forked from mirror/libbpg
158 lines
5.5 KiB
C++
158 lines
5.5 KiB
C++
/*****************************************************************************
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* Copyright (C) 2013 x265 project
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*
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* Author: Steve Borho <steve@borho.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA.
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*
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* This program is also available under a commercial proprietary license.
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* For more information, contact us at license @ x265.com.
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*****************************************************************************/
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#ifndef X265_BITSTREAM_H
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#define X265_BITSTREAM_H 1
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namespace X265_NS {
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// private namespace
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class BitInterface
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{
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public:
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virtual void write(uint32_t val, uint32_t numBits) = 0;
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virtual void writeByte(uint32_t val) = 0;
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virtual void resetBits() = 0;
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virtual uint32_t getNumberOfWrittenBits() const = 0;
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virtual void writeAlignOne() = 0;
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virtual void writeAlignZero() = 0;
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virtual ~BitInterface() {}
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};
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class BitCounter : public BitInterface
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{
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protected:
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uint32_t m_bitCounter;
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public:
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BitCounter() : m_bitCounter(0) {}
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void write(uint32_t, uint32_t num) { m_bitCounter += num; }
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void writeByte(uint32_t) { m_bitCounter += 8; }
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void resetBits() { m_bitCounter = 0; }
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uint32_t getNumberOfWrittenBits() const { return m_bitCounter; }
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void writeAlignOne() { }
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void writeAlignZero() { }
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};
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class Bitstream : public BitInterface
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{
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public:
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Bitstream();
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~Bitstream() { X265_FREE(m_fifo); }
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void resetBits() { m_partialByteBits = m_byteOccupancy = 0; m_partialByte = 0; }
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uint32_t getNumberOfWrittenBytes() const { return m_byteOccupancy; }
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uint32_t getNumberOfWrittenBits() const { return m_byteOccupancy * 8 + m_partialByteBits; }
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const uint8_t* getFIFO() const { return m_fifo; }
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void write(uint32_t val, uint32_t numBits);
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void writeByte(uint32_t val);
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void writeAlignOne(); // insert one bits until the bitstream is byte-aligned
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void writeAlignZero(); // insert zero bits until the bitstream is byte-aligned
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void writeByteAlignment(); // insert 1 bit, then pad to byte-align with zero
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private:
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uint8_t *m_fifo;
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uint32_t m_byteAlloc;
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uint32_t m_byteOccupancy;
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uint32_t m_partialByteBits;
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uint8_t m_partialByte;
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void push_back(uint8_t val);
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};
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static const uint8_t bitSize[256] =
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{
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1, 1, 3, 3, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 7, 7,
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9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
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11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
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11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
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13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
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13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
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13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
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13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
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15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
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15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
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15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
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15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
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15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
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15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
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15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
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15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
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};
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static inline int bs_size_ue(unsigned int val)
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{
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return bitSize[val + 1];
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}
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static inline int bs_size_ue_big(unsigned int val)
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{
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if (val < 255)
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return bitSize[val + 1];
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else
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return bitSize[(val + 1) >> 8] + 16;
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}
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static inline int bs_size_se(int val)
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{
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int tmp = 1 - val * 2;
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if (tmp < 0) tmp = val * 2;
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if (tmp < 256)
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return bitSize[tmp];
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else
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return bitSize[tmp >> 8] + 16;
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}
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class SyntaxElementWriter
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{
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public:
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BitInterface* m_bitIf;
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SyntaxElementWriter() : m_bitIf(NULL) {}
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/* silently discard the name of the syntax element */
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inline void WRITE_CODE(uint32_t code, uint32_t length, const char *) { writeCode(code, length); }
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inline void WRITE_UVLC(uint32_t code, const char *) { writeUvlc(code); }
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inline void WRITE_SVLC(int32_t code, const char *) { writeSvlc(code); }
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inline void WRITE_FLAG(bool flag, const char *) { writeFlag(flag); }
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void writeCode(uint32_t code, uint32_t length) { m_bitIf->write(code, length); }
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void writeUvlc(uint32_t code);
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void writeSvlc(int32_t code) { uint32_t ucode = (code <= 0) ? -code << 1 : (code << 1) - 1; writeUvlc(ucode); }
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void writeFlag(bool code) { m_bitIf->write(code, 1); }
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};
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}
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#endif // ifndef X265_BITSTREAM_H
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