diff --git a/dlls/windowscodecs/tests/ddsformat.c b/dlls/windowscodecs/tests/ddsformat.c
index 5195dada135..a7fd8c19737 100644
--- a/dlls/windowscodecs/tests/ddsformat.c
+++ b/dlls/windowscodecs/tests/ddsformat.c
@@ -120,6 +120,50 @@ static BYTE test_dds_array[] = {
     0xCC, 0x55, 0xCC, 0x55, 0x0E, 0x84, 0x0E, 0x84, 0x00, 0x00, 0x00, 0x00
 };
 
+/* 12x12 compressed(DXT3) texture array, arraySize=2, mipMapCount=4 */
+static BYTE test_dds_dxt3[] = {
+    'D',  'D',  'S',  ' ',  0x7C, 0x00, 0x00, 0x00, 0x07, 0x10, 0x0A, 0x00, 0x0C, 0x00, 0x00, 0x00,
+    0x0C, 0x00, 0x00, 0x00, 0x90, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00,
+    0x04, 0x00, 0x00, 0x00, 'D',  'X',  '1',  '0',  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x10, 0x40, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x4A, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xB5, 0xA7, 0xAD, 0x83,
+    0x60, 0x60, 0xE0, 0x80, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x12, 0x96, 0x6B, 0x72,
+    0xD5, 0xD5, 0xAF, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x30, 0x8D, 0x89, 0x69,
+    0x57, 0x5F, 0x5E, 0xF8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xB4, 0xA7, 0xAD, 0x83,
+    0x00, 0xAA, 0xFF, 0x55, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xF3, 0x9E, 0x6D, 0x83,
+    0x00, 0x00, 0xAA, 0x55, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x12, 0x96, 0xCD, 0x83,
+    0x5C, 0xF8, 0xAA, 0xAF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xEC, 0x7A, 0xC9, 0x71,
+    0x80, 0x60, 0x60, 0x60, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x4A, 0x72, 0xA8, 0x68,
+    0x28, 0xBE, 0xD7, 0xD7, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xAF, 0x8C, 0xEA, 0x71,
+    0x0B, 0xAB, 0xAD, 0xBD, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x54, 0x9F, 0xCC, 0x7A,
+    0x5C, 0xA8, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x50, 0x8D, 0x49, 0x69,
+    0x77, 0xEE, 0x88, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0C, 0x7B, 0x08, 0x69,
+    0xF8, 0x58, 0xF8, 0x58, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x4E, 0x84, 0x6B, 0x72,
+    0x33, 0x99, 0x33, 0x99, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x14, 0x9F, 0x0A, 0x72,
+    0xDC, 0xAA, 0x75, 0xAA, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0E, 0x84, 0x0E, 0x84,
+    0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xB5, 0xA7, 0xAD, 0x83,
+    0x60, 0x60, 0xE0, 0x80, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x12, 0x96, 0x6B, 0x72,
+    0xD5, 0xD5, 0xAF, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x30, 0x8D, 0x89, 0x69,
+    0x57, 0x5F, 0x5E, 0xF8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xB4, 0xA7, 0xAD, 0x83,
+    0x00, 0xAA, 0xFF, 0x55, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xF3, 0x9E, 0x6D, 0x83,
+    0x00, 0x00, 0xAA, 0x55, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x12, 0x96, 0xCD, 0x83,
+    0x5C, 0xF8, 0xAA, 0xAF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xEC, 0x7A, 0xC9, 0x71,
+    0x80, 0x60, 0x60, 0x60, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x4A, 0x72, 0xA8, 0x68,
+    0x28, 0xBE, 0xD7, 0xD7, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xAF, 0x8C, 0xEA, 0x71,
+    0x0B, 0xAB, 0xAD, 0xBD, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x54, 0x9F, 0xCC, 0x7A,
+    0x5C, 0xA8, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x50, 0x8D, 0x49, 0x69,
+    0x77, 0xEE, 0x88, 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0C, 0x7B, 0x08, 0x69,
+    0xF8, 0x58, 0xF8, 0x58, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x4E, 0x84, 0x6B, 0x72,
+    0x33, 0x99, 0x33, 0x99, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x14, 0x9F, 0x0A, 0x72,
+    0xDC, 0xAA, 0x75, 0xAA, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0E, 0x84, 0x0E, 0x84,
+    0x00, 0x00, 0x00, 0x00
+};
+
 static struct test_data {
     BYTE *data;
     UINT size;
@@ -127,13 +171,15 @@ static struct test_data {
     WICDdsParameters expected_parameters;
 } test_data[] = {
     { test_dds_image,   sizeof(test_dds_image),   1,
-      { 4, 4, 1, 1, 1, DXGI_FORMAT_BC1_UNORM, WICDdsTexture2D, WICDdsAlphaModePremultiplied } },
+      { 4,  4,  1, 1, 1, DXGI_FORMAT_BC1_UNORM, WICDdsTexture2D, WICDdsAlphaModePremultiplied } },
     { test_dds_mipmaps, sizeof(test_dds_mipmaps), 3,
-      { 4, 4, 1, 3, 1, DXGI_FORMAT_BC1_UNORM, WICDdsTexture2D, WICDdsAlphaModePremultiplied } },
+      { 4,  4,  1, 3, 1, DXGI_FORMAT_BC1_UNORM, WICDdsTexture2D, WICDdsAlphaModePremultiplied } },
     { test_dds_volume,  sizeof(test_dds_volume),  7,
-      { 4, 4, 4, 3, 1, DXGI_FORMAT_BC1_UNORM, WICDdsTexture3D, WICDdsAlphaModePremultiplied } },
+      { 4,  4,  4, 3, 1, DXGI_FORMAT_BC1_UNORM, WICDdsTexture3D, WICDdsAlphaModePremultiplied } },
     { test_dds_array,   sizeof(test_dds_array),   9,
-      { 4, 4, 1, 3, 3, DXGI_FORMAT_BC1_UNORM, WICDdsTexture2D, WICDdsAlphaModeUnknown } },
+      { 4,  4,  1, 3, 3, DXGI_FORMAT_BC1_UNORM, WICDdsTexture2D, WICDdsAlphaModeUnknown } },
+    { test_dds_dxt3,    sizeof(test_dds_dxt3),    8,
+      { 12, 12, 1, 4, 2, DXGI_FORMAT_BC2_UNORM, WICDdsTexture2D, WICDdsAlphaModeUnknown } },
 };
 
 static IWICImagingFactory *factory = NULL;
@@ -237,6 +283,7 @@ static void test_dds_decoder_initialize(void)
         { test_dds_cube,         sizeof(test_dds_cube),         WINCODEC_ERR_BADHEADER },
         { test_dds_volume,       sizeof(test_dds_volume),       S_OK },
         { test_dds_array,        sizeof(test_dds_array),        S_OK },
+        { test_dds_dxt3,         sizeof(test_dds_dxt3),         S_OK },
         { test_dds_bad_magic,  sizeof(test_dds_bad_magic),  WINCODEC_ERR_UNKNOWNIMAGEFORMAT },
         { test_dds_bad_header, sizeof(test_dds_bad_header), WINCODEC_ERR_BADHEADER },
         { &byte,   sizeof(byte),   WINCODEC_ERR_STREAMREAD },
@@ -472,9 +519,9 @@ static void test_dds_decoder_frame_data(IWICDdsFrameDecode *dds_frame, UINT fram
     HRESULT hr;
     WICDdsFormatInfo format_info;
     WICRect rect = { 0, 0, 1, 1 }, rect_test_a = { 0, 0, 0, 0 }, rect_test_b = { 0, 0, 0xdeadbeaf, 0xdeadbeaf };
-    WICRect rect_test_c = { -0xdeadbeaf, -0xdeadbeaf, 1, 1 }, rect_test_d = { 1, 1, 1, 1 };
-    BYTE buffer[32];
-    UINT stride, width_in_blocks, height_in_blocks;
+    WICRect rect_test_c = { -0xdeadbeaf, -0xdeadbeaf, 1, 1 }, rect_test_d = { 0xdeadbeaf, 0xdeadbeaf, 1, 1 };
+    BYTE buffer[256];
+    UINT stride, frame_stride, width_in_blocks, height_in_blocks;
     UINT width, height, depth, array_index;
     UINT block_offset;
     int slice_index;
@@ -482,7 +529,11 @@ static void test_dds_decoder_frame_data(IWICDdsFrameDecode *dds_frame, UINT fram
     hr = IWICDdsFrameDecode_GetFormatInfo(dds_frame, &format_info);
     ok (hr == S_OK, "%d: [frame %d] GetFormatInfo failed, hr=%x\n", i, frame_index, hr);
     if (hr != S_OK) return;
+    hr = IWICDdsFrameDecode_GetSizeInBlocks(dds_frame, &width_in_blocks, &height_in_blocks);
+    ok (hr == S_OK, "%d: [frame %d] GetSizeInBlocks failed, hr=%x\n", i, frame_index, hr);
+    if (hr != S_OK) return;
     stride = rect.Width * format_info.BytesPerBlock;
+    frame_stride = width_in_blocks * format_info.BytesPerBlock;
 
     hr = IWICDdsFrameDecode_CopyBlocks(dds_frame, &rect_test_a, stride, sizeof(buffer), buffer);
     todo_wine ok (hr == E_INVALIDARG, "%d: [frame %d] Got unexpected hr %x\n", i, frame_index, hr);
@@ -492,7 +543,7 @@ static void test_dds_decoder_frame_data(IWICDdsFrameDecode *dds_frame, UINT fram
     todo_wine ok (hr == E_INVALIDARG, "%d: [frame %d] Got unexpected hr %x\n", i, frame_index, hr);
     hr = IWICDdsFrameDecode_CopyBlocks(dds_frame, &rect_test_d, stride, sizeof(buffer), buffer);
     todo_wine ok (hr == E_INVALIDARG, "%d: [frame %d] Got unexpected hr %x\n", i, frame_index, hr);
-    hr = IWICDdsFrameDecode_CopyBlocks(dds_frame, NULL, stride, sizeof(buffer), buffer);
+    hr = IWICDdsFrameDecode_CopyBlocks(dds_frame, NULL, frame_stride, sizeof(buffer), buffer);
     todo_wine ok (hr == S_OK, "%d: [frame %d] Got unexpected hr %x\n", i, frame_index, hr);
 
     hr = IWICDdsFrameDecode_CopyBlocks(dds_frame, &rect, 0, sizeof(buffer), buffer);