aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/nellymoserenc.c
blob: 85e01736a26f126be28e45e46e1eda77babe495a (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
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
/*
 * Nellymoser encoder
 * This code is developed as part of Google Summer of Code 2008 Program.
 *
 * Copyright (c) 2008 Bartlomiej Wolowiec
 *
 * 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
 * Nellymoser encoder
 * by Bartlomiej Wolowiec
 *
 * Generic codec information: libavcodec/nellymoserdec.c
 *
 * Some information also from: http://samples.mplayerhq.hu/A-codecs/Nelly_Moser/ASAO/ASAO.zip
 *                             (Copyright Joseph Artsimovich and UAB "DKD")
 *
 * for more information about nellymoser format, visit:
 * http://wiki.multimedia.cx/index.php?title=Nellymoser
 */

#include "nellymoser.h"
#include "avcodec.h"
#include "dsputil.h"
#include "fft.h"

#define BITSTREAM_WRITER_LE
#include "put_bits.h"

#define POW_TABLE_SIZE (1<<11)
#define POW_TABLE_OFFSET 3
#define OPT_SIZE ((1<<15) + 3000)

typedef struct NellyMoserEncodeContext {
    AVCodecContext  *avctx;
    int             last_frame;
    int             bufsel;
    int             have_saved;
    DSPContext      dsp;
    FFTContext      mdct_ctx;
    DECLARE_ALIGNED(16, float, mdct_out)[NELLY_SAMPLES];
    DECLARE_ALIGNED(16, float, in_buff)[NELLY_SAMPLES];
    DECLARE_ALIGNED(16, float, buf)[2][3 * NELLY_BUF_LEN];     ///< sample buffer
    float           (*opt )[NELLY_BANDS];
    uint8_t         (*path)[NELLY_BANDS];
} NellyMoserEncodeContext;

static float pow_table[POW_TABLE_SIZE];     ///< -pow(2, -i / 2048.0 - 3.0);

static const uint8_t sf_lut[96] = {
     0,  1,  1,  1,  1,  1,  1,  2,  2,  2,  2,  3,  3,  3,  4,  4,
     5,  5,  5,  6,  7,  7,  8,  8,  9, 10, 11, 11, 12, 13, 13, 14,
    15, 15, 16, 17, 17, 18, 19, 19, 20, 21, 22, 22, 23, 24, 25, 26,
    27, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40,
    41, 41, 42, 43, 44, 45, 45, 46, 47, 48, 49, 50, 51, 52, 52, 53,
    54, 55, 55, 56, 57, 57, 58, 59, 59, 60, 60, 60, 61, 61, 61, 62,
};

static const uint8_t sf_delta_lut[78] = {
     0,  1,  1,  1,  1,  1,  1,  2,  2,  2,  2,  3,  3,  3,  4,  4,
     4,  5,  5,  5,  6,  6,  7,  7,  8,  8,  9, 10, 10, 11, 11, 12,
    13, 13, 14, 15, 16, 17, 17, 18, 19, 19, 20, 21, 21, 22, 22, 23,
    23, 24, 24, 25, 25, 25, 26, 26, 26, 26, 27, 27, 27, 27, 27, 28,
    28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 30,
};

static const uint8_t quant_lut[230] = {
     0,

     0,  1,  2,

     0,  1,  2,  3,  4,  5,  6,

     0,  1,  1,  2,  2,  3,  3,  4,  5,  6,  7,  8,  9, 10, 11, 11,
    12, 13, 13, 13, 14,

     0,  1,  1,  2,  2,  2,  3,  3,  4,  4,  5,  5,  6,  6,  7,  8,
     8,  9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
    22, 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, 28, 28, 29, 29, 29,
    30,

     0,  1,  1,  1,  1,  1,  1,  2,  2,  2,  2,  2,  3,  3,  3,  3,
     4,  4,  4,  5,  5,  5,  6,  6,  7,  7,  7,  8,  8,  9,  9,  9,
    10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 13, 14, 14, 14, 15, 15,
    15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 20, 20, 20,
    21, 21, 22, 22, 23, 23, 24, 25, 26, 26, 27, 28, 29, 30, 31, 32,
    33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 42, 43, 44, 44, 45, 45,
    46, 47, 47, 48, 48, 49, 49, 50, 50, 50, 51, 51, 51, 52, 52, 52,
    53, 53, 53, 54, 54, 54, 55, 55, 55, 56, 56, 56, 57, 57, 57, 57,
    58, 58, 58, 58, 59, 59, 59, 59, 60, 60, 60, 60, 60, 61, 61, 61,
    61, 61, 61, 61, 62,
};

static const float quant_lut_mul[7] = { 0.0,  0.0,  2.0,  2.0,  5.0, 12.0,  36.6 };
static const float quant_lut_add[7] = { 0.0,  0.0,  2.0,  7.0, 21.0, 56.0, 157.0 };
static const uint8_t quant_lut_offset[8] = { 0, 0, 1, 4, 11, 32, 81, 230 };

static void apply_mdct(NellyMoserEncodeContext *s)
{
    memcpy(s->in_buff, s->buf[s->bufsel], NELLY_BUF_LEN * sizeof(float));
    s->dsp.vector_fmul(s->in_buff, ff_sine_128, NELLY_BUF_LEN);
    s->dsp.vector_fmul_reverse(s->in_buff + NELLY_BUF_LEN, s->buf[s->bufsel] + NELLY_BUF_LEN, ff_sine_128,
                               NELLY_BUF_LEN);
    ff_mdct_calc(&s->mdct_ctx, s->mdct_out, s->in_buff);

    s->dsp.vector_fmul(s->buf[s->bufsel] + NELLY_BUF_LEN, ff_sine_128, NELLY_BUF_LEN);
    s->dsp.vector_fmul_reverse(s->buf[s->bufsel] + 2 * NELLY_BUF_LEN, s->buf[1 - s->bufsel], ff_sine_128,
                               NELLY_BUF_LEN);
    ff_mdct_calc(&s->mdct_ctx, s->mdct_out + NELLY_BUF_LEN, s->buf[s->bufsel] + NELLY_BUF_LEN);
}

static av_cold int encode_init(AVCodecContext *avctx)
{
    NellyMoserEncodeContext *s = avctx->priv_data;
    int i;

    if (avctx->channels != 1) {
        av_log(avctx, AV_LOG_ERROR, "Nellymoser supports only 1 channel\n");
        return -1;
    }

    if (avctx->sample_rate != 8000 && avctx->sample_rate != 16000 &&
        avctx->sample_rate != 11025 &&
        avctx->sample_rate != 22050 && avctx->sample_rate != 44100 &&
        avctx->strict_std_compliance >= FF_COMPLIANCE_NORMAL) {
        av_log(avctx, AV_LOG_ERROR, "Nellymoser works only with 8000, 16000, 11025, 22050 and 44100 sample rate\n");
        return -1;
    }

    avctx->frame_size = NELLY_SAMPLES;
    s->avctx = avctx;
    ff_mdct_init(&s->mdct_ctx, 8, 0, 1.0);
    dsputil_init(&s->dsp, avctx);

    /* Generate overlap window */
    ff_sine_window_init(ff_sine_128, 128);
    for (i = 0; i < POW_TABLE_SIZE; i++)
        pow_table[i] = -pow(2, -i / 2048.0 - 3.0 + POW_TABLE_OFFSET);

    if (s->avctx->trellis) {
        s->opt  = av_malloc(NELLY_BANDS * OPT_SIZE * sizeof(float  ));
        s->path = av_malloc(NELLY_BANDS * OPT_SIZE * sizeof(uint8_t));
    }

    return 0;
}

static av_cold int encode_end(AVCodecContext *avctx)
{
    NellyMoserEncodeContext *s = avctx->priv_data;

    ff_mdct_end(&s->mdct_ctx);

    if (s->avctx->trellis) {
        av_free(s->opt);
        av_free(s->path);
    }

    return 0;
}

#define find_best(val, table, LUT, LUT_add, LUT_size) \
    best_idx = \
        LUT[av_clip ((lrintf(val) >> 8) + LUT_add, 0, LUT_size - 1)]; \
    if (fabs(val - table[best_idx]) > fabs(val - table[best_idx + 1])) \
        best_idx++;

static void get_exponent_greedy(NellyMoserEncodeContext *s, float *cand, int *idx_table)
{
    int band, best_idx, power_idx = 0;
    float power_candidate;

    //base exponent
    find_best(cand[0], ff_nelly_init_table, sf_lut, -20, 96);
    idx_table[0] = best_idx;
    power_idx = ff_nelly_init_table[best_idx];

    for (band = 1; band < NELLY_BANDS; band++) {
        power_candidate = cand[band] - power_idx;
        find_best(power_candidate, ff_nelly_delta_table, sf_delta_lut, 37, 78);
        idx_table[band] = best_idx;
        power_idx += ff_nelly_delta_table[best_idx];
    }
}

static inline float distance(float x, float y, int band)
{
    //return pow(fabs(x-y), 2.0);
    float tmp = x - y;
    return tmp * tmp;
}

static void get_exponent_dynamic(NellyMoserEncodeContext *s, float *cand, int *idx_table)
{
    int i, j, band, best_idx;
    float power_candidate, best_val;

    float  (*opt )[NELLY_BANDS] = s->opt ;
    uint8_t(*path)[NELLY_BANDS] = s->path;

    for (i = 0; i < NELLY_BANDS * OPT_SIZE; i++) {
        opt[0][i] = INFINITY;
    }

    for (i = 0; i < 64; i++) {
        opt[0][ff_nelly_init_table[i]] = distance(cand[0], ff_nelly_init_table[i], 0);
        path[0][ff_nelly_init_table[i]] = i;
    }

    for (band = 1; band < NELLY_BANDS; band++) {
        int q, c = 0;
        float tmp;
        int idx_min, idx_max, idx;
        power_candidate = cand[band];
        for (q = 1000; !c && q < OPT_SIZE; q <<= 2) {
            idx_min = FFMAX(0, cand[band] - q);
            idx_max = FFMIN(OPT_SIZE, cand[band - 1] + q);
            for (i = FFMAX(0, cand[band - 1] - q); i < FFMIN(OPT_SIZE, cand[band - 1] + q); i++) {
                if ( isinf(opt[band - 1][i]) )
                    continue;
                for (j = 0; j < 32; j++) {
                    idx = i + ff_nelly_delta_table[j];
                    if (idx > idx_max)
                        break;
                    if (idx >= idx_min) {
                        tmp = opt[band - 1][i] + distance(idx, power_candidate, band);
                        if (opt[band][idx] > tmp) {
                            opt[band][idx] = tmp;
                            path[band][idx] = j;
                            c = 1;
                        }
                    }
                }
            }
        }
        assert(c); //FIXME
    }

    best_val = INFINITY;
    best_idx = -1;
    band = NELLY_BANDS - 1;
    for (i = 0; i < OPT_SIZE; i++) {
        if (best_val > opt[band][i]) {
            best_val = opt[band][i];
            best_idx = i;
        }
    }
    for (band = NELLY_BANDS - 1; band >= 0; band--) {
        idx_table[band] = path[band][best_idx];
        if (band) {
            best_idx -= ff_nelly_delta_table[path[band][best_idx]];
        }
    }
}

/**
 * Encode NELLY_SAMPLES samples. It assumes, that samples contains 3 * NELLY_BUF_LEN values
 *  @param s               encoder context
 *  @param output          output buffer
 *  @param output_size     size of output buffer
 */
static void encode_block(NellyMoserEncodeContext *s, unsigned char *output, int output_size)
{
    PutBitContext pb;
    int i, j, band, block, best_idx, power_idx = 0;
    float power_val, coeff, coeff_sum;
    float pows[NELLY_FILL_LEN];
    int bits[NELLY_BUF_LEN], idx_table[NELLY_BANDS];
    float cand[NELLY_BANDS];

    apply_mdct(s);

    init_put_bits(&pb, output, output_size * 8);

    i = 0;
    for (band = 0; band < NELLY_BANDS; band++) {
        coeff_sum = 0;
        for (j = 0; j < ff_nelly_band_sizes_table[band]; i++, j++) {
            coeff_sum += s->mdct_out[i                ] * s->mdct_out[i                ]
                       + s->mdct_out[i + NELLY_BUF_LEN] * s->mdct_out[i + NELLY_BUF_LEN];
        }
        cand[band] =
            log(FFMAX(1.0, coeff_sum / (ff_nelly_band_sizes_table[band] << 7))) * 1024.0 / M_LN2;
    }

    if (s->avctx->trellis) {
        get_exponent_dynamic(s, cand, idx_table);
    } else {
        get_exponent_greedy(s, cand, idx_table);
    }

    i = 0;
    for (band = 0; band < NELLY_BANDS; band++) {
        if (band) {
            power_idx += ff_nelly_delta_table[idx_table[band]];
            put_bits(&pb, 5, idx_table[band]);
        } else {
            power_idx = ff_nelly_init_table[idx_table[0]];
            put_bits(&pb, 6, idx_table[0]);
        }
        power_val = pow_table[power_idx & 0x7FF] / (1 << ((power_idx >> 11) + POW_TABLE_OFFSET));
        for (j = 0; j < ff_nelly_band_sizes_table[band]; i++, j++) {
            s->mdct_out[i] *= power_val;
            s->mdct_out[i + NELLY_BUF_LEN] *= power_val;
            pows[i] = power_idx;
        }
    }

    ff_nelly_get_sample_bits(pows, bits);

    for (block = 0; block < 2; block++) {
        for (i = 0; i < NELLY_FILL_LEN; i++) {
            if (bits[i] > 0) {
                const float *table = ff_nelly_dequantization_table + (1 << bits[i]) - 1;
                coeff = s->mdct_out[block * NELLY_BUF_LEN + i];
                best_idx =
                    quant_lut[av_clip (
                            coeff * quant_lut_mul[bits[i]] + quant_lut_add[bits[i]],
                            quant_lut_offset[bits[i]],
                            quant_lut_offset[bits[i]+1] - 1
                            )];
                if (fabs(coeff - table[best_idx]) > fabs(coeff - table[best_idx + 1]))
                    best_idx++;

                put_bits(&pb, bits[i], best_idx);
            }
        }
        if (!block)
            put_bits(&pb, NELLY_HEADER_BITS + NELLY_DETAIL_BITS - put_bits_count(&pb), 0);
    }

    flush_put_bits(&pb);
}

static int encode_frame(AVCodecContext *avctx, uint8_t *frame, int buf_size, void *data)
{
    NellyMoserEncodeContext *s = avctx->priv_data;
    const int16_t *samples = data;
    int i;

    if (s->last_frame)
        return 0;

    if (data) {
        for (i = 0; i < avctx->frame_size; i++) {
            s->buf[s->bufsel][i] = samples[i];
        }
        for (; i < NELLY_SAMPLES; i++) {
            s->buf[s->bufsel][i] = 0;
        }
        s->bufsel = 1 - s->bufsel;
        if (!s->have_saved) {
            s->have_saved = 1;
            return 0;
        }
    } else {
        memset(s->buf[s->bufsel], 0, sizeof(s->buf[0][0]) * NELLY_BUF_LEN);
        s->bufsel = 1 - s->bufsel;
        s->last_frame = 1;
    }

    if (s->have_saved) {
        encode_block(s, frame, buf_size);
        return NELLY_BLOCK_LEN;
    }
    return 0;
}

AVCodec nellymoser_encoder = {
    .name = "nellymoser",
    .type = AVMEDIA_TYPE_AUDIO,
    .id = CODEC_ID_NELLYMOSER,
    .priv_data_size = sizeof(NellyMoserEncodeContext),
    .init = encode_init,
    .encode = encode_frame,
    .close = encode_end,
    .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY,
    .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
};