1 /*
2  * Voxware MetaSound decoder
3  * Copyright (c) 2013 Konstantin Shishkov
4  * based on TwinVQ decoder
5  * Copyright (c) 2009 Vitor Sessak
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 #include <inttypes.h>
25 #include <math.h>
26 #include <stdint.h>
27 
28 #define BITSTREAM_READER_LE
29 #include "libavutil/channel_layout.h"
30 #include "libavutil/float_dsp.h"
31 #include "avcodec.h"
32 #include "get_bits.h"
33 #include "fft.h"
34 #include "internal.h"
35 #include "lsp.h"
36 #include "sinewin.h"
37 
38 #include "twinvq.h"
39 #include "metasound_data.h"
40 
add_peak(float period,int width,const float * shape,float ppc_gain,float * speech,int len)41 static void add_peak(float period, int width, const float *shape,
42                      float ppc_gain, float *speech, int len)
43 {
44     int i, j, center;
45     const float *shape_end = shape + len;
46 
47     // First peak centered around zero
48     for (i = 0; i < width / 2; i++)
49         speech[i] += ppc_gain * *shape++;
50 
51     for (i = 1; i < ROUNDED_DIV(len, width); i++) {
52         center = (int)(i * period + 0.5);
53         for (j = -width / 2; j < (width + 1) / 2; j++)
54             speech[j + center] += ppc_gain * *shape++;
55     }
56 
57     // For the last block, be careful not to go beyond the end of the buffer
58     center = (int)(i * period + 0.5);
59     for (j = -width / 2; j < (width + 1) / 2 && shape < shape_end; j++)
60         speech[j + center] += ppc_gain * *shape++;
61 }
62 
decode_ppc(TwinVQContext * tctx,int period_coef,int g_coef,const float * shape,float * speech)63 static void decode_ppc(TwinVQContext *tctx, int period_coef, int g_coef,
64                        const float *shape, float *speech)
65 {
66     const TwinVQModeTab *mtab = tctx->mtab;
67     int isampf       = tctx->avctx->sample_rate / 1000;
68     int ibps         = tctx->avctx->bit_rate / (1000 * tctx->avctx->channels);
69     int width;
70 
71     float ratio = (float)mtab->size / isampf;
72     float min_period, max_period, period_range, period;
73     float some_mult;
74 
75     float pgain_base, pgain_step, ppc_gain;
76 
77     if (tctx->avctx->channels == 1) {
78         min_period = log2(ratio * 0.2);
79         max_period = min_period + log2(6);
80     } else {
81         min_period = (int)(ratio * 0.2 * 400     + 0.5) / 400.0;
82         max_period = (int)(ratio * 0.2 * 400 * 6 + 0.5) / 400.0;
83     }
84     period_range = max_period - min_period;
85     period       = min_period + period_coef * period_range /
86                    ((1 << mtab->ppc_period_bit) - 1);
87     if (tctx->avctx->channels == 1)
88         period = powf(2.0, period);
89     else
90         period = (int)(period * 400 + 0.5) / 400.0;
91 
92     switch (isampf) {
93     case  8: some_mult = 2.0; break;
94     case 11: some_mult = 3.0; break;
95     case 16: some_mult = 3.0; break;
96     case 22: some_mult = ibps == 32 ? 2.0 : 4.0; break;
97     case 44: some_mult = 8.0; break;
98     default: some_mult = 4.0;
99     }
100 
101     width = (int)(some_mult / (mtab->size / period) * mtab->ppc_shape_len);
102     if (isampf == 22 && ibps == 32)
103         width = (int)((2.0 / period + 1) * width + 0.5);
104 
105     pgain_base = tctx->avctx->channels == 2 ? 25000.0 : 20000.0;
106     pgain_step = pgain_base / ((1 << mtab->pgain_bit) - 1);
107     ppc_gain   = 1.0 / 8192 *
108                  twinvq_mulawinv(pgain_step * g_coef + pgain_step / 2,
109                                  pgain_base, TWINVQ_PGAIN_MU);
110 
111     add_peak(period, width, shape, ppc_gain, speech, mtab->ppc_shape_len);
112 }
113 
dec_bark_env(TwinVQContext * tctx,const uint8_t * in,int use_hist,int ch,float * out,float gain,enum TwinVQFrameType ftype)114 static void dec_bark_env(TwinVQContext *tctx, const uint8_t *in, int use_hist,
115                          int ch, float *out, float gain,
116                          enum TwinVQFrameType ftype)
117 {
118     const TwinVQModeTab *mtab = tctx->mtab;
119     int i, j;
120     float *hist     = tctx->bark_hist[ftype][ch];
121 	float val       = ((const float []) { 0.4, 0.35, 0.28 })[ftype];
122 	int bark_n_coef = mtab->fmode[ftype].bark_n_coef;
123     int fw_cb_len   = mtab->fmode[ftype].bark_env_size / bark_n_coef;
124     int idx         = 0;
125 
126 	if (tctx->avctx->channels == 1)
127         val = 0.5;
128     for (i = 0; i < fw_cb_len; i++)
129         for (j = 0; j < bark_n_coef; j++, idx++) {
130             float tmp2 = mtab->fmode[ftype].bark_cb[fw_cb_len * in[j] + i] *
131                          (1.0 / 2048);
132             float st;
133 
134             if (tctx->avctx->channels == 1)
135                 st = use_hist ?
136                     tmp2 + val * hist[idx] + 1.0 : tmp2 + 1.0;
137             else
138                 st = use_hist ? (1.0 - val) * tmp2 + val * hist[idx] + 1.0
139                               : tmp2 + 1.0;
140 
141             hist[idx] = tmp2;
142             if (st < 0.1)
143                 st = 0.1;
144 
145             twinvq_memset_float(out, st * gain,
146                                 mtab->fmode[ftype].bark_tab[idx]);
147             out += mtab->fmode[ftype].bark_tab[idx];
148         }
149 }
150 
read_cb_data(TwinVQContext * tctx,GetBitContext * gb,uint8_t * dst,enum TwinVQFrameType ftype)151 static void read_cb_data(TwinVQContext *tctx, GetBitContext *gb,
152                          uint8_t *dst, enum TwinVQFrameType ftype)
153 {
154     int i;
155 
156     for (i = 0; i < tctx->n_div[ftype]; i++) {
157         int bs_second_part = (i >= tctx->bits_main_spec_change[ftype]);
158 
159         *dst++ = get_bits(gb, tctx->bits_main_spec[0][ftype][bs_second_part]);
160         *dst++ = get_bits(gb, tctx->bits_main_spec[1][ftype][bs_second_part]);
161     }
162 }
163 
metasound_read_bitstream(AVCodecContext * avctx,TwinVQContext * tctx,const uint8_t * buf,int buf_size)164 static int metasound_read_bitstream(AVCodecContext *avctx, TwinVQContext *tctx,
165                                     const uint8_t *buf, int buf_size)
166 {
167     TwinVQFrameData     *bits;
168     const TwinVQModeTab *mtab = tctx->mtab;
169     int channels              = tctx->avctx->channels;
170     int sub;
171     GetBitContext gb;
172     int i, j, k;
173 
174     init_get_bits(&gb, buf, buf_size * 8);
175 
176     for (tctx->cur_frame = 0; tctx->cur_frame < tctx->frames_per_packet;
177          tctx->cur_frame++) {
178         bits = tctx->bits + tctx->cur_frame;
179 
180         bits->window_type = get_bits(&gb, TWINVQ_WINDOW_TYPE_BITS);
181 
182         if (bits->window_type > 8) {
183             av_log(avctx, AV_LOG_ERROR, "Invalid window type, broken sample?\n");
184             return AVERROR_INVALIDDATA;
185         }
186 
187         bits->ftype = ff_twinvq_wtype_to_ftype_table[tctx->bits[tctx->cur_frame].window_type];
188 
189         sub = mtab->fmode[bits->ftype].sub;
190 
191         if (bits->ftype != TWINVQ_FT_SHORT && !tctx->is_6kbps)
192             get_bits(&gb, 2);
193 
194         read_cb_data(tctx, &gb, bits->main_coeffs, bits->ftype);
195 
196         for (i = 0; i < channels; i++)
197             for (j = 0; j < sub; j++)
198                 for (k = 0; k < mtab->fmode[bits->ftype].bark_n_coef; k++)
199                     bits->bark1[i][j][k] =
200                         get_bits(&gb, mtab->fmode[bits->ftype].bark_n_bit);
201 
202         for (i = 0; i < channels; i++)
203             for (j = 0; j < sub; j++)
204                 bits->bark_use_hist[i][j] = get_bits1(&gb);
205 
206         if (bits->ftype == TWINVQ_FT_LONG) {
207             for (i = 0; i < channels; i++)
208                 bits->gain_bits[i] = get_bits(&gb, TWINVQ_GAIN_BITS);
209         } else {
210             for (i = 0; i < channels; i++) {
211                 bits->gain_bits[i] = get_bits(&gb, TWINVQ_GAIN_BITS);
212                 for (j = 0; j < sub; j++)
213                     bits->sub_gain_bits[i * sub + j] =
214                         get_bits(&gb, TWINVQ_SUB_GAIN_BITS);
215             }
216         }
217 
218         for (i = 0; i < channels; i++) {
219             bits->lpc_hist_idx[i] = get_bits(&gb, mtab->lsp_bit0);
220             bits->lpc_idx1[i]     = get_bits(&gb, mtab->lsp_bit1);
221 
222             for (j = 0; j < mtab->lsp_split; j++)
223                 bits->lpc_idx2[i][j] = get_bits(&gb, mtab->lsp_bit2);
224         }
225 
226         if (bits->ftype == TWINVQ_FT_LONG) {
227             read_cb_data(tctx, &gb, bits->ppc_coeffs, 3);
228             for (i = 0; i < channels; i++) {
229                 bits->p_coef[i] = get_bits(&gb, mtab->ppc_period_bit);
230                 bits->g_coef[i] = get_bits(&gb, mtab->pgain_bit);
231             }
232         }
233 
234         // subframes are aligned to nibbles
235         if (get_bits_count(&gb) & 3)
236             skip_bits(&gb, 4 - (get_bits_count(&gb) & 3));
237     }
238 
239     return (get_bits_count(&gb) + 7) / 8;
240 }
241 
242 typedef struct MetasoundProps {
243     uint32_t tag;
244     int      bit_rate;
245     int      channels;
246     int      sample_rate;
247 } MetasoundProps;
248 
249 static const MetasoundProps codec_props[] = {
250     { MKTAG('V','X','0','3'),  6, 1,  8000 },
251     { MKTAG('V','X','0','4'), 12, 2,  8000 },
252 
253     { MKTAG('V','O','X','i'),  8, 1,  8000 },
254     { MKTAG('V','O','X','j'), 10, 1, 11025 },
255     { MKTAG('V','O','X','k'), 16, 1, 16000 },
256     { MKTAG('V','O','X','L'), 24, 1, 22050 },
257     { MKTAG('V','O','X','q'), 32, 1, 44100 },
258     { MKTAG('V','O','X','r'), 40, 1, 44100 },
259     { MKTAG('V','O','X','s'), 48, 1, 44100 },
260     { MKTAG('V','O','X','t'), 16, 2,  8000 },
261     { MKTAG('V','O','X','u'), 20, 2, 11025 },
262     { MKTAG('V','O','X','v'), 32, 2, 16000 },
263     { MKTAG('V','O','X','w'), 48, 2, 22050 },
264     { MKTAG('V','O','X','x'), 64, 2, 44100 },
265     { MKTAG('V','O','X','y'), 80, 2, 44100 },
266     { MKTAG('V','O','X','z'), 96, 2, 44100 },
267 
268     { 0, 0, 0, 0 }
269 };
270 
metasound_decode_init(AVCodecContext * avctx)271 static av_cold int metasound_decode_init(AVCodecContext *avctx)
272 {
273     int isampf, ibps;
274     TwinVQContext *tctx = avctx->priv_data;
275     uint32_t tag;
276     const MetasoundProps *props = codec_props;
277 
278     if (!avctx->extradata || avctx->extradata_size < 16) {
279         av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata\n");
280         return AVERROR_INVALIDDATA;
281     }
282 
283     tag = AV_RL32(avctx->extradata + 12);
284 
285     for (;;) {
286         if (!props->tag) {
287             av_log(avctx, AV_LOG_ERROR, "Could not find tag %08"PRIX32"\n", tag);
288             return AVERROR_INVALIDDATA;
289         }
290         if (props->tag == tag) {
291             avctx->sample_rate = props->sample_rate;
292             avctx->channels    = props->channels;
293             avctx->bit_rate    = props->bit_rate * 1000;
294             isampf             = avctx->sample_rate / 1000;
295             break;
296         }
297         props++;
298     }
299 
300     if (avctx->channels <= 0 || avctx->channels > TWINVQ_CHANNELS_MAX) {
301         av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %i\n",
302                avctx->channels);
303         return AVERROR_INVALIDDATA;
304     }
305     avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
306                                                  : AV_CH_LAYOUT_STEREO;
307 
308     ibps = avctx->bit_rate / (1000 * avctx->channels);
309 
310     switch ((avctx->channels << 16) + (isampf << 8) + ibps) {
311     case (1 << 16) + ( 8 << 8) +  6:
312         tctx->mtab = &ff_metasound_mode0806;
313         break;
314     case (2 << 16) + ( 8 << 8) +  6:
315         tctx->mtab = &ff_metasound_mode0806s;
316         break;
317     case (1 << 16) + ( 8 << 8) +  8:
318         tctx->mtab = &ff_metasound_mode0808;
319         break;
320     case (2 << 16) + ( 8 << 8) +  8:
321         tctx->mtab = &ff_metasound_mode0808s;
322         break;
323     case (1 << 16) + (11 << 8) + 10:
324         tctx->mtab = &ff_metasound_mode1110;
325         break;
326     case (2 << 16) + (11 << 8) + 10:
327         tctx->mtab = &ff_metasound_mode1110s;
328         break;
329     case (1 << 16) + (16 << 8) + 16:
330         tctx->mtab = &ff_metasound_mode1616;
331         break;
332     case (2 << 16) + (16 << 8) + 16:
333         tctx->mtab = &ff_metasound_mode1616s;
334         break;
335     case (1 << 16) + (22 << 8) + 24:
336         tctx->mtab = &ff_metasound_mode2224;
337         break;
338     case (2 << 16) + (22 << 8) + 24:
339         tctx->mtab = &ff_metasound_mode2224s;
340         break;
341     case (1 << 16) + (44 << 8) + 32:
342         tctx->mtab = &ff_metasound_mode4432;
343         break;
344     case (2 << 16) + (44 << 8) + 32:
345         tctx->mtab = &ff_metasound_mode4432s;
346         break;
347     case (1 << 16) + (44 << 8) + 40:
348         tctx->mtab = &ff_metasound_mode4440;
349         break;
350     case (2 << 16) + (44 << 8) + 40:
351         tctx->mtab = &ff_metasound_mode4440s;
352         break;
353     case (1 << 16) + (44 << 8) + 48:
354         tctx->mtab = &ff_metasound_mode4448;
355         break;
356     case (2 << 16) + (44 << 8) + 48:
357         tctx->mtab = &ff_metasound_mode4448s;
358         break;
359     default:
360         av_log(avctx, AV_LOG_ERROR,
361                "This version does not support %d kHz - %d kbit/s/ch mode.\n",
362                isampf, ibps);
363         return AVERROR(ENOSYS);
364     }
365 
366     tctx->codec          = TWINVQ_CODEC_METASOUND;
367     tctx->read_bitstream = metasound_read_bitstream;
368     tctx->dec_bark_env   = dec_bark_env;
369     tctx->decode_ppc     = decode_ppc;
370     tctx->frame_size     = avctx->bit_rate * tctx->mtab->size
371                                            / avctx->sample_rate;
372     tctx->is_6kbps       = ibps == 6;
373 
374     return ff_twinvq_decode_init(avctx);
375 }
376 
377 AVCodec ff_metasound_decoder = {
378 	.name           = "metasound",
379     .long_name      = NULL_IF_CONFIG_SMALL("Voxware MetaSound"),
380     .type           = AVMEDIA_TYPE_AUDIO,
381     .id             = AV_CODEC_ID_METASOUND,
382     .priv_data_size = sizeof(TwinVQContext),
383     .init           = metasound_decode_init,
384     .close          = ff_twinvq_decode_close,
385     .decode         = ff_twinvq_decode_frame,
386     .capabilities   = CODEC_CAP_DR1,
387     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
388                                                       AV_SAMPLE_FMT_NONE },
389 };
390