GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/aptx.h Lines: 0 23 0.0 %
Date: 2020-08-11 16:46:18 Branches: 0 4 0.0 %

Line Branch Exec Source
1
/*
2
 * Audio Processing Technology codec for Bluetooth (aptX)
3
 *
4
 * Copyright (C) 2017  Aurelien Jacobs <aurel@gnuage.org>
5
 *
6
 * This file is part of FFmpeg.
7
 *
8
 * FFmpeg is free software; you can redistribute it and/or
9
 * modify it under the terms of the GNU Lesser General Public
10
 * License as published by the Free Software Foundation; either
11
 * version 2.1 of the License, or (at your option) any later version.
12
 *
13
 * FFmpeg is distributed in the hope that it will be useful,
14
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16
 * Lesser General Public License for more details.
17
 *
18
 * You should have received a copy of the GNU Lesser General Public
19
 * License along with FFmpeg; if not, write to the Free Software
20
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21
 */
22
23
#ifndef AVCODEC_APTX_H
24
#define AVCODEC_APTX_H
25
26
#include "libavutil/intreadwrite.h"
27
#include "avcodec.h"
28
#include "internal.h"
29
#include "mathops.h"
30
#include "audio_frame_queue.h"
31
32
33
enum channels {
34
    LEFT,
35
    RIGHT,
36
    NB_CHANNELS
37
};
38
39
enum subbands {
40
    LF,  // Low Frequency (0-5.5 kHz)
41
    MLF, // Medium-Low Frequency (5.5-11kHz)
42
    MHF, // Medium-High Frequency (11-16.5kHz)
43
    HF,  // High Frequency (16.5-22kHz)
44
    NB_SUBBANDS
45
};
46
47
#define NB_FILTERS 2
48
#define FILTER_TAPS 16
49
50
typedef struct {
51
    int pos;
52
    int32_t buffer[2*FILTER_TAPS];
53
} FilterSignal;
54
55
typedef struct {
56
    FilterSignal outer_filter_signal[NB_FILTERS];
57
    FilterSignal inner_filter_signal[NB_FILTERS][NB_FILTERS];
58
} QMFAnalysis;
59
60
typedef struct {
61
    int32_t quantized_sample;
62
    int32_t quantized_sample_parity_change;
63
    int32_t error;
64
} Quantize;
65
66
typedef struct {
67
    int32_t quantization_factor;
68
    int32_t factor_select;
69
    int32_t reconstructed_difference;
70
} InvertQuantize;
71
72
typedef struct {
73
    int32_t prev_sign[2];
74
    int32_t s_weight[2];
75
    int32_t d_weight[24];
76
    int32_t pos;
77
    int32_t reconstructed_differences[48];
78
    int32_t previous_reconstructed_sample;
79
    int32_t predicted_difference;
80
    int32_t predicted_sample;
81
} Prediction;
82
83
typedef struct {
84
    int32_t codeword_history;
85
    int32_t dither_parity;
86
    int32_t dither[NB_SUBBANDS];
87
88
    QMFAnalysis qmf;
89
    Quantize quantize[NB_SUBBANDS];
90
    InvertQuantize invert_quantize[NB_SUBBANDS];
91
    Prediction prediction[NB_SUBBANDS];
92
} Channel;
93
94
typedef struct {
95
    int hd;
96
    int block_size;
97
    int32_t sync_idx;
98
    Channel channels[NB_CHANNELS];
99
    AudioFrameQueue afq;
100
} AptXContext;
101
102
typedef const struct {
103
    const int32_t *quantize_intervals;
104
    const int32_t *invert_quantize_dither_factors;
105
    const int32_t *quantize_dither_factors;
106
    const int16_t *quantize_factor_select_offset;
107
    int tables_size;
108
    int32_t factor_max;
109
    int32_t prediction_order;
110
} ConstTables;
111
112
extern ConstTables ff_aptx_quant_tables[2][NB_SUBBANDS];
113
114
/* Rounded right shift with optionnal clipping */
115
#define RSHIFT_SIZE(size)                                                     \
116
av_always_inline                                                              \
117
static int##size##_t rshift##size(int##size##_t value, int shift)             \
118
{                                                                             \
119
    int##size##_t rounding = (int##size##_t)1 << (shift - 1);                 \
120
    int##size##_t mask = ((int##size##_t)1 << (shift + 1)) - 1;               \
121
    return ((value + rounding) >> shift) - ((value & mask) == rounding);      \
122
}                                                                             \
123
av_always_inline                                                              \
124
static int##size##_t rshift##size##_clip24(int##size##_t value, int shift)    \
125
{                                                                             \
126
    return av_clip_intp2(rshift##size(value, shift), 23);                     \
127
}
128
RSHIFT_SIZE(32)
129
RSHIFT_SIZE(64)
130
131
/*
132
 * Convolution filter coefficients for the outer QMF of the QMF tree.
133
 * The 2 sets are a mirror of each other.
134
 */
135
static const int32_t aptx_qmf_outer_coeffs[NB_FILTERS][FILTER_TAPS] = {
136
    {
137
        730, -413, -9611, 43626, -121026, 269973, -585547, 2801966,
138
        697128, -160481, 27611, 8478, -10043, 3511, 688, -897,
139
    },
140
    {
141
        -897, 688, 3511, -10043, 8478, 27611, -160481, 697128,
142
        2801966, -585547, 269973, -121026, 43626, -9611, -413, 730,
143
    },
144
};
145
146
/*
147
 * Convolution filter coefficients for the inner QMF of the QMF tree.
148
 * The 2 sets are a mirror of each other.
149
 */
150
static const int32_t aptx_qmf_inner_coeffs[NB_FILTERS][FILTER_TAPS] = {
151
    {
152
       1033, -584, -13592, 61697, -171156, 381799, -828088, 3962579,
153
       985888, -226954, 39048, 11990, -14203, 4966, 973, -1268,
154
    },
155
    {
156
      -1268, 973, 4966, -14203, 11990, 39048, -226954, 985888,
157
      3962579, -828088, 381799, -171156, 61697, -13592, -584, 1033,
158
    },
159
};
160
161
/*
162
 * Push one sample into a circular signal buffer.
163
 */
164
av_always_inline
165
static void aptx_qmf_filter_signal_push(FilterSignal *signal, int32_t sample)
166
{
167
    signal->buffer[signal->pos            ] = sample;
168
    signal->buffer[signal->pos+FILTER_TAPS] = sample;
169
    signal->pos = (signal->pos + 1) & (FILTER_TAPS - 1);
170
}
171
172
/*
173
 * Compute the convolution of the signal with the coefficients, and reduce
174
 * to 24 bits by applying the specified right shifting.
175
 */
176
av_always_inline
177
static int32_t aptx_qmf_convolution(FilterSignal *signal,
178
                                    const int32_t coeffs[FILTER_TAPS],
179
                                    int shift)
180
{
181
    int32_t *sig = &signal->buffer[signal->pos];
182
    int64_t e = 0;
183
    int i;
184
185
    for (i = 0; i < FILTER_TAPS; i++)
186
        e += MUL64(sig[i], coeffs[i]);
187
188
    return rshift64_clip24(e, shift);
189
}
190
191
static inline int32_t aptx_quantized_parity(Channel *channel)
192
{
193
    int32_t parity = channel->dither_parity;
194
    int subband;
195
196
    for (subband = 0; subband < NB_SUBBANDS; subband++)
197
        parity ^= channel->quantize[subband].quantized_sample;
198
199
    return parity & 1;
200
}
201
202
/* For each sample, ensure that the parity of all subbands of all channels
203
 * is 0 except once every 8 samples where the parity is forced to 1. */
204
static inline int aptx_check_parity(Channel channels[NB_CHANNELS], int32_t *idx)
205
{
206
    int32_t parity = aptx_quantized_parity(&channels[LEFT])
207
                   ^ aptx_quantized_parity(&channels[RIGHT]);
208
209
    int eighth = *idx == 7;
210
    *idx = (*idx + 1) & 7;
211
212
    return parity ^ eighth;
213
}
214
215
void ff_aptx_invert_quantize_and_prediction(Channel *channel, int hd);
216
void ff_aptx_generate_dither(Channel *channel);
217
218
int ff_aptx_init(AVCodecContext *avctx);
219
220
#endif /* AVCODEC_APTX_H */