95 lines
2.4 KiB
C++
95 lines
2.4 KiB
C++
#include <nana/audio/detail/audio_stream.hpp>
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#include <nana/charset.hpp>
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namespace nana{ namespace audio
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{
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namespace detail
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{
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//class audio_stream
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bool audio_stream::open(const nana::string& file)
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{
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fs_.open(static_cast<std::string>(charset(file)), std::ios::binary);
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if(fs_)
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{
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wave_spec::master_riff_chunk riff;
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fs_.read(reinterpret_cast<char*>(&riff), sizeof(riff));
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if(riff.ckID == *reinterpret_cast<const unsigned*>("RIFF") && riff.waveID == *reinterpret_cast<const unsigned*>("WAVE"))
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{
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fs_.read(reinterpret_cast<char*>(&ck_format_), sizeof(ck_format_));
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if(ck_format_.ckID == *reinterpret_cast<const unsigned*>("fmt ") && ck_format_.wFormatTag == 1) //Only support PCM format
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{
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if (ck_format_.cksize > 16)
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fs_.seekg(ck_format_.cksize - 16, std::ios::cur);
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std::size_t cksize = _m_locate_chunck(*reinterpret_cast<const unsigned*>("data"));
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if(cksize)
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{
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pcm_data_pos_ = static_cast<std::size_t>(fs_.tellg());
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pcm_data_size_ = cksize;
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return true;
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}
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}
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}
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}
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return false;
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}
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void audio_stream::close()
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{
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fs_.close();
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}
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bool audio_stream::empty() const
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{
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return (!fs_);
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}
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const wave_spec::format_chunck & audio_stream::format() const
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{
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return ck_format_;
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}
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std::size_t audio_stream::data_length() const
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{
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return data_size_;
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}
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void audio_stream::locate()
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{
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fs_.clear();
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fs_.seekg(pcm_data_pos_, std::ios::beg);
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data_size_ = pcm_data_size_;
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}
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std::size_t audio_stream::read(void * buf, std::size_t len)
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{
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fs_.read(reinterpret_cast<char*>(buf), static_cast<std::streamsize>(len <= data_size_ ? len : data_size_));
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std::size_t read_bytes = static_cast<std::size_t>(fs_.gcount());
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data_size_ -= read_bytes;
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return read_bytes;
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}
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std::size_t audio_stream::_m_locate_chunck(unsigned ckID)
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{
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chunck ck;
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while(true)
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{
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fs_.read(reinterpret_cast<char*>(&ck), sizeof(ck));
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if(fs_.gcount() != sizeof(ck))
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break;
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if(ck.ckID == ckID)
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return ck.cksize;
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if(ck.ckID == *reinterpret_cast<const unsigned*>("data"))
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fs_.seekg(ck.cksize + (ck.cksize & 1 ? 1 : 0), std::ios::cur);
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else
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fs_.seekg(ck.cksize, std::ios::cur);
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}
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return 0;
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}
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//end class audio_stream
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}//end namespace detail
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}//end namespace audio
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}//end namespace nana
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