FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/dpcm.c
Date: 2021-09-24 20:55:06
Exec Total Coverage
Lines: 105 184 57.1%
Branches: 43 83 51.8%

Line Branch Exec Source
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
130 14 static av_cold int dpcm_decode_init(AVCodecContext *avctx)
131 {
132 14 DPCMContext *s = avctx->priv_data;
133 int i;
134
135
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14 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 14 s->sample[0] = s->sample[1] = 0;
141
142
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14 switch(avctx->codec->id) {
143
144 5 case AV_CODEC_ID_ROQ_DPCM:
145 /* initialize square table */
146
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645 for (i = 0; i < 128; i++) {
147 640 int16_t square = i * i;
148 640 s->array[i ] = square;
149 640 s->array[i + 128] = -square;
150 }
151 5 break;
152
153 2 case AV_CODEC_ID_SOL_DPCM:
154
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2 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 2 case 3:
164 2 break;
165 default:
166 av_log(avctx, AV_LOG_ERROR, "Unknown SOL subcodec\n");
167 return -1;
168 }
169 2 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 7 default:
197 7 break;
198 }
199
200
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14 if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3)
201 avctx->sample_fmt = AV_SAMPLE_FMT_U8;
202 else
203 14 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
204
205 14 return 0;
206 }
207
208
209 649 static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
210 int *got_frame_ptr, AVPacket *avpkt)
211 {
212 649 int buf_size = avpkt->size;
213 649 DPCMContext *s = avctx->priv_data;
214 649 AVFrame *frame = data;
215 649 int out = 0, ret;
216 int predictor[2];
217 649 int ch = 0;
218 649 int stereo = avctx->channels - 1;
219 int16_t *output_samples, *samples_end;
220 GetByteContext gb;
221
222
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649 if (stereo && (buf_size & 1))
223 buf_size--;
224 649 bytestream2_init(&gb, avpkt->data, buf_size);
225
226 /* calculate output size */
227
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649 switch(avctx->codec->id) {
228 340 case AV_CODEC_ID_ROQ_DPCM:
229 340 out = buf_size - 8;
230 340 break;
231 124 case AV_CODEC_ID_INTERPLAY_DPCM:
232 124 out = buf_size - 6 - avctx->channels;
233 124 break;
234 111 case AV_CODEC_ID_XAN_DPCM:
235 111 out = buf_size - 2 * avctx->channels;
236 111 break;
237 74 case AV_CODEC_ID_SOL_DPCM:
238
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74 if (avctx->codec_tag != 3)
239 out = buf_size * 2;
240 else
241 74 out = buf_size;
242 74 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
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649 if (out <= 0) {
250 av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
251 return AVERROR(EINVAL);
252 }
253
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649 if (out % avctx->channels) {
254 av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n");
255 }
256
257 /* get output buffer */
258 649 frame->nb_samples = (out + avctx->channels - 1) / avctx->channels;
259
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649 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
260 return ret;
261 649 output_samples = (int16_t *)frame->data[0];
262 649 samples_end = output_samples + out;
263
264
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649 switch(avctx->codec->id) {
265
266 340 case AV_CODEC_ID_ROQ_DPCM:
267 340 bytestream2_skipu(&gb, 6);
268
269
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340 if (stereo) {
270 340 predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
271 340 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
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523240 while (output_samples < samples_end) {
278 522900 predictor[ch] += s->array[bytestream2_get_byteu(&gb)];
279 522900 predictor[ch] = av_clip_int16(predictor[ch]);
280 522900 *output_samples++ = predictor[ch];
281
282 /* toggle channel */
283 522900 ch ^= stereo;
284 }
285 340 break;
286
287 124 case AV_CODEC_ID_INTERPLAY_DPCM:
288 124 bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */
289
290
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372 for (ch = 0; ch < avctx->channels; ch++) {
291 248 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
292 248 *output_samples++ = predictor[ch];
293 }
294
295 124 ch = 0;
296
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364752 while (output_samples < samples_end) {
297 364628 predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
298 364628 predictor[ch] = av_clip_int16(predictor[ch]);
299 364628 *output_samples++ = predictor[ch];
300
301 /* toggle channel */
302 364628 ch ^= stereo;
303 }
304 124 break;
305
306 111 case AV_CODEC_ID_XAN_DPCM:
307 {
308 111 int shift[2] = { 4, 4 };
309
310
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333 for (ch = 0; ch < avctx->channels; ch++)
311 222 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
312
313 111 ch = 0;
314
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326229 while (output_samples < samples_end) {
315 326118 int diff = bytestream2_get_byteu(&gb);
316 326118 int n = diff & 3;
317
318
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326118 if (n == 3)
319 134940 shift[ch]++;
320 else
321 191178 shift[ch] -= (2 * n);
322 326118 diff = sign_extend((diff &~ 3) << 8, 16);
323
324 /* saturate the shifter to 0..31 */
325 326118 shift[ch] = av_clip_uintp2(shift[ch], 5);
326
327 326118 diff >>= shift[ch];
328 326118 predictor[ch] += diff;
329
330 326118 predictor[ch] = av_clip_int16(predictor[ch]);
331 326118 *output_samples++ = predictor[ch];
332
333 /* toggle channel */
334 326118 ch ^= stereo;
335 }
336 111 break;
337 }
338 74 case AV_CODEC_ID_SOL_DPCM:
339
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74 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
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299512 while (output_samples < samples_end) {
355 299438 int n = bytestream2_get_byteu(&gb);
356
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299438 if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
357 150564 else s->sample[ch] += sol_table_16[n & 0x7F];
358 299438 s->sample[ch] = av_clip_int16(s->sample[ch]);
359 299438 *output_samples++ = s->sample[ch];
360 /* toggle channel */
361 299438 ch ^= stereo;
362 }
363 }
364 74 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
407 649 *got_frame_ptr = 1;
408
409 649 return avpkt->size;
410 }
411
412 #define DPCM_DECODER(id_, name_, long_name_) \
413 const 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 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, \
423 }
424
425 DPCM_DECODER(AV_CODEC_ID_DERF_DPCM, derf_dpcm, "DPCM Xilam DERF");
426 DPCM_DECODER(AV_CODEC_ID_GREMLIN_DPCM, gremlin_dpcm, "DPCM Gremlin");
427 DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
428 DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
429 DPCM_DECODER(AV_CODEC_ID_SDX2_DPCM, sdx2_dpcm, "DPCM Squareroot-Delta-Exact");
430 DPCM_DECODER(AV_CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
431 DPCM_DECODER(AV_CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");
432