Skip to main content

rusty_opus/silk/
decode_core.rs

1use crate::silk::decoder_structs::{SilkDecoderControl, SilkDecoderState};
2use crate::silk::define::*;
3use crate::silk::macros::*;
4use crate::silk::tables::SILK_QUANTIZATION_OFFSETS_Q10;
5
6pub fn silk_decode_core(
7    ps_dec: &mut SilkDecoderState,
8    ps_dec_ctrl: &SilkDecoderControl,
9    xq: &mut [i16],
10    pulses: &[i16],
11) {
12    let nlsf_interpolation_flag = if ps_dec.indices.nlsf_interp_coef_q2 < 4 {
13        1
14    } else {
15        0
16    };
17
18    let offset_q10 = SILK_QUANTIZATION_OFFSETS_Q10[(ps_dec.indices.signal_type >> 1) as usize]
19        [ps_dec.indices.quant_offset_type as usize] as i32;
20
21    let mut rand_seed = ps_dec.indices.seed as i32;
22    for i in 0..ps_dec.frame_length as usize {
23        rand_seed = silk_rand(rand_seed);
24        ps_dec.exc_q14[i] = (pulses[i] as i32) << 14;
25        if ps_dec.exc_q14[i] > 0 {
26            ps_dec.exc_q14[i] -= QUANT_LEVEL_ADJUST_Q10 << 4;
27        } else if ps_dec.exc_q14[i] < 0 {
28            ps_dec.exc_q14[i] += QUANT_LEVEL_ADJUST_Q10 << 4;
29        }
30        ps_dec.exc_q14[i] += offset_q10 << 4;
31        if rand_seed < 0 {
32            ps_dec.exc_q14[i] = -ps_dec.exc_q14[i];
33        }
34        rand_seed = silk_add32_ovflw(rand_seed, pulses[i] as i32);
35    }
36
37    let mut s_lpc_q14: [i32; MAX_SUB_FRAME_LENGTH + MAX_LPC_ORDER] =
38        [0; MAX_SUB_FRAME_LENGTH + MAX_LPC_ORDER];
39    s_lpc_q14[..MAX_LPC_ORDER].copy_from_slice(&ps_dec.s_lpc_q14_buf);
40
41    let mut pexc_q14_idx: usize = 0;
42    let mut pxq_idx: usize = 0;
43    let mut s_ltp_buf_idx = ps_dec.ltp_mem_length;
44
45    let s_ltp_q15_len = ps_dec.ltp_mem_length as usize + ps_dec.frame_length as usize;
46    let s_ltp_len = ps_dec.ltp_mem_length as usize;
47
48    const MAX_S_LTP_Q15: usize = 640;
49    const MAX_S_LTP: usize = 320;
50    debug_assert!(s_ltp_q15_len <= MAX_S_LTP_Q15);
51    debug_assert!(s_ltp_len <= MAX_S_LTP);
52    let mut s_ltp_q15_buf = [0i32; MAX_S_LTP_Q15];
53    let s_ltp_q15 = &mut s_ltp_q15_buf[..s_ltp_q15_len];
54    let mut s_ltp_buf = [0i16; MAX_S_LTP];
55    let s_ltp = &mut s_ltp_buf[..s_ltp_len];
56
57    for k in 0..ps_dec.nb_subfr as usize {
58        let a_q12 = &ps_dec_ctrl.pred_coef_q12[k >> 1];
59        let b_q14 = &ps_dec_ctrl.ltp_coef_q14[k * LTP_ORDER..];
60        let signal_type = ps_dec.indices.signal_type;
61
62        let mut inv_gain_q31 = silk_inverse32_varq(ps_dec_ctrl.gains_q16[k], 47);
63
64        let gain_adj_q16 = if ps_dec_ctrl.gains_q16[k] != ps_dec.prev_gain_q16 {
65            let adj = silk_div32_varq(ps_dec.prev_gain_q16, ps_dec_ctrl.gains_q16[k], 16);
66
67            for i in 0..MAX_LPC_ORDER {
68                s_lpc_q14[i] = silk_smulww(adj, s_lpc_q14[i]);
69            }
70            adj
71        } else {
72            1 << 16
73        };
74
75        ps_dec.prev_gain_q16 = ps_dec_ctrl.gains_q16[k];
76
77        let (eff_signal_type, eff_pitch_l) = if ps_dec.loss_cnt > 0
78            && ps_dec.prev_signal_type == TYPE_VOICED
79            && ps_dec.indices.signal_type as i32 != TYPE_VOICED
80            && k < MAX_NB_SUBFR / 2
81        {
82            (TYPE_VOICED, ps_dec.lag_prev)
83        } else {
84            (signal_type as i32, ps_dec_ctrl.pitch_l[k])
85        };
86
87        let mut lag = 0;
88        if eff_signal_type == TYPE_VOICED {
89            lag = eff_pitch_l;
90
91            if k == 0 || (k == 2 && nlsf_interpolation_flag != 0) {
92                let start_idx =
93                    ps_dec.ltp_mem_length - lag - ps_dec.lpc_order - (LTP_ORDER / 2) as i32;
94                debug_assert!(start_idx > 0);
95
96                if k == 2 {
97                    let copy_start = ps_dec.ltp_mem_length as usize;
98                    let copy_len = 2 * ps_dec.subfr_length as usize;
99                    ps_dec.out_buf[copy_start..copy_start + copy_len]
100                        .copy_from_slice(&xq[0..copy_len]);
101                }
102
103                let filter_input_offset = start_idx as usize + k * ps_dec.subfr_length as usize;
104                let filter_len = (ps_dec.ltp_mem_length - start_idx) as usize;
105                silk_lpc_analysis_filter_offset(
106                    s_ltp,
107                    start_idx as usize,
108                    &ps_dec.out_buf,
109                    filter_input_offset,
110                    a_q12,
111                    filter_len,
112                    ps_dec.lpc_order as usize,
113                );
114
115                if k == 0 {
116                    inv_gain_q31 =
117                        silk_lshift(silk_smulwb(inv_gain_q31, ps_dec_ctrl.ltp_scale_q14), 2);
118                }
119                for i in 0..(lag + LTP_ORDER as i32 / 2) as usize {
120                    s_ltp_q15[s_ltp_buf_idx as usize - i - 1] = silk_smulwb(
121                        inv_gain_q31,
122                        s_ltp[ps_dec.ltp_mem_length as usize - i - 1] as i32,
123                    );
124                }
125            } else if gain_adj_q16 != (1 << 16) {
126                for i in 0..(lag + LTP_ORDER as i32 / 2) as usize {
127                    s_ltp_q15[s_ltp_buf_idx as usize - i - 1] =
128                        silk_smulww(gain_adj_q16, s_ltp_q15[s_ltp_buf_idx as usize - i - 1]);
129                }
130            }
131        }
132
133        let mut res_q14: [i32; MAX_SUB_FRAME_LENGTH] = [0; MAX_SUB_FRAME_LENGTH];
134
135        if eff_signal_type == TYPE_VOICED {
136            let pred_lag_ptr_start = (s_ltp_buf_idx - lag + LTP_ORDER as i32 / 2) as usize;
137            for i in 0..ps_dec.subfr_length as usize {
138                let mut ltp_pred_q13: i32 = 2;
139                ltp_pred_q13 = silk_smlawb(
140                    ltp_pred_q13,
141                    s_ltp_q15[pred_lag_ptr_start + i],
142                    b_q14[0] as i32,
143                );
144                ltp_pred_q13 = silk_smlawb(
145                    ltp_pred_q13,
146                    s_ltp_q15[pred_lag_ptr_start + i - 1],
147                    b_q14[1] as i32,
148                );
149                ltp_pred_q13 = silk_smlawb(
150                    ltp_pred_q13,
151                    s_ltp_q15[pred_lag_ptr_start + i - 2],
152                    b_q14[2] as i32,
153                );
154                ltp_pred_q13 = silk_smlawb(
155                    ltp_pred_q13,
156                    s_ltp_q15[pred_lag_ptr_start + i - 3],
157                    b_q14[3] as i32,
158                );
159                ltp_pred_q13 = silk_smlawb(
160                    ltp_pred_q13,
161                    s_ltp_q15[pred_lag_ptr_start + i - 4],
162                    b_q14[4] as i32,
163                );
164
165                res_q14[i] = silk_add_lshift32(ps_dec.exc_q14[pexc_q14_idx + i], ltp_pred_q13, 1);
166
167                s_ltp_q15[s_ltp_buf_idx as usize] = res_q14[i] << 1;
168                s_ltp_buf_idx += 1;
169            }
170        } else {
171            res_q14[..(ps_dec.subfr_length as usize)].copy_from_slice(
172                &ps_dec.exc_q14[pexc_q14_idx..(ps_dec.subfr_length as usize + pexc_q14_idx)],
173            );
174        }
175
176        for i in 0..ps_dec.subfr_length as usize {
177            let mut lpc_pred_q10: i32 = ps_dec.lpc_order >> 1;
178
179            lpc_pred_q10 = silk_smlawb(
180                lpc_pred_q10,
181                s_lpc_q14[MAX_LPC_ORDER + i - 1],
182                a_q12[0] as i32,
183            );
184            lpc_pred_q10 = silk_smlawb(
185                lpc_pred_q10,
186                s_lpc_q14[MAX_LPC_ORDER + i - 2],
187                a_q12[1] as i32,
188            );
189            lpc_pred_q10 = silk_smlawb(
190                lpc_pred_q10,
191                s_lpc_q14[MAX_LPC_ORDER + i - 3],
192                a_q12[2] as i32,
193            );
194            lpc_pred_q10 = silk_smlawb(
195                lpc_pred_q10,
196                s_lpc_q14[MAX_LPC_ORDER + i - 4],
197                a_q12[3] as i32,
198            );
199            lpc_pred_q10 = silk_smlawb(
200                lpc_pred_q10,
201                s_lpc_q14[MAX_LPC_ORDER + i - 5],
202                a_q12[4] as i32,
203            );
204            lpc_pred_q10 = silk_smlawb(
205                lpc_pred_q10,
206                s_lpc_q14[MAX_LPC_ORDER + i - 6],
207                a_q12[5] as i32,
208            );
209            lpc_pred_q10 = silk_smlawb(
210                lpc_pred_q10,
211                s_lpc_q14[MAX_LPC_ORDER + i - 7],
212                a_q12[6] as i32,
213            );
214            lpc_pred_q10 = silk_smlawb(
215                lpc_pred_q10,
216                s_lpc_q14[MAX_LPC_ORDER + i - 8],
217                a_q12[7] as i32,
218            );
219            lpc_pred_q10 = silk_smlawb(
220                lpc_pred_q10,
221                s_lpc_q14[MAX_LPC_ORDER + i - 9],
222                a_q12[8] as i32,
223            );
224            lpc_pred_q10 = silk_smlawb(
225                lpc_pred_q10,
226                s_lpc_q14[MAX_LPC_ORDER + i - 10],
227                a_q12[9] as i32,
228            );
229
230            if ps_dec.lpc_order == 16 {
231                lpc_pred_q10 = silk_smlawb(
232                    lpc_pred_q10,
233                    s_lpc_q14[MAX_LPC_ORDER + i - 11],
234                    a_q12[10] as i32,
235                );
236                lpc_pred_q10 = silk_smlawb(
237                    lpc_pred_q10,
238                    s_lpc_q14[MAX_LPC_ORDER + i - 12],
239                    a_q12[11] as i32,
240                );
241                lpc_pred_q10 = silk_smlawb(
242                    lpc_pred_q10,
243                    s_lpc_q14[MAX_LPC_ORDER + i - 13],
244                    a_q12[12] as i32,
245                );
246                lpc_pred_q10 = silk_smlawb(
247                    lpc_pred_q10,
248                    s_lpc_q14[MAX_LPC_ORDER + i - 14],
249                    a_q12[13] as i32,
250                );
251                lpc_pred_q10 = silk_smlawb(
252                    lpc_pred_q10,
253                    s_lpc_q14[MAX_LPC_ORDER + i - 15],
254                    a_q12[14] as i32,
255                );
256                lpc_pred_q10 = silk_smlawb(
257                    lpc_pred_q10,
258                    s_lpc_q14[MAX_LPC_ORDER + i - 16],
259                    a_q12[15] as i32,
260                );
261            }
262
263            s_lpc_q14[MAX_LPC_ORDER + i] =
264                silk_add_sat32(res_q14[i], silk_lshift_sat32(lpc_pred_q10, 4));
265
266            let gain_q10 = ps_dec_ctrl.gains_q16[k] >> 6;
267            let product = silk_smulww(s_lpc_q14[MAX_LPC_ORDER + i], gain_q10);
268            xq[pxq_idx + i] = silk_sat16(silk_rshift_round(product, 8)) as i16;
269        }
270
271        for i in 0..MAX_LPC_ORDER {
272            s_lpc_q14[i] = s_lpc_q14[ps_dec.subfr_length as usize + i];
273        }
274        pexc_q14_idx += ps_dec.subfr_length as usize;
275        pxq_idx += ps_dec.subfr_length as usize;
276    }
277
278    ps_dec
279        .s_lpc_q14_buf
280        .copy_from_slice(&s_lpc_q14[..MAX_LPC_ORDER]);
281}
282
283fn silk_lpc_analysis_filter_offset(
284    out: &mut [i16],
285    out_offset: usize,
286    input: &[i16],
287    input_offset: usize,
288    b: &[i16],
289    len: usize,
290    d: usize,
291) {
292    for ix in 0..d {
293        out[out_offset + ix] = 0;
294    }
295
296    for ix in d..len {
297        let mut out32_q12: i32 = 0;
298        for j in 0..d {
299            out32_q12 = out32_q12.wrapping_add(silk_smulbb(
300                input[input_offset + ix - j - 1] as i32,
301                b[j] as i32,
302            ));
303        }
304
305        out32_q12 = ((input[input_offset + ix] as i32) << 12).wrapping_sub(out32_q12);
306
307        let out32 = silk_rshift_round(out32_q12, 12);
308
309        out[out_offset + ix] = silk_sat16(out32) as i16;
310    }
311}