aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/ra288.c
blob: 0a1d2e4965e3876e15ecd5504e28ce091f30f9c6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
/*
 * RealAudio 2.0 (28.8K)
 * Copyright (c) 2003 the ffmpeg project
 *
 * 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
 */

#include "avcodec.h"
#define ALT_BITSTREAM_READER_LE
#include "bitstream.h"
#include "ra288.h"

typedef struct {
    float history[8];
    float output[40];
    float pr1[36];
    float pr2[10];
    int   phase;

    float st1a[111], st1b[37], st1[37];
    float st2a[38], st2b[11], st2[11];
    float sb[41];
    float lhist[10];
} Real288_internal;

static inline float scalar_product_float(float * v1, float * v2, int size)
{
    float res = 0.;

    while (size--)
        res += *v1++ * *v2++;

    return res;
}

/* Decode and produce output */
static void decode(Real288_internal *glob, float gain, int cb_coef)
{
    int x, y;
    double sumsum;
    float sum, buffer[5];

    memmove(glob->sb + 5, glob->sb, 36 * sizeof(*glob->sb));

    for (x=4; x >= 0; x--)
        glob->sb[x] = -scalar_product_float(glob->sb + x + 1, glob->pr1, 36);

    /* convert log and do rms */
    sum = 32. - scalar_product_float(glob->pr2, glob->lhist, 10);

    sum = av_clipf(sum, 0, 60);

    sumsum = exp(sum * 0.1151292546497) * gain;    /* pow(10.0,sum/20)*f */

    for (x=0; x < 5; x++)
        buffer[x] = codetable[cb_coef][x] * sumsum;

    sum = FFMAX(1, scalar_product_float(buffer, buffer, 5) / 5);

    /* shift and store */
    memmove(glob->lhist, glob->lhist - 1, 10 * sizeof(*glob->lhist));

    *glob->lhist = glob->history[glob->phase] = 10 * log10(sum) - 32;

    for (x=1; x < 5; x++)
        for (y=x-1; y >= 0; y--)
            buffer[x] -= glob->pr1[x-y-1] * buffer[y];

    /* output */
    for (x=0; x < 5; x++) {
        glob->output[glob->phase*5+x] = glob->sb[4-x] =
            av_clipf(glob->sb[4-x] + buffer[x], -4095, 4095);
    }
}

/* column multiply */
static void colmult(float *tgt, float *m1, const float *m2, int n)
{
    while (n--)
        *(tgt++) = (*(m1++)) * (*(m2++));
}

static int pred(float *in, float *tgt, int n)
{
    int x, y;
    double f0, f1, f2;

    if (in[n] == 0)
        return 0;

    if ((f0 = *in) <= 0)
        return 0;

    for (x=1 ; ; x++) {
        float *p1 = in + x;
        float *p2 = tgt;

        if (n < x)
            return 1;

        f1 = *(p1--);

        for (y=0; y < x - 1; y++)
            f1 += (*(p1--))*(*(p2++));

        p1 = tgt + x - 1;
        p2 = tgt;
        *(p1--) = f2 = -f1/f0;
        for (y=x >> 1; y--;) {
            float temp = *p2 + *p1 * f2;
            *(p1--) += *p2 * f2;
            *(p2++) = temp;
        }
        if ((f0 += f1*f2) < 0)
            return 0;
    }
}

/* product sum (lsf) */
static void prodsum(float *tgt, float *src, int len, int n)
{
    for (; n >= 0; n--)
        tgt[n] = scalar_product_float(src, src - n, len);

}

static void co(int n, int i, int j, float *in, float *out, float *st1,
               float *st2, const float *table)
{
    int a, b, c;
    unsigned int x;
    float *fp;
    float buffer1[37];
    float buffer2[37];
    float work[111];

    /* rotate and multiply */
    c = (b = (a = n + i) + j) - i;
    fp = st1 + i;
    for (x=0; x < b; x++) {
        if (x == c)
            fp=in;
        work[x] = *(table++) * (*(st1++) = *(fp++));
    }

    prodsum(buffer1, work + n, i, n);
    prodsum(buffer2, work + a, j, n);

    for (x=0;x<=n;x++) {
        *st2 = *st2 * (0.5625) + buffer1[x];
        out[x] = *(st2++) + buffer2[x];
    }
    *out *= 1.00390625; /* to prevent clipping */
}

static void update(Real288_internal *glob)
{
    float buffer1[40], temp1[37];
    float buffer2[8], temp2[11];

    memcpy(buffer1     , glob->output + 20, 20*sizeof(*buffer1));
    memcpy(buffer1 + 20, glob->output     , 20*sizeof(*buffer1));

    co(36, 40, 35, buffer1, temp1, glob->st1a, glob->st1b, table1);

    if (pred(temp1, glob->st1, 36))
        colmult(glob->pr1, glob->st1, table1a, 36);

    memcpy(buffer2    , glob->history + 4, 4*sizeof(*buffer2));
    memcpy(buffer2 + 4, glob->history    , 4*sizeof(*buffer2));

    co(10, 8, 20, buffer2, temp2, glob->st2a, glob->st2b, table2);

    if (pred(temp2, glob->st2, 10))
        colmult(glob->pr2, glob->st2, table2a, 10);
}

/* Decode a block (celp) */
static int ra288_decode_frame(AVCodecContext * avctx, void *data,
                              int *data_size, const uint8_t * buf,
                              int buf_size)
{
    int16_t *out = data;
    int x, y;
    Real288_internal *glob = avctx->priv_data;
    GetBitContext gb;

    if (buf_size < avctx->block_align) {
        av_log(avctx, AV_LOG_ERROR,
               "Error! Input buffer is too small [%d<%d]\n",
               buf_size, avctx->block_align);
        return 0;
    }

    init_get_bits(&gb, buf, avctx->block_align * 8);

    for (x=0; x < 32; x++) {
        float gain = amptable[get_bits(&gb, 3)];
        int cb_coef = get_bits(&gb, 6 + (x&1));
        glob->phase = x & 7;
        decode(glob, gain, cb_coef);

        for (y=0; y < 5; y++)
            *(out++) = 8 * glob->output[glob->phase*5 + y];

        if (glob->phase == 3)
            update(glob);
    }

    *data_size = (char *)out - (char *)data;
    return avctx->block_align;
}

AVCodec ra_288_decoder =
{
    "real_288",
    CODEC_TYPE_AUDIO,
    CODEC_ID_RA_288,
    sizeof(Real288_internal),
    NULL,
    NULL,
    NULL,
    ra288_decode_frame,
    .long_name = NULL_IF_CONFIG_SMALL("RealAudio 2.0 (28.8K)"),
};