engines/common/Stream.h

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 - 2009 Christian Schoenebeck                       *
 *   Copyright (C) 2009 Grigor Iliev                                       *
 *                                                                         *
 *   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., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#ifndef __LS_STREAM_H__
#define __LS_STREAM_H__

#include "../../common/global.h"
#include "../../common/RingBuffer.h"
#include "Sample.h"

namespace LinuxSampler {

    /** @brief Buffered Disk Stream
     *
     * This encapsulation of a disk stream uses a ring buffer to allow
     * thread safe refilling the stream's buffer with one thread (disk
     * thread) and actual use / extraction of the audio data from the
     * stream's buffer with another thread (audio thread).
     */
    class Stream {
        public:
            // Member Types
            typedef uint32_t OrderID_t;
            typedef uint32_t Handle; ///< unique identifier of a relationship between one stream and a consumer (Voice)
            enum { INVALID_HANDLE = 0 };
            enum state_t {           ///< streams go through severe cyclic state transition (unused->active->end->unused->...)
                state_unused,        ///< stream is not in use, thus can still be launched
                state_active,        ///< stream provides data in it's buffer to be read and hasn't reached the end yet (this is the usual case)
                state_end            ///< stream end reached but still providing data in it's buffer to be read (after the client read all remaining data from the stream buffer, state will change automatically to state_unused)
            };
            struct reference_t {     ///< Defines the current relationship between the stream and a client (voice).
                OrderID_t  OrderID;   ///< Unique identifier that identifies the creation order of a stream requested by a voice.
                Handle     hStream;   ///< Unique identifier of the relationship between stream and client.
                state_t    State;     ///< Current state of the stream that will be pretended to the client (the actual state of the stream might differ though, because the stream might already be in use by another client).
                Stream*    pStream;   ///< Points to the assigned and activated stream or is NULL if the disk thread hasn't launched a stream yet.
            };

            class SampleDescription {
                public:
                    int FrameSize;         ///< Reflects the size (in bytes) of one single sample point
                    int ChannelsPerFrame;
                    int BytesPerSample;    ///< Size of each sample per channel
                    int TotalSampleCount;
            };

            Stream(uint BufferSize, uint BufferWrapElements) {
                this->pExportReference       = NULL;
                this->State                  = state_unused;
                this->hThis                  = 0;
                this->PlaybackState.position = 0;
                this->PlaybackState.reverse  = false;
                this->pRingBuffer            = new RingBuffer<uint8_t,false>(BufferSize * 3, BufferWrapElements * 3);
                UnusedStreams++;
                TotalStreams++;
            }

            virtual ~Stream() { }

            // Methods
            inline int GetReadSpace() {
                return (pRingBuffer && State != state_unused) ? pRingBuffer->read_space() / SampleInfo.BytesPerSample : 0;
            }

            inline int GetWriteSpace() {
                return (pRingBuffer && State == state_active) ? pRingBuffer->write_space() / SampleInfo.BytesPerSample : 0;
            }

            inline int GetWriteSpaceToEnd() {
                return (pRingBuffer && State == state_active) ? pRingBuffer->write_space_to_end_with_wrap() / SampleInfo.BytesPerSample : 0;
            }

            // adjusts the write space to avoid buffer boundaries which would lead to the wrap space
            // within the buffer (needed for interpolation) getting filled only partially
            // for more infos see the docs in ringbuffer.h at adjust_write_space_to_avoid_boundary()
            inline int AdjustWriteSpaceToAvoidBoundary(int cnt, int capped_cnt) {
              return pRingBuffer->adjust_write_space_to_avoid_boundary (cnt * SampleInfo.BytesPerSample, capped_cnt * SampleInfo.BytesPerSample) / SampleInfo.BytesPerSample;
            }

            // gets the current read_ptr within the ringbuffer
            inline uint8_t* GetReadPtr(void) {
                return pRingBuffer->get_read_ptr();
            }

            inline void IncrementReadPos(uint Count)  {
                Count *= SampleInfo.BytesPerSample;
                uint leftspace = pRingBuffer->read_space();
                pRingBuffer->increment_read_ptr(Min(Count, leftspace));
                if (State == state_end && Count >= leftspace) {
                    Reset(); // quit relation between consumer (voice) and stream and reset stream right after
                }
            }

            virtual int  ReadAhead(unsigned long SampleCount) = 0;
            virtual void WriteSilence(unsigned long SilenceSampleWords) = 0;

            // Static Method
            inline static uint       GetUnusedStreams() { return UnusedStreams; }

            template<class R, class IM> friend class DiskThreadBase; // only the disk thread should be able to launch and most important kill a disk stream to avoid race conditions

        protected:
            // Attributes
            RingBuffer<uint8_t,false>*  pRingBuffer;
            SampleDescription           SampleInfo;
            Sample::PlaybackState       PlaybackState;
            reference_t*                pExportReference;
            state_t                     State;
            Handle                      hThis;

            // Static Attributes
            static uint UnusedStreams; //< Reflects how many stream objects of all stream instances are currently not in use.
            static uint TotalStreams; //< Reflects how many stream objects currently exist.

            // Methods

            virtual void   Kill()      { pExportReference = NULL; Reset(); } ///< Will be called by disk thread after a 'deletion' command from the audio thread (within the voice class)
            inline Handle  GetHandle() { return hThis; }
            inline state_t GetState()  { return State; }

            inline void SetState(state_t State) {
                if (pExportReference) pExportReference->State = State;
                this->State = State;
            }

            virtual long Read(uint8_t* pBuf, long SamplesToRead) = 0;
            virtual void Reset() = 0;

        private:

            // Methods
            inline long Min(long a, long b) { return (a < b) ? a : b; }
    };
} // namespace LinuxSampler

#endif // __LS_STREAM_H__
1	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	* Copyright (C) 2005 - 2009 Christian Schoenebeck *
7	* Copyright (C) 2009 Grigor Iliev *
8	* *
9	* This program is free software; you can redistribute it and/or modify *
10	* it under the terms of the GNU General Public License as published by *
11	* the Free Software Foundation; either version 2 of the License, or *
12	* (at your option) any later version. *
13	* *
14	* This program is distributed in the hope that it will be useful, *
15	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
17	* GNU General Public License for more details. *
18	* *
19	* You should have received a copy of the GNU General Public License *
20	* along with this program; if not, write to the Free Software *
21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
22	* MA 02111-1307 USA *
23	***************************************************************************/
24
25	#ifndef __LS_STREAM_H__
26	#define __LS_STREAM_H__
27
28	#include "../../common/global.h"
29	#include "../../common/RingBuffer.h"
30	#include "Sample.h"
31
32	namespace LinuxSampler {
33
34	/** @brief Buffered Disk Stream
35	*
36	* This encapsulation of a disk stream uses a ring buffer to allow
37	* thread safe refilling the stream's buffer with one thread (disk
38	* thread) and actual use / extraction of the audio data from the
39	* stream's buffer with another thread (audio thread).
40	*/
41	class Stream {
42	public:
43	// Member Types
44	typedef uint32_t OrderID_t;
45	typedef uint32_t Handle; ///< unique identifier of a relationship between one stream and a consumer (Voice)
46	enum { INVALID_HANDLE = 0 };
47	enum state_t { ///< streams go through severe cyclic state transition (unused->active->end->unused->...)
48	state_unused, ///< stream is not in use, thus can still be launched
49	state_active, ///< stream provides data in it's buffer to be read and hasn't reached the end yet (this is the usual case)
50	state_end ///< stream end reached but still providing data in it's buffer to be read (after the client read all remaining data from the stream buffer, state will change automatically to state_unused)
51	};
52	struct reference_t { ///< Defines the current relationship between the stream and a client (voice).
53	OrderID_t OrderID; ///< Unique identifier that identifies the creation order of a stream requested by a voice.
54	Handle hStream; ///< Unique identifier of the relationship between stream and client.
55	state_t State; ///< Current state of the stream that will be pretended to the client (the actual state of the stream might differ though, because the stream might already be in use by another client).
56	Stream* pStream; ///< Points to the assigned and activated stream or is NULL if the disk thread hasn't launched a stream yet.
57	};
58
59	class SampleDescription {
60	public:
61	int FrameSize; ///< Reflects the size (in bytes) of one single sample point
62	int ChannelsPerFrame;
63	int BytesPerSample; ///< Size of each sample per channel
64	int TotalSampleCount;
65	};
66
67	Stream(uint BufferSize, uint BufferWrapElements) {
68	this->pExportReference = NULL;
69	this->State = state_unused;
70	this->hThis = 0;
71	this->PlaybackState.position = 0;
72	this->PlaybackState.reverse = false;
73	this->pRingBuffer = new RingBuffer<uint8_t,false>(BufferSize * 3, BufferWrapElements * 3);
74	UnusedStreams++;
75	TotalStreams++;
76	}
77
78	virtual ~Stream() { }
79
80	// Methods
81	inline int GetReadSpace() {
82	return (pRingBuffer && State != state_unused) ? pRingBuffer->read_space() / SampleInfo.BytesPerSample : 0;
83	}
84
85	inline int GetWriteSpace() {
86	return (pRingBuffer && State == state_active) ? pRingBuffer->write_space() / SampleInfo.BytesPerSample : 0;
87	}
88
89	inline int GetWriteSpaceToEnd() {
90	return (pRingBuffer && State == state_active) ? pRingBuffer->write_space_to_end_with_wrap() / SampleInfo.BytesPerSample : 0;
91	}
92
93	// adjusts the write space to avoid buffer boundaries which would lead to the wrap space
94	// within the buffer (needed for interpolation) getting filled only partially
95	// for more infos see the docs in ringbuffer.h at adjust_write_space_to_avoid_boundary()
96	inline int AdjustWriteSpaceToAvoidBoundary(int cnt, int capped_cnt) {
97	return pRingBuffer->adjust_write_space_to_avoid_boundary (cnt * SampleInfo.BytesPerSample, capped_cnt * SampleInfo.BytesPerSample) / SampleInfo.BytesPerSample;
98	}
99
100	// gets the current read_ptr within the ringbuffer
101	inline uint8_t* GetReadPtr(void) {
102	return pRingBuffer->get_read_ptr();
103	}
104
105	inline void IncrementReadPos(uint Count) {
106	Count *= SampleInfo.BytesPerSample;
107	uint leftspace = pRingBuffer->read_space();
108	pRingBuffer->increment_read_ptr(Min(Count, leftspace));
109	if (State == state_end && Count >= leftspace) {
110	Reset(); // quit relation between consumer (voice) and stream and reset stream right after
111	}
112	}
113
114	virtual int ReadAhead(unsigned long SampleCount) = 0;
115	virtual void WriteSilence(unsigned long SilenceSampleWords) = 0;
116
117	// Static Method
118	inline static uint GetUnusedStreams() { return UnusedStreams; }
119
120	template<class R, class IM> friend class DiskThreadBase; // only the disk thread should be able to launch and most important kill a disk stream to avoid race conditions
121
122	protected:
123	// Attributes
124	RingBuffer<uint8_t,false>* pRingBuffer;
125	SampleDescription SampleInfo;
126	Sample::PlaybackState PlaybackState;
127	reference_t* pExportReference;
128	state_t State;
129	Handle hThis;
130
131	// Static Attributes
132	static uint UnusedStreams; //< Reflects how many stream objects of all stream instances are currently not in use.
133	static uint TotalStreams; //< Reflects how many stream objects currently exist.
134
135	// Methods
136
137	virtual void Kill() { pExportReference = NULL; Reset(); } ///< Will be called by disk thread after a 'deletion' command from the audio thread (within the voice class)
138	inline Handle GetHandle() { return hThis; }
139	inline state_t GetState() { return State; }
140
141	inline void SetState(state_t State) {
142	if (pExportReference) pExportReference->State = State;
143	this->State = State;
144	}
145
146	virtual long Read(uint8_t* pBuf, long SamplesToRead) = 0;
147	virtual void Reset() = 0;
148
149	private:
150
151	// Methods
152	inline long Min(long a, long b) { return (a < b) ? a : b; }
153	};
154	} // namespace LinuxSampler
155
156	#endif // __LS_STREAM_H__