trunk/src/stream.cpp

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003 by Benno Senoner                                   *
 *                                                                         *
 *   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                                                   *
 ***************************************************************************/

#include "stream.h"

// FIXME: already independent of audio channels, but assumes sample depth defined by 'sample_t' (usually 16 bit)


// *********** Stream **************
// *

uint Stream::UnusedStreams = 0;

/// Returns number of refilled sample points or a value < 0 on error.
int Stream::ReadAhead(unsigned long SampleCount) {
    if (this->State == state_unused) return -1;
    if (this->State == state_end)    return  0;
    if (!SampleCount)                return  0;
    if (!pRingBuffer->write_space()) return  0;

    long total_readsamples = 0, readsamples = 0;
    long samplestoread = SampleCount / pSample->Channels;

    // refill the disk stream buffer
    pSample->SetPos(this->SampleOffset);

    sample_t* ptr = pRingBuffer->get_write_ptr();
    do {
        readsamples    = pSample->Read(&ptr[total_readsamples * pSample->Channels], samplestoread);
        samplestoread -= readsamples;
        total_readsamples += readsamples;
    } while (samplestoread && readsamples > 0);

    // we must delay the increment_write_ptr_with_wrap() after the while() loop because we need to
    // ensure that we read exactly SampleCount sample, otherwise the buffer wrapping code will fail
    pRingBuffer->increment_write_ptr_with_wrap(total_readsamples * pSample->Channels);

    // we have to store the position within the sample, because other streams might use the same sample
    this->SampleOffset = pSample->GetPos();

    bool endofsamplereached = (SampleOffset >= pSample->SamplesTotal);

    // update stream state
    if (endofsamplereached) SetState(state_end);
    else                    SetState(state_active);

    dmsg(5,("Refilled stream with %d (SamplePos: %d)", SampleCount - samplestoread, this->SampleOffset));
    return (SampleCount - samplestoread);
}

void Stream::WriteSilence(unsigned long SilenceSampleWords) {
    memset(pRingBuffer->get_write_ptr(), 0, SilenceSampleWords);
    pRingBuffer->increment_write_ptr_with_wrap(SilenceSampleWords);
}

Stream::Stream(uint BufferSize, uint BufferWrapElements) {
    this->pExportReference = NULL;
    this->State            = state_unused;
    this->pSample          = NULL;
    this->SampleOffset     = 0;
    this->pRingBuffer      = new RingBuffer<sample_t>(BufferSize, BufferWrapElements);
    UnusedStreams++;
}

Stream::~Stream() {
    Reset();
    if (pRingBuffer) delete pRingBuffer;
}

/// Called by disk thread to activate the disk stream.
void Stream::Launch(reference_t* pExportReference, gig::Sample* pSample, unsigned long SampleOffset) {
    UnusedStreams--;
    this->pExportReference = pExportReference;
    this->pSample      = pSample;
    this->SampleOffset = SampleOffset;
    SetState(state_active);
}
1	schoenebeck	9	/***************************************************************************
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			// FIXME: already independent of audio channels, but assumes sample depth defined by 'sample_t' (usually 16 bit)
26
27
28			// ********* Stream ************
29			// *
30
31			uint Stream::UnusedStreams = 0;
32
33			/// Returns number of refilled sample points or a value < 0 on error.
34			int Stream::ReadAhead(unsigned long SampleCount) {
35			if (this->State == state_unused) return -1;
36			if (this->State == state_end) return 0;
37			if (!SampleCount) return 0;
38			if (!pRingBuffer->write_space()) return 0;
39
40			long total_readsamples = 0, readsamples = 0;
41			long samplestoread = SampleCount / pSample->Channels;
42
43			// refill the disk stream buffer
44			pSample->SetPos(this->SampleOffset);
45
46			sample_t* ptr = pRingBuffer->get_write_ptr();
47			do {
48			readsamples = pSample->Read(&ptr[total_readsamples * pSample->Channels], samplestoread);
49			samplestoread -= readsamples;
50			total_readsamples += readsamples;
51			} while (samplestoread && readsamples > 0);
52
53			// we must delay the increment_write_ptr_with_wrap() after the while() loop because we need to
54			// ensure that we read exactly SampleCount sample, otherwise the buffer wrapping code will fail
55			pRingBuffer->increment_write_ptr_with_wrap(total_readsamples * pSample->Channels);
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			bool endofsamplereached = (SampleOffset >= pSample->SamplesTotal);
61
62			// update stream state
63			if (endofsamplereached) SetState(state_end);
64			else SetState(state_active);
65
66	schoenebeck	12	dmsg(5,("Refilled stream with %d (SamplePos: %d)", SampleCount - samplestoread, this->SampleOffset));
67	schoenebeck	9	return (SampleCount - samplestoread);
68			}
69
70			void Stream::WriteSilence(unsigned long SilenceSampleWords) {
71			memset(pRingBuffer->get_write_ptr(), 0, SilenceSampleWords);
72			pRingBuffer->increment_write_ptr_with_wrap(SilenceSampleWords);
73			}
74
75			Stream::Stream(uint BufferSize, uint BufferWrapElements) {
76			this->pExportReference = NULL;
77			this->State = state_unused;
78			this->pSample = NULL;
79			this->SampleOffset = 0;
80			this->pRingBuffer = new RingBuffer<sample_t>(BufferSize, BufferWrapElements);
81			UnusedStreams++;
82			}
83
84			Stream::~Stream() {
85			Reset();
86			if (pRingBuffer) delete pRingBuffer;
87			}
88
89			/// Called by disk thread to activate the disk stream.
90			void Stream::Launch(reference_t* pExportReference, gig::Sample* pSample, unsigned long SampleOffset) {
91			UnusedStreams--;
92			this->pExportReference = pExportReference;
93			this->pSample = pSample;
94			this->SampleOffset = SampleOffset;
95			SetState(state_active);
96			}