Libav
tta.c
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1 /*
2  * TTA (The Lossless True Audio) decoder
3  * Copyright (c) 2006 Alex Beregszaszi
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
30 #define BITSTREAM_READER_LE
31 #include <limits.h>
32 #include "avcodec.h"
33 #include "get_bits.h"
34 #include "internal.h"
35 #include "libavutil/crc.h"
36 
37 #define FORMAT_SIMPLE 1
38 #define FORMAT_ENCRYPTED 2
39 
40 #define MAX_ORDER 16
41 typedef struct TTAFilter {
46 } TTAFilter;
47 
48 typedef struct TTARice {
49  uint32_t k0, k1, sum0, sum1;
50 } TTARice;
51 
52 typedef struct TTAChannel {
56 } TTAChannel;
57 
58 typedef struct TTAContext {
61  const AVCRC *crc_table;
62 
64  unsigned data_length;
66 
68 
70 } TTAContext;
71 
72 static const uint32_t shift_1[] = {
73  0x00000001, 0x00000002, 0x00000004, 0x00000008,
74  0x00000010, 0x00000020, 0x00000040, 0x00000080,
75  0x00000100, 0x00000200, 0x00000400, 0x00000800,
76  0x00001000, 0x00002000, 0x00004000, 0x00008000,
77  0x00010000, 0x00020000, 0x00040000, 0x00080000,
78  0x00100000, 0x00200000, 0x00400000, 0x00800000,
79  0x01000000, 0x02000000, 0x04000000, 0x08000000,
80  0x10000000, 0x20000000, 0x40000000, 0x80000000,
81  0x80000000, 0x80000000, 0x80000000, 0x80000000,
82  0x80000000, 0x80000000, 0x80000000, 0x80000000
83 };
84 
85 static const uint32_t * const shift_16 = shift_1 + 4;
86 
87 static const int32_t ttafilter_configs[4] = {
88  10,
89  9,
90  10,
91  12
92 };
93 
94 static void ttafilter_init(TTAFilter *c, int32_t shift) {
95  memset(c, 0, sizeof(TTAFilter));
96  c->shift = shift;
97  c->round = shift_1[shift-1];
98 // c->round = 1 << (shift - 1);
99 }
100 
101 // FIXME: copy paste from original
102 static inline void memshl(register int32_t *a, register int32_t *b) {
103  *a++ = *b++;
104  *a++ = *b++;
105  *a++ = *b++;
106  *a++ = *b++;
107  *a++ = *b++;
108  *a++ = *b++;
109  *a++ = *b++;
110  *a = *b;
111 }
112 
113 static inline void ttafilter_process(TTAFilter *c, int32_t *in)
114 {
115  register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round;
116 
117  if (!c->error) {
118  sum += *dl++ * *qm, qm++;
119  sum += *dl++ * *qm, qm++;
120  sum += *dl++ * *qm, qm++;
121  sum += *dl++ * *qm, qm++;
122  sum += *dl++ * *qm, qm++;
123  sum += *dl++ * *qm, qm++;
124  sum += *dl++ * *qm, qm++;
125  sum += *dl++ * *qm, qm++;
126  dx += 8;
127  } else if(c->error < 0) {
128  sum += *dl++ * (*qm -= *dx++), qm++;
129  sum += *dl++ * (*qm -= *dx++), qm++;
130  sum += *dl++ * (*qm -= *dx++), qm++;
131  sum += *dl++ * (*qm -= *dx++), qm++;
132  sum += *dl++ * (*qm -= *dx++), qm++;
133  sum += *dl++ * (*qm -= *dx++), qm++;
134  sum += *dl++ * (*qm -= *dx++), qm++;
135  sum += *dl++ * (*qm -= *dx++), qm++;
136  } else {
137  sum += *dl++ * (*qm += *dx++), qm++;
138  sum += *dl++ * (*qm += *dx++), qm++;
139  sum += *dl++ * (*qm += *dx++), qm++;
140  sum += *dl++ * (*qm += *dx++), qm++;
141  sum += *dl++ * (*qm += *dx++), qm++;
142  sum += *dl++ * (*qm += *dx++), qm++;
143  sum += *dl++ * (*qm += *dx++), qm++;
144  sum += *dl++ * (*qm += *dx++), qm++;
145  }
146 
147  *(dx-0) = ((*(dl-1) >> 30) | 1) << 2;
148  *(dx-1) = ((*(dl-2) >> 30) | 1) << 1;
149  *(dx-2) = ((*(dl-3) >> 30) | 1) << 1;
150  *(dx-3) = ((*(dl-4) >> 30) | 1);
151 
152  c->error = *in;
153  *in += (sum >> c->shift);
154  *dl = *in;
155 
156  *(dl-1) = *dl - *(dl-1);
157  *(dl-2) = *(dl-1) - *(dl-2);
158  *(dl-3) = *(dl-2) - *(dl-3);
159 
160  memshl(c->dl, c->dl + 1);
161  memshl(c->dx, c->dx + 1);
162 }
163 
164 static void rice_init(TTARice *c, uint32_t k0, uint32_t k1)
165 {
166  c->k0 = k0;
167  c->k1 = k1;
168  c->sum0 = shift_16[k0];
169  c->sum1 = shift_16[k1];
170 }
171 
173 {
174  int ret = 0;
175 
176  // count ones
177  while (get_bits_left(gb) > 0 && get_bits1(gb))
178  ret++;
179  return ret;
180 }
181 
182 static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
183 {
184  uint32_t crc, CRC;
185 
186  CRC = AV_RL32(buf + buf_size);
187  crc = av_crc(s->crc_table, 0xFFFFFFFFU, buf, buf_size);
188  if (CRC != (crc ^ 0xFFFFFFFFU)) {
189  av_log(s->avctx, AV_LOG_ERROR, "CRC error\n");
190  return AVERROR_INVALIDDATA;
191  }
192 
193  return 0;
194 }
195 
197 {
198  TTAContext *s = avctx->priv_data;
199  int total_frames;
200 
201  s->avctx = avctx;
202 
203  // 30bytes includes a seektable with one frame
204  if (avctx->extradata_size < 30)
205  return -1;
206 
207  init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size * 8);
208  if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
209  {
210  if (avctx->err_recognition & AV_EF_CRCCHECK) {
212  tta_check_crc(s, avctx->extradata, 18);
213  }
214 
215  /* signature */
216  skip_bits_long(&s->gb, 32);
217 
218  s->format = get_bits(&s->gb, 16);
219  if (s->format > 2) {
220  av_log(s->avctx, AV_LOG_ERROR, "Invalid format\n");
221  return -1;
222  }
223  if (s->format == FORMAT_ENCRYPTED) {
224  avpriv_report_missing_feature(s->avctx, "Encrypted TTA");
225  return AVERROR_PATCHWELCOME;
226  }
227  avctx->channels = s->channels = get_bits(&s->gb, 16);
228  avctx->bits_per_coded_sample = get_bits(&s->gb, 16);
229  s->bps = (avctx->bits_per_coded_sample + 7) / 8;
230  avctx->sample_rate = get_bits_long(&s->gb, 32);
231  s->data_length = get_bits_long(&s->gb, 32);
232  skip_bits_long(&s->gb, 32); // CRC32 of header
233 
234  if (s->channels == 0) {
235  av_log(s->avctx, AV_LOG_ERROR, "Invalid number of channels\n");
236  return AVERROR_INVALIDDATA;
237  } else if (avctx->sample_rate == 0) {
238  av_log(s->avctx, AV_LOG_ERROR, "Invalid samplerate\n");
239  return AVERROR_INVALIDDATA;
240  }
241 
242  switch(s->bps) {
243  case 2:
244  avctx->sample_fmt = AV_SAMPLE_FMT_S16;
245  avctx->bits_per_raw_sample = 16;
246  break;
247  case 3:
248  avctx->sample_fmt = AV_SAMPLE_FMT_S32;
249  avctx->bits_per_raw_sample = 24;
250  break;
251  default:
252  av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported sample format.\n");
253  return AVERROR_INVALIDDATA;
254  }
255 
256  // prevent overflow
257  if (avctx->sample_rate > 0x7FFFFFu) {
258  av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
259  return AVERROR(EINVAL);
260  }
261  s->frame_length = 256 * avctx->sample_rate / 245;
262 
264  total_frames = s->data_length / s->frame_length +
265  (s->last_frame_length ? 1 : 0);
266 
267  av_log(s->avctx, AV_LOG_DEBUG, "format: %d chans: %d bps: %d rate: %d block: %d\n",
268  s->format, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate,
269  avctx->block_align);
270  av_log(s->avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
271  s->data_length, s->frame_length, s->last_frame_length, total_frames);
272 
273  // FIXME: seek table
274  if (avctx->extradata_size <= 26 || total_frames > INT_MAX / 4 ||
275  avctx->extradata_size - 26 < total_frames * 4)
276  av_log(avctx, AV_LOG_WARNING, "Seek table missing or too small\n");
277  else if (avctx->err_recognition & AV_EF_CRCCHECK) {
278  int ret = tta_check_crc(s, avctx->extradata + 22, total_frames * 4);
279  if (ret < 0 && avctx->err_recognition & AV_EF_EXPLODE)
280  return AVERROR_INVALIDDATA;
281  }
282  skip_bits_long(&s->gb, 32 * total_frames);
283  skip_bits_long(&s->gb, 32); // CRC32 of seektable
284 
285  if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
286  av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
287  return -1;
288  }
289 
290  if (s->bps == 2) {
292  if (!s->decode_buffer)
293  return AVERROR(ENOMEM);
294  }
295  s->ch_ctx = av_malloc(avctx->channels * sizeof(*s->ch_ctx));
296  if (!s->ch_ctx) {
297  av_freep(&s->decode_buffer);
298  return AVERROR(ENOMEM);
299  }
300  } else {
301  av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
302  return -1;
303  }
304 
305  return 0;
306 }
307 
308 static int tta_decode_frame(AVCodecContext *avctx, void *data,
309  int *got_frame_ptr, AVPacket *avpkt)
310 {
311  AVFrame *frame = data;
312  const uint8_t *buf = avpkt->data;
313  int buf_size = avpkt->size;
314  TTAContext *s = avctx->priv_data;
315  int i, ret;
316  int cur_chan = 0, framelen = s->frame_length;
317  int32_t *p;
318 
319  if (avctx->err_recognition & AV_EF_CRCCHECK) {
320  if (buf_size < 4 ||
321  (tta_check_crc(s, buf, buf_size - 4) && avctx->err_recognition & AV_EF_EXPLODE))
322  return AVERROR_INVALIDDATA;
323  }
324 
325  init_get_bits(&s->gb, buf, buf_size*8);
326 
327  /* get output buffer */
328  frame->nb_samples = framelen;
329  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
330  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
331  return ret;
332  }
333 
334  // decode directly to output buffer for 24-bit sample format
335  if (s->bps == 3)
336  s->decode_buffer = (int32_t *)frame->data[0];
337 
338  // init per channel states
339  for (i = 0; i < s->channels; i++) {
340  s->ch_ctx[i].predictor = 0;
342  rice_init(&s->ch_ctx[i].rice, 10, 10);
343  }
344 
345  i = 0;
346  for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
347  int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
348  TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
349  TTARice *rice = &s->ch_ctx[cur_chan].rice;
350  uint32_t unary, depth, k;
351  int32_t value;
352 
353  unary = tta_get_unary(&s->gb);
354 
355  if (unary == 0) {
356  depth = 0;
357  k = rice->k0;
358  } else {
359  depth = 1;
360  k = rice->k1;
361  unary--;
362  }
363 
364  if (get_bits_left(&s->gb) < k) {
365  ret = AVERROR_INVALIDDATA;
366  goto error;
367  }
368 
369  if (k) {
370  if (k > MIN_CACHE_BITS) {
371  ret = AVERROR_INVALIDDATA;
372  goto error;
373  }
374  value = (unary << k) + get_bits(&s->gb, k);
375  } else
376  value = unary;
377 
378  // FIXME: copy paste from original
379  switch (depth) {
380  case 1:
381  rice->sum1 += value - (rice->sum1 >> 4);
382  if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
383  rice->k1--;
384  else if(rice->sum1 > shift_16[rice->k1 + 1])
385  rice->k1++;
386  value += shift_1[rice->k0];
387  default:
388  rice->sum0 += value - (rice->sum0 >> 4);
389  if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
390  rice->k0--;
391  else if(rice->sum0 > shift_16[rice->k0 + 1])
392  rice->k0++;
393  }
394 
395  // extract coded value
396  *p = 1 + ((value >> 1) ^ ((value & 1) - 1));
397 
398  // run hybrid filter
399  ttafilter_process(filter, p);
400 
401  // fixed order prediction
402 #define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k)
403  switch (s->bps) {
404  case 1: *p += PRED(*predictor, 4); break;
405  case 2:
406  case 3: *p += PRED(*predictor, 5); break;
407  case 4: *p += *predictor; break;
408  }
409  *predictor = *p;
410 
411  // flip channels
412  if (cur_chan < (s->channels-1))
413  cur_chan++;
414  else {
415  // decorrelate in case of multiple channels
416  if (s->channels > 1) {
417  int32_t *r = p - 1;
418  for (*p += *r / 2; r > p - s->channels; r--)
419  *r = *(r + 1) - *r;
420  }
421  cur_chan = 0;
422  i++;
423  // check for last frame
424  if (i == s->last_frame_length && get_bits_left(&s->gb) / 8 == 4) {
425  frame->nb_samples = framelen = s->last_frame_length;
426  break;
427  }
428  }
429  }
430 
431  align_get_bits(&s->gb);
432  if (get_bits_left(&s->gb) < 32) {
433  ret = AVERROR_INVALIDDATA;
434  goto error;
435  }
436  skip_bits_long(&s->gb, 32); // frame crc
437 
438  // convert to output buffer
439  if (s->bps == 2) {
440  int16_t *samples = (int16_t *)frame->data[0];
441  for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
442  *samples++ = *p;
443  } else {
444  // shift samples for 24-bit sample format
445  int32_t *samples = (int32_t *)frame->data[0];
446  for (i = 0; i < framelen * s->channels; i++)
447  *samples++ <<= 8;
448  // reset decode buffer
449  s->decode_buffer = NULL;
450  }
451 
452  *got_frame_ptr = 1;
453 
454  return buf_size;
455 error:
456  // reset decode buffer
457  if (s->bps == 3)
458  s->decode_buffer = NULL;
459  return ret;
460 }
461 
463  TTAContext *s = avctx->priv_data;
464 
466  av_freep(&s->ch_ctx);
467 
468  return 0;
469 }
470 
472  .name = "tta",
473  .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
474  .type = AVMEDIA_TYPE_AUDIO,
475  .id = AV_CODEC_ID_TTA,
476  .priv_data_size = sizeof(TTAContext),
480  .capabilities = CODEC_CAP_DR1,
481 };