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schoenebeck |
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/*************************************************************************** |
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* * |
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* LinuxSampler - modular, streaming capable sampler * |
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* * |
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* Copyright (C) 2003 by Benno Senoner * |
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* * |
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* This program is free software; you can redistribute it and/or modify * |
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* it under the terms of the GNU General Public License as published by * |
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* the Free Software Foundation; either version 2 of the License, or * |
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* (at your option) any later version. * |
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* * |
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* This program is distributed in the hope that it will be useful, * |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of * |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
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* GNU General Public License for more details. * |
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* * |
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* You should have received a copy of the GNU General Public License * |
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* along with this program; if not, write to the Free Software * |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, * |
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* MA 02111-1307 USA * |
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***************************************************************************/ |
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#include "stream.h" |
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// FIXME: already independent of audio channels, but assumes sample depth defined by 'sample_t' (usually 16 bit) |
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// *********** Stream ************** |
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// * |
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uint Stream::UnusedStreams = 0; |
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/// Returns number of refilled sample points or a value < 0 on error. |
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int Stream::ReadAhead(unsigned long SampleCount) { |
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if (this->State == state_unused) return -1; |
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if (this->State == state_end) return 0; |
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if (!SampleCount) return 0; |
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if (!pRingBuffer->write_space()) return 0; |
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long total_readsamples = 0, readsamples = 0; |
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long samplestoread = SampleCount / pSample->Channels; |
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// refill the disk stream buffer |
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pSample->SetPos(this->SampleOffset); |
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sample_t* ptr = pRingBuffer->get_write_ptr(); |
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do { |
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readsamples = pSample->Read(&ptr[total_readsamples * pSample->Channels], samplestoread); |
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samplestoread -= readsamples; |
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total_readsamples += readsamples; |
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} while (samplestoread && readsamples > 0); |
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// we must delay the increment_write_ptr_with_wrap() after the while() loop because we need to |
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// ensure that we read exactly SampleCount sample, otherwise the buffer wrapping code will fail |
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pRingBuffer->increment_write_ptr_with_wrap(total_readsamples * pSample->Channels); |
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// we have to store the position within the sample, because other streams might use the same sample |
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this->SampleOffset = pSample->GetPos(); |
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bool endofsamplereached = (SampleOffset >= pSample->SamplesTotal); |
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// update stream state |
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if (endofsamplereached) SetState(state_end); |
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else SetState(state_active); |
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// dmsg(("Refilled stream with %d (SamplePos: %d)", SampleCount - samplestoread, this->SampleOffset)); |
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return (SampleCount - samplestoread); |
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} |
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void Stream::WriteSilence(unsigned long SilenceSampleWords) { |
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memset(pRingBuffer->get_write_ptr(), 0, SilenceSampleWords); |
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pRingBuffer->increment_write_ptr_with_wrap(SilenceSampleWords); |
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} |
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Stream::Stream(uint BufferSize, uint BufferWrapElements) { |
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this->pExportReference = NULL; |
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this->State = state_unused; |
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this->pSample = NULL; |
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this->SampleOffset = 0; |
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this->pRingBuffer = new RingBuffer<sample_t>(BufferSize, BufferWrapElements); |
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UnusedStreams++; |
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} |
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Stream::~Stream() { |
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Reset(); |
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if (pRingBuffer) delete pRingBuffer; |
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} |
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/// Called by disk thread to activate the disk stream. |
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void Stream::Launch(reference_t* pExportReference, gig::Sample* pSample, unsigned long SampleOffset) { |
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UnusedStreams--; |
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this->pExportReference = pExportReference; |
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this->pSample = pSample; |
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this->SampleOffset = SampleOffset; |
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SetState(state_active); |
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} |