X-Git-Url: https://git.nihav.org/?a=blobdiff_plain;f=src%2Fio%2Fbitreader.rs;h=b3e478edf64d4a6832eb09d160d6f3bb7b875871;hb=06fd8c8865256ab5348996a23afeeb512bc45835;hp=20753d1561263e788a8d21d6815280c184dc979b;hpb=8ab3904ca48416131be683834f232175b8c76db5;p=nihav.git

diff --git a/src/io/bitreader.rs b/src/io/bitreader.rs
index 20753d1..b3e478e 100644
--- a/src/io/bitreader.rs
+++ b/src/io/bitreader.rs
@@ -51,10 +51,10 @@ impl<'a> BitReader<'a> {
     }
 
     fn fill32le16(&mut self, src: &[u8]) {
-        let mut nw = (((src[1] as u32) << 24) |
-                      ((src[0] as u32) << 16) |
-                      ((src[3] as u32) <<  8) |
-                      ((src[2] as u32) <<  0)) as u64;
+        let nw = (((src[1] as u32) << 24) |
+                  ((src[0] as u32) << 16) |
+                  ((src[3] as u32) <<  8) |
+                  ((src[2] as u32) <<  0)) as u64;
         self.cache |= nw << (32 - self.bits);
     }
 
@@ -196,6 +196,29 @@ impl<'a> BitReader<'a> {
         self.pos = ((nbits / 32) * 4) as usize;
         self.skip(nbits & 0x1F)
     }
+
+    pub fn align(&mut self) {
+        let pos = self.bits & 7;
+        if pos != 0 {
+            self.skip_cache(pos);
+        }
+    }
+}
+
+pub fn reverse_bits(inval: u32, len: u8) -> u32 {
+    if len == 0 { return 0; }
+    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 >> (32 - len)
 }
 
 #[cfg(test)]