GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/fastaudio.c Lines: 0 86 0.0 %
Date: 2020-09-25 14:59:26 Branches: 0 54 0.0 %

Line Branch Exec Source
1
/*
2
 * MOFLEX Fast Audio decoder
3
 * Copyright (c) 2020 Paul B Mahol
4
 *
5
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10
 * version 2.1 of the License, or (at your option) any later version.
11
 *
12
 * FFmpeg is distributed in the hope that it will be useful,
13
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15
 * Lesser General Public License for more details.
16
 *
17
 * You should have received a copy of the GNU Lesser General Public
18
 * License along with FFmpeg; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21
22
#include "libavutil/intreadwrite.h"
23
24
#include "avcodec.h"
25
#include "bytestream.h"
26
#include "internal.h"
27
#include "mathops.h"
28
29
typedef struct ChannelItems {
30
    float f[8];
31
    float last;
32
} ChannelItems;
33
34
typedef struct FastAudioContext {
35
    float table[8][64];
36
37
    ChannelItems *ch;
38
} FastAudioContext;
39
40
static av_cold int fastaudio_init(AVCodecContext *avctx)
41
{
42
    FastAudioContext *s = avctx->priv_data;
43
44
    avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
45
46
    for (int i = 0; i < 8; i++)
47
        s->table[0][i] = (i - 159.5f) / 160.f;
48
    for (int i = 0; i < 11; i++)
49
        s->table[0][i + 8] = (i - 37.5f) / 40.f;
50
    for (int i = 0; i < 27; i++)
51
        s->table[0][i + 8 + 11] = (i - 13.f) / 20.f;
52
    for (int i = 0; i < 11; i++)
53
        s->table[0][i + 8 + 11 + 27] = (i + 27.5f) / 40.f;
54
    for (int i = 0; i < 7; i++)
55
        s->table[0][i + 8 + 11 + 27 + 11] = (i + 152.5f) / 160.f;
56
57
    memcpy(s->table[1], s->table[0], sizeof(s->table[0]));
58
59
    for (int i = 0; i < 7; i++)
60
        s->table[2][i] = (i - 33.5f) / 40.f;
61
    for (int i = 0; i < 25; i++)
62
        s->table[2][i + 7] = (i - 13.f) / 20.f;
63
64
    for (int i = 0; i < 32; i++)
65
        s->table[3][i] = -s->table[2][31 - i];
66
67
    for (int i = 0; i < 16; i++)
68
        s->table[4][i] = i * 0.22f / 3.f - 0.6f;
69
70
    for (int i = 0; i < 16; i++)
71
        s->table[5][i] = i * 0.20f / 3.f - 0.3f;
72
73
    for (int i = 0; i < 8; i++)
74
        s->table[6][i] = i * 0.36f / 3.f - 0.4f;
75
76
    for (int i = 0; i < 8; i++)
77
        s->table[7][i] = i * 0.34f / 3.f - 0.2f;
78
79
    s->ch = av_calloc(avctx->channels, sizeof(*s->ch));
80
    if (!s->ch)
81
        return AVERROR(ENOMEM);
82
83
    return 0;
84
}
85
86
static int read_bits(int bits, int *ppos, unsigned *src)
87
{
88
    int r, pos;
89
90
    pos = *ppos;
91
    pos += bits;
92
    r = src[(pos - 1) / 32] >> (32 - pos % 32);
93
    *ppos = pos;
94
95
    return r & ((1 << bits) - 1);
96
}
97
98
static const uint8_t bits[8] = { 6, 6, 5, 5, 4, 0, 3, 3, };
99
100
static void set_sample(int i, int j, int v, float *result, int *pads, float value)
101
{
102
    result[i * 64 + pads[i] + j * 3] = value * (2 * v - 7);
103
}
104
105
static int fastaudio_decode(AVCodecContext *avctx, void *data,
106
                            int *got_frame, AVPacket *pkt)
107
{
108
    FastAudioContext *s = avctx->priv_data;
109
    GetByteContext gb;
110
    AVFrame *frame = data;
111
    int subframes;
112
    int ret;
113
114
    subframes = pkt->size / (40 * avctx->channels);
115
    frame->nb_samples = subframes * 256;
116
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
117
        return ret;
118
119
    bytestream2_init(&gb, pkt->data, pkt->size);
120
121
    for (int subframe = 0; subframe < subframes; subframe++) {
122
        for (int channel = 0; channel < avctx->channels; channel++) {
123
            ChannelItems *ch = &s->ch[channel];
124
            float result[256] = { 0 };
125
            unsigned src[10];
126
            int inds[4], pads[4];
127
            float m[8];
128
            int pos = 0;
129
130
            for (int i = 0; i < 10; i++)
131
                src[i] = bytestream2_get_le32(&gb);
132
133
            for (int i = 0; i < 8; i++)
134
                m[7 - i] = s->table[i][read_bits(bits[i], &pos, src)];
135
136
            for (int i = 0; i < 4; i++)
137
                inds[3 - i] = read_bits(6, &pos, src);
138
139
            for (int i = 0; i < 4; i++)
140
                pads[3 - i] = read_bits(2, &pos, src);
141
142
            for (int i = 0, index5 = 0; i < 4; i++) {
143
                float value = av_int2float((inds[i] + 1) << 20) * powf(2.f, 116.f);
144
145
                for (int j = 0, tmp = 0; j < 21; j++) {
146
                    set_sample(i, j, j == 20 ? tmp / 2 : read_bits(3, &pos, src), result, pads, value);
147
                    if (j % 10 == 9)
148
                        tmp = 4 * tmp + read_bits(2, &pos, src);
149
                    if (j == 20)
150
                        index5 = FFMIN(2 * index5 + tmp % 2, 63);
151
                }
152
153
                m[2] = s->table[5][index5];
154
            }
155
156
            for (int i = 0; i < 256; i++) {
157
                float x = result[i];
158
159
                for (int j = 0; j < 8; j++) {
160
                    x -= m[j] * ch->f[j];
161
                    ch->f[j] += m[j] * x;
162
                }
163
164
                memmove(&ch->f[0], &ch->f[1], sizeof(float) * 7);
165
                ch->f[7] = x;
166
                ch->last = x + ch->last * 0.86f;
167
                result[i] = ch->last * 2.f;
168
            }
169
170
            memcpy(frame->extended_data[channel] + 1024 * subframe, result, 256 * sizeof(float));
171
        }
172
    }
173
174
    *got_frame = 1;
175
176
    return pkt->size;
177
}
178
179
static av_cold int fastaudio_close(AVCodecContext *avctx)
180
{
181
    FastAudioContext *s = avctx->priv_data;
182
183
    av_freep(&s->ch);
184
185
    return 0;
186
}
187
188
AVCodec ff_fastaudio_decoder = {
189
    .name           = "fastaudio",
190
    .long_name      = NULL_IF_CONFIG_SMALL("MobiClip FastAudio"),
191
    .type           = AVMEDIA_TYPE_AUDIO,
192
    .id             = AV_CODEC_ID_FASTAUDIO,
193
    .priv_data_size = sizeof(FastAudioContext),
194
    .init           = fastaudio_init,
195
    .decode         = fastaudio_decode,
196
    .close          = fastaudio_close,
197
    .capabilities   = AV_CODEC_CAP_DR1,
198
    .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
199
                                                      AV_SAMPLE_FMT_NONE },
200
};