diff options
Diffstat (limited to 'intern/audaspace/SDL/AUD_SDLMixerReader.cpp')
| -rw-r--r-- | intern/audaspace/SDL/AUD_SDLMixerReader.cpp | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/intern/audaspace/SDL/AUD_SDLMixerReader.cpp b/intern/audaspace/SDL/AUD_SDLMixerReader.cpp new file mode 100644 index 00000000000..1a0d990eaf2 --- /dev/null +++ b/intern/audaspace/SDL/AUD_SDLMixerReader.cpp @@ -0,0 +1,214 @@ +/* + * $Id$ + * + * ***** BEGIN LGPL LICENSE BLOCK ***** + * + * Copyright 2009 Jörg Hermann Müller + * + * This file is part of AudaSpace. + * + * AudaSpace is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * AudaSpace 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 Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with AudaSpace. If not, see <http://www.gnu.org/licenses/>. + * + * ***** END LGPL LICENSE BLOCK ***** + */ + +#include "AUD_SDLMixerReader.h" +#include "AUD_Buffer.h" + +inline Uint16 AUD_TO_SDL(AUD_SampleFormat format) +{ + // SDL only supports 8 and 16 bit audio + switch(format) + { + case AUD_FORMAT_U8: + return AUDIO_U8; + case AUD_FORMAT_S16: + return AUDIO_S16SYS; + default: + AUD_THROW(AUD_ERROR_SDL); + } +} + +// greatest common divisor +inline int gcd(int a, int b) +{ + int c; + + // make sure a is the bigger + if(b > a) + { + c = b; + b = a; + a = c; + } + + // greetings from Euclides + while(b != 0) + { + c = a % b; + a = b; + b = c; + } + return a; +} + +AUD_SDLMixerReader::AUD_SDLMixerReader(AUD_IReader* reader, + AUD_Specs specs) +{ + if(reader == NULL) + AUD_THROW(AUD_ERROR_READER); + + m_reader = reader; + m_tspecs = specs; + m_sspecs = reader->getSpecs(); + + try + { + // SDL only supports 8 and 16 bit sample formats + if(SDL_BuildAudioCVT(&m_cvt, + AUD_TO_SDL(m_sspecs.format), + m_sspecs.channels, + m_sspecs.rate, + AUD_TO_SDL(specs.format), + specs.channels, + specs.rate) == -1) + AUD_THROW(AUD_ERROR_SDL); + } + catch(AUD_Exception e) + { + delete m_reader; AUD_DELETE("reader") + throw; + } + + m_eor = false; + m_rsposition = 0; + m_rssize = 0; + m_ssize = m_sspecs.rate / gcd(specs.rate, m_sspecs.rate); + m_tsize = m_tspecs.rate * m_ssize / m_sspecs.rate; + + m_buffer = new AUD_Buffer(); AUD_NEW("buffer") + m_rsbuffer = new AUD_Buffer(); AUD_NEW("buffer") +} + +AUD_SDLMixerReader::~AUD_SDLMixerReader() +{ + delete m_reader; AUD_DELETE("reader") + delete m_buffer; AUD_DELETE("buffer") + delete m_rsbuffer; AUD_DELETE("buffer") +} + +bool AUD_SDLMixerReader::isSeekable() +{ + return m_reader->isSeekable(); +} + +void AUD_SDLMixerReader::seek(int position) +{ + m_reader->seek(position * m_ssize / m_tsize); + m_eor = false; +} + +int AUD_SDLMixerReader::getLength() +{ + return m_reader->getLength() * m_tsize / m_ssize; +} + +int AUD_SDLMixerReader::getPosition() +{ + return m_reader->getPosition() * m_tsize / m_ssize; +} + +AUD_Specs AUD_SDLMixerReader::getSpecs() +{ + return m_tspecs; +} + +AUD_ReaderType AUD_SDLMixerReader::getType() +{ + return m_reader->getType(); +} + +bool AUD_SDLMixerReader::notify(AUD_Message &message) +{ + return m_reader->notify(message); +} + +void AUD_SDLMixerReader::read(int & length, sample_t* & buffer) +{ + // sample count for the target buffer without getting a shift + int tns = length + m_tsize - length % m_tsize; + // sample count for the source buffer without getting a shift + int sns = tns * m_ssize / m_tsize; + // target sample size + int tss = AUD_SAMPLE_SIZE(m_tspecs); + // source sample size + int sss = AUD_SAMPLE_SIZE(m_sspecs); + + // input is output buffer + int buf_size = AUD_MAX(tns*tss, sns*sss); + + // resize if necessary + if(m_rsbuffer->getSize() < buf_size) + m_rsbuffer->resize(buf_size, true); + + if(m_buffer->getSize() < length*tss) + m_buffer->resize(length*tss); + + buffer = m_buffer->getBuffer(); + int size; + int index = 0; + sample_t* buf; + + while(index < length) + { + if(m_rsposition == m_rssize) + { + // no more data + if(m_eor) + length = index; + // mix + else + { + // read from source + size = sns; + m_reader->read(size, buf); + + // prepare + m_cvt.buf = m_rsbuffer->getBuffer(); + m_cvt.len = size*sss; + memcpy(m_cvt.buf, buf, size*sss); + + // convert + SDL_ConvertAudio(&m_cvt); + + // end of reader + if(size < sns) + m_eor = true; + + m_rsposition = 0; + m_rssize = size * m_tsize / m_ssize; + } + } + + // size to copy + size = AUD_MIN(m_rssize-m_rsposition, length-index); + + // copy + memcpy(m_buffer->getBuffer() + index * tss, + m_rsbuffer->getBuffer() + m_rsposition * tss, + size*tss); + m_rsposition += size; + index += size; + } +} |