/[svn]/linuxsampler/trunk/src/engines/gig/Stream.cpp
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Contents of /linuxsampler/trunk/src/engines/gig/Stream.cpp

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Revision 53 - (show annotations) (download)
Mon Apr 26 17:15:51 2004 UTC (19 years, 11 months ago) by schoenebeck
File size: 5590 byte(s)
* completely restructured source tree
* implemented multi channel support
* implemented instrument manager, which controls sharing of instruments
  between multiple sampler engines / sampler channels
* created abstract classes 'AudioOutputDevice' and 'MidiInputDevice' for
  convenient implementation of further audio output driver and MIDI input
  driver for LinuxSampler
* implemented following LSCP commands: 'SET CHANNEL MIDI INPUT TYPE',
  'LOAD ENGINE', 'GET CHANNELS', 'ADD CHANNEL', 'REMOVE CHANNEL',
  'SET CHANNEL AUDIO OUTPUT TYPE'
* temporarily removed all command line options
* LSCP server is now launched by default

1 /***************************************************************************
2 * *
3 * LinuxSampler - modular, streaming capable sampler *
4 * *
5 * Copyright (C) 2003 by Benno Senoner *
6 * *
7 * This program is free software; you can redistribute it and/or modify *
8 * it under the terms of the GNU General Public License as published by *
9 * the Free Software Foundation; either version 2 of the License, or *
10 * (at your option) any later version. *
11 * *
12 * This program is distributed in the hope that it will be useful, *
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15 * GNU General Public License for more details. *
16 * *
17 * You should have received a copy of the GNU General Public License *
18 * along with this program; if not, write to the Free Software *
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20 * MA 02111-1307 USA *
21 ***************************************************************************/
22
23 #include "Stream.h"
24
25 namespace LinuxSampler { namespace gig {
26
27 uint Stream::UnusedStreams = 0;
28
29 /// Returns number of refilled sample points or a value < 0 on error.
30 int Stream::ReadAhead(unsigned long SampleCount) {
31 if (this->State == state_unused) return -1;
32 if (this->State == state_end) return 0;
33 if (!SampleCount) return 0;
34 if (!pRingBuffer->write_space()) return 0;
35
36 long total_readsamples = 0, readsamples = 0;
37 long samplestoread = SampleCount / pSample->Channels;
38 sample_t* pBuf = pRingBuffer->get_write_ptr();
39 bool endofsamplereached;
40
41 // refill the disk stream buffer
42 if (this->DoLoop) { // honor looping
43 total_readsamples = pSample->ReadAndLoop(pBuf, samplestoread, &this->PlaybackState);
44 endofsamplereached = (this->PlaybackState.position >= pSample->SamplesTotal);
45 dmsg(5,("Refilled stream %d with %d (SamplePos: %d)", this->hThis, total_readsamples, this->PlaybackState.position));
46 }
47 else { // normal forward playback
48
49 pSample->SetPos(this->SampleOffset); // recover old position
50
51 do {
52 readsamples = pSample->Read(&pBuf[total_readsamples * pSample->Channels], samplestoread);
53 samplestoread -= readsamples;
54 total_readsamples += readsamples;
55 } while (samplestoread && readsamples > 0);
56
57 // we have to store the position within the sample, because other streams might use the same sample
58 this->SampleOffset = pSample->GetPos();
59
60 endofsamplereached = (SampleOffset >= pSample->SamplesTotal);
61 dmsg(5,("Refilled stream %d with %d (SamplePos: %d)", this->hThis, total_readsamples, this->SampleOffset));
62 }
63
64 // we must delay the increment_write_ptr_with_wrap() after the while() loop because we need to
65 // ensure that we read exactly SampleCount sample, otherwise the buffer wrapping code will fail
66 pRingBuffer->increment_write_ptr_with_wrap(total_readsamples * pSample->Channels);
67
68 // update stream state
69 if (endofsamplereached) SetState(state_end);
70 else SetState(state_active);
71
72 return total_readsamples;
73 }
74
75 void Stream::WriteSilence(unsigned long SilenceSampleWords) {
76 memset(pRingBuffer->get_write_ptr(), 0, SilenceSampleWords);
77 pRingBuffer->increment_write_ptr_with_wrap(SilenceSampleWords);
78 }
79
80 Stream::Stream(uint BufferSize, uint BufferWrapElements) {
81 this->pExportReference = NULL;
82 this->State = state_unused;
83 this->hThis = 0;
84 this->pSample = NULL;
85 this->SampleOffset = 0;
86 this->PlaybackState.position = 0;
87 this->PlaybackState.reverse = false;
88 this->pRingBuffer = new RingBuffer<sample_t>(BufferSize, BufferWrapElements);
89 UnusedStreams++;
90 }
91
92 Stream::~Stream() {
93 Reset();
94 if (pRingBuffer) delete pRingBuffer;
95 }
96
97 /// Called by disk thread to activate the disk stream.
98 void Stream::Launch(Stream::Handle hStream, reference_t* pExportReference, ::gig::Sample* pSample, unsigned long SampleOffset, bool DoLoop) {
99 UnusedStreams--;
100 this->pExportReference = pExportReference;
101 this->hThis = hStream;
102 this->pSample = pSample;
103 this->SampleOffset = SampleOffset;
104 this->PlaybackState.position = SampleOffset;
105 this->PlaybackState.reverse = false;
106 this->PlaybackState.loop_cycles_left = pSample->LoopPlayCount;
107 this->DoLoop = DoLoop;
108 SetState(state_active);
109 }
110
111 }} // namespace LinuxSampler::gig

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