/[svn]/linuxsampler/trunk/src/engines/common/StreamBase.h
ViewVC logotype

Contents of /linuxsampler/trunk/src/engines/common/StreamBase.h

Parent Directory Parent Directory | Revision Log Revision Log


Revision 2012 - (show annotations) (download) (as text)
Fri Oct 23 17:53:17 2009 UTC (9 years, 7 months ago) by iliev
File MIME type: text/x-c++hdr
File size: 6101 byte(s)
* Refactoring: moved the independent code from
  the Gigasampler format engine to base classes
* SFZ format engine: experimental code (not usable yet)
* SoundFont format engine: experimental code (not usable yet)
* Fixed crash which may occur when MIDI key + transpose is out of range

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_STREAMBASE_H__
26 #define __LS_STREAMBASE_H__
27
28 #include "Stream.h"
29 #include "../../common/global.h"
30 #include "../../common/RingBuffer.h"
31 #include <iostream>
32
33 namespace LinuxSampler {
34
35 /** @brief Buffered Disk Stream
36 *
37 * This encapsulation of a disk stream uses a ring buffer to allow
38 * thread safe refilling the stream's buffer with one thread (disk
39 * thread) and actual use / extraction of the audio data from the
40 * stream's buffer with another thread (audio thread).
41 */
42 template <class R>
43 class StreamBase : public Stream {
44 public:
45 // Methods
46 StreamBase(uint BufferSize, uint BufferWrapElements) : Stream(BufferSize, BufferWrapElements) {
47 this->pRegion = NULL;
48 this->SampleOffset = 0;
49 }
50
51 virtual ~StreamBase() {
52 Reset();
53 if (pRingBuffer) delete pRingBuffer;
54 UnusedStreams--;
55 TotalStreams--;
56 }
57
58 /// Returns number of refilled sample points or a value < 0 on error.
59 virtual int ReadAhead(unsigned long SampleCount) {
60 if (this->State == state_unused) return -1;
61 if (this->State == state_end) return 0;
62 if (!SampleCount) return 0;
63 if (!pRingBuffer->write_space()) return 0;
64
65 long samplestoread = SampleCount / SampleInfo.ChannelsPerFrame;
66 uint8_t* pBuf = pRingBuffer->get_write_ptr();
67 long total_readsamples = Read(pBuf, samplestoread);
68
69 // we must delay the increment_write_ptr_with_wrap() after the while() loop because we need to
70 // ensure that we read exactly SampleCount sample, otherwise the buffer wrapping code will fail
71 pRingBuffer->increment_write_ptr_with_wrap(total_readsamples * SampleInfo.FrameSize);
72
73 return total_readsamples;
74 }
75
76 virtual void WriteSilence(unsigned long SilenceSampleWords) {
77 memset(pRingBuffer->get_write_ptr(), 0, SilenceSampleWords * SampleInfo.BytesPerSample);
78 pRingBuffer->increment_write_ptr_with_wrap(SilenceSampleWords * SampleInfo.BytesPerSample);
79 }
80
81 /// Called by disk thread to activate the disk stream.
82 void Launch (
83 Stream::Handle hStream,
84 reference_t* pExportReference,
85 R* pRgn,
86 SampleDescription SampleInfo,
87 Sample::PlaybackState PlaybackState,
88 unsigned long SampleOffset,
89 bool DoLoop
90 ) {
91 UnusedStreams--;
92 this->pExportReference = pExportReference;
93 this->hThis = hStream;
94 this->pRegion = pRgn;
95 this->SampleInfo = SampleInfo;
96 this->PlaybackState = PlaybackState;
97 this->SampleOffset = SampleOffset;
98 this->DoLoop = DoLoop;
99 SetState(state_active);
100 }
101
102 protected:
103 // Attributes
104 unsigned long SampleOffset;
105 R* pRegion;
106 bool DoLoop;
107
108 virtual void Reset() {
109 SampleOffset = 0;
110 pRegion = NULL;
111 PlaybackState.position = 0;
112 PlaybackState.reverse = false;
113 hThis = 0;
114 pRingBuffer->init(); // reset ringbuffer
115 if (State != state_unused) {
116 // we can't do 'SetPos(state_unused)' here, due to possible race conditions)
117 if (pExportReference) {
118 pExportReference->State = state_unused;
119 pExportReference = NULL;
120 }
121 State = state_unused;
122 UnusedStreams++;
123 }
124 }
125
126 private:
127
128 // Methods
129
130 };
131 } // namespace LinuxSampler
132
133 #endif // __LS_STREAMBASE_H__

  ViewVC Help
Powered by ViewVC