/[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 385 - (show annotations) (download)
Thu Feb 17 02:53:45 2005 UTC (19 years, 1 month ago) by schoenebeck
File size: 5835 byte(s)
* lscpserver: we now only use one instrument loader thread; commands for
  loading instruments in the background wait in a queue to be processed one
  by one to avoid possible race conditions and to improve I/O efficiency
* fixed possible race condition while streaming with multiple disk threads
  by using an own decompression buffer for each disk thread
* libgig: fixed some memory leaks caused by non virtual base constructors

1 /***************************************************************************
2 * *
3 * LinuxSampler - modular, streaming capable sampler *
4 * *
5 * Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6 * Copyright (C) 2005 Christian Schoenebeck *
7 * *
8 * This program is free software; you can redistribute it and/or modify *
9 * it under the terms of the GNU General Public License as published by *
10 * the Free Software Foundation; either version 2 of the License, or *
11 * (at your option) any later version. *
12 * *
13 * This program is distributed in the hope that it will be useful, *
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16 * GNU General Public License for more details. *
17 * *
18 * You should have received a copy of the GNU General Public License *
19 * along with this program; if not, write to the Free Software *
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
21 * MA 02111-1307 USA *
22 ***************************************************************************/
23
24 #include "Stream.h"
25
26 namespace LinuxSampler { namespace gig {
27
28 uint Stream::UnusedStreams = 0;
29 uint Stream::TotalStreams = 0;
30
31 /// Returns number of refilled sample points or a value < 0 on error.
32 int Stream::ReadAhead(unsigned long SampleCount) {
33 if (this->State == state_unused) return -1;
34 if (this->State == state_end) return 0;
35 if (!SampleCount) return 0;
36 if (!pRingBuffer->write_space()) return 0;
37
38 long total_readsamples = 0, readsamples = 0;
39 long samplestoread = SampleCount / pSample->Channels;
40 sample_t* pBuf = pRingBuffer->get_write_ptr();
41 bool endofsamplereached;
42
43 // refill the disk stream buffer
44 if (this->DoLoop) { // honor looping
45 total_readsamples = pSample->ReadAndLoop(pBuf, samplestoread, &this->PlaybackState, pDecompressionBuffer);
46 endofsamplereached = (this->PlaybackState.position >= pSample->SamplesTotal);
47 dmsg(5,("Refilled stream %d with %d (SamplePos: %d)", this->hThis, total_readsamples, this->PlaybackState.position));
48 }
49 else { // normal forward playback
50
51 pSample->SetPos(this->SampleOffset); // recover old position
52
53 do {
54 readsamples = pSample->Read(&pBuf[total_readsamples * pSample->Channels], samplestoread, pDecompressionBuffer);
55 samplestoread -= readsamples;
56 total_readsamples += readsamples;
57 } while (samplestoread && readsamples > 0);
58
59 // we have to store the position within the sample, because other streams might use the same sample
60 this->SampleOffset = pSample->GetPos();
61
62 endofsamplereached = (SampleOffset >= pSample->SamplesTotal);
63 dmsg(5,("Refilled stream %d with %d (SamplePos: %d)", this->hThis, total_readsamples, this->SampleOffset));
64 }
65
66 // we must delay the increment_write_ptr_with_wrap() after the while() loop because we need to
67 // ensure that we read exactly SampleCount sample, otherwise the buffer wrapping code will fail
68 pRingBuffer->increment_write_ptr_with_wrap(total_readsamples * pSample->Channels);
69
70 // update stream state
71 if (endofsamplereached) SetState(state_end);
72 else SetState(state_active);
73
74 return total_readsamples;
75 }
76
77 void Stream::WriteSilence(unsigned long SilenceSampleWords) {
78 memset(pRingBuffer->get_write_ptr(), 0, SilenceSampleWords);
79 pRingBuffer->increment_write_ptr_with_wrap(SilenceSampleWords);
80 }
81
82 Stream::Stream( ::gig::buffer_t* pDecompressionBuffer, uint BufferSize, uint BufferWrapElements) {
83 this->pExportReference = NULL;
84 this->State = state_unused;
85 this->hThis = 0;
86 this->pSample = NULL;
87 this->SampleOffset = 0;
88 this->PlaybackState.position = 0;
89 this->PlaybackState.reverse = false;
90 this->pRingBuffer = new RingBuffer<sample_t>(BufferSize, BufferWrapElements);
91 this->pDecompressionBuffer = pDecompressionBuffer;
92 UnusedStreams++;
93 TotalStreams++;
94 }
95
96 Stream::~Stream() {
97 Reset();
98 if (pRingBuffer) delete pRingBuffer;
99 UnusedStreams--;
100 TotalStreams--;
101 }
102
103 /// Called by disk thread to activate the disk stream.
104 void Stream::Launch(Stream::Handle hStream, reference_t* pExportReference, ::gig::Sample* pSample, unsigned long SampleOffset, bool DoLoop) {
105 UnusedStreams--;
106 this->pExportReference = pExportReference;
107 this->hThis = hStream;
108 this->pSample = pSample;
109 this->SampleOffset = SampleOffset;
110 this->PlaybackState.position = SampleOffset;
111 this->PlaybackState.reverse = false;
112 this->PlaybackState.loop_cycles_left = pSample->LoopPlayCount;
113 this->DoLoop = DoLoop;
114 SetState(state_active);
115 }
116
117 }} // namespace LinuxSampler::gig

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