/* 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. * */ #ifndef SOUND_AUDIOSTREAM_H #define SOUND_AUDIOSTREAM_H #include "common/ptr.h" #include "common/scummsys.h" #include "common/str.h" #include "common/types.h" #include "audio/timestamp.h" namespace Audio { /** * 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); 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: Common::DisposablePtr<RewindableAudioStream> _parent; 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); 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: Common::DisposablePtr<SeekableAudioStream> _parent; 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); 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: Common::DisposablePtr<SeekableAudioStream> _parent; 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