FreeCalypso > hg > gsm-codec-lib
view dev/efr-tidsp.c @ 242:f081a6850fb5
libgsmfrp: new refined implementation
The previous implementation exhibited the following defects,
which are now fixed:
1) The last received valid SID was cached forever for the purpose of
handling future invalid SIDs - we could have received some valid
SID ages ago, then lots of speech or NO_DATA, and if we then get
an invalid SID, we would resurrect the last valid SID from ancient
history - a bad design. In our new design, we handle invalid SID
based on the current state, much like BFI.
2) GSM 06.11 spec says clearly that after the second lost SID
(received BFI=1 && TAF=1 in CN state) we need to gradually decrease
the output level, rather than jump directly to emitting silence
frames - we previously failed to implement such logic.
3) Per GSM 06.12 section 5.2, Xmaxc should be the same in all 4 subframes
in a SID frame. What should we do if we receive an otherwise valid
SID frame with different Xmaxc? Our previous approach would
replicate this Xmaxc oddity in every subsequent generated CN frame,
which is rather bad. In our new design, the very first CN frame
(which can be seen as a transformation of the SID frame itself)
retains the original 4 distinct Xmaxc, but all subsequent CN frames
are based on the Xmaxc from the last subframe of the most recent SID.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Tue, 09 May 2023 05:16:31 +0000 |
| parents | 68215020852b |
| children |
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/* * This program constructs a table for extracting a 244-bit EFR codec frame * from a 33-byte frame that has been read out of Calypso DSP buffer on a * TCH/EFS downlink. Our starting material is Osmocom's rendition of * GSM 05.03 Table 6. */ #include <stdio.h> #include <stdlib.h> /* GSM EFR - subjective importance bit ordering */ /* This array encodes GSM 05.03 Table 6. * * It converts between serial parameter output (as described in * GSM 06.60 Table 6 and GSM 05.03 Table 5) and the order needed * before channel encoding. CRC poly and bit repetition must be * applied prior to this table, as in GSM 05.03 3.1.1, to get 260 * bits from a 244 bits raw EFR frame. */ const unsigned short gsm660_bitorder[260] = { 38, 39, 40, 41, 42, 43, /* 0 -> LTP-LAG 1: b8..b3 */ 145, 146, 147, 148, 149, 150, /* 6 -> LTP-LAG 3: b8..b3 */ 93, 94, /* 12 -> LTP-LAG 2: b5..b4 */ 200, 201, /* 14 -> LTP-LAG 4: b5..b4 */ 47, /* 16 -> LTP-GAIN 1: b3 */ 88, /* 17 -> FCB-GAIN 1: b4 */ 99, /* 18 -> LTP-GAIN 2: b3 */ 140, /* 19 -> FCB-GAIN 2: b4 */ 44, /* 20 -> LTP-LAG 1: b2 */ 151, /* 21 -> LTP-LAG 3: b2 */ 95, /* 22 -> LTP-LAG 2: b3 */ 202, /* 23 -> LTP-LAG 4: b3 */ 1, 2, /* 24 -> LPC 1: b5..b4 */ 7, /* 26 -> LPC 2: b7 */ 9, /* 27 -> LPC 2: b5 */ 17, 18, /* 28 -> LPC 3: b6..b5 */ 23, /* 30 -> LPC 3: b0 */ 45, 46, /* 31 -> LTP-LAG 1: b1..b0 */ 152, 153, /* 33 -> LTP-LAG 3: b1..b0 */ 96, /* 35 -> LTP-LAG 2: b2 */ 203, /* 36 -> LTP-LAG 4: b2 */ 3, 4, /* 37 -> LPC 1: b3..b2 */ 10, 11, /* 39 -> LPC 2: b4..b3 */ 15, /* 41 -> LPC 3: b8 */ 8, /* 42 -> LPC 2: b6 */ 5, 6, /* 43 -> LPC 1: b1..b0 */ 12, /* 45 -> LPC 2: b2 */ 16, /* 46 -> LPC 3: b7 */ 19, /* 47 -> LPC 3: b4 */ 97, /* 48 -> LTP-LAG 2: b1 */ 204, /* 49 -> LTP-LAG 4: b1 */ 0, /* 50 -> LPC 1: b6 */ 13, 14, /* 51 -> LPC 2: b1..b0 */ 20, /* 53 -> LPC 3: b3 */ 24, 25, /* 54 -> LPC 4: b7..b6 */ 27, /* 56 -> LPC 4: b4 */ 154, /* 57 -> LTP-GAIN 3: b3 */ 206, /* 58 -> LTP-GAIN 4: b3 */ 195, /* 59 -> FCB-GAIN 3: b4 */ 247, /* 60 -> FCB-GAIN 4: b4 */ 89, /* 61 -> FCB-GAIN 1: b3 */ 141, /* 62 -> FCB-GAIN 2: b3 */ 196, /* 63 -> FCB-GAIN 3: b3 */ 248, /* 64 -> FCB-GAIN 4: b3 */ 252, 253, 254, 255, 256, 257, 258, 259, /* 65 -> CRC-POLY: b7..b0 */ 48, /* 73 -> LTP-GAIN 1: b2 */ 100, /* 74 -> LTP-GAIN 2: b2 */ 155, /* 75 -> LTP-GAIN 3: b2 */ 207, /* 76 -> LTP-GAIN 4: b2 */ 21, 22, /* 77 -> LPC 3: b2..b1 */ 26, /* 79 -> LPC 4: b5 */ 28, /* 80 -> LPC 4: b3 */ 51, /* 81 -> PULSE 1_1: b3 */ 55, /* 82 -> PULSE 1_2: b3 */ 59, /* 83 -> PULSE 1_3: b3 */ 63, /* 84 -> PULSE 1_4: b3 */ 67, /* 85 -> PULSE 1_5: b3 */ 103, /* 86 -> PULSE 2_1: b3 */ 107, /* 87 -> PULSE 2_2: b3 */ 111, /* 88 -> PULSE 2_3: b3 */ 115, /* 89 -> PULSE 2_4: b3 */ 119, /* 90 -> PULSE 2_5: b3 */ 158, /* 91 -> PULSE 3_1: b3 */ 162, /* 92 -> PULSE 3_2: b3 */ 166, /* 93 -> PULSE 3_3: b3 */ 170, /* 94 -> PULSE 3_4: b3 */ 174, /* 95 -> PULSE 3_5: b3 */ 210, /* 96 -> PULSE 4_1: b3 */ 214, /* 97 -> PULSE 4_2: b3 */ 218, /* 98 -> PULSE 4_3: b3 */ 222, /* 99 -> PULSE 4_4: b3 */ 226, /* 100 -> PULSE 4_5: b3 */ 90, /* 101 -> FCB-GAIN 1: b2 */ 142, /* 102 -> FCB-GAIN 2: b2 */ 197, /* 103 -> FCB-GAIN 3: b2 */ 249, /* 104 -> FCB-GAIN 4: b2 */ 49, /* 105 -> LTP-GAIN 1: b1 */ 101, /* 106 -> LTP-GAIN 2: b1 */ 156, /* 107 -> LTP-GAIN 3: b1 */ 208, /* 108 -> LTP-GAIN 4: b1 */ 29, 30, 31, /* 109 -> LPC 4: b2..b0 */ 32, 33, 34, 35, /* 112 -> LPC 5: b5..b2 */ 98, /* 116 -> LTP-LAG 2: b0 */ 205, /* 117 -> LTP-LAG 4: b0 */ 52, /* 118 -> PULSE 1_1: b2 */ 56, /* 119 -> PULSE 1_2: b2 */ 60, /* 120 -> PULSE 1_3: b2 */ 64, /* 121 -> PULSE 1_4: b2 */ 68, /* 122 -> PULSE 1_5: b2 */ 104, /* 123 -> PULSE 2_1: b2 */ 108, /* 124 -> PULSE 2_2: b2 */ 112, /* 125 -> PULSE 2_3: b2 */ 116, /* 126 -> PULSE 2_4: b2 */ 120, /* 127 -> PULSE 2_5: b2 */ 159, /* 128 -> PULSE 3_1: b2 */ 163, /* 129 -> PULSE 3_2: b2 */ 167, /* 130 -> PULSE 3_3: b2 */ 171, /* 131 -> PULSE 3_4: b2 */ 175, /* 132 -> PULSE 3_5: b2 */ 211, /* 133 -> PULSE 4_1: b2 */ 215, /* 134 -> PULSE 4_2: b2 */ 219, /* 135 -> PULSE 4_3: b2 */ 223, /* 136 -> PULSE 4_4: b2 */ 227, /* 137 -> PULSE 4_5: b2 */ 53, /* 138 -> PULSE 1_1: b1 */ 57, /* 139 -> PULSE 1_2: b1 */ 61, /* 140 -> PULSE 1_3: b1 */ 65, /* 141 -> PULSE 1_4: b1 */ 105, /* 142 -> PULSE 2_1: b1 */ 109, /* 143 -> PULSE 2_2: b1 */ 113, /* 144 -> PULSE 2_3: b1 */ 117, /* 145 -> PULSE 2_4: b1 */ 160, /* 146 -> PULSE 3_1: b1 */ 164, /* 147 -> PULSE 3_2: b1 */ 168, /* 148 -> PULSE 3_3: b1 */ 172, /* 149 -> PULSE 3_4: b1 */ 212, /* 150 -> PULSE 4_1: b1 */ 220, /* 151 -> PULSE 4_3: b1 */ 224, /* 152 -> PULSE 4_4: b1 */ 91, /* 153 -> FCB-GAIN 1: b1 */ 143, /* 154 -> FCB-GAIN 2: b1 */ 198, /* 155 -> FCB-GAIN 3: b1 */ 250, /* 156 -> FCB-GAIN 4: b1 */ 50, /* 157 -> LTP-GAIN 1: b0 */ 102, /* 158 -> LTP-GAIN 2: b0 */ 157, /* 159 -> LTP-GAIN 3: b0 */ 209, /* 160 -> LTP-GAIN 4: b0 */ 92, /* 161 -> FCB-GAIN 1: b0 */ 144, /* 162 -> FCB-GAIN 2: b0 */ 199, /* 163 -> FCB-GAIN 3: b0 */ 251, /* 164 -> FCB-GAIN 4: b0 */ 54, /* 165 -> PULSE 1_1: b0 */ 58, /* 166 -> PULSE 1_2: b0 */ 62, /* 167 -> PULSE 1_3: b0 */ 66, /* 168 -> PULSE 1_4: b0 */ 106, /* 169 -> PULSE 2_1: b0 */ 110, /* 170 -> PULSE 2_2: b0 */ 114, /* 171 -> PULSE 2_3: b0 */ 118, /* 172 -> PULSE 2_4: b0 */ 161, /* 173 -> PULSE 3_1: b0 */ 165, /* 174 -> PULSE 3_2: b0 */ 169, /* 175 -> PULSE 3_3: b0 */ 173, /* 176 -> PULSE 3_4: b0 */ 213, /* 177 -> PULSE 4_1: b0 */ 221, /* 178 -> PULSE 4_3: b0 */ 225, /* 179 -> PULSE 4_4: b0 */ 36, 37, /* 180 -> LPC 5: b1..b0 */ 69, /* 182 -> PULSE 1_5: b1 */ 71, 72, /* 183 -> PULSE 1_5: b1..b1 */ 121, /* 185 -> PULSE 2_5: b1 */ 123, 124, /* 186 -> PULSE 2_5: b1..b1 */ 176, /* 188 -> PULSE 3_5: b1 */ 178, 179, /* 189 -> PULSE 3_5: b1..b1 */ 228, /* 191 -> PULSE 4_5: b1 */ 230, 231, /* 192 -> PULSE 4_5: b1..b1 */ 216, 217, /* 194 -> PULSE 4_2: b1..b0 */ 70, /* 196 -> PULSE 1_5: b0 */ 122, /* 197 -> PULSE 2_5: b0 */ 177, /* 198 -> PULSE 3_5: b0 */ 229, /* 199 -> PULSE 4_5: b0 */ 73, /* 200 -> PULSE 1_6: b2 */ 76, /* 201 -> PULSE 1_7: b2 */ 79, /* 202 -> PULSE 1_8: b2 */ 82, /* 203 -> PULSE 1_9: b2 */ 85, /* 204 -> PULSE 1_10: b2 */ 125, /* 205 -> PULSE 2_6: b2 */ 128, /* 206 -> PULSE 2_7: b2 */ 131, /* 207 -> PULSE 2_8: b2 */ 134, /* 208 -> PULSE 2_9: b2 */ 137, /* 209 -> PULSE 2_10: b2 */ 180, /* 210 -> PULSE 3_6: b2 */ 183, /* 211 -> PULSE 3_7: b2 */ 186, /* 212 -> PULSE 3_8: b2 */ 189, /* 213 -> PULSE 3_9: b2 */ 192, /* 214 -> PULSE 3_10: b2 */ 232, /* 215 -> PULSE 4_6: b2 */ 235, /* 216 -> PULSE 4_7: b2 */ 238, /* 217 -> PULSE 4_8: b2 */ 241, /* 218 -> PULSE 4_9: b2 */ 244, /* 219 -> PULSE 4_10: b2 */ 74, /* 220 -> PULSE 1_6: b1 */ 77, /* 221 -> PULSE 1_7: b1 */ 80, /* 222 -> PULSE 1_8: b1 */ 83, /* 223 -> PULSE 1_9: b1 */ 86, /* 224 -> PULSE 1_10: b1 */ 126, /* 225 -> PULSE 2_6: b1 */ 129, /* 226 -> PULSE 2_7: b1 */ 132, /* 227 -> PULSE 2_8: b1 */ 135, /* 228 -> PULSE 2_9: b1 */ 138, /* 229 -> PULSE 2_10: b1 */ 181, /* 230 -> PULSE 3_6: b1 */ 184, /* 231 -> PULSE 3_7: b1 */ 187, /* 232 -> PULSE 3_8: b1 */ 190, /* 233 -> PULSE 3_9: b1 */ 193, /* 234 -> PULSE 3_10: b1 */ 233, /* 235 -> PULSE 4_6: b1 */ 236, /* 236 -> PULSE 4_7: b1 */ 239, /* 237 -> PULSE 4_8: b1 */ 242, /* 238 -> PULSE 4_9: b1 */ 245, /* 239 -> PULSE 4_10: b1 */ 75, /* 240 -> PULSE 1_6: b0 */ 78, /* 241 -> PULSE 1_7: b0 */ 81, /* 242 -> PULSE 1_8: b0 */ 84, /* 243 -> PULSE 1_9: b0 */ 87, /* 244 -> PULSE 1_10: b0 */ 127, /* 245 -> PULSE 2_6: b0 */ 130, /* 246 -> PULSE 2_7: b0 */ 133, /* 247 -> PULSE 2_8: b0 */ 136, /* 248 -> PULSE 2_9: b0 */ 139, /* 249 -> PULSE 2_10: b0 */ 182, /* 250 -> PULSE 3_6: b0 */ 185, /* 251 -> PULSE 3_7: b0 */ 188, /* 252 -> PULSE 3_8: b0 */ 191, /* 253 -> PULSE 3_9: b0 */ 194, /* 254 -> PULSE 3_10: b0 */ 234, /* 255 -> PULSE 4_6: b0 */ 237, /* 256 -> PULSE 4_7: b0 */ 240, /* 257 -> PULSE 4_8: b0 */ 243, /* 258 -> PULSE 4_9: b0 */ 246, /* 259 -> PULSE 4_10: b0 */ }; unsigned short new_table[244]; static void gen_new_table() { int i, w, s, ti; for (i = 0; i < 260; i++) { w = gsm660_bitorder[i]; /* not doing CRC bits */ if (w >= 252) continue; /* not doing repetition bits */ if (w == 71 || w == 72) continue; if (w == 123 || w == 124) continue; if (w == 178 || w == 179) continue; if (w == 230 || w == 231) continue; /* get s number back from w */ if (w >= 232) s = w - 8; else if (w >= 180) s = w - 6; else if (w >= 125) s = w - 4; else if (w >= 73) s = w - 2; else s = w; /* TI bit number: gap of 4 between 182 and 78 */ if (i >= 182) ti = i + 4; else ti = i; new_table[s] = ti; } } static void emit_output() { int i; for (i = 0; i < 244; i++) { if (i % 12) putchar(' '); else { putchar('\n'); putchar('\t'); } printf("%3u,", new_table[i]); } putchar('\n'); } main(argc, argv) char **argv; { gen_new_table(); emit_output(); exit(0); }