AudioDecoder Class Reference

The class for decoding compressed audio file to PCM buffer. More...

#include <AudioDecoder.h>

Inherited by AudioDecoderEXT, AudioDecoderMp3, AudioDecoderOgg, and AudioDecoderWav.

Public Member Functions
virtual bool	open (std::string_view path)=0
	Opens an audio file specified by a file path.
virtual bool	isOpened () const
	Checks whether decoder has opened file successfully.
virtual void	close ()=0
	Closes opened audio file.
virtual uint32_t	read (uint32_t framesToRead, char *pcmBuf)=0
	Reads audio frames of PCM format.
virtual uint32_t	readFixedFrames (uint32_t framesToRead, char *pcmBuf)
	Reads fixed audio frames of PCM format.
virtual bool	seek (uint32_t frameOffset)=0
	Sets frame offest to be read.
virtual uint32_t	getTotalFrames () const
	Gets total frames of current audio.
virtual uint32_t	framesToBytes (uint32_t frames) const
	The helper function for convert frames to bytes.
virtual uint32_t	bytesToFrames (uint32_t bytes) const
	The helper function for convert bytes to frames.
virtual uint32_t	getSampleRate () const
	Gets sample rate of current audio.
virtual uint32_t	getChannelCount () const
	Gets the channel count of current audio.

Detailed Description

The class for decoding compressed audio file to PCM buffer.

Member Function Documentation

open()

virtual bool open ( std::string_view path )

pure virtual

Opens an audio file specified by a file path.

Returns

true if succeed, otherwise false.

Implemented in AudioDecoderEXT, AudioDecoderMp3, AudioDecoderOgg, and AudioDecoderWav.

isOpened()

virtual bool isOpened ( ) const

virtual

Checks whether decoder has opened file successfully.

Returns

true if succeed, otherwise false.

close()

virtual void close ( )

pure virtual

Closes opened audio file.

Note

The method will also be automatically invoked in the destructor.

Implemented in AudioDecoderEXT, AudioDecoderMp3, AudioDecoderOgg, and AudioDecoderWav.

read()

virtual uint32_t read ( uint32_t framesToRead, char * pcmBuf )

pure virtual

Reads audio frames of PCM format.

Parameters

framesToRead	The number of frames excepted to be read.
pcmBuf	The buffer to hold the frames to be read, its size should be >= |framesToRead| / samplesPerBlock * _bytesPerBlock.

Returns

The number of frames actually read, it's probably less than 'framesToRead'. Returns 0 means reach the end of file.

Implemented in AudioDecoderEXT, AudioDecoderMp3, AudioDecoderOgg, and AudioDecoderWav.

readFixedFrames()

virtual uint32_t readFixedFrames ( uint32_t framesToRead, char * pcmBuf )

virtual

Reads fixed audio frames of PCM format.

Parameters

framesToRead	The number of frames excepted to be read.
pcmBuf	The buffer to hold the frames to be read, its size should be >= |framesToRead| / samplesPerBlock * _bytesPerBlock.

Returns

The number of frames actually read, it's probably less than |framesToRead|. Returns 0 means reach the end of file.

Note

The different between |read| and |readFixedFrames| is |readFixedFrames| will do multiple reading operations if |framesToRead| frames isn't filled entirely, while |read| just does reading operation once whatever |framesToRead| is or isn't filled entirely. If current position reaches the end of frames, the return value may smaller than |framesToRead| and the remaining buffer in |pcmBuf| will be set with silence data (0x00).

seek()

virtual bool seek ( uint32_t frameOffset )

pure virtual

Sets frame offest to be read.

Parameters

frameOffset

The frame offest to be set.

Returns

true if succeed, otherwise false

Implemented in AudioDecoderEXT, AudioDecoderMp3, AudioDecoderOgg, and AudioDecoderWav.

getChannelCount()

virtual uint32_t getChannelCount ( ) const

virtual

Gets the channel count of current audio.

Note

Currently we only support 1 or 2 channels.

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

• AudioDecoder.h