From 8ab3904ca48416131be683834f232175b8c76db5 Mon Sep 17 00:00:00 2001 From: Kostya Shishkov Date: Thu, 15 Jun 2017 14:11:07 +0200 Subject: [PATCH] bitreader: fix LE**MSB modes --- src/io/bitreader.rs | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/src/io/bitreader.rs b/src/io/bitreader.rs index 99bb34f..20753d1 100644 --- a/src/io/bitreader.rs +++ b/src/io/bitreader.rs @@ -50,21 +50,24 @@ impl<'a> BitReader<'a> { self.cache |= nw << (32 - self.bits); } - fn fill32le16(&mut self, src: &[u8], realbits: u8) { + 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; - if realbits <= 16 { nw >>= 16; } - self.cache |= nw << self.bits; + self.cache |= nw << (32 - self.bits); } - fn fill32le32(&mut self, src: &[u8]) { + fn fill32le32(&mut self, src: &[u8], lsb: bool) { let nw = (((src[3] as u32) << 24) | ((src[2] as u32) << 16) | ((src[1] as u32) << 8) | ((src[0] as u32) << 0)) as u64; - self.cache |= nw << self.bits; + if lsb { + self.cache |= nw << self.bits; + } else { + self.cache |= nw << (32 - self.bits); + } } fn refill(&mut self) -> BitReaderResult<()> { @@ -74,9 +77,9 @@ impl<'a> BitReader<'a> { let buf = &self.src[self.pos..]; match self.mode { BitReaderMode::BE => self.fill32be (buf), - BitReaderMode::LE16MSB => self.fill32le16(buf, 32), - BitReaderMode::LE => self.fill32le32(buf), - BitReaderMode::LE32MSB => self.fill32le32(buf), + BitReaderMode::LE16MSB => self.fill32le16(buf), + BitReaderMode::LE => self.fill32le32(buf, true), + BitReaderMode::LE32MSB => self.fill32le32(buf, false), } self.pos += 4; self.bits += 32; @@ -93,9 +96,9 @@ impl<'a> BitReader<'a> { if newbits == 0 { break; } match self.mode { BitReaderMode::BE => self.fill32be (&buf), - BitReaderMode::LE16MSB => self.fill32le16(&buf, newbits), - BitReaderMode::LE => self.fill32le32(&buf), - BitReaderMode::LE32MSB => self.fill32le32(&buf), + BitReaderMode::LE16MSB => self.fill32le16(&buf), + BitReaderMode::LE => self.fill32le32(&buf, true), + BitReaderMode::LE32MSB => self.fill32le32(&buf, false), } self.bits += newbits; } -- 2.39.2