Build your own WebP codec in Swift

Transcript

1. #VJME
   ZPVS
   PXO
   8FC1
   DPEFD
   JO
   4XJGU LJTIJLBXB
   LBUTVNJ !LJTIJLBXBLBUTVNJ!IBDIZEFSNJP LJTIJLBXBLBUTVNJ ࡞ֶͬͯͿ8FC1ೖ໳
2. #VJME
   ZPVS
   PXO
   8FC1
   DPEFD
   JO
   4XJGU LJTIJLBXB
   LBUTVNJ !LJTIJLBXBLBUTVNJ!IBDIZEFSNJP LJTIJLBXBLBUTVNJ ࡞ֶͬͯͿ8FC1ೖ໳ $PEFS %FDPEFS
3. r 8FC1ʹֶ͍ͭͯͿࡍͷোนΛऔΓআ͘ ࡞ֶͬͯͿ8FC1ೖ໳ (PBM
4. r ن֨ॻ͕લఏ஌ࣝ͋Γ͖Ͱॻ͔Ε͍ͯΔ
   r ࢀߟ࣮૷͸΄΅$ݴޠͰॻ͔ΕͨMJCXFCQͷΈ
   r ࢓༷ΛಡΜͰ΋ίʔυΛಡΜͰ΋ཧղ͠ʹ͍͘ 8FC1ΛֶͿࡍͷোน લఏ஌͕ࣝඞਢ
5. r ͍ͭ͘΋ͷখ͞ͳ޻ఔΛॱʹॏͶͯɺ࠷ޙʹαΠζΛখ͍ͯ͘͞͠Δ
   r ్தͷσʔλ͸ɺਓ͕ݟͯ΋ҙຯΛऔΓʹ͍͘ܗʹ͕࢟มΘΔ
   r ݩʹ໭͢ͱ͖͸޻ఔΛٯ޲͖ʹͨͲΔͨΊɺ௚ײʹ߹͍ʹ͍͘
   r Ͳͷ޻ఔͰԿ͕Ͳ͏มΘͬͨͷ͔͕Ұ໨Ͱ෼͔ΓͮΒ͍ 8FC1ΛֶͿࡍͷোน ͳͥ࢓૊Έ͕ཧղ͠ʹ͍͘ͷ͔
6. োนΛऔΓআ͘ ࠷খݶͷ࣮૷ͱςετσʔλ r খ͞ͳ8FC1Τϯίʔμʗσίʔμ
   r ςετσʔλ
   r ೖྗͱग़ྗ͕໌֬
   r ֤޻ఔΛಠཱʹ֬ೝͰ͖Δ
   r σόοά͠΍͍͢
7. 4BNQMF
   $PEF ➡
   IUUQTHJUIVCDPNLJTIJLBXBLBUTVNJXFCQFYFSDJTFT
8. r 8FC1ͬͯͳʹʁ
   r ̎छྨͷѹॖϞʔυ
   r J04Ͱ͸Ͳ͜·Ͱ࢖͑Δʁ
   r σʔλߏ଄ʹ͍ͭͯ
   r ϔομΛಡΉ
   r খ͞ͳ࣮૷Ͱʮ8FC1ը૾ʯΛ࡞Δ
   
   r ·ͱΊͱ࣍ͷεςοϓ 0VUMJOF ໨࣍
9. 8FC1ͬͯͳʹʁ
10. r 8FCαΠτͰར༻͢Δը૾ͷͨΊʹ࡞ΒΕͨը૾ѹॖܗࣜ
    r ಉ͡ݟͨ໨ͰϑΝΠϧ͕খ͘͞ͳΓ΍͍͢ͷͰωοτϫʔΫΛ௨ͨ͡഑৴ʹద͍ͯ͠Δ
    r എܠͷಁաΛαϙʔτ
    ‣ ΞΠίϯ΍ϩΰʹར༻͠΍͍͢
    r ΞχϝʔγϣϯΛαϙʔτ
    r छྨͷѹॖϞʔυ
    ‣ -PTTZʢඇՄٯѹॖʣ
    ʜ
    ࡉ෦ͷ඼࣭͸Θ͔ͣʹࣦΘΕΔ͕ඇৗʹαΠζ͕খ͘͞ͳΔ
    ‣ -PTTMFTTʢՄٯѹॖʣ
    ʜ
    ݩͷըૉΛ׬શʹ෮ݩͰ͖Δ 8FC1ͬͯͳʹʁ
11. r -PTTZʢඇՄٯѹॖʣ
    r ࡉ෦ͷ඼࣭͸Θ͔ͣʹࣦΘΕΔ͕ඇৗʹαΠζ͕খ͘͞ͳΔ
    r ࣸਅͳͲओʹ+1&(͕࢖ΘΕ͍ͯͨը૾ʹରͯ͠ޮՌ͕ߴ͍
    r -PTTMFTTʢՄٯѹॖʣ
    r ݩͷըૉΛ׬શʹ෮ݩͰ͖Δ
    r ΞΠίϯ΍ΠϥετͳͲ1/(ͷ୅ସͱͯ͠࢖͑ɺΑΓখ͘͞ͳΓ΍͍͢ 8FC1ͬͯͳʹʁ ̎छྨͷѹॖϞʔυ
12. 8FC1ͬͯͳʹʁ ̎छྨͷѹॖϞʔυ r -PTTZʢඇՄٯѹॖʣ
    r ࡉ෦ͷ඼࣭͸Θ͔ͣʹࣦΘΕΔ͕ඇৗʹαΠζ͕খ͘͞ͳΔ
    r ࣸਅͳͲओʹ+1&(͕࢖ΘΕ͍ͯͨը૾ʹରͯ͠ޮՌ͕ߴ͍
    r ར༻͕ଟ͍ɺπʔϧͷσϑΥϧτͷઃఆ΋-PTTZ͕΄ͱΜͲ
    r -PTTMFTTʢՄٯѹॖʣ
    r ݩͷըૉΛ׬શʹ෮ݩͰ͖Δ
    r ΞΠίϯ΍ΠϥετͳͲ1/(ͷ୅ସͱͯ͠࢖͑ɺΑΓখ͘͞ͳΓ΍͍͢
13. 8FC1ͬͯͳʹʁ r 8FCαΠτͰར༻͢Δը૾ͷͨΊʹ࡞ΒΕͨը૾ѹॖܗࣜ
    r ಉ͡ݟͨ໨ͰϑΝΠϧ͕খ͘͞ͳΓ΍͍͢ͷͰωοτϫʔΫΛ௨ͨ͡഑৴ʹద͍ͯ͠Δ
    r എܠͷಁաΛαϙʔτ
    ‣ ΞΠίϯ΍ϩΰʹར༻͠΍͍͢
    r ΞχϝʔγϣϯΛαϙʔτ
    r छྨͷѹॖϞʔυ
    ‣ -PTTZʢඇՄٯѹॖʣ
    ʜ
    ࡉ෦ͷ඼࣭͸Θ͔ͣʹࣦΘΕΔ͕ඇৗʹαΠζ͕খ͘͞ͳΔ
    ‣ -PTTMFTTʢՄٯѹॖʣ
    ʜ
    ݩͷըૉΛ׬શʹ෮ݩͰ͖Δ
14. x J04Ͱ͸Ͳ͜·Ͱ࢖͑Δʁ
15. r J04
    
    ‣ 4BGBSJ
    
    8,8FC7JFX
    J04
    
    IUUQTEFWFMPQFSBQQMFDPNEPDVNFOUBUJPOTBGBSJSFMFBTFOPUFTTBGBSJSFMFBTFOPUFT.FEJB
    ‣ *NBHF
    *0ʢ$(*NBHF4PVSDFʣ
    ‣ 6**NBHF EBUB
    r Τϯίʔυʢ8FC1ը૾Λ࡞੒͢Δʣ͸ະαϙʔτ J04Ͱ͸Ͳ͜·Ͱ࢖͑Δʁ
16. σʔλߏ଄ʹ͍ͭͯ
17. σʔλߏ଄ʹ͍ͭͯ )FBEFS %BUB
18. σʔλߏ଄ʹ͍ͭͯ 3*''
    $POUBJOFS 3*''
    3FTPVSDF
    *OUFSDIBOHF
    'JMF
    'PSNBU )FBEFS %BUB
19. σʔλߏ଄ʹ͍ͭͯ $IVOL
    'PVS$$ $IVOL
    4J[F $IVOL
    1BZMPBE 3*''
    $POUBJOFS 3*''
    3FTPVSDF
    *OUFSDIBOHF
    'JMF
    'PSNBU )FBEFS %BUB $IVOL
20. 'R' 'I' 'F' 'F' 
    CZUFT $IVOL
    1BZMPBE 3*''
    $POUBJOFS 
    CZUFT 
    CZUFT σʔλߏ଄ʹ͍ͭͯ 3*''
    3FTPVSDF
    *OUFSDIBOHF
    'JMF
    'PSNBU
21. 'R' 'I' 'F' 'F' 
    CZUFT 3*''
    $POUBJOFS 'R' 'I' 'F' 'F' 'W' 'E' 'B' 'P' σʔλߏ଄ʹ͍ͭͯ 3*''
    3FTPVSDF
    *OUFSDIBOHF
    'JMF
    'PSNBU
22. 'R' 'I' 'F' 'F' 
    CZUFT 3*''
    $POUBJOFS 'R' 'I' 'F' 'F' 'W' 'E' 'B' 'P' $IVOL
    'PVS$$ $IVOL
    4J[F $IVOL
    1BZMPBE σʔλߏ଄ʹ͍ͭͯ 3*''
    3FTPVSDF
    *OUFSDIBOHF
    'JMF
    'PSNBU 8FC1
    )FBEFS
23. r -PTTZʢඇՄٯѹॖʣ
    r -PTTMFTTʢՄٯѹॖʣ
    r Ξχϝʔγϣϯ
    ‣ ֤ΞχϝʔγϣϯϑϨʔϜ͸-PTTZͱ-PTTMFTTΛࠞࡏՄೳ
    r ϝλσʔλʢ&9*'ɺ*$$ΧϥʔϓϩϑΝΠϧɺͳͲʣ ෳ਺ͷը૾ܗࣜɾػೳΛαϙʔτ
24. 'R' 'I' 'F' 'F' 
    CZUFT 3*''
    $POUBJOFS 'R' 'I' 'F' 'F' 'W' 'E' 'B' 'P' 'V' 'P' '8' ' ' $IVOL
    4J[F $IVOL
    1BZMPBE 4JNQMF
    'JMF
    'PSNBU 71
    -PTTZ
25. 'R' 'I' 'F' 'F' 
    CZUFT 3*''
    $POUBJOFS 'R' 'I' 'F' 'F' 'W' 'E' 'B' 'P' 'V' 'P' '8' 'L' $IVOL
    1BZMPBE 4JNQMF
    'JMF
    'PSNBU 71-
    -PTTMFTT $IVOL
    4J[F
26. 'R' 'I' 'F' 'F' 
    CZUFT 3*''
    $POUBJOFS 'R' 'I' 'F' 'F' 'W' 'E' 'B' 'P' 'V' 'P' '8' 'L' 
    CZUFT $IVOL
    1BZMPBE 4JNQMF
    'JMF
    'PSNBU 71
    -PTTZ 
    CZUFT 
    CZUFT 
    CZUFT
27. 'R' 'I' 'F' 'F' 
    CZUFT 3*''
    $POUBJOFS 'R' 'I' 'F' 'F' 'W' 'E' 'B' 'P' 'V' 'P' '8' 'L' 
    CZUFT $IVOL
    1BZMPBE 4JNQMF
    'JMF
    'PSNBU 71-
    -PTTMFTT 
    CZUFT 
    CZUFT 
    CZUFT
28. 'R' 'I' 'F' 'F' 
    CZUFT 3*''
    $POUBJOFS 'R' 'I' 'F' 'F' 'W' 'E' 'B' 'P' 'V' 'P' '8' 'X' 
    CZUF $IVOL
    1BZMPBE &YUFOEFE
    'JMF
    'PSNBU *$$
    1SP fi MF
    "MQIB
    DIBOOFM
    "OJNBUJPO
    &9*'9.1
    NFUBEBUB 'E' 'X' 'I' 'F' $IVOL 4J[F $IVOL 1BZMPBE
29. 'A' 'N' 'I' 'M' 3*''
    $POUBJOFS 'A' 'N' 'M' 'F' &YUFOEFE
    'JMF
    'PSNBU *$$
    1SP fi MF
    "MQIB
    DIBOOFM
    "OJNBUJPO
    &9*'9.1
    NFUBEBUB 'A' 'N' 'M' 'F' $IVOL
    1BZMPBE $IVOL
    1BZMPBE
30. '?' '?' '?' '?' 3*''
    $POUBJOFS 6OLOPXO
    $IVOLT ೚ҙͷσʔλΛಠࣗͷνϟϯΫʹ֨ೲ͢Δ $IVOL
    1BZMPBE
31. ϔομʔΛಡΉ
32. 3*''
    )FBEFS
    3FBEFS 4BNQMF
    $PEF 'PVS$$ 4J[F
33. 3*''
    )FBEFS
    3FBEFS 4BNQMF
    $PEF struct RIFFHeaderReader { static func read(_ data: Data) throws -> (header: RIFFHeader, chunks: [RIFFChunk]) { var reader = ByteReader(data) let sig = try reader.readFourCC() let riffSize = try reader.readUInt32LE() let formType = try reader.readFourCC() let logicalEnd = 8 + Int(riffSizeLE) guard logicalEnd <= data.count else { throw WebPListError.truncatedRIFF } var chunks: [RIFFChunk] = [] while reader.offset + 8 <= logicalEnd { let fourCC = try r.readFourCC() let size = try r.readUInt32LE() let payloadStart = r.offset let payloadEnd = payloadStart + Int(size) try reader.skip(Int(sizeLE)) if (size & 1) == 1 { try reader.skip(1) } } let header = RIFFHeader(signature: sig, fileSizeLE: riffSize, formType: formType) return (header, chunks) } }
34. খ͞ͳ࣮૷Ͱʮ8FC1ը૾ʯΛ࡞Δ
    
35. খ͞ͳ࣮૷Ͱʮ8FC1ը૾ʯΛ࡞Δ
    – 'VP8 ' ʜ
    -PTTZʢඇՄٯѹॖʣ – 'VP8L' ʜ
    -PTTMFTTʢՄٯѹॖʣ – 'ALPH'ʜ
    -PTTZʢඇՄٯѹॖʣϑΥʔϚοτͷΞϧϑΝ৘ใ r ANIM''ANMF' ʜ
    ΞχϝʔγϣϯʗΞχϝʔγϣϯϑϨʔϜ
    – 'ICCP' ʜ
    *$$ΧϥʔϓϩϑΝΠϧ r 'EXIF''XMP '
    ʜ
    ϝλσʔλ
36. – 'VP8 ' ʜ
    -PTTZʢඇՄٯѹॖʣ – 'VP8L' ʜ
    -PTTMFTTʢՄٯѹॖʣ – 'ALPH'ʜ
    -PTTZʢඇՄٯѹॖʣϑΥʔϚοτͷΞϧϑΝ৘ใ r ANIM''ANMF' ʜ
    ΞχϝʔγϣϯʗΞχϝʔγϣϯϑϨʔϜ
    – 'ICCP' ʜ
    *$$ΧϥʔϓϩϑΝΠϧ r 'EXIF''XMP '
    ʜ
    ϝλσʔλ খ͞ͳ࣮૷Ͱʮ8FC1ը૾ʯΛ࡞Δ
    
37. – 'VP8 ' ʜ
    -PTTZʢඇՄٯѹॖʣ – 'VP8L' ʜ
    -PTTMFTTʢՄٯѹॖʣ – 'ALPH'ʜ
    -PTTZʢඇՄٯѹॖʣϑΥʔϚοτͷΞϧϑΝ৘ใ r ANIM''ANMF' ʜ
    ΞχϝʔγϣϯʗΞχϝʔγϣϯϑϨʔϜ
    – 'ICCP' ʜ
    *$$ΧϥʔϓϩϑΝΠϧ r 'EXIF''XMP '
    ʜ
    ϝλσʔλ খ͞ͳ࣮૷Ͱʮ8FC1ը૾ʯΛ࡞Δ
    
38. – 'VP8 ' ʜ
    -PTTZʢඇՄٯѹॖʣ – 'VP8L' ʜ
    -PTTMFTTʢՄٯѹॖʣ – 'ALPH'ʜ
    -PTTZʢඇՄٯѹॖʣϑΥʔϚοτͷΞϧϑΝ৘ใ r ANIM''ANMF' ʜ
    ΞχϝʔγϣϯʗΞχϝʔγϣϯϑϨʔϜ
    – 'ICCP' ʜ
    *$$ΧϥʔϓϩϑΝΠϧ r 'EXIF''XMP '
    ʜ
    ϝλσʔλ খ͞ͳ࣮૷Ͱʮ8FC1ը૾ʯΛ࡞Δ
    എܠ͕෼͔ΕͯͨΓΩϟϯόεશମͰ͸ͳ͘
    ಈ͘෦෼͚ͩ֨ೲ͢ΔͳͲएׯͷ௥Ճ࣮૷͕ඞཁ
39. – 'VP8 ' ʜ
    -PTTZʢඇՄٯѹॖʣ – 'VP8L' ʜ
    -PTTMFTTʢՄٯѹॖʣ – 'ALPH'ʜ
    -PTTZʢඇՄٯѹॖʣϑΥʔϚοτͷΞϧϑΝ৘ใ r ANIM''ANMF' ʜ
    ΞχϝʔγϣϯʗΞχϝʔγϣϯϑϨʔϜ
    – 'ICCP' ʜ
    *$$ΧϥʔϓϩϑΝΠϧ r 'EXIF''XMP '
    ʜ
    ϝλσʔλ খ͞ͳ࣮૷Ͱʮ8FC1ը૾ʯΛ࡞Δ
    
40. – 'VP8 ' ʜ
    -PTTZʢඇՄٯѹॖʣ – 'VP8L' ʜ
    -PTTMFTTʢՄٯѹॖʣ – 'ALPH'ʜ
    -PTTZʢඇՄٯѹॖʣϑΥʔϚοτͷΞϧϑΝ৘ใ r ANIM''ANMF' ʜ
    ΞχϝʔγϣϯʗΞχϝʔγϣϯϑϨʔϜ
    – 'ICCP' ʜ
    *$$ΧϥʔϓϩϑΝΠϧ r 'EXIF''XMP '
    ʜ
    ϝλσʔλ খ͞ͳ࣮૷Ͱʮ8FC1ը૾ʯΛ࡞Δ
    
41. খ͞ͳ࣮૷ͰʮѹॖσʔλʯΛ࡞ͬͯΈΔ 71-ͷϏοτετϦʔϜ 0x2F Width - 1 Hight - 1 Ver. A 
    CJU
    
    
    CZUF 
    CJU 
    CJU 
    CJU 
    CJU 
    CJU
42. খ͞ͳ࣮૷ͰʮѹॖσʔλʯΛ࡞ͬͯΈΔ 71-ͷϏοτετϦʔϜ 0x2F Width - 1 Hight - 1 Ver. A 
    CJU
    
    
    CZUF 
    CJU 
    CJU 
    CJU 
    CJU 
    CJU
43. #JU
    3FBEFS 4BNQMF
    $PEF struct BitReader { var bits: UInt32 = 0 // Buffered bits (LSB-first). var nBits: UInt32 = 0 // Number of valid bits currently in `bits`. var reader: ByteReader init(data: Data) { self.reader = ByteReader(data) } mutating func read(_ n: UInt32) throws -> UInt32 { precondition((1...32).contains(n), "n must be in 1…32") // Refill until we have enough bits. while nBits < n { guard let byte = try reader.read() else { throw BitStreamError.unexpectedEOF } // Append the byte at the current high position. bits |= UInt32(byte) << nBits nBits += 8 } // Mask out the requested bits. let result = bits & ((1 << n) &- 1) // (&- avoids overflow trap when n == 32) // Shift away the bits we've consumed. bits >>= n nBits -= n return result } }
44. ը૾ͷαΠζ
45. ը૾ͷαΠζ
46. ը૾ͷαΠζ
47. ը૾ͷαΠζ
48. ৭ม׵ Color Indexing Subtract Green Cross Color Color Cache Predictor LZ77 τʔΫϯԽ খ͞ͳ࣮૷ͰʮѹॖσʔλʯΛ࡞ͬͯΈΔ )VGGNBO
    $PEJOH )VGGNBO
    $PEJOH
49. খ͞ͳ࣮૷ͰʮѹॖσʔλʯΛ࡞ͬͯΈΔ )VGGNBO
    %FDPEJOH )VGGNBO
    %FDPEJOH Color Cache LZ77 τʔΫϯ෮ݩ όοΫϦϑΝϨϯεղܾ Color Indexing Subtract Green Cross Color Predictor ٯτϥϯεϑΥʔϜ
50. খ͞ͳ࣮૷ͰʮѹॖσʔλʯΛ࡞ͬͯΈΔ Color Cache LZ77 τʔΫϯ෮ݩ όοΫϦϑΝϨϯεղܾ Color Indexing Subtract Green Cross Color Predictor ٯτϥϯεϑΥʔϜ )VGGNBO
    %FDPEJOH )VGGNBO
    %FDPEJOH
51. 4BNQMF
    $PEF ➡
    IUUQTHJUIVCDPNLJTIJLBXBLBUTVNJXFCQFYFSDJTFT 📦
    1SF fi Y
    $PEJOH 4VCUSBDU
    (SFFO -; 1SFEJDUPS Cross Color $PMPS
    *OEFYJOH $PMPS
    $BDIF 
    1SF fi Y
    $PEJOH 🗜📤 
    4VCUSBDU
    (SFFO 🗜📤 🗜📤 
    -; 🗜📤 🗜📤 
    1SFEJDUPS 🗜📤 🗜📤 
    $SPTT
    $PMPS 🗜📤 🗜📤 
    $PMPS
    *OEFYJOH 🗜📤 🗜📤 
    $PMPS
    $BDIF 🗜📤 🗜📤 
    $PNQMFUF 🗜📤 🗜📤 🗜📤 🗜📤 🗜📤 🗜📤 🗜📤
52. 1SFGJY
    $PEJOH Α͘࢖͏஋Λ୹͘දݱ͢Δ
53. 1SFGJY
    $PEJOH
    $BOPOJDBM
    )VGGNBO
    $PEJOH ઀಄ූ߸Խʢਖ਼४ʗਖ਼نԽϋϑϚϯූ߸Խʣ 1SFGJY
    $PEJOHʢ઀಄ූ߸Խʣ )VGGNBO
    $PEJOH $BOPOJDBM
    )VGGNBO
    $PEJOH
54. σʔλͷ౷ܭతͳภΓΛར༻ͨ͠ѹॖ ϋϑϚϯූ߸Խ
55. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 BOOKKEEPER
56. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 BOOKKEEPER γϯϘϧ & 0 , # 1 3 ग़ݱස౓      
57. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 BOOKKEEPER γϯϘϧ & 0 , # 1 3 ग़ݱස౓       ௿ස౓ ߴස౓
58. ϋϑϚϯූ߸Խͷखॱ ϋϑϚϯ໦Λ࡞Δ r ͢΂ͯγϯϘϧΛʮॏΈʹग़ݱස౓ʯͷ༿ϊʔυͱͯ͠༻ҙ͢Δ
    r ࠷খස౓ͷϊʔυΛऔΓग़͠ɺ਌ϊʔυʢॏΈʹͭͷ࿨ʣΛ࡞Δ
    r ਌ϊʔυΛू߹ʹՃ͑Δ
    r ্هΛϊʔυʹͳΔ·Ͱ܁Γฦ͢
59. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P γϯϘϧ & 0 , 3 # 1 ग़ݱස౓         O K R E    
60. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P γϯϘϧ & 0 , 3 # 1 ग़ݱස౓         O K R E    
61. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P γϯϘϧ & 0 , 3 # 1 ग़ݱස౓         O K R E     
62. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P γϯϘϧ & 0 , 3 # 1 ग़ݱස౓         O K R E      
63. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P γϯϘϧ & 0 , 3 # 1 ग़ݱස౓         O K R E     2 
64. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P   O K R E       
65. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P   O K R E       
66. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P   O K R E        
67. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P   O K R E        
68. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P   O K R E         
69. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 B P   O K R E         
70. B P O K R E γϯϘϧ & 0 , 3 # 1 ग़ݱස౓       ූ߸ 0 0 1 0 1 1 1 0 1 0
71. B P O K R E γϯϘϧ & 0 , 3 # 1 ग़ݱස౓       ූ߸ 00 0 0 1 0 1 1 1 0 1 0
72. γϯϘϧ & 0 , 3 # 1 ग़ݱස౓       ූ߸ 00 10 B P O K R E 2 0 0 1 0 1 1 1 0 1 0
73. B P O K R E γϯϘϧ & 0 , 3 # 1 ग़ݱස౓       ූ߸ 00 10 010 0 0 1 0 1 1 1 0 1 0
74. γϯϘϧ & 0 , 3 # 1 ग़ݱස౓       ූ߸ 00 10 010 011 110 111 B P O K R E 0 0 1 0 1 1 1 0 1 0
75. ϋϑϚϯූ߸Խ ྫ
    #00,,&&1&3 γϯϘϧ & 0 , 3 # 1 ग़ݱස౓       ූ߸ 00 10 010 011 110 111 B O O K K E E P E R 100 101 101 01 01 00 00 110 00 111
76. B P   O K R E          γϯϘϧ & 0 , 3 # 1 ग़ݱස౓       ූ߸ 00 10 010 011 110 111
77. r ୹͍ූ߸௕ͷάϧʔϓ͔Βॱʹʢ୹͍ˠ௕͍ͷॱͰ෇༩ʣ
    r ಉ͡ූ߸௕ͷதͰ͸ɺܾΊͨγϯϘϧॱʹैͬͯූ߸ͷࣙॻॱʢϏοτͷঢ ॱʣͰ࿈൪ΛৼΔ
    r ֤ූ߸௕ͷ࠷ॳͷίʔυ͸ɺલͷ௕͞ͷʮ࣍ͷ஋ʯΛϏοτࠨʹͣΒͯ͠։࢝ $BOPOJDBM
    )VGGNBO
    $PEJOH ਖ਼४ʢਖ਼نԽʣϋϑϚϯූ߸Խ
78. ූ߸௕ 
    CJU 
    CJU B P O K R E $BOPOJDBM
    )VGGNBO
    $PEJOH ਖ਼४ʢਖ਼نԽʣϋϑϚϯූ߸Խ 
    CJU
79. ූ߸௕ 
    CJU 
    CJU P R O B K E $BOPOJDBM
    )VGGNBO
    $PEJOH ਖ਼४ʢਖ਼نԽʣϋϑϚϯූ߸Խ 
    CJU
80. ූ߸௕ 
    CJU 
    CJU P R O B K E $BOPOJDBM
    )VGGNBO
    $PEJOH ਖ਼४ʢਖ਼نԽʣϋϑϚϯූ߸Խ 
    CJU 00 01
81. ූ߸௕ 
    CJU 
    CJU P R O B K E $BOPOJDBM
    )VGGNBO
    $PEJOH ਖ਼४ʢਖ਼نԽʣϋϑϚϯූ߸Խ 
    CJU 00 01 100 101 110 111
82. B O O K K E E P E R 100 01 01 101 101 00 00 110 00 111 $BOPOJDBM
    )VGGNBO
    $PEJOH ਖ਼४ʢਖ਼نԽʣϋϑϚϯූ߸Խ [A:0, B:3, C:0, D:0, E:2, F:0, G:0, H:0, I:0, J:0, K:3, L:0, M:0, N:0, O:2, P:3, Q:0, R:3, S:0, T:0, U:0, V:0, W:0, X:0, Y:0, Z:0]
83. B O O K K E E P E R 100 01 01 101 101 00 00 110 00 111 $BOPOJDBM
    )VGGNBO
    $PEJOH ਖ਼४ʢਖ਼نԽʣϋϑϚϯූ߸Խ [0,3,0,0,2,0,0,0,0,0,3,0,0,0,2,3,0,3,0,0,0,0,0,0,0,0]
84. $BOPOJDBM
    )VGGNBO
    $PEJOH ਖ਼४ʢਖ਼نԽʣϋϑϚϯූ߸Խ [0,3,0,0,2,0,0,0,0,0,3,0,0,0,2,3,0,3,0,0,0,0,0,0,0,0]
85. r ग़ݱ͢Δස౓ͷߴ͍σʔλʹ୹͍ූ߸ΛׂΓ౰ͯΔ
    r 8FC1Ͱ࢖ΘΕΔͷ͸ΧϊχΧϧϋϑϚϯූ߸Խ
    r ΧϊχΧϧϋϑϚϯූ߸Խͷ෮߸͸ූ߸௕͕Θ͔Ε͹͍͍
    r ූ߸௕ͷྻ͸ϋϑϚϯූ߸ԽͷѹॖޮՌ͕ߴ͍
    r ࣮ࡍʹ8FC1Ͱ͸ූ߸௕ͷྻ͸ϋϑϚϯූ߸ԽͰѹॖ͞ΕΔ ϋϑϚϯූ߸Խͷ·ͱΊ 8FC1ͷσʔλ͸࠷ऴతʹϋϑϚϯූ߸Խ͞ΕΔ
86. r ग़ݱ͢Δස౓ͷߴ͍σʔλʹ୹͍ූ߸ΛׂΓ౰ͯΔ
    r 8FC1Ͱ࢖ΘΕΔͷ͸ΧϊχΧϧϋϑϚϯූ߸Խ
    r ΧϊχΧϧϋϑϚϯූ߸Խͷ෮߸͸ූ߸௕͕Θ͔Ε͹͍͍
    r ූ߸௕ͷྻ͸ϋϑϚϯූ߸ԽͷѹॖޮՌ͕ߴ͍
    r ࣮ࡍʹ8FC1Ͱ͸ූ߸௕ͷྻ͸ϋϑϚϯූ߸ԽͰѹॖ͞ΕΔ ϋϑϚϯූ߸Խͷ·ͱΊ 8FC1ͷσʔλ͸࠷ऴతʹϋϑϚϯූ߸Խ͞ΕΔ
87. r ग़ݱ͢Δස౓ͷߴ͍σʔλʹ୹͍ූ߸ΛׂΓ౰ͯΔ
    r 8FC1Ͱ࢖ΘΕΔͷ͸ΧϊχΧϧϋϑϚϯූ߸Խ
    r ΧϊχΧϧϋϑϚϯූ߸Խͷ෮߸͸ූ߸௕͕Θ͔Ε͹͍͍
    r ූ߸௕ͷྻ͸ϋϑϚϯූ߸ԽͷѹॖޮՌ͕ߴ͍
    r ࣮ࡍʹ8FC1Ͱ͸ූ߸௕ͷྻ͸ϋϑϚϯූ߸ԽͰѹॖ͞ΕΔ
    r 8FC1ͷ޻ఔ͸ϋϑϚϯූ߸ԽͷޮՌΛ࠷େʹ͢ΔͨΊͷલॲཧ ϋϑϚϯූ߸Խͷ·ͱΊ 8FC1ͷσʔλ͸࠷ऴతʹϋϑϚϯූ߸Խ͞ΕΔ
91. γϯϘϧ         ग़ݱස౓        
92. γϯϘϧ         ग़ݱස౓         ූ߸ 0 101 110 100 11111 11100 11101 11110
93. 1,302 bytes 384 bytes
94. r ը૾σʔλ͸ଟ͘ͷະ࢖༻γϯϘϧͱภΓ͕͋Δ
    r 8FC1ͷ֤޻ఔ͸ϋϑϚϯූ߸ԽͷޮՌΛ࠷େʹ͢ΔͨΊʹ͋Δ
    r ϋϑϚϯූ߸ԽΛਖ਼࣮͘͠૷͢Ε͹ΰʔϧ͸͙ͦ͢͜ ϋϑϚϯූ߸Խͷ·ͱΊ 8FC1ͷσʔλ͸࠷ऴతʹϋϑϚϯූ߸Խ͞ΕΔ
95. ৭ม׵ Color Indexing Subtract Green Cross Color Color Cache Predictor LZ77 τʔΫϯԽ )VGGNBO
    $PEJOH )VGGNBO
    $PEJOH 3FRVJSFE 0QUJPOBM
96. 4VCUSBDU
    (SFFO ྘Λج४ʹϜμΛҾ͘
97. 4VCUSBDU
    (SFFO Τϯίʔυ func applySubtractGreenTransform(pixels: inout [NRGBA]) { for i in pixels.indices { pixels[i].r = pixels[i].r &- pixels[i].g pixels[i].b = pixels[i].b &- pixels[i].g } }
98. 4VCUSBDU
    (SFFO σίʔυʢٯม׵ʣ func inverseSubtractGreen(_ pixel: [UInt8]) -> [UInt8] { var out = pixel var i = 0 while p < out.count { let g = out[i + 1] // green out[i + 0] &+= g // red += green out[i + 2] &+= g // blue += green I += 4 } return out }
99. 4VCUSBDU
    (SFFO ޮՌ [52, 50, 47] [106, 110, 97] [147, 150, 156] [202, 200, 197]
100. 4VCUSBDU
     (SFFO ޮՌ [52, 50, 47] [106, 110, 97] [147, 150, 156] [202, 200, 197] [2, 50, -3] [-4, 100, -3] [-3, 150, 6] [2, 200, -3]
101. -; ͘Γฦ͠͸ʮڑ཭º௕͞ʯͰৼΓฦΔ
102. -; Τϯίʔυ
103. -; Τϯίʔυ
104. -; Τϯίʔυ
105. -; Τϯίʔυ
106. -; Τϯίʔυ
107. -; Τϯίʔυ ݸલ͔Βݸ 
     
     
108. 1SFEJDUPS ͱͳΓͷ৭Ͱ࣍ͷ৭Λ౰ͯΔ
109. 1SFEJDUPS Τϯίʔυ
110. 1SFEJDUPS Τϯίʔυ
111. $SPTT
     $PMPS ৭Ͳ͏͠ͷॏͳΓΛ΄Ͳ͘
112. r ը૾ΛλΠϧʹ෼͚ɺλΠϧ͝ͱʹ܎਺ΛܾΊΔ
     r 3(#ͦΕͧΕʹ܎਺Λֻ͚ͨ஋Λ࢖ͬͯ3ͱ#Λඍௐ੔͢Δ
     r ਓഽ΍ࣳੜͳͲɺ৭͕গࠞ͟͠Γ͕ͪͳ৔ॴͰޮՌ͕͋Δ
     r 4VCUSBDU(SFFO͸྘ͱͷ૬͕ؔͩ੺ͱ੨ͷؒͷӨڹ΋ิਖ਼Ͱ͖Δ $SPTT
     $PMPS Τϯίʔυ
113. $PMPS
     *OEFYJOH Α͘࢖͏৭ʹ൪߸ΛৼΔ
114. r ࢖ΘΕ͍ͯΔ৭ͷ਺͕৭ҎԼ
     r ৭ʹ൪߸ΛৼΔ
     r ൪߸ͱ৭ͷରԠʢύϨοτʣΛૹΓɺ৭͸൪߸Ͱஔ͖׵͑Δ
     r ϋϑϚϯූ߸ԽͰѻ͏ه߸ͷछྨ͕ҰؾʹݮΔͷͰѹॖ͕ޮ͘ $PMPS
     *OEFYJOH Τϯίʔυ
115. $PMPS
     $BDIF ௚લͷ৭ΛΩϟογϡ͢Δ
116. r ग़ྗͨ͠ϐΫηϧΛΩϟογϡʹೖΕΔ
     r ͦͷ͋ͱͰಡΜͩϐΫηϧ͕Ωϟογϡʹ͋Ε͹ΠϯσοΫε͚ͩΛૹΔ $PMPS
     $BDIF Τϯίʔυ
117. r σίʔυͨ͠ϐΫηϧΛΩϟογϡʹೖΕΔ
     r ͦͷ͋ͱͰσίʔυͨ͠ϐΫηϧ͕Ωϟογϡʹ͋Ε͹ΠϯσοΫε͔Βσ ίʔυ͢Δ $PMPS
     $BDIF σίʔυ
118. 8SBQ
     6Q r 8FC1ͷ޻ఔ͸ϋϑϚϯූ߸ԽΛ࠷େݶޮՌతʹൃشͤ͞ΔͨΊͷલॲཧ
     r ϋϑϚϯූ߸Խ͸ଟஈͰద༻͞Ε͍ͯͯ໎͍΍͍͢ͷͰ࢓૊Έͷཧղ͕ॏཁ
     r ͻͱͭͻͱͭͷ޻ఔ͸ҙ֎ͱγϯϓϧ
     r ϋϑϚϯූ߸Խ͚ͩΛద༻ͨ͠8FC1ը૾͸ଘࡏ͠ͳ͍ͷͰ࡞Δ
     r ϋϑϚϯූ߸Խ͚ͩద༻ͨ͠ը૾͕͋Ε͹࢒Γͷॲཧ͸Ұͭͣͭ࡞͍͚ͬͯΔ
119. 3FGFSFODFT r 4BNQMF
     $PEF
     IUUQTHJUIVCDPNLJTIJLBXBLBUTVNJXFCQFYFSDJTFT
     r "O
     JNBHF
     GPSNBU
     GPS
     UIF
     8FC
     c
     8FC1
     c
     (PPHMF
     GPS
     %FWFMPQFST
     IUUQTEFWFMPQFSTHPPHMFDPNTQFFEXFCQ
     r MJCXFCQ
     IUUQTDISPNJVNHPPHMFTPVSDFDPNXFCNMJCXFCQ
     r MJCXFCQUFTUEBUB
     IUUQTDISPNJVNHPPHMFTPVSDFDPNXFCNMJCXFCQUFTUEBUB