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ffmpeg-4.2.2/libavcodec/sbc.h 3.37 KB
aac5773f   hucm   功能基本完成,接口待打磨
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  /*
   * Bluetooth low-complexity, subband codec (SBC)
   *
   * Copyright (C) 2017  Aurelien Jacobs <aurel@gnuage.org>
   * Copyright (C) 2012-2014  Intel Corporation
   * Copyright (C) 2008-2010  Nokia Corporation
   * Copyright (C) 2004-2010  Marcel Holtmann <marcel@holtmann.org>
   * Copyright (C) 2004-2005  Henryk Ploetz <henryk@ploetzli.ch>
   * Copyright (C) 2005-2006  Brad Midgley <bmidgley@xmission.com>
   *
   * 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
   */
  
  /**
   * @file
   * SBC common definitions for the encoder and decoder
   */
  
  #ifndef AVCODEC_SBC_H
  #define AVCODEC_SBC_H
  
  #include "avcodec.h"
  #include "libavutil/crc.h"
  
  #define MSBC_BLOCKS 15
  
  /* sampling frequency */
  #define SBC_FREQ_16000  0x00
  #define SBC_FREQ_32000  0x01
  #define SBC_FREQ_44100  0x02
  #define SBC_FREQ_48000  0x03
  
  /* blocks */
  #define SBC_BLK_4       0x00
  #define SBC_BLK_8       0x01
  #define SBC_BLK_12      0x02
  #define SBC_BLK_16      0x03
  
  /* channel mode */
  #define SBC_MODE_MONO         0x00
  #define SBC_MODE_DUAL_CHANNEL 0x01
  #define SBC_MODE_STEREO       0x02
  #define SBC_MODE_JOINT_STEREO 0x03
  
  /* allocation method */
  #define SBC_AM_LOUDNESS 0x00
  #define SBC_AM_SNR      0x01
  
  /* subbands */
  #define SBC_SB_4        0x00
  #define SBC_SB_8        0x01
  
  /* synchronisation words */
  #define SBC_SYNCWORD   0x9C
  #define MSBC_SYNCWORD  0xAD
  
  /* extra bits of precision for the synthesis filter input data */
  #define SBCDEC_FIXED_EXTRA_BITS 2
  
  /*
   * Enforce 16 byte alignment for the data, which is supposed to be used
   * with SIMD optimized code.
   */
  #define SBC_ALIGN 16
  
  /* This structure contains an unpacked SBC frame.
     Yes, there is probably quite some unused space herein */
  struct sbc_frame {
      uint8_t frequency;
      uint8_t blocks;
      enum {
          MONO         = SBC_MODE_MONO,
          DUAL_CHANNEL = SBC_MODE_DUAL_CHANNEL,
          STEREO       = SBC_MODE_STEREO,
          JOINT_STEREO = SBC_MODE_JOINT_STEREO
      } mode;
      uint8_t channels;
      enum {
          LOUDNESS = SBC_AM_LOUDNESS,
          SNR      = SBC_AM_SNR
      } allocation;
      uint8_t subbands;
      uint8_t bitpool;
      uint16_t codesize;
  
      /* bit number x set means joint stereo has been used in subband x */
      uint8_t joint;
  
      /* only the lower 4 bits of every element are to be used */
      DECLARE_ALIGNED(SBC_ALIGN, uint32_t, scale_factor)[2][8];
  
      /* raw integer subband samples in the frame */
      DECLARE_ALIGNED(SBC_ALIGN, int32_t, sb_sample_f)[16][2][8];
  
      /* modified subband samples */
      DECLARE_ALIGNED(SBC_ALIGN, int32_t, sb_sample)[16][2][8];
  
      const AVCRC *crc_ctx;
  };
  
  uint8_t ff_sbc_crc8(const AVCRC *crc_ctx, const uint8_t *data, size_t len);
  void ff_sbc_calculate_bits(const struct sbc_frame *frame, int (*bits)[8]);
  
  #endif /* AVCODEC_SBC_H */