1/*
2 * DSP Group TrueSpeech compatible decoder
3 * Copyright (c) 2005 Konstantin Shishkov
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#include "avcodec.h"
24
25#include "truespeech_data.h"
26/**
27 * @file
28 * TrueSpeech decoder.
29 */
30
31/**
32 * TrueSpeech decoder context
33 */
34typedef struct {
35    /* input data */
36    int16_t vector[8];  //< input vector: 5/5/4/4/4/3/3/3
37    int offset1[2];     //< 8-bit value, used in one copying offset
38    int offset2[4];     //< 7-bit value, encodes offsets for copying and for two-point filter
39    int pulseoff[4];    //< 4-bit offset of pulse values block
40    int pulsepos[4];    //< 27-bit variable, encodes 7 pulse positions
41    int pulseval[4];    //< 7x2-bit pulse values
42    int flag;           //< 1-bit flag, shows how to choose filters
43    /* temporary data */
44    int filtbuf[146];   // some big vector used for storing filters
45    int prevfilt[8];    // filter from previous frame
46    int16_t tmp1[8];    // coefficients for adding to out
47    int16_t tmp2[8];    // coefficients for adding to out
48    int16_t tmp3[8];    // coefficients for adding to out
49    int16_t cvector[8]; // correlated input vector
50    int filtval;        // gain value for one function
51    int16_t newvec[60]; // tmp vector
52    int16_t filters[32]; // filters for every subframe
53} TSContext;
54
55static av_cold int truespeech_decode_init(AVCodecContext * avctx)
56{
57//    TSContext *c = avctx->priv_data;
58
59    avctx->sample_fmt = SAMPLE_FMT_S16;
60    return 0;
61}
62
63static void truespeech_read_frame(TSContext *dec, const uint8_t *input)
64{
65    uint32_t t;
66
67    /* first dword */
68    t = AV_RL32(input);
69    input += 4;
70
71    dec->flag = t & 1;
72
73    dec->vector[0] = ts_codebook[0][(t >>  1) & 0x1F];
74    dec->vector[1] = ts_codebook[1][(t >>  6) & 0x1F];
75    dec->vector[2] = ts_codebook[2][(t >> 11) &  0xF];
76    dec->vector[3] = ts_codebook[3][(t >> 15) &  0xF];
77    dec->vector[4] = ts_codebook[4][(t >> 19) &  0xF];
78    dec->vector[5] = ts_codebook[5][(t >> 23) &  0x7];
79    dec->vector[6] = ts_codebook[6][(t >> 26) &  0x7];
80    dec->vector[7] = ts_codebook[7][(t >> 29) &  0x7];
81
82    /* second dword */
83    t = AV_RL32(input);
84    input += 4;
85
86    dec->offset2[0] = (t >>  0) & 0x7F;
87    dec->offset2[1] = (t >>  7) & 0x7F;
88    dec->offset2[2] = (t >> 14) & 0x7F;
89    dec->offset2[3] = (t >> 21) & 0x7F;
90
91    dec->offset1[0] = ((t >> 28) & 0xF) << 4;
92
93    /* third dword */
94    t = AV_RL32(input);
95    input += 4;
96
97    dec->pulseval[0] = (t >>  0) & 0x3FFF;
98    dec->pulseval[1] = (t >> 14) & 0x3FFF;
99
100    dec->offset1[1] = (t >> 28) & 0x0F;
101
102    /* fourth dword */
103    t = AV_RL32(input);
104    input += 4;
105
106    dec->pulseval[2] = (t >>  0) & 0x3FFF;
107    dec->pulseval[3] = (t >> 14) & 0x3FFF;
108
109    dec->offset1[1] |= ((t >> 28) & 0x0F) << 4;
110
111    /* fifth dword */
112    t = AV_RL32(input);
113    input += 4;
114
115    dec->pulsepos[0] = (t >> 4) & 0x7FFFFFF;
116
117    dec->pulseoff[0] = (t >> 0) & 0xF;
118
119    dec->offset1[0] |= (t >> 31) & 1;
120
121    /* sixth dword */
122    t = AV_RL32(input);
123    input += 4;
124
125    dec->pulsepos[1] = (t >> 4) & 0x7FFFFFF;
126
127    dec->pulseoff[1] = (t >> 0) & 0xF;
128
129    dec->offset1[0] |= ((t >> 31) & 1) << 1;
130
131    /* seventh dword */
132    t = AV_RL32(input);
133    input += 4;
134
135    dec->pulsepos[2] = (t >> 4) & 0x7FFFFFF;
136
137    dec->pulseoff[2] = (t >> 0) & 0xF;
138
139    dec->offset1[0] |= ((t >> 31) & 1) << 2;
140
141    /* eighth dword */
142    t = AV_RL32(input);
143    input += 4;
144
145    dec->pulsepos[3] = (t >> 4) & 0x7FFFFFF;
146
147    dec->pulseoff[3] = (t >> 0) & 0xF;
148
149    dec->offset1[0] |= ((t >> 31) & 1) << 3;
150
151}
152
153static void truespeech_correlate_filter(TSContext *dec)
154{
155    int16_t tmp[8];
156    int i, j;
157
158    for(i = 0; i < 8; i++){
159        if(i > 0){
160            memcpy(tmp, dec->cvector, i * 2);
161            for(j = 0; j < i; j++)
162                dec->cvector[j] = ((tmp[i - j - 1] * dec->vector[i]) +
163                                   (dec->cvector[j] << 15) + 0x4000) >> 15;
164        }
165        dec->cvector[i] = (8 - dec->vector[i]) >> 3;
166    }
167    for(i = 0; i < 8; i++)
168        dec->cvector[i] = (dec->cvector[i] * ts_230[i]) >> 15;
169
170    dec->filtval = dec->vector[0];
171}
172
173static void truespeech_filters_merge(TSContext *dec)
174{
175    int i;
176
177    if(!dec->flag){
178        for(i = 0; i < 8; i++){
179            dec->filters[i + 0] = dec->prevfilt[i];
180            dec->filters[i + 8] = dec->prevfilt[i];
181        }
182    }else{
183        for(i = 0; i < 8; i++){
184            dec->filters[i + 0]=(dec->cvector[i] * 21846 + dec->prevfilt[i] * 10923 + 16384) >> 15;
185            dec->filters[i + 8]=(dec->cvector[i] * 10923 + dec->prevfilt[i] * 21846 + 16384) >> 15;
186        }
187    }
188    for(i = 0; i < 8; i++){
189        dec->filters[i + 16] = dec->cvector[i];
190        dec->filters[i + 24] = dec->cvector[i];
191    }
192}
193
194static void truespeech_apply_twopoint_filter(TSContext *dec, int quart)
195{
196    int16_t tmp[146 + 60], *ptr0, *ptr1;
197    const int16_t *filter;
198    int i, t, off;
199
200    t = dec->offset2[quart];
201    if(t == 127){
202        memset(dec->newvec, 0, 60 * 2);
203        return;
204    }
205    for(i = 0; i < 146; i++)
206        tmp[i] = dec->filtbuf[i];
207    off = (t / 25) + dec->offset1[quart >> 1] + 18;
208    ptr0 = tmp + 145 - off;
209    ptr1 = tmp + 146;
210    filter = (const int16_t*)ts_240 + (t % 25) * 2;
211    for(i = 0; i < 60; i++){
212        t = (ptr0[0] * filter[0] + ptr0[1] * filter[1] + 0x2000) >> 14;
213        ptr0++;
214        dec->newvec[i] = t;
215        ptr1[i] = t;
216    }
217}
218
219static void truespeech_place_pulses(TSContext *dec, int16_t *out, int quart)
220{
221    int16_t tmp[7];
222    int i, j, t;
223    const int16_t *ptr1;
224    int16_t *ptr2;
225    int coef;
226
227    memset(out, 0, 60 * 2);
228    for(i = 0; i < 7; i++) {
229        t = dec->pulseval[quart] & 3;
230        dec->pulseval[quart] >>= 2;
231        tmp[6 - i] = ts_562[dec->pulseoff[quart] * 4 + t];
232    }
233
234    coef = dec->pulsepos[quart] >> 15;
235    ptr1 = (const int16_t*)ts_140 + 30;
236    ptr2 = tmp;
237    for(i = 0, j = 3; (i < 30) && (j > 0); i++){
238        t = *ptr1++;
239        if(coef >= t)
240            coef -= t;
241        else{
242            out[i] = *ptr2++;
243            ptr1 += 30;
244            j--;
245        }
246    }
247    coef = dec->pulsepos[quart] & 0x7FFF;
248    ptr1 = (const int16_t*)ts_140;
249    for(i = 30, j = 4; (i < 60) && (j > 0); i++){
250        t = *ptr1++;
251        if(coef >= t)
252            coef -= t;
253        else{
254            out[i] = *ptr2++;
255            ptr1 += 30;
256            j--;
257        }
258    }
259
260}
261
262static void truespeech_update_filters(TSContext *dec, int16_t *out, int quart)
263{
264    int i;
265
266    for(i = 0; i < 86; i++)
267        dec->filtbuf[i] = dec->filtbuf[i + 60];
268    for(i = 0; i < 60; i++){
269        dec->filtbuf[i + 86] = out[i] + dec->newvec[i] - (dec->newvec[i] >> 3);
270        out[i] += dec->newvec[i];
271    }
272}
273
274static void truespeech_synth(TSContext *dec, int16_t *out, int quart)
275{
276    int i,k;
277    int t[8];
278    int16_t *ptr0, *ptr1;
279
280    ptr0 = dec->tmp1;
281    ptr1 = dec->filters + quart * 8;
282    for(i = 0; i < 60; i++){
283        int sum = 0;
284        for(k = 0; k < 8; k++)
285            sum += ptr0[k] * ptr1[k];
286        sum = (sum + (out[i] << 12) + 0x800) >> 12;
287        out[i] = av_clip(sum, -0x7FFE, 0x7FFE);
288        for(k = 7; k > 0; k--)
289            ptr0[k] = ptr0[k - 1];
290        ptr0[0] = out[i];
291    }
292
293    for(i = 0; i < 8; i++)
294        t[i] = (ts_5E2[i] * ptr1[i]) >> 15;
295
296    ptr0 = dec->tmp2;
297    for(i = 0; i < 60; i++){
298        int sum = 0;
299        for(k = 0; k < 8; k++)
300            sum += ptr0[k] * t[k];
301        for(k = 7; k > 0; k--)
302            ptr0[k] = ptr0[k - 1];
303        ptr0[0] = out[i];
304        out[i] = ((out[i] << 12) - sum) >> 12;
305    }
306
307    for(i = 0; i < 8; i++)
308        t[i] = (ts_5F2[i] * ptr1[i]) >> 15;
309
310    ptr0 = dec->tmp3;
311    for(i = 0; i < 60; i++){
312        int sum = out[i] << 12;
313        for(k = 0; k < 8; k++)
314            sum += ptr0[k] * t[k];
315        for(k = 7; k > 0; k--)
316            ptr0[k] = ptr0[k - 1];
317        ptr0[0] = av_clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);
318
319        sum = ((ptr0[1] * (dec->filtval - (dec->filtval >> 2))) >> 4) + sum;
320        sum = sum - (sum >> 3);
321        out[i] = av_clip((sum + 0x800) >> 12, -0x7FFE, 0x7FFE);
322    }
323}
324
325static void truespeech_save_prevvec(TSContext *c)
326{
327    int i;
328
329    for(i = 0; i < 8; i++)
330        c->prevfilt[i] = c->cvector[i];
331}
332
333static int truespeech_decode_frame(AVCodecContext *avctx,
334                void *data, int *data_size,
335                AVPacket *avpkt)
336{
337    const uint8_t *buf = avpkt->data;
338    int buf_size = avpkt->size;
339    TSContext *c = avctx->priv_data;
340
341    int i, j;
342    short *samples = data;
343    int consumed = 0;
344    int16_t out_buf[240];
345    int iterations;
346
347    if (!buf_size)
348        return 0;
349
350    iterations = FFMIN(buf_size / 32, *data_size / 480);
351    for(j = 0; j < iterations; j++) {
352        truespeech_read_frame(c, buf + consumed);
353        consumed += 32;
354
355        truespeech_correlate_filter(c);
356        truespeech_filters_merge(c);
357
358        memset(out_buf, 0, 240 * 2);
359        for(i = 0; i < 4; i++) {
360            truespeech_apply_twopoint_filter(c, i);
361            truespeech_place_pulses(c, out_buf + i * 60, i);
362            truespeech_update_filters(c, out_buf + i * 60, i);
363            truespeech_synth(c, out_buf + i * 60, i);
364        }
365
366        truespeech_save_prevvec(c);
367
368        /* finally output decoded frame */
369        for(i = 0; i < 240; i++)
370            *samples++ = out_buf[i];
371
372    }
373
374    *data_size = consumed * 15;
375
376    return consumed;
377}
378
379AVCodec truespeech_decoder = {
380    "truespeech",
381    AVMEDIA_TYPE_AUDIO,
382    CODEC_ID_TRUESPEECH,
383    sizeof(TSContext),
384    truespeech_decode_init,
385    NULL,
386    NULL,
387    truespeech_decode_frame,
388    .long_name = NULL_IF_CONFIG_SMALL("DSP Group TrueSpeech"),
389};
390