X-Git-Url: https://git.nihav.org/?a=blobdiff_plain;f=src%2Fio%2Fcodebook.rs;h=3d1e8d0e0112e2d2032788e6723bfb17f06014a0;hb=1f7e9371e2ec548b6821bb01ce7ba82c4cd8068d;hp=0e03ded1c63b236d0ce651f5774cfd2083bbf280;hpb=0ca65ffdfd8d16f8eb3b13f9a0832c60921934cf;p=nihav.git

diff --git a/src/io/codebook.rs b/src/io/codebook.rs
index 0e03ded..3d1e8d0 100644
--- a/src/io/codebook.rs
+++ b/src/io/codebook.rs
@@ -46,21 +46,6 @@ pub trait CodebookReader<S> {
     fn read_cb(&mut self, cb: &Codebook<S>) -> CodebookResult<S>;
 }
 
-pub fn reverse_bits(inval: u32) -> u32 {
-    const REV_TAB: [u8; 16] = [
-        0b0000, 0b1000, 0b0100, 0b1100, 0b0010, 0b1010, 0b0110, 0b1110,
-        0b0001, 0b1001, 0b0101, 0b1101, 0b0011, 0b1011, 0b0111, 0b1111,
-    ];
-
-    let mut ret = 0;
-    let mut val = inval;
-    for _ in 0..8 {
-        ret = (ret << 4) | (REV_TAB[(val & 0xF) as usize] as u32);
-        val = val >> 4;
-    }
-    ret
-}
-
 const TABLE_FILL_VALUE: u32 = 0x7F;
 const MAX_LUT_BITS: u8 = 10;
 
@@ -173,7 +158,7 @@ fn build_esc_lut(table: &mut Vec<u32>,
 
     for code in &bucket.codes {
         let bits = code.bits;
-        if code.bits < MAX_LUT_BITS {
+        if code.bits <= MAX_LUT_BITS {
             fill_lut(table, mode, bucket.offset, code.code, bits,
                      maxlen, code.idx as u32, false);
         } else {
@@ -196,7 +181,7 @@ fn build_esc_lut(table: &mut Vec<u32>,
     for (_, sec_bucket) in &escape_list {
         build_esc_lut(table, mode, sec_bucket)?;
     }
-    
+
     Ok(())
 }
 
@@ -210,7 +195,12 @@ impl<S: Copy> Codebook<S> {
         let mut symidx: usize = 0;
         for i in 0..cb.len() {
             let bits = cb.bits(i);
-            if bits > 0 { nnz = nnz + 1; }
+            if bits > 0 {
+                nnz = nnz + 1;
+                if cb.code(i) >= (1 << bits) {
+                    return Err(CodebookError::InvalidCodebook);
+                }
+            }
             maxbits = max(bits, maxbits);
             if bits > MAX_LUT_BITS {
                 let code = cb.code(i);
@@ -324,6 +314,25 @@ impl CodebookDescReader<u32> for ShortCodebookDescReader {
     fn len(&mut self) -> usize { self.data.len() }
 }
 
+pub struct TableCodebookDescReader<CodeType:'static, IndexType:'static> {
+    bits:       &'static [u8],
+    codes:      &'static [CodeType],
+    idx_map:    fn(usize) -> IndexType,
+}
+
+impl<'a, CodeType, IndexType> TableCodebookDescReader<CodeType, IndexType> {
+    pub fn new(codes: &'static [CodeType], bits: &'static [u8], idx_map: fn(usize) -> IndexType) -> Self {
+        Self { bits, codes, idx_map }
+    }
+}
+impl<CodeType: Copy+Into<u32>, IndexType> CodebookDescReader<IndexType> for TableCodebookDescReader<CodeType, IndexType>
+{
+    fn bits(&mut self, idx: usize) -> u8  { self.bits[idx] }
+    fn code(&mut self, idx: usize) -> u32 { self.codes[idx].into() }
+    fn sym (&mut self, idx: usize) -> IndexType { (self.idx_map)(idx) }
+    fn len(&mut self) -> usize { self.bits.len() }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -376,7 +385,7 @@ mod test {
         assert_eq!(br2.read_cb(&cb).unwrap(), 5);
         assert_eq!(br2.read_cb(&cb).unwrap(), 8);
 
-        assert_eq!(reverse_bits(0b0000_0101_1011_1011_1101_1111_0111_1111),
+        assert_eq!(reverse_bits(0b0000_0101_1011_1011_1101_1111_0111_1111, 32),
                                 0b1111_1110_1111_1011_1101_1101_1010_0000);
 
         const BITS_LE: [u8; 3] = [0b11101111, 0b01110010, 0b01];