AVAudioEngineでリアルタイムレンダリング

iOSDC Japan 2020

1. :VLJ
   :BTPTIJNB
   
   !ZBTP@TBO
   
    "7"VEJP&OHJOFͰ
   ϦΞϧλΠϜϨϯμϦϯά J04%$
   +BQBO
   
2. ಺༰ ΦʔσΟΦೖग़ྗͷ࢓૊Έ
   J04ͷΦʔσΟΦ"1*
   ҆ఆͯ͠ϦΞϧλΠϜʹϨϯμϦϯάΛ͢Δʹ͸ IUUQTHJUIVCDPNPCKFDUJWFBVEJP"VEJP6OJU3FOEFSJOH&YBNQMF αϯϓϧίʔυ
3. ΦʔσΟΦೖग़ྗͷ࢓૊Έ
4. ίʔϧόοΫ ΦʔσΟΦೖग़ྗͷ࢓૊Έ ΦʔσΟΦॲཧΛ։࢝͢Δͱઐ༻ͷεϨουͰ܁Γฦ͠ίʔϧόοΫ͕ݺ͹ΕΔ ʢඵʹ͖ͭ਺ेճҎ্ʣ
5. ίʔϧόοΫ ग़ྗ ΦʔσΟΦೖग़ྗͷ࢓૊Έ ίʔϧόοΫ಺ͰσʔλΛ౉͢ͱԻ੠͕ग़ྗ͞ΕΔ
6. ίʔϧόοΫ ग़ྗ ೖྗ ΦʔσΟΦೖग़ྗͷ࢓૊Έ ίʔϧόοΫʹೖྗ͞ΕͨԻ੠ͷσʔλ͕౉ͬͯ͘Δ
7. ίʔϧόοΫ ग़ྗ ೖྗ ΦʔσΟΦೖग़ྗͷ࢓૊Έ ❌ ίʔϧόοΫͷॲཧʹ͕͔͔࣌ؒΔͱɺԻ్͕੾ΕͨΓऔΓ͜΅ͨ͠Γ͢Δ͜ ͱʹͳΔ
8. "7"VEJP1MBZFSɾ"7"VEJP3FDPSEFSͳͲͷߴϨϕϧͳ"1*͸ɺ͜ͷΑ͏ͳ௿Ϩ ϕϧॲཧΛؾʹ͠ͳͯ͘΋؆୯ʹ࢖͑ΔΑ͏ʹͳ͍ͬͯΔ
   ϦΞϧλΠϜʹࣗ༝ʹԻΛѻ͍͍ͨ৔߹͸ɺ௿ϨϕϧͳॲཧΛ͢Δඞཁ͕͋Δ ΦʔσΟΦೖग़ྗͷ࢓૊Έ
9. J04ͷΦʔσΟΦ"1*
10. J04ॳظͷࠒ͔Β͋Δ$ݴޠͷ"1* $BSCPO
    DPNQPOFOUCBTFE
    "VEJP6OJUT
    "6(SBQI
    "VEJP
    2VFVF
    4FSWJDFT
11. ඇਪ঑ʹͳͬͨ"1* J04
    3FMFBTF
    /PUFT
    ΑΓ "6(SBQI
    ʢʙJ04ʣ
    *OUFS"QQ
    BVEJP
    ʢʙJ04ʣ
    $BSCPO
    DPNQPOFOUCBTFE
    "VEJP6OJUT
    ʢ͍ۙ͏ͪʹ࢖͑ͳ͘ͳΔʣ
12. ௥Ճ͞Εͨ"1* "7"VEJP&OHJOFʢJ04ʙʣ
    "VEJP6OJU
    7
    
    "VEJP
    6OJU
    &YUFOTJPOTʢJ04ʙʣ
    "7"VEJP4PVSDF/PEF
    
    "7"VEJP4JOL/PEFʢJ04ʙʣ
13. J04ҎલͷϦΞϧλΠϜϨϯμϦϯά $ݴޠͷ"VEJP6OJU
    "6"VEJP6OJUΛܧঝ͢Δ͜ͱͰ"7"VEJP&OHJOFͰ΋Մೳʹ͸ͳΔʢϓϥάΠϯ ͷ࢓૊ΈͰ࡞ΔͷͰɺηοτΞοϓ͕໘౗Ͱෳࡶʣ
14. "7"VEJP4PVSDF/PEF
    
    "7"VEJP4JOL/PEF
    ͕ొ৔
    ϓϥάΠϯͱൺ΂ͯηοτΞοϓ͕༰қʹͳͬͨ J04Ҏ߱ͷϦΞϧλΠϜϨϯμϦϯά
15. "7"VEJP4PVSDF/PEF ΦʔσΟΦΛग़ྗ͢ΔσʔλΛ౉͢ 4PVSDF/PEF 0VUQVU/PEF "7"VEJP&OHJOF 3FOEFS
    #MPDL @interface AVAudioSourceNode : AVAudioNode <AVAudioMixing> - (instancetype)initWithRenderBlock:(AVAudioSourceNodeRenderBlock)block; - (instancetype)initWithFormat:(AVAudioFormat *)format renderBlock:(AVAudioSourceNodeRenderBlock)block; @end
16. "7"VEJP4JOL/PEF ΦʔσΟΦͷೖྗ͞ΕͨσʔλΛड͚औΔ *OQVU/PEF 4JOL/PEF "7"VEJP&OHJOF 3FDFJWFS
    #MPDL @interface AVAudioSinkNode : AVAudioNode - (instancetype)initWithReceiverBlock:(AVAudioSinkNodeReceiverBlock)block; @end
17. ҆ఆͨ͠ϨϯμϦϯάΛߦ͏
18. ΦʔσΟΦ*0ͷεϨουʹ͓͍ͯ ϝϞϦͷ֬อΛ͠ͳ͍
    MJCEJTQBUDI͸࢖Θͳ͍
    $$ ͰॲཧΛॻ͘
    "DDFMFSBUF
    'SBNFXPSLΛ׆༻͢Δ
    ଞͷεϨουͱͷϩοΫΛආ͚Δʢ4XJGU΍0CKFDUJWF$ͷݺͼग़͠ɺϑΝΠϧ ೖग़ྗͷதʹ͋Δʣ IUUQTQPTUEDDGPVSDPNNPONJTUBLFTJOBVEJPEFWFMPQNFOU
19. αϯϓϧίʔυ "7"VEJP4PVSDF/PEF
    
    αΠϯ೾ͷ࠶ੜ
    ʲ%JSFDUʳ
    प೾਺ͷૢ࡞Λ͙͢ʹ൓ө
    ʲ%FGFSSFEʳ
    ཷΊ͍ͯΔόοϑΝʹରͯ͠प೾਺ͷૢ࡞Λ൓ө
    "7"VEJP4JOL/PEF
    
    ೖྗԻͷϝʔλʔදࣔ IUUQTHJUIVCDPNPCKFDUJWFBVEJP"VEJP6OJU3FOEFSJOH&YBNQMF
20. αϯϓϧίʔυͷݴޠߏ੒ 3FOEFS#MPDL3FDFJWFS#MPDLͷத͸$ Ͱهड़
    0CKFDUJWF$Ͱϥοϓͯ͠/PEFΛฦ͢
    "7"VEJP&OHJOFͷߏங΍6*͸4XJGUͰهड़
21. εϨουؒͷ΍ΓͱΓ
22. TUEBUPNJD ಛ௃ ੔਺ܕɾුಈখ਺఺਺ܕɾϙΠϯλܕΛεϨουηʔϑʹѻ͑ΔΫϥε
    JT@MPDL@GSFF ؔ਺ͰϩοΫ͞ΕΔ͔औಘͰ͖Δʢࠓ࣌ͷσόΠεͳΒ·ͣ USVFʣ
23. ෳ਺ͷ஋ΛΞτϛοΫʹ͢Δ ڞ༻ମͰTUEBUPNJDͷܕͱTUSVDUΛม׵ union Value { void *v; struct { float const level; float const peak; }; }; static_assert(sizeof(Value) == sizeof(void *), "");
24. ෳ਺ͷ஋ΛΞτϛοΫʹ͢Δ ڞ༻ମͰTUEBUPNJDͷܕͱTUSVDUΛม׵ std::atomic<void *> atomicValue; // atomicͷ஋ʹηοτ͢Δ Value setValue{.level = 0.0f, .peak = 0.0f}; atomicValue = setValue.v; // atomicͷ஋͔Βήοτ͢Δ Value getValue{.v = atomicValue};
25. TUETIBSFE@QUS ಛ௃ $ ͷΫϥεΛࢀরΧ΢ϯτํࣜͰอ࣋͢Δ
    ࢀরΧ΢ϯλ͸εϨουηʔϑ
    ϨϯμϦϯάதʹίϐʔ͠ͳ͍Α͏ʹؾΛ͚ͭΔ
26. TUETIBSFE@QUS ίϐʔͯ͠͠·͏ॻ͖ํ void sample(std::shared_ptr<SineData> data) { auto localData = data; } ίϐʔ͞ΕΔ ͭղ์͞ΕΔ ίϐʔ͞ΕΔ
27. TUETIBSFE@QUS ίϐʔ͞Εͳ͍ॻ͖ํ void sample(std::shared_ptr<SineData> const &data) { auto const &localData = data; } ίϐʔ͞Εͳ͍ ίϐʔ͞Εͳ͍ Կ΋ى͖ͳ͍
28. ͭͷεϨου͔Βಉ͡σʔλʹॻ͖ࠐΉ %FGFSSFEͷαϯϓϧ
29. ͭͷεϨου͔Βಉ͡σʔλΛѻ͏ %FGFSSFEͷαϯϓϧ αΠϯ೾ੜ੒εϨου αΠϯ೾Λ
    ॻ͖ࠐΈ ग़ྗόοϑΝʹ
    ಡΈࠐΈ ڞ༗͢Δσʔλ ͭ ࠷ޙ·ͰಡΈࠐΜͩΒ
    ಡΈࠐΈݩΛ੾Γସ͑
    αΠϯ೾ͷ
    ॻ͖ࠐΈΛࢦࣔ ඵؒͷ
    ΦʔσΟΦσʔλ ग़ྗεϨου
30. ͭͷεϨου͔Βಉ͡σʔλΛѻ͏ %FGFSSFEͷαϯϓϧ αΠϯ೾ੜ੒εϨου 8SJUJOH 3FBEJOH ΞτϛοΫͳϑϥά 8SJUJOHͳΒ
    αΠϯ೾Λॻ͖ࠐΜͰ
    3FBEJOHʹ͢Δ 3FBEJOHͳΒ
    ग़ྗόοϑΝʹ
    σʔλΛಡΈࠐΜͰ
    ࠷ޙ·ͰߦͬͨΒ
    8SJUJOHʹ͢Δ ڞ༗͢Δσʔλ ͭ ඵؒͷ
    ΦʔσΟΦσʔλ ग़ྗεϨου
31. ·ͱΊ $ݴޠͷ"1*͸ඇਪ঑ɻ࣌୅͸"7"VEJP&OHJOF
    ΦʔσΟΦͷεϨου͕ϩοΫͯ͠͠·Θͳ͍Α͏ʹؾΛ෇͚Δ