diff options
author | Aurelien Jacobs <aurel@gnuage.org> | 2017-12-17 21:53:35 +0300 |
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committer | Aurelien Jacobs <aurel@gnuage.org> | 2018-03-08 00:26:53 +0300 |
commit | 4439887198025a9782f2ed52f8fda995269aad07 (patch) | |
tree | dc152252a5996d3530972b441c306863220f1410 /libavcodec/sbc.h | |
parent | 0b4ad86959cdd5c53474faf2c0b46e0f8a057fe1 (diff) |
sbc: implement SBC decoder (low-complexity subband codec)
This was originally based on libsbc, and was fully integrated into ffmpeg.
Diffstat (limited to 'libavcodec/sbc.h')
-rw-r--r-- | libavcodec/sbc.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/libavcodec/sbc.h b/libavcodec/sbc.h new file mode 100644 index 0000000000..405fadc3a6 --- /dev/null +++ b/libavcodec/sbc.h @@ -0,0 +1,118 @@ +/* + * 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 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 */ |