1/* 2 * Assorted DPCM codecs 3 * Copyright (c) 2003 The ffmpeg Project 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 * Assorted DPCM (differential pulse code modulation) audio codecs 25 * by Mike Melanson (melanson@pcisys.net) 26 * Xan DPCM decoder by Mario Brito (mbrito@student.dei.uc.pt) 27 * for more information on the specific data formats, visit: 28 * http://www.pcisys.net/~melanson/codecs/simpleaudio.html 29 * SOL DPCMs implemented by Konstantin Shishkov 30 * 31 * Note about using the Xan DPCM decoder: Xan DPCM is used in AVI files 32 * found in the Wing Commander IV computer game. These AVI files contain 33 * WAVEFORMAT headers which report the audio format as 0x01: raw PCM. 34 * Clearly incorrect. To detect Xan DPCM, you will probably have to 35 * special-case your AVI demuxer to use Xan DPCM if the file uses 'Xxan' 36 * (Xan video) for its video codec. Alternately, such AVI files also contain 37 * the fourcc 'Axan' in the 'auds' chunk of the AVI header. 38 */ 39 40#include "libavutil/intreadwrite.h" 41#include "avcodec.h" 42#include "bytestream.h" 43#include "internal.h" 44#include "mathops.h" 45 46typedef struct DPCMContext { 47 int16_t roq_square_array[256]; 48 int sample[2]; ///< previous sample (for SOL_DPCM) 49 const int8_t *sol_table; ///< delta table for SOL_DPCM 50} DPCMContext; 51 52static const int16_t interplay_delta_table[] = { 53 0, 1, 2, 3, 4, 5, 6, 7, 54 8, 9, 10, 11, 12, 13, 14, 15, 55 16, 17, 18, 19, 20, 21, 22, 23, 56 24, 25, 26, 27, 28, 29, 30, 31, 57 32, 33, 34, 35, 36, 37, 38, 39, 58 40, 41, 42, 43, 47, 51, 56, 61, 59 66, 72, 79, 86, 94, 102, 112, 122, 60 133, 145, 158, 173, 189, 206, 225, 245, 61 267, 292, 318, 348, 379, 414, 452, 493, 62 538, 587, 640, 699, 763, 832, 908, 991, 63 1081, 1180, 1288, 1405, 1534, 1673, 1826, 1993, 64 2175, 2373, 2590, 2826, 3084, 3365, 3672, 4008, 65 4373, 4772, 5208, 5683, 6202, 6767, 7385, 8059, 66 8794, 9597, 10472, 11428, 12471, 13609, 14851, 16206, 67 17685, 19298, 21060, 22981, 25078, 27367, 29864, 32589, 68 -29973, -26728, -23186, -19322, -15105, -10503, -5481, -1, 69 1, 1, 5481, 10503, 15105, 19322, 23186, 26728, 70 29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298, 71 -17685, -16206, -14851, -13609, -12471, -11428, -10472, -9597, 72 -8794, -8059, -7385, -6767, -6202, -5683, -5208, -4772, 73 -4373, -4008, -3672, -3365, -3084, -2826, -2590, -2373, 74 -2175, -1993, -1826, -1673, -1534, -1405, -1288, -1180, 75 -1081, -991, -908, -832, -763, -699, -640, -587, 76 -538, -493, -452, -414, -379, -348, -318, -292, 77 -267, -245, -225, -206, -189, -173, -158, -145, 78 -133, -122, -112, -102, -94, -86, -79, -72, 79 -66, -61, -56, -51, -47, -43, -42, -41, 80 -40, -39, -38, -37, -36, -35, -34, -33, 81 -32, -31, -30, -29, -28, -27, -26, -25, 82 -24, -23, -22, -21, -20, -19, -18, -17, 83 -16, -15, -14, -13, -12, -11, -10, -9, 84 -8, -7, -6, -5, -4, -3, -2, -1 85 86}; 87 88static const int8_t sol_table_old[16] = { 89 0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15, 90 -0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1, 0x0 91}; 92 93static const int8_t sol_table_new[16] = { 94 0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15, 95 0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15 96}; 97 98static const int16_t sol_table_16[128] = { 99 0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080, 100 0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120, 101 0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0, 102 0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230, 103 0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280, 104 0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0, 105 0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320, 106 0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370, 107 0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0, 108 0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480, 109 0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700, 110 0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00, 111 0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000 112}; 113 114 115static av_cold int dpcm_decode_init(AVCodecContext *avctx) 116{ 117 DPCMContext *s = avctx->priv_data; 118 int i; 119 120 if (avctx->channels < 1 || avctx->channels > 2) { 121 av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n"); 122 return AVERROR(EINVAL); 123 } 124 125 s->sample[0] = s->sample[1] = 0; 126 127 switch(avctx->codec->id) { 128 129 case AV_CODEC_ID_ROQ_DPCM: 130 /* initialize square table */ 131 for (i = 0; i < 128; i++) { 132 int16_t square = i * i; 133 s->roq_square_array[i ] = square; 134 s->roq_square_array[i + 128] = -square; 135 } 136 break; 137 138 case AV_CODEC_ID_SOL_DPCM: 139 switch(avctx->codec_tag){ 140 case 1: 141 s->sol_table = sol_table_old; 142 s->sample[0] = s->sample[1] = 0x80; 143 break; 144 case 2: 145 s->sol_table = sol_table_new; 146 s->sample[0] = s->sample[1] = 0x80; 147 break; 148 case 3: 149 break; 150 default: 151 av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n"); 152 return -1; 153 } 154 break; 155 156 default: 157 break; 158 } 159 160 if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3) 161 avctx->sample_fmt = AV_SAMPLE_FMT_U8; 162 else 163 avctx->sample_fmt = AV_SAMPLE_FMT_S16; 164 165 return 0; 166} 167 168 169static int dpcm_decode_frame(AVCodecContext *avctx, void *data, 170 int *got_frame_ptr, AVPacket *avpkt) 171{ 172 int buf_size = avpkt->size; 173 DPCMContext *s = avctx->priv_data; 174 AVFrame *frame = data; 175 int out = 0, ret; 176 int predictor[2]; 177 int ch = 0; 178 int stereo = avctx->channels - 1; 179 int16_t *output_samples, *samples_end; 180 GetByteContext gb; 181 182 if (stereo && (buf_size & 1)) 183 buf_size--; 184 bytestream2_init(&gb, avpkt->data, buf_size); 185 186 /* calculate output size */ 187 switch(avctx->codec->id) { 188 case AV_CODEC_ID_ROQ_DPCM: 189 out = buf_size - 8; 190 break; 191 case AV_CODEC_ID_INTERPLAY_DPCM: 192 out = buf_size - 6 - avctx->channels; 193 break; 194 case AV_CODEC_ID_XAN_DPCM: 195 out = buf_size - 2 * avctx->channels; 196 break; 197 case AV_CODEC_ID_SOL_DPCM: 198 if (avctx->codec_tag != 3) 199 out = buf_size * 2; 200 else 201 out = buf_size; 202 break; 203 } 204 if (out <= 0) { 205 av_log(avctx, AV_LOG_ERROR, "packet is too small\n"); 206 return AVERROR(EINVAL); 207 } 208 if (out % avctx->channels) { 209 av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n"); 210 } 211 212 /* get output buffer */ 213 frame->nb_samples = (out + avctx->channels - 1) / avctx->channels; 214 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 215 return ret; 216 output_samples = (int16_t *)frame->data[0]; 217 samples_end = output_samples + out; 218 219 switch(avctx->codec->id) { 220 221 case AV_CODEC_ID_ROQ_DPCM: 222 bytestream2_skipu(&gb, 6); 223 224 if (stereo) { 225 predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16); 226 predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16); 227 } else { 228 predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16); 229 } 230 231 /* decode the samples */ 232 while (output_samples < samples_end) { 233 predictor[ch] += s->roq_square_array[bytestream2_get_byteu(&gb)]; 234 predictor[ch] = av_clip_int16(predictor[ch]); 235 *output_samples++ = predictor[ch]; 236 237 /* toggle channel */ 238 ch ^= stereo; 239 } 240 break; 241 242 case AV_CODEC_ID_INTERPLAY_DPCM: 243 bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */ 244 245 for (ch = 0; ch < avctx->channels; ch++) { 246 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16); 247 *output_samples++ = predictor[ch]; 248 } 249 250 ch = 0; 251 while (output_samples < samples_end) { 252 predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)]; 253 predictor[ch] = av_clip_int16(predictor[ch]); 254 *output_samples++ = predictor[ch]; 255 256 /* toggle channel */ 257 ch ^= stereo; 258 } 259 break; 260 261 case AV_CODEC_ID_XAN_DPCM: 262 { 263 int shift[2] = { 4, 4 }; 264 265 for (ch = 0; ch < avctx->channels; ch++) 266 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16); 267 268 ch = 0; 269 while (output_samples < samples_end) { 270 int diff = bytestream2_get_byteu(&gb); 271 int n = diff & 3; 272 273 if (n == 3) 274 shift[ch]++; 275 else 276 shift[ch] -= (2 * n); 277 diff = sign_extend((diff &~ 3) << 8, 16); 278 279 /* saturate the shifter to a lower limit of 0 */ 280 if (shift[ch] < 0) 281 shift[ch] = 0; 282 283 diff >>= shift[ch]; 284 predictor[ch] += diff; 285 286 predictor[ch] = av_clip_int16(predictor[ch]); 287 *output_samples++ = predictor[ch]; 288 289 /* toggle channel */ 290 ch ^= stereo; 291 } 292 break; 293 } 294 case AV_CODEC_ID_SOL_DPCM: 295 if (avctx->codec_tag != 3) { 296 uint8_t *output_samples_u8 = frame->data[0], 297 *samples_end_u8 = output_samples_u8 + out; 298 while (output_samples_u8 < samples_end_u8) { 299 int n = bytestream2_get_byteu(&gb); 300 301 s->sample[0] += s->sol_table[n >> 4]; 302 s->sample[0] = av_clip_uint8(s->sample[0]); 303 *output_samples_u8++ = s->sample[0]; 304 305 s->sample[stereo] += s->sol_table[n & 0x0F]; 306 s->sample[stereo] = av_clip_uint8(s->sample[stereo]); 307 *output_samples_u8++ = s->sample[stereo]; 308 } 309 } else { 310 while (output_samples < samples_end) { 311 int n = bytestream2_get_byteu(&gb); 312 if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F]; 313 else s->sample[ch] += sol_table_16[n & 0x7F]; 314 s->sample[ch] = av_clip_int16(s->sample[ch]); 315 *output_samples++ = s->sample[ch]; 316 /* toggle channel */ 317 ch ^= stereo; 318 } 319 } 320 break; 321 } 322 323 *got_frame_ptr = 1; 324 325 return avpkt->size; 326} 327 328#define DPCM_DECODER(id_, name_, long_name_) \ 329AVCodec ff_ ## name_ ## _decoder = { \ 330 .name = #name_, \ 331 .long_name = NULL_IF_CONFIG_SMALL(long_name_), \ 332 .type = AVMEDIA_TYPE_AUDIO, \ 333 .id = id_, \ 334 .priv_data_size = sizeof(DPCMContext), \ 335 .init = dpcm_decode_init, \ 336 .decode = dpcm_decode_frame, \ 337 .capabilities = CODEC_CAP_DR1, \ 338} 339 340DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay"); 341DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ"); 342DPCM_DECODER(AV_CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol"); 343DPCM_DECODER(AV_CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan"); 344