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
46 typedef struct DPCMContext {
47 int16_t 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
52 static const int32_t derf_steps[96] = {
53 0, 1, 2, 3, 4, 5, 6, 7,
54 8, 9, 10, 11, 12, 13, 14, 16,
55 17, 19, 21, 23, 25, 28, 31, 34,
56 37, 41, 45, 50, 55, 60, 66, 73,
57 80, 88, 97, 107, 118, 130, 143, 157,
58 173, 190, 209, 230, 253, 279, 307, 337,
59 371, 408, 449, 494, 544, 598, 658, 724,
60 796, 876, 963, 1060, 1166, 1282, 1411, 1552,
61 1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327,
62 3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132,
63 7845, 8630, 9493, 10442, 11487, 12635, 13899, 15289,
64 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767,
65 };
66
67 static const int16_t interplay_delta_table[] = {
68 0, 1, 2, 3, 4, 5, 6, 7,
69 8, 9, 10, 11, 12, 13, 14, 15,
70 16, 17, 18, 19, 20, 21, 22, 23,
71 24, 25, 26, 27, 28, 29, 30, 31,
72 32, 33, 34, 35, 36, 37, 38, 39,
73 40, 41, 42, 43, 47, 51, 56, 61,
74 66, 72, 79, 86, 94, 102, 112, 122,
75 133, 145, 158, 173, 189, 206, 225, 245,
76 267, 292, 318, 348, 379, 414, 452, 493,
77 538, 587, 640, 699, 763, 832, 908, 991,
78 1081, 1180, 1288, 1405, 1534, 1673, 1826, 1993,
79 2175, 2373, 2590, 2826, 3084, 3365, 3672, 4008,
80 4373, 4772, 5208, 5683, 6202, 6767, 7385, 8059,
81 8794, 9597, 10472, 11428, 12471, 13609, 14851, 16206,
82 17685, 19298, 21060, 22981, 25078, 27367, 29864, 32589,
83 -29973, -26728, -23186, -19322, -15105, -10503, -5481, -1,
84 1, 1, 5481, 10503, 15105, 19322, 23186, 26728,
85 29973, -32589, -29864, -27367, -25078, -22981, -21060, -19298,
86 -17685, -16206, -14851, -13609, -12471, -11428, -10472, -9597,
87 -8794, -8059, -7385, -6767, -6202, -5683, -5208, -4772,
88 -4373, -4008, -3672, -3365, -3084, -2826, -2590, -2373,
89 -2175, -1993, -1826, -1673, -1534, -1405, -1288, -1180,
90 -1081, -991, -908, -832, -763, -699, -640, -587,
91 -538, -493, -452, -414, -379, -348, -318, -292,
92 -267, -245, -225, -206, -189, -173, -158, -145,
93 -133, -122, -112, -102, -94, -86, -79, -72,
94 -66, -61, -56, -51, -47, -43, -42, -41,
95 -40, -39, -38, -37, -36, -35, -34, -33,
96 -32, -31, -30, -29, -28, -27, -26, -25,
97 -24, -23, -22, -21, -20, -19, -18, -17,
98 -16, -15, -14, -13, -12, -11, -10, -9,
99 -8, -7, -6, -5, -4, -3, -2, -1
100
101 };
102
103 static const int8_t sol_table_old[16] = {
104 0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15,
105 -0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1, 0x0
106 };
107
108 static const int8_t sol_table_new[16] = {
109 0x0, 0x1, 0x2, 0x3, 0x6, 0xA, 0xF, 0x15,
110 0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15
111 };
112
113 static const int16_t sol_table_16[128] = {
114 0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
115 0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
116 0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
117 0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
118 0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
119 0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
120 0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
121 0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
122 0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
123 0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
124 0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
125 0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
126 0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
127 };
128
129
dpcm_decode_init(AVCodecContext * avctx)130 static av_cold int dpcm_decode_init(AVCodecContext *avctx)
131 {
132 DPCMContext *s = avctx->priv_data;
133 int i;
134
135 if (avctx->channels < 1 || avctx->channels > 2) {
136 av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
137 return AVERROR(EINVAL);
138 }
139
140 s->sample[0] = s->sample[1] = 0;
141
142 switch(avctx->codec->id) {
143
144 case AV_CODEC_ID_ROQ_DPCM:
145 /* initialize square table */
146 for (i = 0; i < 128; i++) {
147 int16_t square = i * i;
148 s->array[i ] = square;
149 s->array[i + 128] = -square;
150 }
151 break;
152
153 case AV_CODEC_ID_SOL_DPCM:
154 switch(avctx->codec_tag){
155 case 1:
156 s->sol_table = sol_table_old;
157 s->sample[0] = s->sample[1] = 0x80;
158 break;
159 case 2:
160 s->sol_table = sol_table_new;
161 s->sample[0] = s->sample[1] = 0x80;
162 break;
163 case 3:
164 break;
165 default:
166 av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n");
167 return -1;
168 }
169 break;
170
171 case AV_CODEC_ID_SDX2_DPCM:
172 for (i = -128; i < 128; i++) {
173 int16_t square = i * i * 2;
174 s->array[i+128] = i < 0 ? -square: square;
175 }
176 break;
177
178 case AV_CODEC_ID_GREMLIN_DPCM: {
179 int delta = 0;
180 int code = 64;
181 int step = 45;
182
183 s->array[0] = 0;
184 for (i = 0; i < 127; i++) {
185 delta += (code >> 5);
186 code += step;
187 step += 2;
188
189 s->array[i*2 + 1] = delta;
190 s->array[i*2 + 2] = -delta;
191 }
192 s->array[255] = delta + (code >> 5);
193 }
194 break;
195
196 default:
197 break;
198 }
199
200 if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3)
201 avctx->sample_fmt = AV_SAMPLE_FMT_U8;
202 else
203 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
204
205 return 0;
206 }
207
208
dpcm_decode_frame(AVCodecContext * avctx,void * data,int * got_frame_ptr,AVPacket * avpkt)209 static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
210 int *got_frame_ptr, AVPacket *avpkt)
211 {
212 int buf_size = avpkt->size;
213 DPCMContext *s = avctx->priv_data;
214 AVFrame *frame = data;
215 int out = 0, ret;
216 int predictor[2];
217 int ch = 0;
218 int stereo = avctx->channels - 1;
219 int16_t *output_samples, *samples_end;
220 GetByteContext gb;
221
222 if (stereo && (buf_size & 1))
223 buf_size--;
224 bytestream2_init(&gb, avpkt->data, buf_size);
225
226 /* calculate output size */
227 switch(avctx->codec->id) {
228 case AV_CODEC_ID_ROQ_DPCM:
229 out = buf_size - 8;
230 break;
231 case AV_CODEC_ID_INTERPLAY_DPCM:
232 out = buf_size - 6 - avctx->channels;
233 break;
234 case AV_CODEC_ID_XAN_DPCM:
235 out = buf_size - 2 * avctx->channels;
236 break;
237 case AV_CODEC_ID_SOL_DPCM:
238 if (avctx->codec_tag != 3)
239 out = buf_size * 2;
240 else
241 out = buf_size;
242 break;
243 case AV_CODEC_ID_DERF_DPCM:
244 case AV_CODEC_ID_GREMLIN_DPCM:
245 case AV_CODEC_ID_SDX2_DPCM:
246 out = buf_size;
247 break;
248 }
249 if (out <= 0) {
250 av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
251 return AVERROR(EINVAL);
252 }
253 if (out % avctx->channels) {
254 av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n");
255 }
256
257 /* get output buffer */
258 frame->nb_samples = (out + avctx->channels - 1) / avctx->channels;
259 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
260 return ret;
261 output_samples = (int16_t *)frame->data[0];
262 samples_end = output_samples + out;
263
264 switch(avctx->codec->id) {
265
266 case AV_CODEC_ID_ROQ_DPCM:
267 bytestream2_skipu(&gb, 6);
268
269 if (stereo) {
270 predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
271 predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
272 } else {
273 predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
274 }
275
276 /* decode the samples */
277 while (output_samples < samples_end) {
278 predictor[ch] += s->array[bytestream2_get_byteu(&gb)];
279 predictor[ch] = av_clip_int16(predictor[ch]);
280 *output_samples++ = predictor[ch];
281
282 /* toggle channel */
283 ch ^= stereo;
284 }
285 break;
286
287 case AV_CODEC_ID_INTERPLAY_DPCM:
288 bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */
289
290 for (ch = 0; ch < avctx->channels; ch++) {
291 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
292 *output_samples++ = predictor[ch];
293 }
294
295 ch = 0;
296 while (output_samples < samples_end) {
297 predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
298 predictor[ch] = av_clip_int16(predictor[ch]);
299 *output_samples++ = predictor[ch];
300
301 /* toggle channel */
302 ch ^= stereo;
303 }
304 break;
305
306 case AV_CODEC_ID_XAN_DPCM:
307 {
308 int shift[2] = { 4, 4 };
309
310 for (ch = 0; ch < avctx->channels; ch++)
311 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
312
313 ch = 0;
314 while (output_samples < samples_end) {
315 int diff = bytestream2_get_byteu(&gb);
316 int n = diff & 3;
317
318 if (n == 3)
319 shift[ch]++;
320 else
321 shift[ch] -= (2 * n);
322 diff = sign_extend((diff &~ 3) << 8, 16);
323
324 /* saturate the shifter to 0..31 */
325 shift[ch] = av_clip_uintp2(shift[ch], 5);
326
327 diff >>= shift[ch];
328 predictor[ch] += diff;
329
330 predictor[ch] = av_clip_int16(predictor[ch]);
331 *output_samples++ = predictor[ch];
332
333 /* toggle channel */
334 ch ^= stereo;
335 }
336 break;
337 }
338 case AV_CODEC_ID_SOL_DPCM:
339 if (avctx->codec_tag != 3) {
340 uint8_t *output_samples_u8 = frame->data[0],
341 *samples_end_u8 = output_samples_u8 + out;
342 while (output_samples_u8 < samples_end_u8) {
343 int n = bytestream2_get_byteu(&gb);
344
345 s->sample[0] += s->sol_table[n >> 4];
346 s->sample[0] = av_clip_uint8(s->sample[0]);
347 *output_samples_u8++ = s->sample[0];
348
349 s->sample[stereo] += s->sol_table[n & 0x0F];
350 s->sample[stereo] = av_clip_uint8(s->sample[stereo]);
351 *output_samples_u8++ = s->sample[stereo];
352 }
353 } else {
354 while (output_samples < samples_end) {
355 int n = bytestream2_get_byteu(&gb);
356 if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
357 else s->sample[ch] += sol_table_16[n & 0x7F];
358 s->sample[ch] = av_clip_int16(s->sample[ch]);
359 *output_samples++ = s->sample[ch];
360 /* toggle channel */
361 ch ^= stereo;
362 }
363 }
364 break;
365
366 case AV_CODEC_ID_SDX2_DPCM:
367 while (output_samples < samples_end) {
368 int8_t n = bytestream2_get_byteu(&gb);
369
370 if (!(n & 1))
371 s->sample[ch] = 0;
372 s->sample[ch] += s->array[n + 128];
373 s->sample[ch] = av_clip_int16(s->sample[ch]);
374 *output_samples++ = s->sample[ch];
375 ch ^= stereo;
376 }
377 break;
378
379 case AV_CODEC_ID_GREMLIN_DPCM: {
380 int idx = 0;
381
382 while (output_samples < samples_end) {
383 uint8_t n = bytestream2_get_byteu(&gb);
384
385 *output_samples++ = s->sample[idx] += (unsigned)s->array[n];
386 idx ^= 1;
387 }
388 }
389 break;
390
391 case AV_CODEC_ID_DERF_DPCM: {
392 int idx = 0;
393
394 while (output_samples < samples_end) {
395 uint8_t n = bytestream2_get_byteu(&gb);
396 int index = FFMIN(n & 0x7f, 95);
397
398 s->sample[idx] += (n & 0x80 ? -1: 1) * derf_steps[index];
399 s->sample[idx] = av_clip_int16(s->sample[idx]);
400 *output_samples++ = s->sample[idx];
401 idx ^= stereo;
402 }
403 }
404 break;
405 }
406
407 *got_frame_ptr = 1;
408
409 return avpkt->size;
410 }
411
412 #define DPCM_DECODER(id_, name_, long_name_) \
413 AVCodec ff_ ## name_ ## _decoder = { \
414 .name = #name_, \
415 .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
416 .type = AVMEDIA_TYPE_AUDIO, \
417 .id = id_, \
418 .priv_data_size = sizeof(DPCMContext), \
419 .init = dpcm_decode_init, \
420 .decode = dpcm_decode_frame, \
421 .capabilities = AV_CODEC_CAP_DR1, \
422 }
423
424 DPCM_DECODER(AV_CODEC_ID_DERF_DPCM, derf_dpcm, "DPCM Xilam DERF");
425 DPCM_DECODER(AV_CODEC_ID_GREMLIN_DPCM, gremlin_dpcm, "DPCM Gremlin");
426 DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
427 DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
428 DPCM_DECODER(AV_CODEC_ID_SDX2_DPCM, sdx2_dpcm, "DPCM Squareroot-Delta-Exact");
429 DPCM_DECODER(AV_CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
430 DPCM_DECODER(AV_CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");
431