| @@ -0,0 +1,316 @@ |
| | 1 | /* |
| | 2 | * gsm 06.10 decoder |
| | 3 | * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de> |
| | 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 | /** |
| | 23 | * @file |
| | 24 | * GSM decoder |
| | 25 | */ |
| | 26 | |
| | 27 | #define ALT_BITSTREAM_READER_LE |
| | 28 | #include "avcodec.h" |
| | 29 | #include "get_bits.h" |
| | 30 | |
| | 31 | // input and output sizes in byte |
| | 32 | #define GSM_BLOCK_SIZE 33 |
| | 33 | #define GSM_MS_BLOCK_SIZE 65 |
| | 34 | #define GSM_FRAME_SIZE 160 |
| | 35 | |
| | 36 | typedef struct { |
| | 37 | int16_t ref_buf[280]; |
| | 38 | int v[9]; |
| | 39 | int lar[2][8]; |
| | 40 | int lar_idx; |
| | 41 | int msr; |
| | 42 | } GSMContext; |
| | 43 | |
| | 44 | static av_cold int gsm_init(AVCodecContext *avctx) |
| | 45 | { |
| | 46 | avctx->channels = 1; |
| | 47 | if (!avctx->sample_rate) |
| | 48 | avctx->sample_rate = 8000; |
| | 49 | avctx->sample_fmt = SAMPLE_FMT_S16; |
| | 50 | |
| | 51 | switch (avctx->codec_id) { |
| | 52 | case CODEC_ID_GSM: |
| | 53 | avctx->frame_size = GSM_FRAME_SIZE; |
| | 54 | avctx->block_align = GSM_BLOCK_SIZE; |
| | 55 | break; |
| | 56 | case CODEC_ID_GSM_MS: |
| | 57 | avctx->frame_size = 2 * GSM_FRAME_SIZE; |
| | 58 | avctx->block_align = GSM_MS_BLOCK_SIZE; |
| | 59 | } |
| | 60 | |
| | 61 | return 0; |
| | 62 | } |
| | 63 | |
| | 64 | static const int16_t dequant_tab[64][8] = { |
| | 65 | { -28, -20, -12, -4, 4, 12, 20, 28}, |
| | 66 | { -56, -40, -24, -8, 8, 24, 40, 56}, |
| | 67 | { -84, -60, -36, -12, 12, 36, 60, 84}, |
| | 68 | { -112, -80, -48, -16, 16, 48, 80, 112}, |
| | 69 | { -140, -100, -60, -20, 20, 60, 100, 140}, |
| | 70 | { -168, -120, -72, -24, 24, 72, 120, 168}, |
| | 71 | { -196, -140, -84, -28, 28, 84, 140, 196}, |
| | 72 | { -224, -160, -96, -32, 32, 96, 160, 224}, |
| | 73 | { -252, -180, -108, -36, 36, 108, 180, 252}, |
| | 74 | { -280, -200, -120, -40, 40, 120, 200, 280}, |
| | 75 | { -308, -220, -132, -44, 44, 132, 220, 308}, |
| | 76 | { -336, -240, -144, -48, 48, 144, 240, 336}, |
| | 77 | { -364, -260, -156, -52, 52, 156, 260, 364}, |
| | 78 | { -392, -280, -168, -56, 56, 168, 280, 392}, |
| | 79 | { -420, -300, -180, -60, 60, 180, 300, 420}, |
| | 80 | { -448, -320, -192, -64, 64, 192, 320, 448}, |
| | 81 | { -504, -360, -216, -72, 72, 216, 360, 504}, |
| | 82 | { -560, -400, -240, -80, 80, 240, 400, 560}, |
| | 83 | { -616, -440, -264, -88, 88, 264, 440, 616}, |
| | 84 | { -672, -480, -288, -96, 96, 288, 480, 672}, |
| | 85 | { -728, -520, -312, -104, 104, 312, 520, 728}, |
| | 86 | { -784, -560, -336, -112, 112, 336, 560, 784}, |
| | 87 | { -840, -600, -360, -120, 120, 360, 600, 840}, |
| | 88 | { -896, -640, -384, -128, 128, 384, 640, 896}, |
| | 89 | { -1008, -720, -432, -144, 144, 432, 720, 1008}, |
| | 90 | { -1120, -800, -480, -160, 160, 480, 800, 1120}, |
| | 91 | { -1232, -880, -528, -176, 176, 528, 880, 1232}, |
| | 92 | { -1344, -960, -576, -192, 192, 576, 960, 1344}, |
| | 93 | { -1456, -1040, -624, -208, 208, 624, 1040, 1456}, |
| | 94 | { -1568, -1120, -672, -224, 224, 672, 1120, 1568}, |
| | 95 | { -1680, -1200, -720, -240, 240, 720, 1200, 1680}, |
| | 96 | { -1792, -1280, -768, -256, 256, 768, 1280, 1792}, |
| | 97 | { -2016, -1440, -864, -288, 288, 864, 1440, 2016}, |
| | 98 | { -2240, -1600, -960, -320, 320, 960, 1600, 2240}, |
| | 99 | { -2464, -1760, -1056, -352, 352, 1056, 1760, 2464}, |
| | 100 | { -2688, -1920, -1152, -384, 384, 1152, 1920, 2688}, |
| | 101 | { -2912, -2080, -1248, -416, 416, 1248, 2080, 2912}, |
| | 102 | { -3136, -2240, -1344, -448, 448, 1344, 2240, 3136}, |
| | 103 | { -3360, -2400, -1440, -480, 480, 1440, 2400, 3360}, |
| | 104 | { -3584, -2560, -1536, -512, 512, 1536, 2560, 3584}, |
| | 105 | { -4032, -2880, -1728, -576, 576, 1728, 2880, 4032}, |
| | 106 | { -4480, -3200, -1920, -640, 640, 1920, 3200, 4480}, |
| | 107 | { -4928, -3520, -2112, -704, 704, 2112, 3520, 4928}, |
| | 108 | { -5376, -3840, -2304, -768, 768, 2304, 3840, 5376}, |
| | 109 | { -5824, -4160, -2496, -832, 832, 2496, 4160, 5824}, |
| | 110 | { -6272, -4480, -2688, -896, 896, 2688, 4480, 6272}, |
| | 111 | { -6720, -4800, -2880, -960, 960, 2880, 4800, 6720}, |
| | 112 | { -7168, -5120, -3072, -1024, 1024, 3072, 5120, 7168}, |
| | 113 | { -8063, -5759, -3456, -1152, 1152, 3456, 5760, 8064}, |
| | 114 | { -8959, -6399, -3840, -1280, 1280, 3840, 6400, 8960}, |
| | 115 | { -9855, -7039, -4224, -1408, 1408, 4224, 7040, 9856}, |
| | 116 | {-10751, -7679, -4608, -1536, 1536, 4608, 7680, 10752}, |
| | 117 | {-11647, -8319, -4992, -1664, 1664, 4992, 8320, 11648}, |
| | 118 | {-12543, -8959, -5376, -1792, 1792, 5376, 8960, 12544}, |
| | 119 | {-13439, -9599, -5760, -1920, 1920, 5760, 9600, 13440}, |
| | 120 | {-14335, -10239, -6144, -2048, 2048, 6144, 10240, 14336}, |
| | 121 | {-16127, -11519, -6912, -2304, 2304, 6912, 11519, 16127}, |
| | 122 | {-17919, -12799, -7680, -2560, 2560, 7680, 12799, 17919}, |
| | 123 | {-19711, -14079, -8448, -2816, 2816, 8448, 14079, 19711}, |
| | 124 | {-21503, -15359, -9216, -3072, 3072, 9216, 15359, 21503}, |
| | 125 | {-23295, -16639, -9984, -3328, 3328, 9984, 16639, 23295}, |
| | 126 | {-25087, -17919, -10752, -3584, 3584, 10752, 17919, 25087}, |
| | 127 | {-26879, -19199, -11520, -3840, 3840, 11520, 19199, 26879}, |
| | 128 | {-28671, -20479, -12288, -4096, 4096, 12288, 20479, 28671} |
| | 129 | }; |
| | 130 | |
| | 131 | static void apcm_dequant_add(GetBitContext *gb, int16_t *dst) |
| | 132 | { |
| | 133 | int i; |
| | 134 | int maxidx = get_bits(gb, 6); |
| | 135 | const int16_t *tab = dequant_tab[maxidx]; |
| | 136 | for (i = 0; i < 13; i++) |
| | 137 | dst[3*i] += tab[get_bits(gb, 3)]; |
| | 138 | } |
| | 139 | |
| | 140 | static inline int gsm_mult(int a, int b) |
| | 141 | { |
| | 142 | return (a * b + (1 << 14)) >> 15; |
| | 143 | } |
| | 144 | |
| | 145 | static const uint16_t long_term_gain_tab[4] = { |
| | 146 | 3277, 11469, 21299, 32767 |
| | 147 | }; |
| | 148 | |
| | 149 | static void long_term_synth(int16_t *dst, int lag, int gain_idx) |
| | 150 | { |
| | 151 | int i; |
| | 152 | const int16_t *src = dst - lag; |
| | 153 | uint16_t gain = long_term_gain_tab[gain_idx]; |
| | 154 | for (i = 0; i < 40; i++) |
| | 155 | dst[i] = gsm_mult(gain, src[i]); |
| | 156 | } |
| | 157 | |
| | 158 | static inline int decode_log_area(int coded, int factor, int offset) |
| | 159 | { |
| | 160 | coded <<= 10; |
| | 161 | coded -= offset; |
| | 162 | return gsm_mult(coded, factor) << 1; |
| | 163 | } |
| | 164 | |
| | 165 | static av_noinline int get_rrp(int filtered) |
| | 166 | { |
| | 167 | int abs = FFABS(filtered); |
| | 168 | if (abs < 11059) abs <<= 1; |
| | 169 | else if (abs < 20070) abs += 11059; |
| | 170 | else abs = (abs >> 2) + 26112; |
| | 171 | return filtered < 0 ? -abs : abs; |
| | 172 | } |
| | 173 | |
| | 174 | static int filter_value(int in, int rrp[8], int v[9]) |
| | 175 | { |
| | 176 | int i; |
| | 177 | for (i = 7; i >= 0; i--) { |
| | 178 | in -= gsm_mult(rrp[i], v[i]); |
| | 179 | v[i + 1] = v[i] + gsm_mult(rrp[i], in); |
| | 180 | } |
| | 181 | v[0] = in; |
| | 182 | return in; |
| | 183 | } |
| | 184 | |
| | 185 | static void short_term_synth(GSMContext *ctx, int16_t *dst, const int16_t *src) |
| | 186 | { |
| | 187 | int i; |
| | 188 | int rrp[8]; |
| | 189 | int *lar = ctx->lar[ctx->lar_idx]; |
| | 190 | int *lar_prev = ctx->lar[ctx->lar_idx ^ 1]; |
| | 191 | for (i = 0; i < 8; i++) |
| | 192 | rrp[i] = get_rrp((lar_prev[i] >> 2) + (lar_prev[i] >> 1) + (lar[i] >> 2)); |
| | 193 | for (i = 0; i < 13; i++) |
| | 194 | dst[i] = filter_value(src[i], rrp, ctx->v); |
| | 195 | |
| | 196 | for (i = 0; i < 8; i++) |
| | 197 | rrp[i] = get_rrp((lar_prev[i] >> 1) + (lar [i] >> 1)); |
| | 198 | for (i = 13; i < 27; i++) |
| | 199 | dst[i] = filter_value(src[i], rrp, ctx->v); |
| | 200 | |
| | 201 | for (i = 0; i < 8; i++) |
| | 202 | rrp[i] = get_rrp((lar_prev[i] >> 2) + (lar [i] >> 1) + (lar[i] >> 2)); |
| | 203 | for (i = 27; i < 40; i++) |
| | 204 | dst[i] = filter_value(src[i], rrp, ctx->v); |
| | 205 | |
| | 206 | for (i = 0; i < 8; i++) |
| | 207 | rrp[i] = get_rrp(lar[i]); |
| | 208 | for (i = 40; i < 160; i++) |
| | 209 | dst[i] = filter_value(src[i], rrp, ctx->v); |
| | 210 | |
| | 211 | ctx->lar_idx ^= 1; |
| | 212 | } |
| | 213 | |
| | 214 | static int postprocess(int16_t *data, int msr) |
| | 215 | { |
| | 216 | int i; |
| | 217 | for (i = 0; i < 160; i++) { |
| | 218 | msr = av_clip_int16(data[i] + gsm_mult(msr, 28180)); |
| | 219 | data[i] = av_clip_int16(msr << 1) & ~7; |
| | 220 | } |
| | 221 | return msr; |
| | 222 | } |
| | 223 | |
| | 224 | static int gsm_decode_block(AVCodecContext *avctx, int16_t *samples, |
| | 225 | GetBitContext *gb) |
| | 226 | { |
| | 227 | GSMContext *ctx = avctx->priv_data; |
| | 228 | int i; |
| | 229 | int16_t *ref_dst = ctx->ref_buf + 120; |
| | 230 | int *lar = ctx->lar[ctx->lar_idx]; |
| | 231 | lar[0] = decode_log_area(get_bits(gb, 6), 13107, 1 << 15); |
| | 232 | lar[1] = decode_log_area(get_bits(gb, 6), 13107, 1 << 15); |
| | 233 | lar[2] = decode_log_area(get_bits(gb, 5), 13107, (1 << 14) + 2048*2); |
| | 234 | lar[3] = decode_log_area(get_bits(gb, 5), 13107, (1 << 14) - 2560*2); |
| | 235 | lar[4] = decode_log_area(get_bits(gb, 4), 19223, (1 << 13) + 94*2); |
| | 236 | lar[5] = decode_log_area(get_bits(gb, 4), 17476, (1 << 13) - 1792*2); |
| | 237 | lar[6] = decode_log_area(get_bits(gb, 3), 31454, (1 << 12) - 341*2); |
| | 238 | lar[7] = decode_log_area(get_bits(gb, 3), 29708, (1 << 12) - 1144*2); |
| | 239 | |
| | 240 | for (i = 0; i < 4; i++) { |
| | 241 | int lag = get_bits(gb, 7); |
| | 242 | int gain_idx = get_bits(gb, 2); |
| | 243 | int offset = get_bits(gb, 2); |
| | 244 | lag = av_clip(lag, 40, 120); |
| | 245 | long_term_synth(ref_dst, lag, gain_idx); |
| | 246 | apcm_dequant_add(gb, ref_dst + offset); |
| | 247 | ref_dst += 40; |
| | 248 | } |
| | 249 | memcpy(ctx->ref_buf, ctx->ref_buf + 160, 120 * sizeof(*ctx->ref_buf)); |
| | 250 | short_term_synth(ctx, samples, ctx->ref_buf + 120); |
| | 251 | // for optimal speed this could be merged with short_term_synth, |
| | 252 | // not done yet because it is a bit ugly |
| | 253 | ctx->msr = postprocess(samples, ctx->msr); |
| | 254 | return 0; |
| | 255 | } |
| | 256 | |
| | 257 | static int gsm_decode_frame(AVCodecContext *avctx, void *data, |
| | 258 | int *data_size, AVPacket *avpkt) |
| | 259 | { |
| | 260 | int res; |
| | 261 | GetBitContext gb; |
| | 262 | const uint8_t *buf = avpkt->data; |
| | 263 | int buf_size = avpkt->size; |
| | 264 | int16_t *samples = data; |
| | 265 | int frame_bytes = 2 * avctx->frame_size; |
| | 266 | |
| | 267 | if (*data_size < frame_bytes) |
| | 268 | return -1; |
| | 269 | *data_size = 0; |
| | 270 | if(buf_size < avctx->block_align) |
| | 271 | return AVERROR_INVALIDDATA; |
| | 272 | init_get_bits(&gb, buf, buf_size * 8); |
| | 273 | |
| | 274 | switch (avctx->codec_id) { |
| | 275 | case CODEC_ID_GSM: |
| | 276 | if (get_bits(&gb, 4) != 0xd) |
| | 277 | av_log(avctx, AV_LOG_WARNING, "Missing GSM magic!\n"); |
| | 278 | res = gsm_decode_block(avctx, samples, &gb); |
| | 279 | if (res < 0) |
| | 280 | return res; |
| | 281 | break; |
| | 282 | case CODEC_ID_GSM_MS: |
| | 283 | res = gsm_decode_block(avctx, samples, &gb); |
| | 284 | if (res < 0) |
| | 285 | return res; |
| | 286 | res = gsm_decode_block(avctx, samples + GSM_FRAME_SIZE, &gb); |
| | 287 | if (res < 0) |
| | 288 | return res; |
| | 289 | } |
| | 290 | *data_size = frame_bytes; |
| | 291 | return avctx->block_align; |
| | 292 | } |
| | 293 | |
| | 294 | AVCodec gsm_decoder = { |
| | 295 | "gsm", |
| | 296 | AVMEDIA_TYPE_AUDIO, |
| | 297 | CODEC_ID_GSM, |
| | 298 | sizeof(GSMContext), |
| | 299 | gsm_init, |
| | 300 | NULL, |
| | 301 | NULL, |
| | 302 | gsm_decode_frame, |
| | 303 | .long_name = NULL_IF_CONFIG_SMALL("GSM"), |
| | 304 | }; |
| | 305 | |
| | 306 | AVCodec gsm_ms_decoder = { |
| | 307 | "gsm_ms", |
| | 308 | AVMEDIA_TYPE_AUDIO, |
| | 309 | CODEC_ID_GSM_MS, |
| | 310 | sizeof(GSMContext), |
| | 311 | gsm_init, |
| | 312 | NULL, |
| | 313 | NULL, |
| | 314 | gsm_decode_frame, |
| | 315 | .long_name = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"), |
| | 316 | }; |