diff options
| -rw-r--r-- | libFDK/include/FDK_bitstream.h | 47 | ||||
| -rw-r--r-- | libFDK/src/FDK_bitbuffer.cpp | 18 |
2 files changed, 45 insertions, 20 deletions
diff --git a/libFDK/include/FDK_bitstream.h b/libFDK/include/FDK_bitstream.h index fc8d7de..d2a7e7d 100644 --- a/libFDK/include/FDK_bitstream.h +++ b/libFDK/include/FDK_bitstream.h @@ -212,9 +212,20 @@ FDK_INLINE UINT FDKreadBits(HANDLE_FDK_BITSTREAM hBitStream, INT missingBits = numberOfBits - hBitStream->BitsInCache; if (missingBits > 0) { - UINT bits = hBitStream->CacheWord << missingBits; - hBitStream->CacheWord = FDK_get32 (&hBitStream->hBitBuf) ; - hBitStream->BitsInCache = CACHE_BITS - missingBits; + const UINT bits = hBitStream->CacheWord << missingBits; + const UINT validBits = FDK_getValidBits (&hBitStream->hBitBuf); + + if (validBits >= 32) + { + hBitStream->CacheWord = FDK_get32 (&hBitStream->hBitBuf) ; + hBitStream->BitsInCache = CACHE_BITS - missingBits; + } + else + { + hBitStream->CacheWord = FDK_get (&hBitStream->hBitBuf,validBits) ; + hBitStream->BitsInCache = validBits - missingBits; + } + return ( bits | (hBitStream->CacheWord >> hBitStream->BitsInCache)) & BitMask[numberOfBits]; } @@ -226,10 +237,12 @@ FDK_INLINE UINT FDKreadBits(HANDLE_FDK_BITSTREAM hBitStream, if (hBitStream->BitsInCache <= numberOfBits) { - const INT freeBits = (CACHE_BITS-1) - hBitStream->BitsInCache ; + const UINT validBits = FDK_getValidBits (&hBitStream->hBitBuf) ; + const INT freeBits = (CACHE_BITS-1) - hBitStream->BitsInCache ; + const INT bitsToRead = (freeBits <= validBits) ? freeBits : validBits ; - hBitStream->CacheWord = (hBitStream->CacheWord << freeBits) | FDK_get (&hBitStream->hBitBuf,freeBits) ; - hBitStream->BitsInCache += freeBits ; + hBitStream->CacheWord = (hBitStream->CacheWord << bitsToRead) | FDK_get (&hBitStream->hBitBuf,bitsToRead) ; + hBitStream->BitsInCache += bitsToRead ; } hBitStream->BitsInCache -= numberOfBits ; @@ -243,8 +256,18 @@ FDK_INLINE UINT FDKreadBit(HANDLE_FDK_BITSTREAM hBitStream) #ifdef OPTIMIZE_FDKREADBITS if (!hBitStream->BitsInCache) { - hBitStream->CacheWord = FDK_get32 (&hBitStream->hBitBuf); - hBitStream->BitsInCache = CACHE_BITS; + const UINT validBits = FDK_getValidBits (&hBitStream->hBitBuf); + + if (validBits >= 32) + { + hBitStream->CacheWord = FDK_get32 (&hBitStream->hBitBuf); + hBitStream->BitsInCache = CACHE_BITS; + } + else + { + hBitStream->CacheWord = FDK_get (&hBitStream->hBitBuf,validBits); + hBitStream->BitsInCache = validBits; + } } hBitStream->BitsInCache--; @@ -268,10 +291,12 @@ inline UINT FDKread2Bits(HANDLE_FDK_BITSTREAM hBitStream) UINT BitsInCache = hBitStream->BitsInCache; if (BitsInCache < 2) /* Comparison changed from 'less-equal' to 'less' */ { - const INT freeBits = (CACHE_BITS-1) - BitsInCache ; + const UINT validBits = FDK_getValidBits (&hBitStream->hBitBuf) ; + const INT freeBits = (CACHE_BITS-1) - BitsInCache ; + const INT bitsToRead = (freeBits <= validBits) ? freeBits : validBits ; - hBitStream->CacheWord = (hBitStream->CacheWord << freeBits) | FDK_get (&hBitStream->hBitBuf,freeBits) ; - BitsInCache += freeBits; + hBitStream->CacheWord = (hBitStream->CacheWord << bitsToRead) | FDK_get (&hBitStream->hBitBuf,bitsToRead) ; + BitsInCache += bitsToRead; } hBitStream->BitsInCache = BitsInCache - 2; return (hBitStream->CacheWord >> hBitStream->BitsInCache) & 0x3; diff --git a/libFDK/src/FDK_bitbuffer.cpp b/libFDK/src/FDK_bitbuffer.cpp index 680ceae..9076d84 100644 --- a/libFDK/src/FDK_bitbuffer.cpp +++ b/libFDK/src/FDK_bitbuffer.cpp @@ -157,6 +157,8 @@ void FDK_ResetBitBuffer ( HANDLE_FDK_BITBUF hBitBuf ) INT FDK_get (HANDLE_FDK_BITBUF hBitBuf, const UINT numberOfBits) { + if (numberOfBits == 0 || numberOfBits > hBitBuf->ValidBits) return 0; + UINT byteOffset = hBitBuf->BitNdx >> 3 ; UINT bitOffset = hBitBuf->BitNdx & 0x07 ; @@ -166,22 +168,20 @@ INT FDK_get (HANDLE_FDK_BITBUF hBitBuf, const UINT numberOfBits) UINT byteMask = hBitBuf->bufSize - 1 ; - UINT tx = (hBitBuf->Buffer [ byteOffset & byteMask] << 24) | - (hBitBuf->Buffer [(byteOffset+1) & byteMask] << 16) | - (hBitBuf->Buffer [(byteOffset+2) & byteMask] << 8) | - hBitBuf->Buffer [(byteOffset+3) & byteMask]; + UINT tx = hBitBuf->Buffer [ byteOffset & byteMask] << 24 << bitOffset; - if (bitOffset) - { - tx <<= bitOffset; - tx |= hBitBuf->Buffer [(byteOffset+4) & byteMask] >> (8-bitOffset); - } + if (numberOfBits + bitOffset > 8) tx |= hBitBuf->Buffer [(byteOffset+1) & byteMask] << 16 << bitOffset; + if (numberOfBits + bitOffset > 16) tx |= hBitBuf->Buffer [(byteOffset+2) & byteMask] << 8 << bitOffset; + if (numberOfBits + bitOffset > 24) tx |= hBitBuf->Buffer [(byteOffset+3) & byteMask] << bitOffset; + if (numberOfBits + bitOffset > 32) tx |= hBitBuf->Buffer [(byteOffset+4) & byteMask] >> (8 - bitOffset); return (tx >> (32 - numberOfBits)) ; } INT FDK_get32 (HANDLE_FDK_BITBUF hBitBuf) { + if (hBitBuf->ValidBits < 32) return 0; + UINT BitNdx = hBitBuf->BitNdx + 32; if (BitNdx <= hBitBuf->bufBits) { |