libavcodec/sbc.h

   1 /*
   2  * Bluetooth low-complexity, subband codec (SBC)
   3  *
   4  * Copyright (C) 2017  Aurelien Jacobs <aurel@gnuage.org>
   5  * Copyright (C) 2012-2014  Intel Corporation
   6  * Copyright (C) 2008-2010  Nokia Corporation
   7  * Copyright (C) 2004-2010  Marcel Holtmann <marcel@holtmann.org>
   8  * Copyright (C) 2004-2005  Henryk Ploetz <henryk@ploetzli.ch>
   9  * Copyright (C) 2005-2006  Brad Midgley <bmidgley@xmission.com>
  10  *
  11  * This file is part of FFmpeg.
  12  *
  13  * FFmpeg is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU Lesser General Public
  15  * License as published by the Free Software Foundation; either
  16  * version 2.1 of the License, or (at your option) any later version.
  17  *
  18  * FFmpeg is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21  * Lesser General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU Lesser General Public
  24  * License along with FFmpeg; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  26  */
  27
  28 /**
  29  * @file
  30  * SBC common definitions for the encoder and decoder
  31  */
  32
  33 #ifndef AVCODEC_SBC_H
  34 #define AVCODEC_SBC_H
  35
  36 #include <stddef.h>
  37 #include <stdint.h>
  38 #include "libavutil/crc.h"
  39 #include "libavutil/mem_internal.h"
  40
  41 #define MSBC_BLOCKS 15
  42
  43 /* sampling frequency */
  44 #define SBC_FREQ_16000  0x00
  45 #define SBC_FREQ_32000  0x01
  46 #define SBC_FREQ_44100  0x02
  47 #define SBC_FREQ_48000  0x03
  48
  49 /* blocks */
  50 #define SBC_BLK_4       0x00
  51 #define SBC_BLK_8       0x01
  52 #define SBC_BLK_12      0x02
  53 #define SBC_BLK_16      0x03
  54
  55 /* channel mode */
  56 #define SBC_MODE_MONO         0x00
  57 #define SBC_MODE_DUAL_CHANNEL 0x01
  58 #define SBC_MODE_STEREO       0x02
  59 #define SBC_MODE_JOINT_STEREO 0x03
  60
  61 /* allocation method */
  62 #define SBC_AM_LOUDNESS 0x00
  63 #define SBC_AM_SNR      0x01
  64
  65 /* subbands */
  66 #define SBC_SB_4        0x00
  67 #define SBC_SB_8        0x01
  68
  69 /* synchronisation words */
  70 #define SBC_SYNCWORD   0x9C
  71 #define MSBC_SYNCWORD  0xAD
  72
  73 /* extra bits of precision for the synthesis filter input data */
  74 #define SBCDEC_FIXED_EXTRA_BITS 2
  75
  76 /*
  77  * Enforce 16 byte alignment for the data, which is supposed to be used
  78  * with SIMD optimized code.
  79  */
  80 #define SBC_ALIGN 16
  81
  82 /* This structure contains an unpacked SBC frame.
  83    Yes, there is probably quite some unused space herein */
  84 struct sbc_frame {
  85     uint8_t frequency;
  86     uint8_t blocks;
  87     enum {
  88         MONO         = SBC_MODE_MONO,
  89         DUAL_CHANNEL = SBC_MODE_DUAL_CHANNEL,
  90         STEREO       = SBC_MODE_STEREO,
  91         JOINT_STEREO = SBC_MODE_JOINT_STEREO
  92     } mode;
  93     uint8_t channels;
  94     enum {
  95         LOUDNESS = SBC_AM_LOUDNESS,
  96         SNR      = SBC_AM_SNR
  97     } allocation;
  98     uint8_t subbands;
  99     uint8_t bitpool;
 100     uint16_t codesize;
 101
 102     /* bit number x set means joint stereo has been used in subband x */
 103     uint8_t joint;
 104
 105     /* only the lower 4 bits of every element are to be used */
 106     DECLARE_ALIGNED(SBC_ALIGN, uint32_t, scale_factor)[2][8];
 107
 108     /* raw integer subband samples in the frame */
 109     DECLARE_ALIGNED(SBC_ALIGN, int32_t, sb_sample_f)[16][2][8];
 110
 111     /* modified subband samples */
 112     DECLARE_ALIGNED(SBC_ALIGN, int32_t, sb_sample)[16][2][8];
 113
 114     const AVCRC *crc_ctx;
 115 };
 116
 117 uint8_t ff_sbc_crc8(const AVCRC *crc_ctx, const uint8_t *data, size_t len);
 118 void ff_sbc_calculate_bits(const struct sbc_frame *frame, int (*bits)[8]);
 119
 120 #endif /* AVCODEC_SBC_H */