1 /*
2  * TwinVQ decoder
3  * Copyright (c) 2009 Vitor Sessak
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 <math.h>
23 #include <stdint.h>
24 
25 #include "libavutil/channel_layout.h"
26 #include "avcodec.h"
27 #include "get_bits.h"
28 #include "internal.h"
29 #include "twinvq.h"
30 #include "twinvq_data.h"
31 
32 static const TwinVQModeTab mode_08_08 = {
33     {
34         { 8, bark_tab_s08_64,  10, tab.fcb08s, 1, 5, tab.cb0808s0, tab.cb0808s1, 18 },
35         { 2, bark_tab_m08_256, 20, tab.fcb08m, 2, 5, tab.cb0808m0, tab.cb0808m1, 16 },
36         { 1, bark_tab_l08_512, 30, tab.fcb08l, 3, 6, tab.cb0808l0, tab.cb0808l1, 17 }
37     },
38     512, 12, tab.lsp08, 1, 5, 3, 3, tab.shape08, 8, 28, 20, 6, 40
39 };
40 
41 static const TwinVQModeTab mode_11_08 = {
42     {
43         { 8, bark_tab_s11_64,  10, tab.fcb11s, 1, 5, tab.cb1108s0, tab.cb1108s1, 29 },
44         { 2, bark_tab_m11_256, 20, tab.fcb11m, 2, 5, tab.cb1108m0, tab.cb1108m1, 24 },
45         { 1, bark_tab_l11_512, 30, tab.fcb11l, 3, 6, tab.cb1108l0, tab.cb1108l1, 27 }
46     },
47     512, 16, tab.lsp11, 1, 6, 4, 3, tab.shape11, 9, 36, 30, 7, 90
48 };
49 
50 static const TwinVQModeTab mode_11_10 = {
51     {
52         { 8, bark_tab_s11_64,  10, tab.fcb11s, 1, 5, tab.cb1110s0, tab.cb1110s1, 21 },
53         { 2, bark_tab_m11_256, 20, tab.fcb11m, 2, 5, tab.cb1110m0, tab.cb1110m1, 18 },
54         { 1, bark_tab_l11_512, 30, tab.fcb11l, 3, 6, tab.cb1110l0, tab.cb1110l1, 20 }
55     },
56     512, 16, tab.lsp11, 1, 6, 4, 3, tab.shape11, 9, 36, 30, 7, 90
57 };
58 
59 static const TwinVQModeTab mode_16_16 = {
60     {
61         { 8, bark_tab_s16_128,  10, tab.fcb16s, 1, 5, tab.cb1616s0, tab.cb1616s1, 16 },
62         { 2, bark_tab_m16_512,  20, tab.fcb16m, 2, 5, tab.cb1616m0, tab.cb1616m1, 15 },
63         { 1, bark_tab_l16_1024, 30, tab.fcb16l, 3, 6, tab.cb1616l0, tab.cb1616l1, 16 }
64     },
65     1024, 16, tab.lsp16, 1, 6, 4, 3, tab.shape16, 9, 56, 60, 7, 180
66 };
67 
68 static const TwinVQModeTab mode_22_20 = {
69     {
70         { 8, bark_tab_s22_128,  10, tab.fcb22s_1, 1, 6, tab.cb2220s0, tab.cb2220s1, 18 },
71         { 2, bark_tab_m22_512,  20, tab.fcb22m_1, 2, 6, tab.cb2220m0, tab.cb2220m1, 17 },
72         { 1, bark_tab_l22_1024, 32, tab.fcb22l_1, 4, 6, tab.cb2220l0, tab.cb2220l1, 18 }
73     },
74     1024, 16, tab.lsp22_1, 1, 6, 4, 3, tab.shape22_1, 9, 56, 36, 7, 144
75 };
76 
77 static const TwinVQModeTab mode_22_24 = {
78     {
79         { 8, bark_tab_s22_128,  10, tab.fcb22s_1, 1, 6, tab.cb2224s0, tab.cb2224s1, 15 },
80         { 2, bark_tab_m22_512,  20, tab.fcb22m_1, 2, 6, tab.cb2224m0, tab.cb2224m1, 14 },
81         { 1, bark_tab_l22_1024, 32, tab.fcb22l_1, 4, 6, tab.cb2224l0, tab.cb2224l1, 15 }
82     },
83     1024, 16, tab.lsp22_1, 1, 6, 4, 3, tab.shape22_1, 9, 56, 36, 7, 144
84 };
85 
86 static const TwinVQModeTab mode_22_32 = {
87     {
88         { 4, bark_tab_s22_128, 10, tab.fcb22s_2, 1, 6, tab.cb2232s0, tab.cb2232s1, 11 },
89         { 2, bark_tab_m22_256, 20, tab.fcb22m_2, 2, 6, tab.cb2232m0, tab.cb2232m1, 11 },
90         { 1, bark_tab_l22_512, 32, tab.fcb22l_2, 4, 6, tab.cb2232l0, tab.cb2232l1, 12 }
91     },
92     512, 16, tab.lsp22_2, 1, 6, 4, 4, tab.shape22_2, 9, 56, 36, 7, 72
93 };
94 
95 static const TwinVQModeTab mode_44_40 = {
96     {
97         { 16, bark_tab_s44_128,  10, tab.fcb44s, 1, 6, tab.cb4440s0, tab.cb4440s1, 18 },
98         { 4,  bark_tab_m44_512,  20, tab.fcb44m, 2, 6, tab.cb4440m0, tab.cb4440m1, 17 },
99         { 1,  bark_tab_l44_2048, 40, tab.fcb44l, 4, 6, tab.cb4440l0, tab.cb4440l1, 17 }
100     },
101     2048, 20, tab.lsp44, 1, 6, 4, 4, tab.shape44, 9, 84, 54, 7, 432
102 };
103 
104 static const TwinVQModeTab mode_44_48 = {
105     {
106         { 16, bark_tab_s44_128,  10, tab.fcb44s, 1, 6, tab.cb4448s0, tab.cb4448s1, 15 },
107         { 4,  bark_tab_m44_512,  20, tab.fcb44m, 2, 6, tab.cb4448m0, tab.cb4448m1, 14 },
108         { 1,  bark_tab_l44_2048, 40, tab.fcb44l, 4, 6, tab.cb4448l0, tab.cb4448l1, 14 }
109     },
110     2048, 20, tab.lsp44, 1, 6, 4, 4, tab.shape44, 9, 84, 54, 7, 432
111 };
112 
113 /**
114  * Evaluate a * b / 400 rounded to the nearest integer. When, for example,
115  * a * b == 200 and the nearest integer is ill-defined, use a table to emulate
116  * the following broken float-based implementation used by the binary decoder:
117  *
118  * @code
119  * static int very_broken_op(int a, int b)
120  * {
121  *    static float test; // Ugh, force gcc to do the division first...
122  *
123  *    test = a / 400.0;
124  *    return b * test + 0.5;
125  * }
126  * @endcode
127  *
128  * @note if this function is replaced by just ROUNDED_DIV(a * b, 400.0), the
129  * stddev between the original file (before encoding with Yamaha encoder) and
130  * the decoded output increases, which leads one to believe that the encoder
131  * expects exactly this broken calculation.
132  */
very_broken_op(int a,int b)133 static int very_broken_op(int a, int b)
134 {
135     int x = a * b + 200;
136     int size;
137     const uint8_t *rtab;
138 
139     if (x % 400 || b % 5)
140         return x / 400;
141 
142     x /= 400;
143 
144     size = tabs[b / 5].size;
145     rtab = tabs[b / 5].tab;
146     return x - rtab[size * av_log2(2 * (x - 1) / size) + (x - 1) % size];
147 }
148 
149 /**
150  * Sum to data a periodic peak of a given period, width and shape.
151  *
152  * @param period the period of the peak divided by 400.0
153  */
add_peak(int period,int width,const float * shape,float ppc_gain,float * speech,int len)154 static void add_peak(int period, int width, const float *shape,
155                      float ppc_gain, float *speech, int len)
156 {
157     int i, j;
158 
159     const float *shape_end = shape + len;
160     int center;
161 
162     // First peak centered around zero
163     for (i = 0; i < width / 2; i++)
164         speech[i] += ppc_gain * *shape++;
165 
166     for (i = 1; i < ROUNDED_DIV(len, width); i++) {
167         center = very_broken_op(period, i);
168         for (j = -width / 2; j < (width + 1) / 2; j++)
169             speech[j + center] += ppc_gain * *shape++;
170     }
171 
172     // For the last block, be careful not to go beyond the end of the buffer
173     center = very_broken_op(period, i);
174     for (j = -width / 2; j < (width + 1) / 2 && shape < shape_end; j++)
175         speech[j + center] += ppc_gain * *shape++;
176 }
177 
decode_ppc(TwinVQContext * tctx,int period_coef,int g_coef,const float * shape,float * speech)178 static void decode_ppc(TwinVQContext *tctx, int period_coef, int g_coef,
179                        const float *shape, float *speech)
180 {
181     const TwinVQModeTab *mtab = tctx->mtab;
182     int isampf = tctx->avctx->sample_rate /  1000;
183     int ibps   = tctx->avctx->bit_rate    / (1000 * tctx->avctx->channels);
184     int min_period   = ROUNDED_DIV(40 * 2 * mtab->size, isampf);
185     int max_period   = ROUNDED_DIV(40 * 2 * mtab->size * 6, isampf);
186     int period_range = max_period - min_period;
187     float pgain_step = 25000.0 / ((1 << mtab->pgain_bit) - 1);
188     float ppc_gain   = 1.0 / 8192 *
189                        twinvq_mulawinv(pgain_step * g_coef +
190                                            pgain_step / 2,
191                                        25000.0, TWINVQ_PGAIN_MU);
192 
193     // This is actually the period multiplied by 400. It is just linearly coded
194     // between its maximum and minimum value.
195     int period = min_period +
196                  ROUNDED_DIV(period_coef * period_range,
197                              (1 << mtab->ppc_period_bit) - 1);
198     int width;
199 
200     if (isampf == 22 && ibps == 32) {
201         // For some unknown reason, NTT decided to code this case differently...
202         width = ROUNDED_DIV((period + 800) * mtab->peak_per2wid,
203                             400 * mtab->size);
204     } else
205         width = period * mtab->peak_per2wid / (400 * mtab->size);
206 
207     add_peak(period, width, shape, ppc_gain, speech, mtab->ppc_shape_len);
208 }
209 
dec_bark_env(TwinVQContext * tctx,const uint8_t * in,int use_hist,int ch,float * out,float gain,enum TwinVQFrameType ftype)210 static void dec_bark_env(TwinVQContext *tctx, const uint8_t *in, int use_hist,
211                          int ch, float *out, float gain,
212                          enum TwinVQFrameType ftype)
213 {
214     const TwinVQModeTab *mtab = tctx->mtab;
215     int i, j;
216     float *hist     = tctx->bark_hist[ftype][ch];
217     float val       = ((const float []) { 0.4, 0.35, 0.28 })[ftype];
218     int bark_n_coef = mtab->fmode[ftype].bark_n_coef;
219     int fw_cb_len   = mtab->fmode[ftype].bark_env_size / bark_n_coef;
220     int idx         = 0;
221 
222     for (i = 0; i < fw_cb_len; i++)
223         for (j = 0; j < bark_n_coef; j++, idx++) {
224             float tmp2 = mtab->fmode[ftype].bark_cb[fw_cb_len * in[j] + i] *
225                          (1.0 / 4096);
226             float st   = use_hist ? (1.0 - val) * tmp2 + val * hist[idx] + 1.0
227                                   : tmp2 + 1.0;
228 
229             hist[idx] = tmp2;
230             if (st < -1.0)
231                 st = 1.0;
232 
233             twinvq_memset_float(out, st * gain, mtab->fmode[ftype].bark_tab[idx]);
234             out += mtab->fmode[ftype].bark_tab[idx];
235         }
236 }
237 
read_cb_data(TwinVQContext * tctx,GetBitContext * gb,uint8_t * dst,enum TwinVQFrameType ftype)238 static void read_cb_data(TwinVQContext *tctx, GetBitContext *gb,
239                          uint8_t *dst, enum TwinVQFrameType ftype)
240 {
241     int i;
242 
243     for (i = 0; i < tctx->n_div[ftype]; i++) {
244         int bs_second_part = (i >= tctx->bits_main_spec_change[ftype]);
245 
246         *dst++ = get_bits(gb, tctx->bits_main_spec[0][ftype][bs_second_part]);
247         *dst++ = get_bits(gb, tctx->bits_main_spec[1][ftype][bs_second_part]);
248     }
249 }
250 
twinvq_read_bitstream(AVCodecContext * avctx,TwinVQContext * tctx,const uint8_t * buf,int buf_size)251 static int twinvq_read_bitstream(AVCodecContext *avctx, TwinVQContext *tctx,
252                                  const uint8_t *buf, int buf_size)
253 {
254     TwinVQFrameData     *bits = &tctx->bits[0];
255     const TwinVQModeTab *mtab = tctx->mtab;
256     int channels              = tctx->avctx->channels;
257     int sub;
258     GetBitContext gb;
259     int i, j, k, ret;
260 
261     if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
262         return ret;
263     skip_bits(&gb, get_bits(&gb, 8));
264 
265     bits->window_type = get_bits(&gb, TWINVQ_WINDOW_TYPE_BITS);
266 
267     if (bits->window_type > 8) {
268         av_log(avctx, AV_LOG_ERROR, "Invalid window type, broken sample?\n");
269         return AVERROR_INVALIDDATA;
270     }
271 
272     bits->ftype = ff_twinvq_wtype_to_ftype_table[tctx->bits[0].window_type];
273 
274     sub = mtab->fmode[bits->ftype].sub;
275 
276     read_cb_data(tctx, &gb, bits->main_coeffs, bits->ftype);
277 
278     for (i = 0; i < channels; i++)
279         for (j = 0; j < sub; j++)
280             for (k = 0; k < mtab->fmode[bits->ftype].bark_n_coef; k++)
281                 bits->bark1[i][j][k] =
282                     get_bits(&gb, mtab->fmode[bits->ftype].bark_n_bit);
283 
284     for (i = 0; i < channels; i++)
285         for (j = 0; j < sub; j++)
286             bits->bark_use_hist[i][j] = get_bits1(&gb);
287 
288     if (bits->ftype == TWINVQ_FT_LONG) {
289         for (i = 0; i < channels; i++)
290             bits->gain_bits[i] = get_bits(&gb, TWINVQ_GAIN_BITS);
291     } else {
292         for (i = 0; i < channels; i++) {
293             bits->gain_bits[i] = get_bits(&gb, TWINVQ_GAIN_BITS);
294             for (j = 0; j < sub; j++)
295                 bits->sub_gain_bits[i * sub + j] = get_bits(&gb,
296                                                        TWINVQ_SUB_GAIN_BITS);
297         }
298     }
299 
300     for (i = 0; i < channels; i++) {
301         bits->lpc_hist_idx[i] = get_bits(&gb, mtab->lsp_bit0);
302         bits->lpc_idx1[i]     = get_bits(&gb, mtab->lsp_bit1);
303 
304         for (j = 0; j < mtab->lsp_split; j++)
305             bits->lpc_idx2[i][j] = get_bits(&gb, mtab->lsp_bit2);
306     }
307 
308     if (bits->ftype == TWINVQ_FT_LONG) {
309         read_cb_data(tctx, &gb, bits->ppc_coeffs, 3);
310         for (i = 0; i < channels; i++) {
311             bits->p_coef[i] = get_bits(&gb, mtab->ppc_period_bit);
312             bits->g_coef[i] = get_bits(&gb, mtab->pgain_bit);
313         }
314     }
315 
316     return (get_bits_count(&gb) + 7) / 8;
317 }
318 
twinvq_decode_init(AVCodecContext * avctx)319 static av_cold int twinvq_decode_init(AVCodecContext *avctx)
320 {
321     int isampf, ibps;
322     TwinVQContext *tctx = avctx->priv_data;
323 
324     if (!avctx->extradata || avctx->extradata_size < 12) {
325         av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata\n");
326         return AVERROR_INVALIDDATA;
327     }
328     avctx->channels = AV_RB32(avctx->extradata)     + 1;
329     avctx->bit_rate = AV_RB32(avctx->extradata + 4) * 1000;
330     isampf          = AV_RB32(avctx->extradata + 8);
331 
332     if (isampf < 8 || isampf > 44) {
333         av_log(avctx, AV_LOG_ERROR, "Unsupported sample rate\n");
334         return AVERROR_INVALIDDATA;
335     }
336     switch (isampf) {
337     case 44:
338         avctx->sample_rate = 44100;
339         break;
340     case 22:
341         avctx->sample_rate = 22050;
342         break;
343     case 11:
344         avctx->sample_rate = 11025;
345         break;
346     default:
347         avctx->sample_rate = isampf * 1000;
348         break;
349     }
350 
351     if (avctx->channels <= 0 || avctx->channels > TWINVQ_CHANNELS_MAX) {
352         av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %i\n",
353                avctx->channels);
354         return -1;
355     }
356     avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
357                                                  : AV_CH_LAYOUT_STEREO;
358 
359     ibps = avctx->bit_rate / (1000 * avctx->channels);
360     if (ibps < 8 || ibps > 48) {
361         av_log(avctx, AV_LOG_ERROR, "Bad bitrate per channel value %d\n", ibps);
362         return AVERROR_INVALIDDATA;
363     }
364 
365     switch ((isampf << 8) + ibps) {
366     case (8 << 8) + 8:
367         tctx->mtab = &mode_08_08;
368         break;
369     case (11 << 8) + 8:
370         tctx->mtab = &mode_11_08;
371         break;
372     case (11 << 8) + 10:
373         tctx->mtab = &mode_11_10;
374         break;
375     case (16 << 8) + 16:
376         tctx->mtab = &mode_16_16;
377         break;
378     case (22 << 8) + 20:
379         tctx->mtab = &mode_22_20;
380         break;
381     case (22 << 8) + 24:
382         tctx->mtab = &mode_22_24;
383         break;
384     case (22 << 8) + 32:
385         tctx->mtab = &mode_22_32;
386         break;
387     case (44 << 8) + 40:
388         tctx->mtab = &mode_44_40;
389         break;
390     case (44 << 8) + 48:
391         tctx->mtab = &mode_44_48;
392         break;
393     default:
394         av_log(avctx, AV_LOG_ERROR,
395                "This version does not support %d kHz - %d kbit/s/ch mode.\n",
396                isampf, isampf);
397         return -1;
398     }
399 
400     tctx->codec          = TWINVQ_CODEC_VQF;
401     tctx->read_bitstream = twinvq_read_bitstream;
402     tctx->dec_bark_env   = dec_bark_env;
403     tctx->decode_ppc     = decode_ppc;
404     tctx->frame_size     = avctx->bit_rate * tctx->mtab->size
405                                            / avctx->sample_rate + 8;
406     tctx->is_6kbps       = 0;
407     if (avctx->block_align && avctx->block_align * 8 / tctx->frame_size > 1) {
408         av_log(avctx, AV_LOG_ERROR,
409                "VQF TwinVQ should have only one frame per packet\n");
410         return AVERROR_INVALIDDATA;
411     }
412 
413     return ff_twinvq_decode_init(avctx);
414 }
415 
416 AVCodec ff_twinvq_decoder = {
417     .name           = "twinvq",
418     .long_name      = NULL_IF_CONFIG_SMALL("VQF TwinVQ"),
419     .type           = AVMEDIA_TYPE_AUDIO,
420     .id             = AV_CODEC_ID_TWINVQ,
421     .priv_data_size = sizeof(TwinVQContext),
422     .init           = twinvq_decode_init,
423     .close          = ff_twinvq_decode_close,
424     .decode         = ff_twinvq_decode_frame,
425     .capabilities   = AV_CODEC_CAP_DR1,
426     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
427                                                       AV_SAMPLE_FMT_NONE },
428 };
429