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 #include "libavutil/mem_internal.h" 39 40 #define MSBC_BLOCKS 15 41 42 /* sampling frequency */ 43 #define SBC_FREQ_16000 0x00 44 #define SBC_FREQ_32000 0x01 45 #define SBC_FREQ_44100 0x02 46 #define SBC_FREQ_48000 0x03 47 48 /* blocks */ 49 #define SBC_BLK_4 0x00 50 #define SBC_BLK_8 0x01 51 #define SBC_BLK_12 0x02 52 #define SBC_BLK_16 0x03 53 54 /* channel mode */ 55 #define SBC_MODE_MONO 0x00 56 #define SBC_MODE_DUAL_CHANNEL 0x01 57 #define SBC_MODE_STEREO 0x02 58 #define SBC_MODE_JOINT_STEREO 0x03 59 60 /* allocation method */ 61 #define SBC_AM_LOUDNESS 0x00 62 #define SBC_AM_SNR 0x01 63 64 /* subbands */ 65 #define SBC_SB_4 0x00 66 #define SBC_SB_8 0x01 67 68 /* synchronisation words */ 69 #define SBC_SYNCWORD 0x9C 70 #define MSBC_SYNCWORD 0xAD 71 72 /* extra bits of precision for the synthesis filter input data */ 73 #define SBCDEC_FIXED_EXTRA_BITS 2 74 75 /* 76 * Enforce 16 byte alignment for the data, which is supposed to be used 77 * with SIMD optimized code. 78 */ 79 #define SBC_ALIGN 16 80 81 /* This structure contains an unpacked SBC frame. 82 Yes, there is probably quite some unused space herein */ 83 struct sbc_frame { 84 uint8_t frequency; 85 uint8_t blocks; 86 enum { 87 MONO = SBC_MODE_MONO, 88 DUAL_CHANNEL = SBC_MODE_DUAL_CHANNEL, 89 STEREO = SBC_MODE_STEREO, 90 JOINT_STEREO = SBC_MODE_JOINT_STEREO 91 } mode; 92 uint8_t channels; 93 enum { 94 LOUDNESS = SBC_AM_LOUDNESS, 95 SNR = SBC_AM_SNR 96 } allocation; 97 uint8_t subbands; 98 uint8_t bitpool; 99 uint16_t codesize; 100 101 /* bit number x set means joint stereo has been used in subband x */ 102 uint8_t joint; 103 104 /* only the lower 4 bits of every element are to be used */ 105 DECLARE_ALIGNED(SBC_ALIGN, uint32_t, scale_factor)[2][8]; 106 107 /* raw integer subband samples in the frame */ 108 DECLARE_ALIGNED(SBC_ALIGN, int32_t, sb_sample_f)[16][2][8]; 109 110 /* modified subband samples */ 111 DECLARE_ALIGNED(SBC_ALIGN, int32_t, sb_sample)[16][2][8]; 112 113 const AVCRC *crc_ctx; 114 }; 115 116 uint8_t ff_sbc_crc8(const AVCRC *crc_ctx, const uint8_t *data, size_t len); 117 void ff_sbc_calculate_bits(const struct sbc_frame *frame, int (*bits)[8]); 118 119 #endif /* AVCODEC_SBC_H */ 120