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A440
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HORINOUCHI Masato
February 16, 2016
Technology
0
58
A440
社内LT大会 0x64物語 #05 Number 資料
HORINOUCHI Masato
February 16, 2016
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Transcript
A440 2016/02/16 0x64 Tales #05 Number Livesense Inc. HORINOUCHI Masato
A440 ͬͯͳʹ? • ΦΫλʔϒ 4 ͷ A (ϥ) ͷपΛ 440Hz
ͱ͢Δ͜ͱɻج४ϐο ν(Իߴ) ͱͯ͠ࠃࡍඪ४ͱͳ͍ͬͯΔɻ • 1955 ʹ ISO ʹΑΓ A=440 ͕ఆΊΒΕΔલྺ࢙తܦҢʹΑ Γ A=415, A=430, A=466 ͳͲ༷ʑͳج४ϐον͕༻͍ΒΕ͖ͯ ͨɻ • গʑߴ͍ج४ϐονͷํ͕՚͔ʹௌ͑͜ΔͷͰɺݱࡏͰ A=442, A=444 ͦΕΛӽ͑ΔΦʔέετϥଟ͍ɻ
ΈΜͳͬͯΔ A440 • ࣌ใ • "me_signal.wav • 440Hz 440Hz 440Hz
880Hz ͱ͍͏पͰ໐͍ͬͯΔɻ
ΦΫλʔϒ • 1ΦΫλʔϒ্ͷԻΛ໐Β͢ʹपΛ 2ഒʹ͢Δɻ • 1ΦΫλʔϒԼͷԻΛ໐Β͢ʹपΛ 1/2ഒʹ͢Δɻ • ΦΫλʔϒ x
ͷ A ͷपൺྻ • 1 => 55, 2 => 110, 3 => 220, 4 => 440, 5 => 880 … • f(x) = 27.5 * (2 ** x)
Ի ԻఔͷपΛͲͷΑ͏ʹنఆ͢Δ͔ɻ • ฏۉ • 1ΦΫλʔϒΛ 12ͨ͠Իɻ • (0..12).each {|i|
2.0 ** (i.to_f / 12) } ͷൺྻɻ • ७ਖ਼ • ७ਖ਼Իఔ(पൺ͕୯७ͳൺͱͳΔ)Λ༻͍ͨԻɻ • ԻͰഒԻͷ͏ͳΓ͕ൃੜ͠ͳ͍ɻCϝδϟʔͰͷ C-E-G ͕ 4:5:6 ͱͳΔɻ
ฏۉͱ७ਖ਼ʹΑΔԻఔ ฏۉ ͔ΒҾ༻
σϞ CϝδϟʔͰશԻ֊ͱ C-E-G , F-A-C , G-B-D ͷࡾԻɻ • ฏۉ
A440: temp_12tet_a440.wav • ฏۉ A444: temp_12tet_a444.wav • ७ਖ਼ A440: temp_just.wav
ࠓճͷݕূɺ ॳϦΞϧλΠϜੜͨ͠ܗσ ʔλΛ /dev/dsp ʹग़ྗ͠Α͏ͱߟ ͍͑ͯͨͷ͕ͩ…ɻ
σʔλͲ͏ͬͯ࡞ͬͨͷ? • MML ύʔαʔ࡞ͬͯܗσʔλʹม͢Εྑ͍ͷͰ… • ܗσʔλ͑͞࡞ΕͨΒ .wav ग़ྗ؆୯ͩΑͶɻ • ܗੜؔม͑Εਖ਼ݭҎ֎ग़ྗͰ͖ΔΑͶɻ
• ܗσʔλΛ߹Ͱ͖ΕϚϧντϥοΫԽͰ͖ΔΑͶɻ • ࡞ͬͯΈͨ ← ΠϚίί
to be con(nued...