/*
* 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 */