Merge pull request #6486 from REDxEYE/improved_dds

Tests/test_file_dds.py

@@ -17,6 +17,9 @@ TEST_FILE_DX10_BC4_UNORM = "Tests/images/bc4_unorm.dds"
 TEST_FILE_DX10_BC5_TYPELESS = "Tests/images/bc5_typeless.dds"
 TEST_FILE_DX10_BC5_UNORM = "Tests/images/bc5_unorm.dds"
 TEST_FILE_DX10_BC5_SNORM = "Tests/images/bc5_snorm.dds"
+TEST_FILE_DX10_BC1 = "Tests/images/bc1.dds"
+TEST_FILE_DX10_BC1_TYPELESS = "Tests/images/bc1_typeless.dds"
+TEST_FILE_BC4U = "Tests/images/bc4u.dds"
 TEST_FILE_BC5S = "Tests/images/bc5s.dds"
 TEST_FILE_BC5U = "Tests/images/bc5u.dds"
 TEST_FILE_BC6H = "Tests/images/bc6h.dds"
@@ -31,11 +34,20 @@ TEST_FILE_UNCOMPRESSED_RGB = "Tests/images/hopper.dds"
 TEST_FILE_UNCOMPRESSED_RGB_WITH_ALPHA = "Tests/images/uncompressed_rgb.dds"
 
 
-def test_sanity_dxt1():
+@pytest.mark.parametrize(
-    """Check DXT1 images can be opened"""
+    "image_path",
+    (
+        TEST_FILE_DXT1,
+        # hexeditted to use DX10 FourCC
+        TEST_FILE_DX10_BC1,
+        TEST_FILE_DX10_BC1_TYPELESS,
+    ),
+)
+def test_sanity_dxt1_bc1(image_path):
+    """Check DXT1 and BC1 images can be opened"""
     with Image.open(TEST_FILE_DXT1.replace(".dds", ".png")) as target:
         target = target.convert("RGBA")
-    with Image.open(TEST_FILE_DXT1) as im:
+    with Image.open(image_path) as im:
         im.load()
 
         assert im.format == "DDS"
@@ -71,10 +83,18 @@ def test_sanity_dxt5():
     assert_image_equal_tofile(im, TEST_FILE_DXT5.replace(".dds", ".png"))
 
 
-def test_sanity_ati1():
+@pytest.mark.parametrize(
-    """Check ATI1 images can be opened"""
+    "image_path",
+    (
+        TEST_FILE_ATI1,
+        # hexeditted to use BC4U FourCC
+        TEST_FILE_BC4U,
+    ),
+)
+def test_sanity_ati1_bc4u(image_path):
+    """Check ATI1 and BC4U images can be opened"""
 
-    with Image.open(TEST_FILE_ATI1) as im:
+    with Image.open(image_path) as im:
         im.load()
 
         assert im.format == "DDS"
@@ -222,12 +242,6 @@ def test_dx10_r8g8b8a8_unorm_srgb():
         )
 
 
-def test_unimplemented_dxgi_format():
-    with pytest.raises(NotImplementedError):
-        with Image.open("Tests/images/unimplemented_dxgi_format.dds"):
-            pass
-
-
 @pytest.mark.parametrize(
     ("mode", "size", "test_file"),
     [
@@ -326,9 +340,29 @@ def test_palette():
         assert_image_equal_tofile(im, "Tests/images/transparent.gif")
 
 
-def test_unimplemented_pixel_format():
+@pytest.mark.parametrize(
+    "test_file",
+    (
+        "Tests/images/unsupported_bitcount_rgb.dds",
+        "Tests/images/unsupported_bitcount_luminance.dds",
+    ),
+)
+def test_unsupported_bitcount(test_file):
+    with pytest.raises(OSError):
+        with Image.open(test_file):
+            pass
+
+
+@pytest.mark.parametrize(
+    "test_file",
+    (
+        "Tests/images/unimplemented_dxgi_format.dds",
+        "Tests/images/unimplemented_pfflags.dds",
+    ),
+)
+def test_not_implemented(test_file):
     with pytest.raises(NotImplementedError):
-        with Image.open("Tests/images/unimplemented_pixel_format.dds"):
+        with Image.open(test_file):
             pass
 
 

docs/reference/plugins.rst

@@ -33,6 +33,14 @@ Plugin reference
     :undoc-members:
     :show-inheritance:
 
+:mod:`~PIL.DdsImagePlugin` Module
+---------------------------------
+
+.. automodule:: PIL.DdsImagePlugin
+    :members:
+    :undoc-members:
+    :show-inheritance:
+
 :mod:`~PIL.EpsImagePlugin` Module
 ---------------------------------
 

docs/releasenotes/10.2.0.rst

@@ -0,0 +1,56 @@
+10.2.0
+------
+
+Backwards Incompatible Changes
+==============================
+
+TODO
+^^^^
+
+TODO
+
+Deprecations
+============
+
+TODO
+^^^^
+
+TODO
+
+API Changes
+===========
+
+TODO
+^^^^
+
+TODO
+
+API Additions
+=============
+
+Added DdsImagePlugin enums
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+:py:class:`~PIL.DdsImagePlugin.DDSD`, :py:class:`~PIL.DdsImagePlugin.DDSCAPS`,
+:py:class:`~PIL.DdsImagePlugin.DDSCAPS2`, :py:class:`~PIL.DdsImagePlugin.DDPF`,
+:py:class:`~PIL.DdsImagePlugin.DXGI_FORMAT` and :py:class:`~PIL.DdsImagePlugin.D3DFMT`
+enums have been added to :py:class:`PIL.DdsImagePlugin`.
+
+Security
+========
+
+TODO
+^^^^
+
+TODO
+
+Other Changes
+=============
+
+Added DDS BC4U and DX10 BC1 and BC4 reading
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Support has been added to read the BC4U format of DDS images.
+
+Support has also been added to read DX10 BC1 and BC4, whether UNORM or
+TYPELESS.

docs/releasenotes/index.rst

@@ -14,6 +14,7 @@ expected to be backported to earlier versions.
 .. toctree::
   :maxdepth: 2
 
+  10.2.0
   10.1.0
   10.0.1
   10.0.0

src/PIL/DdsImagePlugin.py

@@ -10,104 +10,314 @@ Full text of the CC0 license:
 https://creativecommons.org/publicdomain/zero/1.0/
 """
 
+import io
 import struct
-from io import BytesIO
+import sys
+from enum import IntEnum, IntFlag
 
 from . import Image, ImageFile, ImagePalette
+from ._binary import i32le as i32
 from ._binary import o32le as o32
 
 # Magic ("DDS ")
 DDS_MAGIC = 0x20534444
 
+
 # DDS flags
-DDSD_CAPS = 0x1
+class DDSD(IntFlag):
-DDSD_HEIGHT = 0x2
+    CAPS = 0x1
-DDSD_WIDTH = 0x4
+    HEIGHT = 0x2
-DDSD_PITCH = 0x8
+    WIDTH = 0x4
-DDSD_PIXELFORMAT = 0x1000
+    PITCH = 0x8
-DDSD_MIPMAPCOUNT = 0x20000
+    PIXELFORMAT = 0x1000
-DDSD_LINEARSIZE = 0x80000
+    MIPMAPCOUNT = 0x20000
-DDSD_DEPTH = 0x800000
+    LINEARSIZE = 0x80000
+    DEPTH = 0x800000
+
 
 # DDS caps
-DDSCAPS_COMPLEX = 0x8
+class DDSCAPS(IntFlag):
-DDSCAPS_TEXTURE = 0x1000
+    COMPLEX = 0x8
-DDSCAPS_MIPMAP = 0x400000
+    TEXTURE = 0x1000
+    MIPMAP = 0x400000
+
+
+class DDSCAPS2(IntFlag):
+    CUBEMAP = 0x200
+    CUBEMAP_POSITIVEX = 0x400
+    CUBEMAP_NEGATIVEX = 0x800
+    CUBEMAP_POSITIVEY = 0x1000
+    CUBEMAP_NEGATIVEY = 0x2000
+    CUBEMAP_POSITIVEZ = 0x4000
+    CUBEMAP_NEGATIVEZ = 0x8000
+    VOLUME = 0x200000
 
-DDSCAPS2_CUBEMAP = 0x200
-DDSCAPS2_CUBEMAP_POSITIVEX = 0x400
-DDSCAPS2_CUBEMAP_NEGATIVEX = 0x800
-DDSCAPS2_CUBEMAP_POSITIVEY = 0x1000
-DDSCAPS2_CUBEMAP_NEGATIVEY = 0x2000
-DDSCAPS2_CUBEMAP_POSITIVEZ = 0x4000
-DDSCAPS2_CUBEMAP_NEGATIVEZ = 0x8000
-DDSCAPS2_VOLUME = 0x200000
 
 # Pixel Format
-DDPF_ALPHAPIXELS = 0x1
+class DDPF(IntFlag):
-DDPF_ALPHA = 0x2
+    ALPHAPIXELS = 0x1
-DDPF_FOURCC = 0x4
+    ALPHA = 0x2
-DDPF_PALETTEINDEXED8 = 0x20
+    FOURCC = 0x4
-DDPF_RGB = 0x40
+    PALETTEINDEXED8 = 0x20
-DDPF_LUMINANCE = 0x20000
+    RGB = 0x40
-
+    LUMINANCE = 0x20000
-
-# dds.h
-
-DDS_FOURCC = DDPF_FOURCC
-DDS_RGB = DDPF_RGB
-DDS_RGBA = DDPF_RGB | DDPF_ALPHAPIXELS
-DDS_LUMINANCE = DDPF_LUMINANCE
-DDS_LUMINANCEA = DDPF_LUMINANCE | DDPF_ALPHAPIXELS
-DDS_ALPHA = DDPF_ALPHA
-DDS_PAL8 = DDPF_PALETTEINDEXED8
-
-DDS_HEADER_FLAGS_TEXTURE = DDSD_CAPS | DDSD_HEIGHT | DDSD_WIDTH | DDSD_PIXELFORMAT
-DDS_HEADER_FLAGS_MIPMAP = DDSD_MIPMAPCOUNT
-DDS_HEADER_FLAGS_VOLUME = DDSD_DEPTH
-DDS_HEADER_FLAGS_PITCH = DDSD_PITCH
-DDS_HEADER_FLAGS_LINEARSIZE = DDSD_LINEARSIZE
-
-DDS_HEIGHT = DDSD_HEIGHT
-DDS_WIDTH = DDSD_WIDTH
-
-DDS_SURFACE_FLAGS_TEXTURE = DDSCAPS_TEXTURE
-DDS_SURFACE_FLAGS_MIPMAP = DDSCAPS_COMPLEX | DDSCAPS_MIPMAP
-DDS_SURFACE_FLAGS_CUBEMAP = DDSCAPS_COMPLEX
-
-DDS_CUBEMAP_POSITIVEX = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_POSITIVEX
-DDS_CUBEMAP_NEGATIVEX = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_NEGATIVEX
-DDS_CUBEMAP_POSITIVEY = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_POSITIVEY
-DDS_CUBEMAP_NEGATIVEY = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_NEGATIVEY
-DDS_CUBEMAP_POSITIVEZ = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_POSITIVEZ
-DDS_CUBEMAP_NEGATIVEZ = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_NEGATIVEZ
-
-
-# DXT1
-DXT1_FOURCC = 0x31545844
-
-# DXT3
-DXT3_FOURCC = 0x33545844
-
-# DXT5
-DXT5_FOURCC = 0x35545844
 
 
 # dxgiformat.h
+class DXGI_FORMAT(IntEnum):
+    UNKNOWN = 0
+    R32G32B32A32_TYPELESS = 1
+    R32G32B32A32_FLOAT = 2
+    R32G32B32A32_UINT = 3
+    R32G32B32A32_SINT = 4
+    R32G32B32_TYPELESS = 5
+    R32G32B32_FLOAT = 6
+    R32G32B32_UINT = 7
+    R32G32B32_SINT = 8
+    R16G16B16A16_TYPELESS = 9
+    R16G16B16A16_FLOAT = 10
+    R16G16B16A16_UNORM = 11
+    R16G16B16A16_UINT = 12
+    R16G16B16A16_SNORM = 13
+    R16G16B16A16_SINT = 14
+    R32G32_TYPELESS = 15
+    R32G32_FLOAT = 16
+    R32G32_UINT = 17
+    R32G32_SINT = 18
+    R32G8X24_TYPELESS = 19
+    D32_FLOAT_S8X24_UINT = 20
+    R32_FLOAT_X8X24_TYPELESS = 21
+    X32_TYPELESS_G8X24_UINT = 22
+    R10G10B10A2_TYPELESS = 23
+    R10G10B10A2_UNORM = 24
+    R10G10B10A2_UINT = 25
+    R11G11B10_FLOAT = 26
+    R8G8B8A8_TYPELESS = 27
+    R8G8B8A8_UNORM = 28
+    R8G8B8A8_UNORM_SRGB = 29
+    R8G8B8A8_UINT = 30
+    R8G8B8A8_SNORM = 31
+    R8G8B8A8_SINT = 32
+    R16G16_TYPELESS = 33
+    R16G16_FLOAT = 34
+    R16G16_UNORM = 35
+    R16G16_UINT = 36
+    R16G16_SNORM = 37
+    R16G16_SINT = 38
+    R32_TYPELESS = 39
+    D32_FLOAT = 40
+    R32_FLOAT = 41
+    R32_UINT = 42
+    R32_SINT = 43
+    R24G8_TYPELESS = 44
+    D24_UNORM_S8_UINT = 45
+    R24_UNORM_X8_TYPELESS = 46
+    X24_TYPELESS_G8_UINT = 47
+    R8G8_TYPELESS = 48
+    R8G8_UNORM = 49
+    R8G8_UINT = 50
+    R8G8_SNORM = 51
+    R8G8_SINT = 52
+    R16_TYPELESS = 53
+    R16_FLOAT = 54
+    D16_UNORM = 55
+    R16_UNORM = 56
+    R16_UINT = 57
+    R16_SNORM = 58
+    R16_SINT = 59
+    R8_TYPELESS = 60
+    R8_UNORM = 61
+    R8_UINT = 62
+    R8_SNORM = 63
+    R8_SINT = 64
+    A8_UNORM = 65
+    R1_UNORM = 66
+    R9G9B9E5_SHAREDEXP = 67
+    R8G8_B8G8_UNORM = 68
+    G8R8_G8B8_UNORM = 69
+    BC1_TYPELESS = 70
+    BC1_UNORM = 71
+    BC1_UNORM_SRGB = 72
+    BC2_TYPELESS = 73
+    BC2_UNORM = 74
+    BC2_UNORM_SRGB = 75
+    BC3_TYPELESS = 76
+    BC3_UNORM = 77
+    BC3_UNORM_SRGB = 78
+    BC4_TYPELESS = 79
+    BC4_UNORM = 80
+    BC4_SNORM = 81
+    BC5_TYPELESS = 82
+    BC5_UNORM = 83
+    BC5_SNORM = 84
+    B5G6R5_UNORM = 85
+    B5G5R5A1_UNORM = 86
+    B8G8R8A8_UNORM = 87
+    B8G8R8X8_UNORM = 88
+    R10G10B10_XR_BIAS_A2_UNORM = 89
+    B8G8R8A8_TYPELESS = 90
+    B8G8R8A8_UNORM_SRGB = 91
+    B8G8R8X8_TYPELESS = 92
+    B8G8R8X8_UNORM_SRGB = 93
+    BC6H_TYPELESS = 94
+    BC6H_UF16 = 95
+    BC6H_SF16 = 96
+    BC7_TYPELESS = 97
+    BC7_UNORM = 98
+    BC7_UNORM_SRGB = 99
+    AYUV = 100
+    Y410 = 101
+    Y416 = 102
+    NV12 = 103
+    P010 = 104
+    P016 = 105
+    OPAQUE_420 = 106
+    YUY2 = 107
+    Y210 = 108
+    Y216 = 109
+    NV11 = 110
+    AI44 = 111
+    IA44 = 112
+    P8 = 113
+    A8P8 = 114
+    B4G4R4A4_UNORM = 115
+    P208 = 130
+    V208 = 131
+    V408 = 132
+    SAMPLER_FEEDBACK_MIN_MIP_OPAQUE = 189
+    SAMPLER_FEEDBACK_MIP_REGION_USED_OPAQUE = 190
 
-DXGI_FORMAT_R8G8B8A8_TYPELESS = 27
+
-DXGI_FORMAT_R8G8B8A8_UNORM = 28
+class D3DFMT(IntEnum):
-DXGI_FORMAT_R8G8B8A8_UNORM_SRGB = 29
+    UNKNOWN = 0
-DXGI_FORMAT_BC4_TYPELESS = 79
+    R8G8B8 = 20
-DXGI_FORMAT_BC4_UNORM = 80
+    A8R8G8B8 = 21
-DXGI_FORMAT_BC5_TYPELESS = 82
+    X8R8G8B8 = 22
-DXGI_FORMAT_BC5_UNORM = 83
+    R5G6B5 = 23
-DXGI_FORMAT_BC5_SNORM = 84
+    X1R5G5B5 = 24
-DXGI_FORMAT_BC6H_UF16 = 95
+    A1R5G5B5 = 25
-DXGI_FORMAT_BC6H_SF16 = 96
+    A4R4G4B4 = 26
-DXGI_FORMAT_BC7_TYPELESS = 97
+    R3G3B2 = 27
-DXGI_FORMAT_BC7_UNORM = 98
+    A8 = 28
-DXGI_FORMAT_BC7_UNORM_SRGB = 99
+    A8R3G3B2 = 29
+    X4R4G4B4 = 30
+    A2B10G10R10 = 31
+    A8B8G8R8 = 32
+    X8B8G8R8 = 33
+    G16R16 = 34
+    A2R10G10B10 = 35
+    A16B16G16R16 = 36
+    A8P8 = 40
+    P8 = 41
+    L8 = 50
+    A8L8 = 51
+    A4L4 = 52
+    V8U8 = 60
+    L6V5U5 = 61
+    X8L8V8U8 = 62
+    Q8W8V8U8 = 63
+    V16U16 = 64
+    A2W10V10U10 = 67
+    D16_LOCKABLE = 70
+    D32 = 71
+    D15S1 = 73
+    D24S8 = 75
+    D24X8 = 77
+    D24X4S4 = 79
+    D16 = 80
+    D32F_LOCKABLE = 82
+    D24FS8 = 83
+    D32_LOCKABLE = 84
+    S8_LOCKABLE = 85
+    L16 = 81
+    VERTEXDATA = 100
+    INDEX16 = 101
+    INDEX32 = 102
+    Q16W16V16U16 = 110
+    R16F = 111
+    G16R16F = 112
+    A16B16G16R16F = 113
+    R32F = 114
+    G32R32F = 115
+    A32B32G32R32F = 116
+    CxV8U8 = 117
+    A1 = 118
+    A2B10G10R10_XR_BIAS = 119
+    BINARYBUFFER = 199
+
+    UYVY = i32(b"UYVY")
+    R8G8_B8G8 = i32(b"RGBG")
+    YUY2 = i32(b"YUY2")
+    G8R8_G8B8 = i32(b"GRGB")
+    DXT1 = i32(b"DXT1")
+    DXT2 = i32(b"DXT2")
+    DXT3 = i32(b"DXT3")
+    DXT4 = i32(b"DXT4")
+    DXT5 = i32(b"DXT5")
+    DX10 = i32(b"DX10")
+    BC4S = i32(b"BC4S")
+    BC4U = i32(b"BC4U")
+    BC5S = i32(b"BC5S")
+    BC5U = i32(b"BC5U")
+    ATI1 = i32(b"ATI1")
+    ATI2 = i32(b"ATI2")
+    MULTI2_ARGB8 = i32(b"MET1")
+
+
+# Backward compatibility layer
+module = sys.modules[__name__]
+for item in DDSD:
+    setattr(module, "DDSD_" + item.name, item.value)
+for item in DDSCAPS:
+    setattr(module, "DDSCAPS_" + item.name, item.value)
+for item in DDSCAPS2:
+    setattr(module, "DDSCAPS2_" + item.name, item.value)
+for item in DDPF:
+    setattr(module, "DDPF_" + item.name, item.value)
+
+DDS_FOURCC = DDPF.FOURCC
+DDS_RGB = DDPF.RGB
+DDS_RGBA = DDPF.RGB | DDPF.ALPHAPIXELS
+DDS_LUMINANCE = DDPF.LUMINANCE
+DDS_LUMINANCEA = DDPF.LUMINANCE | DDPF.ALPHAPIXELS
+DDS_ALPHA = DDPF.ALPHA
+DDS_PAL8 = DDPF.PALETTEINDEXED8
+
+DDS_HEADER_FLAGS_TEXTURE = DDSD.CAPS | DDSD.HEIGHT | DDSD.WIDTH | DDSD.PIXELFORMAT
+DDS_HEADER_FLAGS_MIPMAP = DDSD.MIPMAPCOUNT
+DDS_HEADER_FLAGS_VOLUME = DDSD.DEPTH
+DDS_HEADER_FLAGS_PITCH = DDSD.PITCH
+DDS_HEADER_FLAGS_LINEARSIZE = DDSD.LINEARSIZE
+
+DDS_HEIGHT = DDSD.HEIGHT
+DDS_WIDTH = DDSD.WIDTH
+
+DDS_SURFACE_FLAGS_TEXTURE = DDSCAPS.TEXTURE
+DDS_SURFACE_FLAGS_MIPMAP = DDSCAPS.COMPLEX | DDSCAPS.MIPMAP
+DDS_SURFACE_FLAGS_CUBEMAP = DDSCAPS.COMPLEX
+
+DDS_CUBEMAP_POSITIVEX = DDSCAPS2.CUBEMAP | DDSCAPS2.CUBEMAP_POSITIVEX
+DDS_CUBEMAP_NEGATIVEX = DDSCAPS2.CUBEMAP | DDSCAPS2.CUBEMAP_NEGATIVEX
+DDS_CUBEMAP_POSITIVEY = DDSCAPS2.CUBEMAP | DDSCAPS2.CUBEMAP_POSITIVEY
+DDS_CUBEMAP_NEGATIVEY = DDSCAPS2.CUBEMAP | DDSCAPS2.CUBEMAP_NEGATIVEY
+DDS_CUBEMAP_POSITIVEZ = DDSCAPS2.CUBEMAP | DDSCAPS2.CUBEMAP_POSITIVEZ
+DDS_CUBEMAP_NEGATIVEZ = DDSCAPS2.CUBEMAP | DDSCAPS2.CUBEMAP_NEGATIVEZ
+
+DXT1_FOURCC = D3DFMT.DXT1
+DXT3_FOURCC = D3DFMT.DXT3
+DXT5_FOURCC = D3DFMT.DXT5
+
+DXGI_FORMAT_R8G8B8A8_TYPELESS = DXGI_FORMAT.R8G8B8A8_TYPELESS
+DXGI_FORMAT_R8G8B8A8_UNORM = DXGI_FORMAT.R8G8B8A8_UNORM
+DXGI_FORMAT_R8G8B8A8_UNORM_SRGB = DXGI_FORMAT.R8G8B8A8_UNORM_SRGB
+DXGI_FORMAT_BC5_TYPELESS = DXGI_FORMAT.BC5_TYPELESS
+DXGI_FORMAT_BC5_UNORM = DXGI_FORMAT.BC5_UNORM
+DXGI_FORMAT_BC5_SNORM = DXGI_FORMAT.BC5_SNORM
+DXGI_FORMAT_BC6H_UF16 = DXGI_FORMAT.BC6H_UF16
+DXGI_FORMAT_BC6H_SF16 = DXGI_FORMAT.BC6H_SF16
+DXGI_FORMAT_BC7_TYPELESS = DXGI_FORMAT.BC7_TYPELESS
+DXGI_FORMAT_BC7_UNORM = DXGI_FORMAT.BC7_UNORM
+DXGI_FORMAT_BC7_UNORM_SRGB = DXGI_FORMAT.BC7_UNORM_SRGB
 
 
 class DdsImageFile(ImageFile.ImageFile):
@@ -126,118 +336,140 @@ class DdsImageFile(ImageFile.ImageFile):
         if len(header_bytes) != 120:
             msg = f"Incomplete header: {len(header_bytes)} bytes"
             raise OSError(msg)
-        header = BytesIO(header_bytes)
+        header = io.BytesIO(header_bytes)
 
         flags, height, width = struct.unpack("<3I", header.read(12))
         self._size = (width, height)
-        self._mode = "RGBA"
 
         pitch, depth, mipmaps = struct.unpack("<3I", header.read(12))
         struct.unpack("<11I", header.read(44))  # reserved
 
         # pixel format
-        pfsize, pfflags = struct.unpack("<2I", header.read(8))
+        pfsize, pfflags, fourcc, bitcount = struct.unpack("<4I", header.read(16))
-        fourcc = header.read(4)
+        n = 0
-        (bitcount,) = struct.unpack("<I", header.read(4))
+        rawmode = None
+        if pfflags & DDPF.RGB:
+            # Texture contains uncompressed RGB data
             masks = struct.unpack("<4I", header.read(16))
-        if pfflags & DDPF_LUMINANCE:
+            masks = {mask: ["R", "G", "B", "A"][i] for i, mask in enumerate(masks)}
-            # Texture contains uncompressed L or LA data
+            if bitcount == 24:
-            if pfflags & DDPF_ALPHAPIXELS:
+                self._mode = "RGB"
+                rawmode = masks[0x000000FF] + masks[0x0000FF00] + masks[0x00FF0000]
+            elif bitcount == 32 and pfflags & DDPF.ALPHAPIXELS:
+                self._mode = "RGBA"
+                rawmode = (
+                    masks[0x000000FF]
+                    + masks[0x0000FF00]
+                    + masks[0x00FF0000]
+                    + masks[0xFF000000]
+                )
+            else:
+                msg = f"Unsupported bitcount {bitcount} for {pfflags}"
+                raise OSError(msg)
+        elif pfflags & DDPF.LUMINANCE:
+            if bitcount == 8:
+                self._mode = "L"
+            elif bitcount == 16 and pfflags & DDPF.ALPHAPIXELS:
                 self._mode = "LA"
             else:
-                self._mode = "L"
+                msg = f"Unsupported bitcount {bitcount} for {pfflags}"
-
+                raise OSError(msg)
-            self.tile = [("raw", (0, 0) + self.size, 0, (self.mode, 0, 1))]
+        elif pfflags & DDPF.PALETTEINDEXED8:
-        elif pfflags & DDPF_RGB:
-            # Texture contains uncompressed RGB data
-            masks = {mask: ["R", "G", "B", "A"][i] for i, mask in enumerate(masks)}
-            rawmode = ""
-            if pfflags & DDPF_ALPHAPIXELS:
-                rawmode += masks[0xFF000000]
-            else:
-                self._mode = "RGB"
-            rawmode += masks[0xFF0000] + masks[0xFF00] + masks[0xFF]
-
-            self.tile = [("raw", (0, 0) + self.size, 0, (rawmode[::-1], 0, 1))]
-        elif pfflags & DDPF_PALETTEINDEXED8:
             self._mode = "P"
             self.palette = ImagePalette.raw("RGBA", self.fp.read(1024))
-            self.tile = [("raw", (0, 0) + self.size, 0, "L")]
+        elif pfflags & DDPF.FOURCC:
-        else:
+            offset = header_size + 4
-            data_start = header_size + 4
+            if fourcc == D3DFMT.DXT1:
-            n = 0
+                self._mode = "RGBA"
-            if fourcc == b"DXT1":
                 self.pixel_format = "DXT1"
                 n = 1
-            elif fourcc == b"DXT3":
+            elif fourcc == D3DFMT.DXT3:
+                self._mode = "RGBA"
                 self.pixel_format = "DXT3"
                 n = 2
-            elif fourcc == b"DXT5":
+            elif fourcc == D3DFMT.DXT5:
+                self._mode = "RGBA"
                 self.pixel_format = "DXT5"
                 n = 3
-            elif fourcc == b"ATI1":
+            elif fourcc in (D3DFMT.BC4U, D3DFMT.ATI1):
+                self._mode = "L"
                 self.pixel_format = "BC4"
                 n = 4
-                self._mode = "L"
+            elif fourcc == D3DFMT.BC5S:
-            elif fourcc in (b"ATI2", b"BC5U"):
-                self.pixel_format = "BC5"
-                n = 5
                 self._mode = "RGB"
-            elif fourcc == b"BC5S":
                 self.pixel_format = "BC5S"
                 n = 5
+            elif fourcc in (D3DFMT.BC5U, D3DFMT.ATI2):
                 self._mode = "RGB"
-            elif fourcc == b"DX10":
+                self.pixel_format = "BC5"
-                data_start += 20
+                n = 5
+            elif fourcc == D3DFMT.DX10:
+                offset += 20
                 # ignoring flags which pertain to volume textures and cubemaps
                 (dxgi_format,) = struct.unpack("<I", self.fp.read(4))
                 self.fp.read(16)
-                if dxgi_format in (DXGI_FORMAT_BC4_TYPELESS, DXGI_FORMAT_BC4_UNORM):
+                if dxgi_format in (
+                    DXGI_FORMAT.BC1_UNORM,
+                    DXGI_FORMAT.BC1_TYPELESS,
+                ):
+                    self._mode = "RGBA"
+                    self.pixel_format = "BC1"
+                    n = 1
+                elif dxgi_format in (DXGI_FORMAT.BC4_TYPELESS, DXGI_FORMAT.BC4_UNORM):
+                    self._mode = "L"
                     self.pixel_format = "BC4"
                     n = 4
-                    self._mode = "L"
+                elif dxgi_format in (DXGI_FORMAT.BC5_TYPELESS, DXGI_FORMAT.BC5_UNORM):
-                elif dxgi_format in (DXGI_FORMAT_BC5_TYPELESS, DXGI_FORMAT_BC5_UNORM):
+                    self._mode = "RGB"
                     self.pixel_format = "BC5"
                     n = 5
+                elif dxgi_format == DXGI_FORMAT.BC5_SNORM:
                     self._mode = "RGB"
-                elif dxgi_format == DXGI_FORMAT_BC5_SNORM:
                     self.pixel_format = "BC5S"
                     n = 5
+                elif dxgi_format == DXGI_FORMAT.BC6H_UF16:
                     self._mode = "RGB"
-                elif dxgi_format == DXGI_FORMAT_BC6H_UF16:
                     self.pixel_format = "BC6H"
                     n = 6
+                elif dxgi_format == DXGI_FORMAT.BC6H_SF16:
                     self._mode = "RGB"
-                elif dxgi_format == DXGI_FORMAT_BC6H_SF16:
                     self.pixel_format = "BC6HS"
                     n = 6
-                    self._mode = "RGB"
-                elif dxgi_format in (DXGI_FORMAT_BC7_TYPELESS, DXGI_FORMAT_BC7_UNORM):
-                    self.pixel_format = "BC7"
-                    n = 7
-                elif dxgi_format == DXGI_FORMAT_BC7_UNORM_SRGB:
-                    self.pixel_format = "BC7"
-                    self.info["gamma"] = 1 / 2.2
-                    n = 7
                 elif dxgi_format in (
-                    DXGI_FORMAT_R8G8B8A8_TYPELESS,
+                    DXGI_FORMAT.BC7_TYPELESS,
-                    DXGI_FORMAT_R8G8B8A8_UNORM,
+                    DXGI_FORMAT.BC7_UNORM,
-                    DXGI_FORMAT_R8G8B8A8_UNORM_SRGB,
+                    DXGI_FORMAT.BC7_UNORM_SRGB,
                 ):
-                    self.tile = [("raw", (0, 0) + self.size, 0, ("RGBA", 0, 1))]
+                    self._mode = "RGBA"
-                    if dxgi_format == DXGI_FORMAT_R8G8B8A8_UNORM_SRGB:
+                    self.pixel_format = "BC7"
+                    n = 7
+                    if dxgi_format == DXGI_FORMAT.BC7_UNORM_SRGB:
+                        self.info["gamma"] = 1 / 2.2
+                elif dxgi_format in (
+                    DXGI_FORMAT.R8G8B8A8_TYPELESS,
+                    DXGI_FORMAT.R8G8B8A8_UNORM,
+                    DXGI_FORMAT.R8G8B8A8_UNORM_SRGB,
+                ):
+                    self._mode = "RGBA"
+                    if dxgi_format == DXGI_FORMAT.R8G8B8A8_UNORM_SRGB:
                         self.info["gamma"] = 1 / 2.2
-                    return
                 else:
                     msg = f"Unimplemented DXGI format {dxgi_format}"
                     raise NotImplementedError(msg)
             else:
                 msg = f"Unimplemented pixel format {repr(fourcc)}"
                 raise NotImplementedError(msg)
+        else:
+            msg = f"Unknown pixel format flags {pfflags}"
+            raise NotImplementedError(msg)
 
+        extents = (0, 0) + self.size
+        if n:
             self.tile = [
-                ("bcn", (0, 0) + self.size, data_start, (n, self.pixel_format))
+                ImageFile._Tile("bcn", extents, offset, (n, self.pixel_format))
             ]
+        else:
+            self.tile = [ImageFile._Tile("raw", extents, 0, rawmode or self.mode)]
 
     def load_seek(self, pos):
         pass
@@ -248,48 +480,51 @@ def _save(im, fp, filename):
         msg = f"cannot write mode {im.mode} as DDS"
         raise OSError(msg)
 
+    alpha = im.mode[-1] == "A"
+    if im.mode[0] == "L":
+        pixel_flags = DDPF.LUMINANCE
         rawmode = im.mode
-    masks = [0xFF0000, 0xFF00, 0xFF]
+        if alpha:
-    if im.mode in ("L", "LA"):
+            rgba_mask = [0x000000FF, 0x000000FF, 0x000000FF]
-        pixel_flags = DDPF_LUMINANCE
         else:
-        pixel_flags = DDPF_RGB
+            rgba_mask = [0xFF000000, 0xFF000000, 0xFF000000]
-        rawmode = rawmode[::-1]
+    else:
-    if im.mode in ("LA", "RGBA"):
+        pixel_flags = DDPF.RGB
-        pixel_flags |= DDPF_ALPHAPIXELS
+        rawmode = im.mode[::-1]
-        masks.append(0xFF000000)
+        rgba_mask = [0x00FF0000, 0x0000FF00, 0x000000FF]
 
-    bitcount = len(masks) * 8
+        if alpha:
-    while len(masks) < 4:
+            r, g, b, a = im.split()
-        masks.append(0)
+            im = Image.merge("RGBA", (a, r, g, b))
+    if alpha:
+        pixel_flags |= DDPF.ALPHAPIXELS
+    rgba_mask.append(0xFF000000 if alpha else 0)
+
+    flags = DDSD.CAPS | DDSD.HEIGHT | DDSD.WIDTH | DDSD.PITCH | DDSD.PIXELFORMAT
+    bitcount = len(im.getbands()) * 8
+    pitch = (im.width * bitcount + 7) // 8
 
     fp.write(
         o32(DDS_MAGIC)
-        + o32(124)  # header size
+        + struct.pack(
-        + o32(
+            "<7I",
-            DDSD_CAPS | DDSD_HEIGHT | DDSD_WIDTH | DDSD_PITCH | DDSD_PIXELFORMAT
+            124,  # header size
-        )  # flags
+            flags,  # flags
-        + o32(im.height)
+            im.height,
-        + o32(im.width)
+            im.width,
-        + o32((im.width * bitcount + 7) // 8)  # pitch
+            pitch,
-        + o32(0)  # depth
+            0,  # depth
-        + o32(0)  # mipmaps
+            0,  # mipmaps
-        + o32(0) * 11  # reserved
+        )
-        + o32(32)  # pfsize
+        + struct.pack("11I", *((0,) * 11))  # reserved
-        + o32(pixel_flags)  # pfflags
+        # pfsize, pfflags, fourcc, bitcount
-        + o32(0)  # fourcc
+        + struct.pack("<4I", 32, pixel_flags, 0, bitcount)
-        + o32(bitcount)  # bitcount
+        + struct.pack("<4I", *rgba_mask)  # dwRGBABitMask
-        + b"".join(o32(mask) for mask in masks)  # rgbabitmask
+        + struct.pack("<5I", DDSCAPS.TEXTURE, 0, 0, 0, 0)
-        + o32(DDSCAPS_TEXTURE)  # dwCaps
+    )
-        + o32(0)  # dwCaps2
+    ImageFile._save(
-        + o32(0)  # dwCaps3
+        im, fp, [ImageFile._Tile("raw", (0, 0) + im.size, 0, (rawmode, 0, 1))]
-        + o32(0)  # dwCaps4
-        + o32(0)  # dwReserved2
     )
-    if im.mode == "RGBA":
-        r, g, b, a = im.split()
-        im = Image.merge("RGBA", (a, r, g, b))
-    ImageFile._save(im, fp, [("raw", (0, 0) + im.size, 0, (rawmode, 0, 1))])
 
 
 def _accept(prefix):

src/PIL/ImageFile.py

@@ -26,11 +26,13 @@
 #
 # See the README file for information on usage and redistribution.
 #
+from __future__ import annotations
 
 import io
 import itertools
 import struct
 import sys
+from typing import NamedTuple
 
 from . import Image
 from ._util import is_path
@@ -77,6 +79,13 @@ def _tilesort(t):
     return t[2]
 
 
+class _Tile(NamedTuple):
+    encoder_name: str
+    extents: tuple[int, int, int, int]
+    offset: int
+    args: tuple | str | None
+
+
 #
 # --------------------------------------------------------------------
 # ImageFile base class
@@ -520,13 +529,13 @@ def _save(im, fp, tile, bufsize=0):
         fp.flush()
 
 
-def _encode_tile(im, fp, tile, bufsize, fh, exc=None):
+def _encode_tile(im, fp, tile: list[_Tile], bufsize, fh, exc=None):
-    for e, b, o, a in tile:
+    for encoder_name, extents, offset, args in tile:
-        if o > 0:
+        if offset > 0:
-            fp.seek(o)
+            fp.seek(offset)
-        encoder = Image._getencoder(im.mode, e, a, im.encoderconfig)
+        encoder = Image._getencoder(im.mode, encoder_name, args, im.encoderconfig)
         try:
-            encoder.setimage(im.im, b)
+            encoder.setimage(im.im, extents)
             if encoder.pushes_fd:
                 encoder.setfd(fp)
                 errcode = encoder.encode_to_pyfd()[1]