funai_bdp: add support of uncmpr(sparse like) and decompressing image rom

src/formats/funai_bdp/include.rs

@@ -6,10 +6,62 @@ pub struct IndexTableEntry {
     name_bytes: [u8; 32],
     pub offset: u32,
     pub size: u32,
-    _unk: u32,
+    _checksum: u32,
 }
 impl IndexTableEntry {
     pub fn name(&self) -> String {
         common::string_from_bytes(&self.name_bytes)
     }
+}
+
+//cmpr
+
+#[derive(BinRead)]
+pub struct CmprHeader {
+    pub out_checksum: u32,
+    pub count: u32,
+    pub data_size: u32,
+    #[br(count=count)] pub entries: Vec<CmprEntry>,
+}
+
+#[derive(BinRead)]
+pub struct CmprEntry {
+    pub size: u32,
+    pub mode: u32,
+    pub fill: u32,
+}
+
+//dumb check, since this information is not stored in header
+pub fn is_cmpr(data: &[u8], size: u32) -> bool {
+    if data.len() < 0x20+12 {return false};
+
+    let count = u32::from_le_bytes(data[0x20+4..0x20+8].try_into().unwrap());
+    let data_size = u32::from_le_bytes(data[0x20+8..0x20+12].try_into().unwrap());
+
+    if count > size || data_size > size {return false};
+
+    return (size - 0x20 - (count*12) - 12) == data_size;
+}
+
+//image rom
+#[derive(BinRead)]
+pub struct ImageRomHeader {
+    pub count: u32,
+    _unk: u32,
+    _pad1: [u8; 8],
+    _entry_table_sha1: [u8; 20],
+    _pad2: [u8; 12],
+    pub start_offset: u32,
+    _pad3: [u8; 12],
+    #[br(count=count)] pub entries: Vec<ImageRomEntry>,
+}
+
+#[derive(BinRead)]
+pub struct ImageRomEntry {
+    _decompressed_sha1: [u8; 20],
+    _compressed_sha1: [u8; 20],
+    _pad1: [u8; 8],
+    pub offset: u32, //relative to start_offset in header
+    pub size: u32,
+    _pad2: [u8; 8],
 }