patterns: Add support for smk (#399)

* patterns: Add support for smk

* patterns: Use builtin function and separate SMK struct

---------

Co-authored-by: paxcut <53811119+paxcut@users.noreply.github.com>

README.md

@@ -156,6 +156,7 @@ Everything will immediately show up in ImHex's Content Store and gets bundled wi
 | Shell Link | `application/x-ms-shortcut` | [`patterns/lnk.hexpat`](patterns/lnk.hexpat) | Windows Shell Link file format |
 | shp | | [`patterns/shp.hexpat`](patterns/shp.hexpat) | ESRI shape file |
 | shx | | [`patterns/shx.hexpat`](patterns/shx.hexpat) | ESRI index file |
+| smk | | [`patterns/smk.hexpat`](patterns/smk.hexpat) | Smacker video file |
 | sup | | [`patterns/sup.hexpat`](patterns/sup.hexpat) | PGS Subtitle |
 | SPIRV | | [`patterns/spirv.hexpat`](patterns/spirv.hexpat) | SPIR-V header and instructions |
 | STDF | | [`patterns/stdfv4.hexpat`](patterns/stdfv4.hexpat) | Standard test data format for IC testers |

patterns/smk.hexpat

@@ -0,0 +1,218 @@
+#pragma author xZise
+#pragma description Smacker video file
+#pragma endian little
+#pragma magic [53 4D 4B 32] @ 0x0
+
+import std.core;
+import std.io;
+import std.mem;
+
+bitfield HeaderFlags {
+    ContainsRingFrame : 1;
+    YInterlaced : 1;
+    YDoubled : 1;
+    padding : 29;
+};
+
+bitfield HeaderAudioFlags {
+    isCompressed : 1;
+    hasAudio : 1;
+    is16BitAudio : 1;
+    isStereo : 1;
+    soundDecompression : 2;
+    padding : 2;
+    audioSampleRate : 24;
+};
+
+fn format_frame_rate(auto frame_rate) {
+    float fps;
+    if (frame_rate > 0) {
+        fps = 1000.0 / frame_rate;
+    } else if (frame_rate < 0) {
+        fps = 100000.0 / (-frame_rate);
+    } else {
+        fps = 10;
+    }
+    return std::format("{} fps", fps);
+};
+
+struct Header {
+  char Signature[4];
+  u32 Width;
+  u32 Height;
+  u32 FrameCount;
+  s32 FrameRate [[format("format_frame_rate")]];
+  HeaderFlags Flags;
+  u32 AudioSize[7];
+  u32 TreesSize;
+  u32 MMap_Size;
+  u32 MClr_Size;
+  u32 Full_Size;
+  u32 Type_Size;
+  HeaderAudioFlags AudioRate[7];
+  padding[4];
+};
+
+fn format_size(auto size) {
+    if (size.keyframe != 0) {
+        return std::format("[K] {} B", size.size);
+    }
+    return std::format("[ ] {} B", size.size);
+};
+
+bitfield Size {
+    keyframe : 1;
+    padding : 1;
+    dwordCount : 30;
+
+    u32 size = dwordCount * 4;
+} [[format("format_size")]];
+
+
+bitfield FrameType {
+    ContainsPaletteRecord : 1;
+    ContainsAudioTrack0 : 1;
+    ContainsAudioTrack1 : 1;
+    ContainsAudioTrack2 : 1;
+    ContainsAudioTrack3 : 1;
+    ContainsAudioTrack4 : 1;
+    ContainsAudioTrack5 : 1;
+    ContainsAudioTrack6 : 1;
+};
+
+fn format_palette_copy_only(auto copy_only) {
+    return std::format("copy: {0}", copy_only.copy);
+};
+
+bitfield PaletteCopyOnly {
+    copy: 7;
+    mode: 1;
+} [[format("format_palette_copy_only")]];
+
+fn format_palette_copy_skip(auto copy_skip) {
+    return std::format("copy: {0}, skip: {1}", copy_skip.copy, copy_skip.skip);
+};
+
+bitfield PaletteCopySkip {
+    copy: 6;
+    mode: 2;
+    skip: 8;
+} [[format("format_palette_copy_skip")]];
+
+bitfield PaletteColor {
+    blue: 6 [[color("0000FF")]];
+    mode: 2;
+    green: 6 [[color("00FF00")]];
+    padding: 2;
+    red: 6 [[color("FF0000")]];
+    padding: 2;
+
+    u8 r8 = red << 2 | red >> 4;
+    u8 g8 = green << 2 | green >> 4;
+    u8 b8 = blue << 2 | blue >> 4;
+} [[hex::inline_visualize("color", r8, g8, b8, 0xff)]];
+
+fn format_palette_chunk_block(auto entry) {
+    u8 first = entry.type;
+    if (first & 0x80 == 0x80) {
+        return format_palette_copy_only(entry.copy);
+    } else if (first & 0x40 == 0x40) {
+        return format_palette_copy_skip(entry.copy_skip);
+    } else {
+        return std::format("color: 0x{0:02x}{1:02x}{2:02x}", entry.color.r8, entry.color.g8, entry.color.b8);
+    }
+};
+
+enum PaletteChunkBlockType: u8 {
+    Color = 0x00 ... 0x3F,
+    CopySkip = 0x40 ... 0x7F,
+    CopyOnly = 0x80 ... 0xFF
+};
+
+// Unfortunately the match expression does not support ranges, so this is a helper for the following code:
+// PaletteChunkBlockType type = std::mem::read_unsigned($, 1)
+fn get_palette_chunk_block_type() {
+    u8 type = std::mem::read_unsigned($, 1);
+    if (type & 0x80 == 0x80) {
+        return PaletteChunkBlockType::CopyOnly;
+    } else if (type & 0x40 == 0x40) {
+        return PaletteChunkBlockType::CopySkip;
+    } else {
+        return PaletteChunkBlockType::Color;
+    }
+};
+
+fn get_last_position() {
+    PaletteChunkBlockType type = get_palette_chunk_block_type();
+    match (type) {
+        (PaletteChunkBlockType::CopyOnly): return $;
+        (PaletteChunkBlockType::CopySkip): return $ + 1;
+        (PaletteChunkBlockType::Color): return $ + 2;
+    }
+};
+
+struct PaletteChunkBlock {
+    PaletteChunkBlockType type = get_palette_chunk_block_type() [[export]];
+    match (type) {
+        (PaletteChunkBlockType::CopyOnly): PaletteCopyOnly copy;
+        (PaletteChunkBlockType::CopySkip): PaletteCopySkip copy_skip;
+        (PaletteChunkBlockType::Color): PaletteColor color;
+    }
+} [[format("format_palette_chunk_block")]];
+
+struct PaletteChunk {
+    u8 length;
+    u128 end = $ + length * 4 - 1;
+    PaletteChunkBlock blocks[while(get_last_position() < end)];
+    if ($ < end) {
+        padding[end - $];
+    }
+};
+
+struct AudioTrack<auto trackIndex> {
+    u32 length;
+    if (parent.parent.header.AudioRate[trackIndex].isCompressed) {
+        u32 decompressedSize;
+    }
+    u8 trackData[length - ($ - addressof(this))];
+};
+
+struct FramesData {
+    u32 frame_index = std::core::array_index();
+    u32 size = parent.sizes[frame_index].size;
+    if (parent.frameTypes[frame_index].ContainsPaletteRecord) {
+        PaletteChunk palette;
+    }
+    if (parent.frameTypes[frame_index].ContainsAudioTrack0) {
+        AudioTrack<0> audioTrack0;
+    }
+    if (parent.frameTypes[frame_index].ContainsAudioTrack1) {
+        AudioTrack<1> audioTrack1;
+    }
+    if (parent.frameTypes[frame_index].ContainsAudioTrack2) {
+        AudioTrack<2> audioTrack2;
+    }
+    if (parent.frameTypes[frame_index].ContainsAudioTrack3) {
+        AudioTrack<3> audioTrack3;
+    }
+    if (parent.frameTypes[frame_index].ContainsAudioTrack4) {
+        AudioTrack<4> audioTrack4;
+    }
+    if (parent.frameTypes[frame_index].ContainsAudioTrack5) {
+        AudioTrack<5> audioTrack5;
+    }
+    if (parent.frameTypes[frame_index].ContainsAudioTrack6) {
+        AudioTrack<6> audioTrack6;
+    }
+    u8 video[size - ($ - addressof(this))];
+};
+
+struct SMK {
+    Header header;
+    Size sizes[header.FrameCount];
+    FrameType frameTypes[header.FrameCount] ;
+    u8 trees[header.TreesSize];
+    FramesData frames[header.FrameCount];
+};
+
+SMK smk @ 0x00 [[inline]];