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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL: https://scummvm.svn.sourceforge.net/svnroot/scummvm/scummvm/trunk/sound/audiostream.h $
* $Id: audiostream.h 54098 2010-11-05 15:38:31Z lordhoto $
*
*/
#ifndef SOUND_AUDIOSTREAM_H
#define SOUND_AUDIOSTREAM_H
#include "common/util.h"
#include "common/scummsys.h"
#include "common/types.h"
#include "sound/timestamp.h"
namespace Audio {
class SeekableAudioStream;
/**
* Generic audio input stream. Subclasses of this are used to feed arbitrary
* sampled audio data into ScummVM's audio mixer.
*/
class AudioStream {
public:
virtual ~AudioStream() {}
/**
* Fill the given buffer with up to numSamples samples. Returns the actual
* number of samples read, or -1 if a critical error occurred (note: you
* *must* check if this value is less than what you requested, this can
* happen when the stream is fully used up).
*
* Data has to be in native endianess, 16 bit per sample, signed. For stereo
* stream, buffer will be filled with interleaved left and right channel
* samples, starting with a left sample. Furthermore, the samples in the
* left and right are summed up. So if you request 4 samples from a stereo
* stream, you will get a total of two left channel and two right channel
* samples.
*/
virtual int readBuffer(int16 *buffer, const int numSamples) = 0;
/** Is this a stereo stream? */
virtual bool isStereo() const = 0;
/** Sample rate of the stream. */
virtual int getRate() const = 0;
/**
* End of data reached? If this returns true, it means that at this
* time there is no data available in the stream. However there may be
* more data in the future.
* This is used by e.g. a rate converter to decide whether to keep on
* converting data or stop.
*/
virtual bool endOfData() const = 0;
/**
* End of stream reached? If this returns true, it means that all data
* in this stream is used up and no additional data will appear in it
* in the future.
* This is used by the mixer to decide whether a given stream shall be
* removed from the list of active streams (and thus be destroyed).
* By default this maps to endOfData()
*/
virtual bool endOfStream() const { return endOfData(); }
};
/**
* A rewindable audio stream. This allows for reseting the AudioStream
* to its initial state. Note that rewinding itself is not required to
* be working when the stream is being played by Mixer!
*/
class RewindableAudioStream : public AudioStream {
public:
/**
* Rewinds the stream to its start.
*
* @return true on success, false otherwise.
*/
virtual bool rewind() = 0;
};
/**
* A looping audio stream. This object does nothing besides using
* a RewindableAudioStream to play a stream in a loop.
*/
class LoopingAudioStream : public AudioStream {
public:
/**
* Creates a looping audio stream object.
*
* Note that on creation of the LoopingAudioStream object
* the underlying stream will be rewound.
*
* @see makeLoopingAudioStream
*
* @param stream Stream to loop
* @param loops How often to loop (0 = infinite)
* @param disposeAfterUse Destroy the stream after the LoopingAudioStream has finished playback.
*/
LoopingAudioStream(RewindableAudioStream *stream, uint loops, DisposeAfterUse::Flag disposeAfterUse = DisposeAfterUse::YES);
~LoopingAudioStream();
int readBuffer(int16 *buffer, const int numSamples);
bool endOfData() const;
bool isStereo() const { return _parent->isStereo(); }
int getRate() const { return _parent->getRate(); }
/**
* Returns number of loops the stream has played.
*
* @param numLoops number of loops to play, 0 - infinite
*/
uint getCompleteIterations() const { return _completeIterations; }
private:
RewindableAudioStream *_parent;
DisposeAfterUse::Flag _disposeAfterUse;
uint _loops;
uint _completeIterations;
};
/**
* Wrapper functionality to efficiently create a stream, which might be looped.
*
* Note that this function does not return a LoopingAudioStream, because it does
* not create one when the loop count is "1". This allows to keep the runtime
* overhead down, when the code does not require any functionality only offered
* by LoopingAudioStream.
*
* @param stream Stream to loop (will be automatically destroyed, when the looping is done)
* @param loops How often to loop (0 = infinite)
* @return A new AudioStream, which offers the desired functionality.
*/
AudioStream *makeLoopingAudioStream(RewindableAudioStream *stream, uint loops);
/**
* A seekable audio stream. Subclasses of this class implement an
* interface for seeking. The seeking itself is not required to be
* working while the stream is being played by Mixer!
*/
class SeekableAudioStream : public RewindableAudioStream {
public:
/**
* Tries to load a file by trying all available formats.
* In case of an error, the file handle will be closed, but deleting
* it is still the responsibility of the caller.
*
* @param basename a filename without an extension
* @return an SeekableAudioStream ready to use in case of success;
* NULL in case of an error (e.g. invalid/nonexisting file)
*/
static SeekableAudioStream *openStreamFile(const Common::String &basename);
/**
* Seeks to a given offset in the stream.
*
* @param where offset in milliseconds
* @return true on success, false on failure.
*/
bool seek(uint32 where) {
return seek(Timestamp(where, getRate()));
}
/**
* Seeks to a given offset in the stream.
*
* @param where offset as timestamp
* @return true on success, false on failure.
*/
virtual bool seek(const Timestamp &where) = 0;
/**
* Returns the length of the stream.
*
* @return length as Timestamp.
*/
virtual Timestamp getLength() const = 0;
virtual bool rewind() { return seek(0); }
};
/**
* Wrapper functionality to efficiently create a stream, which might be looped
* in a certain interval.
*
* This automatically starts the stream at time "start"!
*
* Note that this function does not return a LoopingAudioStream, because it does
* not create one when the loop count is "1". This allows to keep the runtime
* overhead down, when the code does not require any functionality only offered
* by LoopingAudioStream.
*
* @param stream Stream to loop (will be automatically destroyed, when the looping is done)
* @param start Starttime of the stream interval to be looped
* @param end End of the stream interval to be looped (a zero time, means till end)
* @param loops How often to loop (0 = infinite)
* @return A new AudioStream, which offers the desired functionality.
*/
AudioStream *makeLoopingAudioStream(SeekableAudioStream *stream, Timestamp start, Timestamp end, uint loops);
/**
* A looping audio stream, which features looping of a nested part of the
* stream.
*
* NOTE:
* Currently this implementation stops after the nested loop finished
* playback.
*
* IMPORTANT:
* This might be merged with SubSeekableAudioStream for playback purposes.
* (After extending it to accept a start time).
*/
class SubLoopingAudioStream : public AudioStream {
public:
/**
* Constructor for a SubLoopingAudioStream.
*
* Note that on creation of the SubLoopingAudioStream object
* the underlying stream will be rewound.
*
* @param stream Stream to loop
* @param loops How often the stream should be looped (0 means infinite)
* @param loopStart Start of the loop (this must be smaller than loopEnd)
* @param loopEnd End of the loop (thus must be greater than loopStart)
* @param disposeAfterUse Whether the stream should be disposed, when the
* SubLoopingAudioStream is destroyed.
*/
SubLoopingAudioStream(SeekableAudioStream *stream, uint loops,
const Timestamp loopStart,
const Timestamp loopEnd,
DisposeAfterUse::Flag disposeAfterUse = DisposeAfterUse::YES);
~SubLoopingAudioStream();
int readBuffer(int16 *buffer, const int numSamples);
bool endOfData() const { return _done; }
bool isStereo() const { return _parent->isStereo(); }
int getRate() const { return _parent->getRate(); }
private:
SeekableAudioStream *_parent;
DisposeAfterUse::Flag _disposeAfterUse;
uint _loops;
Timestamp _pos;
Timestamp _loopStart, _loopEnd;
bool _done;
};
/**
* A SubSeekableAudioStream provides access to a SeekableAudioStream
* just in the range [start, end).
* The same caveats apply to SubSeekableAudioStream as do to SeekableAudioStream.
*
* Manipulating the parent stream directly /will/ mess up a substream.
*/
class SubSeekableAudioStream : public SeekableAudioStream {
public:
/**
* Creates a new SubSeekableAudioStream.
*
* @param parent parent stream object.
* @param start Start time.
* @param end End time.
* @param disposeAfterUse Whether the parent stream object should be destroyed on destruction of the SubSeekableAudioStream.
*/
SubSeekableAudioStream(SeekableAudioStream *parent, const Timestamp start, const Timestamp end, DisposeAfterUse::Flag disposeAfterUse = DisposeAfterUse::YES);
~SubSeekableAudioStream();
int readBuffer(int16 *buffer, const int numSamples);
bool isStereo() const { return _parent->isStereo(); }
int getRate() const { return _parent->getRate(); }
bool endOfData() const { return (_pos >= _length) || _parent->endOfStream(); }
bool seek(const Timestamp &where);
Timestamp getLength() const { return _length; }
private:
SeekableAudioStream *_parent;
DisposeAfterUse::Flag _disposeAfterUse;
const Timestamp _start;
const Timestamp _length;
Timestamp _pos;
};
class QueuingAudioStream : public Audio::AudioStream {
public:
/**
* Queue an audio stream for playback. This stream plays all queued
* streams, in the order they were queued. If disposeAfterUse is set to
* DisposeAfterUse::YES, then the queued stream is deleted after all data
* contained in it has been played.
*/
virtual void queueAudioStream(Audio::AudioStream *audStream,
DisposeAfterUse::Flag disposeAfterUse = DisposeAfterUse::YES) = 0;
/**
* Queue a block of raw audio data for playback. This stream plays all
* queued block, in the order they were queued. If disposeAfterUse is set
* to DisposeAfterUse::YES, then the queued block is released using free()
* after all data contained in it has been played.
*
* @note Make sure to allocate the data block with malloc(), not with new[].
*
* @param data pointer to the audio data block
* @param size length of the audio data block
* @param disposeAfterUse if equal to DisposeAfterUse::YES, the block is released using free() after use.
* @param flags a bit-ORed combination of RawFlags describing the audio data format
*/
void queueBuffer(byte *data, uint32 size, DisposeAfterUse::Flag disposeAfterUse, byte flags);
/**
* Mark this stream as finished. That is, signal that no further data
* will be queued to it. Only after this has been done can this
* stream ever 'end'.
*/
virtual void finish() = 0;
/**
* Return the number of streams still queued for playback (including
* the currently playing stream).
*/
virtual uint32 numQueuedStreams() const = 0;
};
/**
* Factory function for an QueuingAudioStream.
*/
QueuingAudioStream *makeQueuingAudioStream(int rate, bool stereo);
/**
* Converts a point in time to a precise sample offset
* with the given parameters.
*
* @param where Point in time.
* @param rate Rate of the stream.
* @param isStereo Is the stream a stereo stream?
*/
Timestamp convertTimeToStreamPos(const Timestamp &where, int rate, bool isStereo);
} // End of namespace Audio
#endif
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