short *  target_buffer, int  target_buffer_size  )

private

This private member is called by GetFingerprint() and creates a mono mix from stereo or multichannel audio data. Note: target_buffer has to be source_numsamples / source_numberofchannels in size

void AdoreStreamer::ResetLastFingerprint ( )

inline

erases a previously created fingerprint.

See Also

GetLastFingerprint()

void AdoreStreamer::SetEngine

(

GstEngine *

engine

)

Pass the GStreamer Engine object to the class and get a BufferConsumer hook.

void AdoreStreamer::StartProbing

(

)

tell ConsumeBuffer() to start collecting audio buffers for later fingerprinting

void AdoreStreamer::StopProbing

(

)

stops collecting buffers and erases existing audio data from the fingerprinting buffer

Member Data Documentation

QBuffer AdoreStreamer::buffer_

private

fingerprinting buffer to collect audio buffers for some seconds before creating a fingerprint

GstEngine* AdoreStreamer::engine_

private

the GStreamer engine object, necessary to peek into the audio stream

QString AdoreStreamer::fingerprint_

private

ascii (base64) representation of the result created by GetFingerprint().

See Also

GetFingerprint()

GetLastFingerprint()

QString AdoreStreamer::fingerprinting_algorithm_

private

either 'echoprint' or 'chromapint', depending on the #define uncommented in the cpp file. This is set in the constructor.

See Also

GetFingerprintingAlgorithm()

QString AdoreStreamer::fingerprinting_algorithm_version_

private

current version of the fingerprinting algorithm. This is set in the constructor.

See Also

GetFingerprintingAlgorithmVersion()

bool AdoreStreamer::probing_

private

controls the collection.

See Also

StartProbing()

StopProbing()

QTime AdoreStreamer::probing_start_time

private

used to measure when MINIMUM_PROBING_DURATION has been reached and then create a fingerprint

int AdoreStreamer::samplerate_

private

computed in ConsumeBuffer() and stored to determine whether the rate has changed and the audio buffer collection needs a restart.

See Also

ConsumeBuffer()

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

• /home/tm/Code/Clementine/src/internet/adore/adorestreamer.h
• /home/tm/Code/Clementine/src/internet/adore/adorestreamer.cpp