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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 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->square_array[i ] = square;
134 s->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 case AV_CODEC_ID_SDX2_DPCM:
157 for (i = -128; i < 128; i++) {
158 int16_t square = i * i * 2;
159 s->square_array[i+128] = i < 0 ? -square: square;
160 }
161 break;
162
163 default:
164 break;
165 }
166
167 if (avctx->codec->id == AV_CODEC_ID_SOL_DPCM && avctx->codec_tag != 3)
168 avctx->sample_fmt = AV_SAMPLE_FMT_U8;
169 else
170 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
171
172 return 0;
173}
174
175
176static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
177 int *got_frame_ptr, AVPacket *avpkt)
178{
179 int buf_size = avpkt->size;
180 DPCMContext *s = avctx->priv_data;
181 AVFrame *frame = data;
182 int out = 0, ret;
183 int predictor[2];
184 int ch = 0;
185 int stereo = avctx->channels - 1;
186 int16_t *output_samples, *samples_end;
187 GetByteContext gb;
188
189 if (stereo && (buf_size & 1))
190 buf_size--;
191 bytestream2_init(&gb, avpkt->data, buf_size);
192
193 /* calculate output size */
194 switch(avctx->codec->id) {
195 case AV_CODEC_ID_ROQ_DPCM:
196 out = buf_size - 8;
197 break;
198 case AV_CODEC_ID_INTERPLAY_DPCM:
199 out = buf_size - 6 - avctx->channels;
200 break;
201 case AV_CODEC_ID_XAN_DPCM:
202 out = buf_size - 2 * avctx->channels;
203 break;
204 case AV_CODEC_ID_SOL_DPCM:
205 if (avctx->codec_tag != 3)
206 out = buf_size * 2;
207 else
208 out = buf_size;
209 break;
210 case AV_CODEC_ID_SDX2_DPCM:
211 out = buf_size;
212 break;
213 }
214 if (out <= 0) {
215 av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
216 return AVERROR(EINVAL);
217 }
218 if (out % avctx->channels) {
219 av_log(avctx, AV_LOG_WARNING, "channels have differing number of samples\n");
220 }
221
222 /* get output buffer */
223 frame->nb_samples = (out + avctx->channels - 1) / avctx->channels;
224 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
225 return ret;
226 output_samples = (int16_t *)frame->data[0];
227 samples_end = output_samples + out;
228
229 switch(avctx->codec->id) {
230
231 case AV_CODEC_ID_ROQ_DPCM:
232 bytestream2_skipu(&gb, 6);
233
234 if (stereo) {
235 predictor[1] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
236 predictor[0] = sign_extend(bytestream2_get_byteu(&gb) << 8, 16);
237 } else {
238 predictor[0] = sign_extend(bytestream2_get_le16u(&gb), 16);
239 }
240
241 /* decode the samples */
242 while (output_samples < samples_end) {
243 predictor[ch] += s->square_array[bytestream2_get_byteu(&gb)];
244 predictor[ch] = av_clip_int16(predictor[ch]);
245 *output_samples++ = predictor[ch];
246
247 /* toggle channel */
248 ch ^= stereo;
249 }
250 break;
251
252 case AV_CODEC_ID_INTERPLAY_DPCM:
253 bytestream2_skipu(&gb, 6); /* skip over the stream mask and stream length */
254
255 for (ch = 0; ch < avctx->channels; ch++) {
256 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
257 *output_samples++ = predictor[ch];
258 }
259
260 ch = 0;
261 while (output_samples < samples_end) {
262 predictor[ch] += interplay_delta_table[bytestream2_get_byteu(&gb)];
263 predictor[ch] = av_clip_int16(predictor[ch]);
264 *output_samples++ = predictor[ch];
265
266 /* toggle channel */
267 ch ^= stereo;
268 }
269 break;
270
271 case AV_CODEC_ID_XAN_DPCM:
272 {
273 int shift[2] = { 4, 4 };
274
275 for (ch = 0; ch < avctx->channels; ch++)
276 predictor[ch] = sign_extend(bytestream2_get_le16u(&gb), 16);
277
278 ch = 0;
279 while (output_samples < samples_end) {
280 int diff = bytestream2_get_byteu(&gb);
281 int n = diff & 3;
282
283 if (n == 3)
284 shift[ch]++;
285 else
286 shift[ch] -= (2 * n);
287 diff = sign_extend((diff &~ 3) << 8, 16);
288
289 /* saturate the shifter to a lower limit of 0 */
290 if (shift[ch] < 0)
291 shift[ch] = 0;
292
293 diff >>= shift[ch];
294 predictor[ch] += diff;
295
296 predictor[ch] = av_clip_int16(predictor[ch]);
297 *output_samples++ = predictor[ch];
298
299 /* toggle channel */
300 ch ^= stereo;
301 }
302 break;
303 }
304 case AV_CODEC_ID_SOL_DPCM:
305 if (avctx->codec_tag != 3) {
306 uint8_t *output_samples_u8 = frame->data[0],
307 *samples_end_u8 = output_samples_u8 + out;
308 while (output_samples_u8 < samples_end_u8) {
309 int n = bytestream2_get_byteu(&gb);
310
311 s->sample[0] += s->sol_table[n >> 4];
312 s->sample[0] = av_clip_uint8(s->sample[0]);
313 *output_samples_u8++ = s->sample[0];
314
315 s->sample[stereo] += s->sol_table[n & 0x0F];
316 s->sample[stereo] = av_clip_uint8(s->sample[stereo]);
317 *output_samples_u8++ = s->sample[stereo];
318 }
319 } else {
320 while (output_samples < samples_end) {
321 int n = bytestream2_get_byteu(&gb);
322 if (n & 0x80) s->sample[ch] -= sol_table_16[n & 0x7F];
323 else s->sample[ch] += sol_table_16[n & 0x7F];
324 s->sample[ch] = av_clip_int16(s->sample[ch]);
325 *output_samples++ = s->sample[ch];
326 /* toggle channel */
327 ch ^= stereo;
328 }
329 }
330 break;
331
332 case AV_CODEC_ID_SDX2_DPCM:
333 while (output_samples < samples_end) {
334 int8_t n = bytestream2_get_byteu(&gb);
335
336 if (!(n & 1))
337 s->sample[ch] = 0;
338 s->sample[ch] += s->square_array[n + 128];
339 s->sample[ch] = av_clip_int16(s->sample[ch]);
340 *output_samples++ = s->sample[ch];
341 ch ^= stereo;
342 }
343 break;
344 }
345
346 *got_frame_ptr = 1;
347
348 return avpkt->size;
349}
350
351#define DPCM_DECODER(id_, name_, long_name_) \
352AVCodec ff_ ## name_ ## _decoder = { \
353 .name = #name_, \
354 .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
355 .type = AVMEDIA_TYPE_AUDIO, \
356 .id = id_, \
357 .priv_data_size = sizeof(DPCMContext), \
358 .init = dpcm_decode_init, \
359 .decode = dpcm_decode_frame, \
360 .capabilities = AV_CODEC_CAP_DR1, \
361}
362
363DPCM_DECODER(AV_CODEC_ID_INTERPLAY_DPCM, interplay_dpcm, "DPCM Interplay");
364DPCM_DECODER(AV_CODEC_ID_ROQ_DPCM, roq_dpcm, "DPCM id RoQ");
365DPCM_DECODER(AV_CODEC_ID_SDX2_DPCM, sdx2_dpcm, "DPCM Squareroot-Delta-Exact");
366DPCM_DECODER(AV_CODEC_ID_SOL_DPCM, sol_dpcm, "DPCM Sol");
367DPCM_DECODER(AV_CODEC_ID_XAN_DPCM, xan_dpcm, "DPCM Xan");
368
generated by cgit at 2024-05-18 01:38:18 (GMT)