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 "avcodec.h" 37 #include "libavutil/crc.h" 38 39 #define MSBC_BLOCKS 15 40 41 /* sampling frequency */ 42 #define SBC_FREQ_16000 0x00 43 #define SBC_FREQ_32000 0x01 44 #define SBC_FREQ_44100 0x02 45 #define SBC_FREQ_48000 0x03 46 47 /* blocks */ 48 #define SBC_BLK_4 0x00 49 #define SBC_BLK_8 0x01 50 #define SBC_BLK_12 0x02 51 #define SBC_BLK_16 0x03 52 53 /* channel mode */ 54 #define SBC_MODE_MONO 0x00 55 #define SBC_MODE_DUAL_CHANNEL 0x01 56 #define SBC_MODE_STEREO 0x02 57 #define SBC_MODE_JOINT_STEREO 0x03 58 59 /* allocation method */ 60 #define SBC_AM_LOUDNESS 0x00 61 #define SBC_AM_SNR 0x01 62 63 /* subbands */ 64 #define SBC_SB_4 0x00 65 #define SBC_SB_8 0x01 66 67 /* synchronisation words */ 68 #define SBC_SYNCWORD 0x9C 69 #define MSBC_SYNCWORD 0xAD 70 71 /* extra bits of precision for the synthesis filter input data */ 72 #define SBCDEC_FIXED_EXTRA_BITS 2 73 74 /* 75 * Enforce 16 byte alignment for the data, which is supposed to be used 76 * with SIMD optimized code. 77 */ 78 #define SBC_ALIGN 16 79 80 /* This structure contains an unpacked SBC frame. 81 Yes, there is probably quite some unused space herein */ 82 struct sbc_frame { 83 uint8_t frequency; 84 uint8_t blocks; 85 enum { 86 MONO = SBC_MODE_MONO, 87 DUAL_CHANNEL = SBC_MODE_DUAL_CHANNEL, 88 STEREO = SBC_MODE_STEREO, 89 JOINT_STEREO = SBC_MODE_JOINT_STEREO 90 } mode; 91 uint8_t channels; 92 enum { 93 LOUDNESS = SBC_AM_LOUDNESS, 94 SNR = SBC_AM_SNR 95 } allocation; 96 uint8_t subbands; 97 uint8_t bitpool; 98 uint16_t codesize; 99 100 /* bit number x set means joint stereo has been used in subband x */ 101 uint8_t joint; 102 103 /* only the lower 4 bits of every element are to be used */ 104 DECLARE_ALIGNED(SBC_ALIGN, uint32_t, scale_factor)[2][8]; 105 106 /* raw integer subband samples in the frame */ 107 DECLARE_ALIGNED(SBC_ALIGN, int32_t, sb_sample_f)[16][2][8]; 108 109 /* modified subband samples */ 110 DECLARE_ALIGNED(SBC_ALIGN, int32_t, sb_sample)[16][2][8]; 111 112 const AVCRC *crc_ctx; 113 }; 114 115 uint8_t ff_sbc_crc8(const AVCRC *crc_ctx, const uint8_t *data, size_t len); 116 void ff_sbc_calculate_bits(const struct sbc_frame *frame, int (*bits)[8]); 117 118 #endif /* AVCODEC_SBC_H */ 119