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Diffstat (limited to 'lib/rbcodec/codecs/libopus/silk/stereo_LR_to_MS.c')
-rw-r--r-- | lib/rbcodec/codecs/libopus/silk/stereo_LR_to_MS.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libopus/silk/stereo_LR_to_MS.c b/lib/rbcodec/codecs/libopus/silk/stereo_LR_to_MS.c new file mode 100644 index 0000000000..c8226663c8 --- /dev/null +++ b/lib/rbcodec/codecs/libopus/silk/stereo_LR_to_MS.c | |||
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1 | /*********************************************************************** | ||
2 | Copyright (c) 2006-2011, Skype Limited. All rights reserved. | ||
3 | Redistribution and use in source and binary forms, with or without | ||
4 | modification, are permitted provided that the following conditions | ||
5 | are met: | ||
6 | - Redistributions of source code must retain the above copyright notice, | ||
7 | this list of conditions and the following disclaimer. | ||
8 | - Redistributions in binary form must reproduce the above copyright | ||
9 | notice, this list of conditions and the following disclaimer in the | ||
10 | documentation and/or other materials provided with the distribution. | ||
11 | - Neither the name of Internet Society, IETF or IETF Trust, nor the | ||
12 | names of specific contributors, may be used to endorse or promote | ||
13 | products derived from this software without specific prior written | ||
14 | permission. | ||
15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | ||
16 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
17 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
18 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | ||
19 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | ||
20 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | ||
21 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | ||
22 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | ||
23 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | ||
24 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | ||
25 | POSSIBILITY OF SUCH DAMAGE. | ||
26 | ***********************************************************************/ | ||
27 | |||
28 | #ifdef HAVE_CONFIG_H | ||
29 | #include "config.h" | ||
30 | #endif | ||
31 | |||
32 | #include "main.h" | ||
33 | #include "stack_alloc.h" | ||
34 | |||
35 | /* Convert Left/Right stereo signal to adaptive Mid/Side representation */ | ||
36 | void silk_stereo_LR_to_MS( | ||
37 | stereo_enc_state *state, /* I/O State */ | ||
38 | opus_int16 x1[], /* I/O Left input signal, becomes mid signal */ | ||
39 | opus_int16 x2[], /* I/O Right input signal, becomes side signal */ | ||
40 | opus_int8 ix[ 2 ][ 3 ], /* O Quantization indices */ | ||
41 | opus_int8 *mid_only_flag, /* O Flag: only mid signal coded */ | ||
42 | opus_int32 mid_side_rates_bps[], /* O Bitrates for mid and side signals */ | ||
43 | opus_int32 total_rate_bps, /* I Total bitrate */ | ||
44 | opus_int prev_speech_act_Q8, /* I Speech activity level in previous frame */ | ||
45 | opus_int toMono, /* I Last frame before a stereo->mono transition */ | ||
46 | opus_int fs_kHz, /* I Sample rate (kHz) */ | ||
47 | opus_int frame_length /* I Number of samples */ | ||
48 | ) | ||
49 | { | ||
50 | opus_int n, is10msFrame, denom_Q16, delta0_Q13, delta1_Q13; | ||
51 | opus_int32 sum, diff, smooth_coef_Q16, pred_Q13[ 2 ], pred0_Q13, pred1_Q13; | ||
52 | opus_int32 LP_ratio_Q14, HP_ratio_Q14, frac_Q16, frac_3_Q16, min_mid_rate_bps, width_Q14, w_Q24, deltaw_Q24; | ||
53 | VARDECL( opus_int16, side ); | ||
54 | VARDECL( opus_int16, LP_mid ); | ||
55 | VARDECL( opus_int16, HP_mid ); | ||
56 | VARDECL( opus_int16, LP_side ); | ||
57 | VARDECL( opus_int16, HP_side ); | ||
58 | opus_int16 *mid = &x1[ -2 ]; | ||
59 | SAVE_STACK; | ||
60 | |||
61 | ALLOC( side, frame_length + 2, opus_int16 ); | ||
62 | /* Convert to basic mid/side signals */ | ||
63 | for( n = 0; n < frame_length + 2; n++ ) { | ||
64 | sum = x1[ n - 2 ] + (opus_int32)x2[ n - 2 ]; | ||
65 | diff = x1[ n - 2 ] - (opus_int32)x2[ n - 2 ]; | ||
66 | mid[ n ] = (opus_int16)silk_RSHIFT_ROUND( sum, 1 ); | ||
67 | side[ n ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( diff, 1 ) ); | ||
68 | } | ||
69 | |||
70 | /* Buffering */ | ||
71 | silk_memcpy( mid, state->sMid, 2 * sizeof( opus_int16 ) ); | ||
72 | silk_memcpy( side, state->sSide, 2 * sizeof( opus_int16 ) ); | ||
73 | silk_memcpy( state->sMid, &mid[ frame_length ], 2 * sizeof( opus_int16 ) ); | ||
74 | silk_memcpy( state->sSide, &side[ frame_length ], 2 * sizeof( opus_int16 ) ); | ||
75 | |||
76 | /* LP and HP filter mid signal */ | ||
77 | ALLOC( LP_mid, frame_length, opus_int16 ); | ||
78 | ALLOC( HP_mid, frame_length, opus_int16 ); | ||
79 | for( n = 0; n < frame_length; n++ ) { | ||
80 | sum = silk_RSHIFT_ROUND( silk_ADD_LSHIFT( mid[ n ] + (opus_int32)mid[ n + 2 ], mid[ n + 1 ], 1 ), 2 ); | ||
81 | LP_mid[ n ] = sum; | ||
82 | HP_mid[ n ] = mid[ n + 1 ] - sum; | ||
83 | } | ||
84 | |||
85 | /* LP and HP filter side signal */ | ||
86 | ALLOC( LP_side, frame_length, opus_int16 ); | ||
87 | ALLOC( HP_side, frame_length, opus_int16 ); | ||
88 | for( n = 0; n < frame_length; n++ ) { | ||
89 | sum = silk_RSHIFT_ROUND( silk_ADD_LSHIFT( side[ n ] + (opus_int32)side[ n + 2 ], side[ n + 1 ], 1 ), 2 ); | ||
90 | LP_side[ n ] = sum; | ||
91 | HP_side[ n ] = side[ n + 1 ] - sum; | ||
92 | } | ||
93 | |||
94 | /* Find energies and predictors */ | ||
95 | is10msFrame = frame_length == 10 * fs_kHz; | ||
96 | smooth_coef_Q16 = is10msFrame ? | ||
97 | SILK_FIX_CONST( STEREO_RATIO_SMOOTH_COEF / 2, 16 ) : | ||
98 | SILK_FIX_CONST( STEREO_RATIO_SMOOTH_COEF, 16 ); | ||
99 | smooth_coef_Q16 = silk_SMULWB( silk_SMULBB( prev_speech_act_Q8, prev_speech_act_Q8 ), smooth_coef_Q16 ); | ||
100 | |||
101 | pred_Q13[ 0 ] = silk_stereo_find_predictor( &LP_ratio_Q14, LP_mid, LP_side, &state->mid_side_amp_Q0[ 0 ], frame_length, smooth_coef_Q16 ); | ||
102 | pred_Q13[ 1 ] = silk_stereo_find_predictor( &HP_ratio_Q14, HP_mid, HP_side, &state->mid_side_amp_Q0[ 2 ], frame_length, smooth_coef_Q16 ); | ||
103 | /* Ratio of the norms of residual and mid signals */ | ||
104 | frac_Q16 = silk_SMLABB( HP_ratio_Q14, LP_ratio_Q14, 3 ); | ||
105 | frac_Q16 = silk_min( frac_Q16, SILK_FIX_CONST( 1, 16 ) ); | ||
106 | |||
107 | /* Determine bitrate distribution between mid and side, and possibly reduce stereo width */ | ||
108 | total_rate_bps -= is10msFrame ? 1200 : 600; /* Subtract approximate bitrate for coding stereo parameters */ | ||
109 | if( total_rate_bps < 1 ) { | ||
110 | total_rate_bps = 1; | ||
111 | } | ||
112 | min_mid_rate_bps = silk_SMLABB( 2000, fs_kHz, 600 ); | ||
113 | silk_assert( min_mid_rate_bps < 32767 ); | ||
114 | /* Default bitrate distribution: 8 parts for Mid and (5+3*frac) parts for Side. so: mid_rate = ( 8 / ( 13 + 3 * frac ) ) * total_ rate */ | ||
115 | frac_3_Q16 = silk_MUL( 3, frac_Q16 ); | ||
116 | mid_side_rates_bps[ 0 ] = silk_DIV32_varQ( total_rate_bps, SILK_FIX_CONST( 8 + 5, 16 ) + frac_3_Q16, 16+3 ); | ||
117 | /* If Mid bitrate below minimum, reduce stereo width */ | ||
118 | if( mid_side_rates_bps[ 0 ] < min_mid_rate_bps ) { | ||
119 | mid_side_rates_bps[ 0 ] = min_mid_rate_bps; | ||
120 | mid_side_rates_bps[ 1 ] = total_rate_bps - mid_side_rates_bps[ 0 ]; | ||
121 | /* width = 4 * ( 2 * side_rate - min_rate ) / ( ( 1 + 3 * frac ) * min_rate ) */ | ||
122 | width_Q14 = silk_DIV32_varQ( silk_LSHIFT( mid_side_rates_bps[ 1 ], 1 ) - min_mid_rate_bps, | ||
123 | silk_SMULWB( SILK_FIX_CONST( 1, 16 ) + frac_3_Q16, min_mid_rate_bps ), 14+2 ); | ||
124 | width_Q14 = silk_LIMIT( width_Q14, 0, SILK_FIX_CONST( 1, 14 ) ); | ||
125 | } else { | ||
126 | mid_side_rates_bps[ 1 ] = total_rate_bps - mid_side_rates_bps[ 0 ]; | ||
127 | width_Q14 = SILK_FIX_CONST( 1, 14 ); | ||
128 | } | ||
129 | |||
130 | /* Smoother */ | ||
131 | state->smth_width_Q14 = (opus_int16)silk_SMLAWB( state->smth_width_Q14, width_Q14 - state->smth_width_Q14, smooth_coef_Q16 ); | ||
132 | |||
133 | /* At very low bitrates or for inputs that are nearly amplitude panned, switch to panned-mono coding */ | ||
134 | *mid_only_flag = 0; | ||
135 | if( toMono ) { | ||
136 | /* Last frame before stereo->mono transition; collapse stereo width */ | ||
137 | width_Q14 = 0; | ||
138 | pred_Q13[ 0 ] = 0; | ||
139 | pred_Q13[ 1 ] = 0; | ||
140 | silk_stereo_quant_pred( pred_Q13, ix ); | ||
141 | } else if( state->width_prev_Q14 == 0 && | ||
142 | ( 8 * total_rate_bps < 13 * min_mid_rate_bps || silk_SMULWB( frac_Q16, state->smth_width_Q14 ) < SILK_FIX_CONST( 0.05, 14 ) ) ) | ||
143 | { | ||
144 | /* Code as panned-mono; previous frame already had zero width */ | ||
145 | /* Scale down and quantize predictors */ | ||
146 | pred_Q13[ 0 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 0 ] ), 14 ); | ||
147 | pred_Q13[ 1 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 1 ] ), 14 ); | ||
148 | silk_stereo_quant_pred( pred_Q13, ix ); | ||
149 | /* Collapse stereo width */ | ||
150 | width_Q14 = 0; | ||
151 | pred_Q13[ 0 ] = 0; | ||
152 | pred_Q13[ 1 ] = 0; | ||
153 | mid_side_rates_bps[ 0 ] = total_rate_bps; | ||
154 | mid_side_rates_bps[ 1 ] = 0; | ||
155 | *mid_only_flag = 1; | ||
156 | } else if( state->width_prev_Q14 != 0 && | ||
157 | ( 8 * total_rate_bps < 11 * min_mid_rate_bps || silk_SMULWB( frac_Q16, state->smth_width_Q14 ) < SILK_FIX_CONST( 0.02, 14 ) ) ) | ||
158 | { | ||
159 | /* Transition to zero-width stereo */ | ||
160 | /* Scale down and quantize predictors */ | ||
161 | pred_Q13[ 0 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 0 ] ), 14 ); | ||
162 | pred_Q13[ 1 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 1 ] ), 14 ); | ||
163 | silk_stereo_quant_pred( pred_Q13, ix ); | ||
164 | /* Collapse stereo width */ | ||
165 | width_Q14 = 0; | ||
166 | pred_Q13[ 0 ] = 0; | ||
167 | pred_Q13[ 1 ] = 0; | ||
168 | } else if( state->smth_width_Q14 > SILK_FIX_CONST( 0.95, 14 ) ) { | ||
169 | /* Full-width stereo coding */ | ||
170 | silk_stereo_quant_pred( pred_Q13, ix ); | ||
171 | width_Q14 = SILK_FIX_CONST( 1, 14 ); | ||
172 | } else { | ||
173 | /* Reduced-width stereo coding; scale down and quantize predictors */ | ||
174 | pred_Q13[ 0 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 0 ] ), 14 ); | ||
175 | pred_Q13[ 1 ] = silk_RSHIFT( silk_SMULBB( state->smth_width_Q14, pred_Q13[ 1 ] ), 14 ); | ||
176 | silk_stereo_quant_pred( pred_Q13, ix ); | ||
177 | width_Q14 = state->smth_width_Q14; | ||
178 | } | ||
179 | |||
180 | /* Make sure to keep on encoding until the tapered output has been transmitted */ | ||
181 | if( *mid_only_flag == 1 ) { | ||
182 | state->silent_side_len += frame_length - STEREO_INTERP_LEN_MS * fs_kHz; | ||
183 | if( state->silent_side_len < LA_SHAPE_MS * fs_kHz ) { | ||
184 | *mid_only_flag = 0; | ||
185 | } else { | ||
186 | /* Limit to avoid wrapping around */ | ||
187 | state->silent_side_len = 10000; | ||
188 | } | ||
189 | } else { | ||
190 | state->silent_side_len = 0; | ||
191 | } | ||
192 | |||
193 | if( *mid_only_flag == 0 && mid_side_rates_bps[ 1 ] < 1 ) { | ||
194 | mid_side_rates_bps[ 1 ] = 1; | ||
195 | mid_side_rates_bps[ 0 ] = silk_max_int( 1, total_rate_bps - mid_side_rates_bps[ 1 ]); | ||
196 | } | ||
197 | |||
198 | /* Interpolate predictors and subtract prediction from side channel */ | ||
199 | pred0_Q13 = -state->pred_prev_Q13[ 0 ]; | ||
200 | pred1_Q13 = -state->pred_prev_Q13[ 1 ]; | ||
201 | w_Q24 = silk_LSHIFT( state->width_prev_Q14, 10 ); | ||
202 | denom_Q16 = silk_DIV32_16( (opus_int32)1 << 16, STEREO_INTERP_LEN_MS * fs_kHz ); | ||
203 | delta0_Q13 = -silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 ); | ||
204 | delta1_Q13 = -silk_RSHIFT_ROUND( silk_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 ); | ||
205 | deltaw_Q24 = silk_LSHIFT( silk_SMULWB( width_Q14 - state->width_prev_Q14, denom_Q16 ), 10 ); | ||
206 | for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) { | ||
207 | pred0_Q13 += delta0_Q13; | ||
208 | pred1_Q13 += delta1_Q13; | ||
209 | w_Q24 += deltaw_Q24; | ||
210 | sum = silk_LSHIFT( silk_ADD_LSHIFT( mid[ n ] + (opus_int32)mid[ n + 2 ], mid[ n + 1 ], 1 ), 9 ); /* Q11 */ | ||
211 | sum = silk_SMLAWB( silk_SMULWB( w_Q24, side[ n + 1 ] ), sum, pred0_Q13 ); /* Q8 */ | ||
212 | sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)mid[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */ | ||
213 | x2[ n - 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) ); | ||
214 | } | ||
215 | |||
216 | pred0_Q13 = -pred_Q13[ 0 ]; | ||
217 | pred1_Q13 = -pred_Q13[ 1 ]; | ||
218 | w_Q24 = silk_LSHIFT( width_Q14, 10 ); | ||
219 | for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) { | ||
220 | sum = silk_LSHIFT( silk_ADD_LSHIFT( mid[ n ] + (opus_int32)mid[ n + 2 ], mid[ n + 1 ], 1 ), 9 ); /* Q11 */ | ||
221 | sum = silk_SMLAWB( silk_SMULWB( w_Q24, side[ n + 1 ] ), sum, pred0_Q13 ); /* Q8 */ | ||
222 | sum = silk_SMLAWB( sum, silk_LSHIFT( (opus_int32)mid[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */ | ||
223 | x2[ n - 1 ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( sum, 8 ) ); | ||
224 | } | ||
225 | state->pred_prev_Q13[ 0 ] = (opus_int16)pred_Q13[ 0 ]; | ||
226 | state->pred_prev_Q13[ 1 ] = (opus_int16)pred_Q13[ 1 ]; | ||
227 | state->width_prev_Q14 = (opus_int16)width_Q14; | ||
228 | RESTORE_STACK; | ||
229 | } | ||