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ffmpeg-4.2.2/libavcodec/dirac_vlc.h 1.81 KB
aac5773f   hucm   功能基本完成,接口待打磨
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  /*
   * Copyright (C) 2016 Open Broadcast Systems Ltd.
   * Author        2016 Rostislav Pehlivanov <rpehlivanov@obe.tv>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #ifndef AVCODEC_DIRAC_VLC_H
  #define AVCODEC_DIRAC_VLC_H
  
  #include "libavutil/avutil.h"
  
  /* Can be 32 bits wide for some performance gain on some machines, but it will
   * incorrectly decode very long coefficients (usually only 1 or 2 per frame) */
  typedef uint64_t residual;
  
  #define LUT_BITS 8
  
  /* Exactly 64 bytes */
  typedef struct DiracGolombLUT {
      residual preamble, leftover;
      int32_t  ready[LUT_BITS];
      int32_t  preamble_bits, leftover_bits, ready_num;
      int8_t   need_s, sign;
  } DiracGolombLUT;
  
  av_cold int ff_dirac_golomb_reader_init(DiracGolombLUT **lut_ctx);
  
  int ff_dirac_golomb_read_32bit(DiracGolombLUT *lut_ctx, const uint8_t *buf,
                                 int bytes, uint8_t *dst, int coeffs);
  
  int ff_dirac_golomb_read_16bit(DiracGolombLUT *lut_ctx, const uint8_t *buf,
                                 int bytes, uint8_t *_dst, int coeffs);
  
  av_cold void ff_dirac_golomb_reader_end(DiracGolombLUT **lut_ctx);
  
  #endif /* AVCODEC_DIRAC_VLC_H */