////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2017 Laurent Gomila (laurent@sfml-dev.org)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
// you must not claim that you wrote the original software.
// If you use this software in a product, an acknowledgment
// in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
// and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
////////////////////////////////////////////////////////////
#ifndef SFML_SOUNDSTREAM_HPP
#define SFML_SOUNDSTREAM_HPP
////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Audio/Export.hpp>
#include <SFML/Audio/SoundSource.hpp>
#include <SFML/System/Thread.hpp>
#include <SFML/System/Time.hpp>
#include <SFML/System/Mutex.hpp>
#include <cstdlib>
namespace sf
{
////////////////////////////////////////////////////////////
/// \brief Abstract base class for streamed audio sources
///
////////////////////////////////////////////////////////////
class SFML_AUDIO_API SoundStream : public SoundSource
{
public:
////////////////////////////////////////////////////////////
/// \brief Structure defining a chunk of audio data to stream
///
////////////////////////////////////////////////////////////
struct Chunk
{
const Int16* samples; ///< Pointer to the audio samples
std::size_t sampleCount; ///< Number of samples pointed by Samples
};
////////////////////////////////////////////////////////////
/// \brief Destructor
///
////////////////////////////////////////////////////////////
virtual ~SoundStream();
////////////////////////////////////////////////////////////
/// \brief Start or resume playing the audio stream
///
/// This function starts the stream if it was stopped, resumes
/// it if it was paused, and restarts it from the beginning if
/// it was already playing.
/// This function uses its own thread so that it doesn't block
/// the rest of the program while the stream is played.
///
/// \see pause, stop
///
////////////////////////////////////////////////////////////
void play();
////////////////////////////////////////////////////////////
/// \brief Pause the audio stream
///
/// This function pauses the stream if it was playing,
/// otherwise (stream already paused or stopped) it has no effect.
///
/// \see play, stop
///
////////////////////////////////////////////////////////////
void pause();
////////////////////////////////////////////////////////////
/// \brief Stop playing the audio stream
///
/// This function stops the stream if it was playing or paused,
/// and does nothing if it was already stopped.
/// It also resets the playing position (unlike pause()).
///
/// \see play, pause
///
////////////////////////////////////////////////////////////
void stop();
////////////////////////////////////////////////////////////
/// \brief Return the number of channels of the stream
///
/// 1 channel means a mono sound, 2 means stereo, etc.
///
/// \return Number of channels
///
////////////////////////////////////////////////////////////
unsigned int getChannelCount() const;
////////////////////////////////////////////////////////////
/// \brief Get the stream sample rate of the stream
///
/// The sample rate is the number of audio samples played per
/// second. The higher, the better the quality.
///
/// \return Sample rate, in number of samples per second
///
////////////////////////////////////////////////////////////
unsigned int getSampleRate() const;
////////////////////////////////////////////////////////////
/// \brief Get the current status of the stream (stopped, paused, playing)
///
/// \return Current status
///
////////////////////////////////////////////////////////////
Status getStatus() const;
////////////////////////////////////////////////////////////
/// \brief Change the current playing position of the stream
///
/// The playing position can be changed when the stream is
/// either paused or playing. Changing the playing position
/// when the stream is stopped has no effect, since playing
/// the stream would reset its position.
///
/// \param timeOffset New playing position, from the beginning of the stream
///
/// \see getPlayingOffset
///
////////////////////////////////////////////////////////////
void setPlayingOffset(Time timeOffset);
////////////////////////////////////////////////////////////
/// \brief Get the current playing position of the stream
///
/// \return Current playing position, from the beginning of the stream
///
/// \see setPlayingOffset
///
////////////////////////////////////////////////////////////
Time getPlayingOffset() const;
////////////////////////////////////////////////////////////
/// \brief Set whether or not the stream should loop after reaching the end
///
/// If set, the stream will restart from beginning after
/// reaching the end and so on, until it is stopped or
/// setLoop(false) is called.
/// The default looping state for streams is false.
///
/// \param loop True to play in loop, false to play once
///
/// \see getLoop
///
////////////////////////////////////////////////////////////
void setLoop(bool loop);
////////////////////////////////////////////////////////////
/// \brief Tell whether or not the stream is in loop mode
///
/// \return True if the stream is looping, false otherwise
///
/// \see setLoop
///
////////////////////////////////////////////////////////////
bool getLoop() const;
protected:
////////////////////////////////////////////////////////////
/// \brief Default constructor
///
/// This constructor is only meant to be called by derived classes.
///
////////////////////////////////////////////////////////////
SoundStream();
////////////////////////////////////////////////////////////
/// \brief Define the audio stream parameters
///
/// This function must be called by derived classes as soon
/// as they know the audio settings of the stream to play.
/// Any attempt to manipulate the stream (play(), ...) before
/// calling this function will fail.
/// It can be called multiple times if the settings of the
/// audio stream change, but only when the stream is stopped.
///
/// \param channelCount Number of channels of the stream
/// \param sampleRate Sample rate, in samples per second
///
////////////////////////////////////////////////////////////
void initialize(unsigned int channelCount, unsigned int sampleRate);
////////////////////////////////////////////////////////////
/// \brief Request a new chunk of audio samples from the stream source
///
/// This function must be overridden by derived classes to provide
/// the audio samples to play. It is called continuously by the
/// streaming loop, in a separate thread.
/// The source can choose to stop the streaming loop at any time, by
/// returning false to the caller.
/// If you return true (i.e. continue streaming) it is important that
/// the returned array of samples is not empty; this would stop the stream
/// due to an internal limitation.
///
/// \param data Chunk of data to fill
///
/// \return True to continue playback, false to stop
///
////////////////////////////////////////////////////////////
virtual bool onGetData(Chunk& data) = 0;
////////////////////////////////////////////////////////////
/// \brief Change the current playing position in the stream source
///
/// This function must be overridden by derived classes to
/// allow random seeking into the stream source.
///
/// \param timeOffset New playing position, relative to the beginning of the stream
///
////////////////////////////////////////////////////////////
virtual void onSeek(Time timeOffset) = 0;
private:
////////////////////////////////////////////////////////////
/// \brief Function called as the entry point of the thread
///
/// This function starts the streaming loop, and returns
/// only when the sound is stopped.
///
////////////////////////////////////////////////////////////
void streamData();
////////////////////////////////////////////////////////////
/// \brief Fill a new buffer with audio samples, and append
/// it to the playing queue
///
/// This function is called as soon as a buffer has been fully
/// consumed; it fills it again and inserts it back into the
/// playing queue.
///
/// \param bufferNum Number of the buffer to fill (in [0, BufferCount])
///
/// \return True if the stream source has requested to stop, false otherwise
///
////////////////////////////////////////////////////////////
bool fillAndPushBuffer(unsigned int bufferNum);
////////////////////////////////////////////////////////////
/// \brief Fill the audio buffers and put them all into the playing queue
///
/// This function is called when playing starts and the
/// playing queue is empty.
///
/// \return True if the derived class has requested to stop, false otherwise
///
////////////////////////////////////////////////////////////
bool fillQueue();
////////////////////////////////////////////////////////////
/// \brief Clear all the audio buffers and empty the playing queue
///
/// This function is called when the stream is stopped.
///
////////////////////////////////////////////////////////////
void clearQueue();
enum
{
BufferCount = 3 ///< Number of audio buffers used by the streaming loop
};
////////////////////////////////////////////////////////////
// Member data
////////////////////////////////////////////////////////////
Thread m_thread; ///< Thread running the background tasks
mutable Mutex m_threadMutex; ///< Thread mutex
Status m_threadStartState; ///< State the thread starts in (Playing, Paused, Stopped)
bool m_isStreaming; ///< Streaming state (true = playing, false = stopped)
unsigned int m_buffers[BufferCount]; ///< Sound buffers used to store temporary audio data
unsigned int m_channelCount; ///< Number of channels (1 = mono, 2 = stereo, ...)
unsigned int m_sampleRate; ///< Frequency (samples / second)
Uint32 m_format; ///< Format of the internal sound buffers
bool m_loop; ///< Loop flag (true to loop, false to play once)
Uint64 m_samplesProcessed; ///< Number of buffers processed since beginning of the stream
bool m_endBuffers[BufferCount]; ///< Each buffer is marked as "end buffer" or not, for proper duration calculation
};
} // namespace sf
#endif // SFML_SOUNDSTREAM_HPP
////////////////////////////////////////////////////////////
/// \class sf::SoundStream
/// \ingroup audio
///
/// Unlike audio buffers (see sf::SoundBuffer), audio streams
/// are never completely loaded in memory. Instead, the audio
/// data is acquired continuously while the stream is playing.
/// This behavior allows to play a sound with no loading delay,
/// and keeps the memory consumption very low.
///
/// Sound sources that need to be streamed are usually big files
/// (compressed audio musics that would eat hundreds of MB in memory)
/// or files that would take a lot of time to be received
/// (sounds played over the network).
///
/// sf::SoundStream is a base class that doesn't care about the
/// stream source, which is left to the derived class. SFML provides
/// a built-in specialization for big files (see sf::Music).
/// No network stream source is provided, but you can write your own
/// by combining this class with the network module.
///
/// A derived class has to override two virtual functions:
/// \li onGetData fills a new chunk of audio data to be played
/// \li onSeek changes the current playing position in the source
///
/// It is important to note that each SoundStream is played in its
/// own separate thread, so that the streaming loop doesn't block the
/// rest of the program. In particular, the OnGetData and OnSeek
/// virtual functions may sometimes be called from this separate thread.
/// It is important to keep this in mind, because you may have to take
/// care of synchronization issues if you share data between threads.
///
/// Usage example:
/// \code
/// class CustomStream : public sf::SoundStream
/// {
/// public:
///
/// bool open(const std::string& location)
/// {
/// // Open the source and get audio settings
/// ...
/// unsigned int channelCount = ...;
/// unsigned int sampleRate = ...;
///
/// // Initialize the stream -- important!
/// initialize(channelCount, sampleRate);
/// }
///
/// private:
///
/// virtual bool onGetData(Chunk& data)
/// {
/// // Fill the chunk with audio data from the stream source
/// // (note: must not be empty if you want to continue playing)
/// data.samples = ...;
/// data.sampleCount = ...;
///
/// // Return true to continue playing
/// return true;
/// }
///
/// virtual void onSeek(Uint32 timeOffset)
/// {
/// // Change the current position in the stream source
/// ...
/// }
/// }
///
/// // Usage
/// CustomStream stream;
/// stream.open("path/to/stream");
/// stream.play();
/// \endcode
///
/// \see sf::Music
///
////////////////////////////////////////////////////////////