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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 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  * TTA (The Lossless True Audio) decoder
25  * @see http://www.true-audio.com/
26  * @see http://tta.corecodec.org/
27  * @author Alex Beregszaszi
28  */
29 
30 #define BITSTREAM_READER_LE
31 #include <limits.h>
32 #include "ttadata.h"
33 #include "ttadsp.h"
34 #include "avcodec.h"
35 #include "get_bits.h"
36 #include "thread.h"
37 #include "unary.h"
38 #include "internal.h"
39 #include "libavutil/crc.h"
40 #include "libavutil/intreadwrite.h"
41 #include "libavutil/opt.h"
42 
43 #define FORMAT_SIMPLE 1
44 #define FORMAT_ENCRYPTED 2
45 
46 typedef struct TTAContext {
47  AVClass *class;
49  const AVCRC *crc_table;
50 
52  unsigned data_length;
54 
56 
61 } TTAContext;
62 
63 static const int64_t tta_channel_layouts[7] = {
67  0,
69  AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER,
71 };
72 
73 static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
74 {
75  uint32_t crc, CRC;
76 
77  CRC = AV_RL32(buf + buf_size);
78  crc = av_crc(s->crc_table, 0xFFFFFFFFU, buf, buf_size);
79  if (CRC != (crc ^ 0xFFFFFFFFU)) {
80  av_log(s->avctx, AV_LOG_ERROR, "CRC error\n");
81  return AVERROR_INVALIDDATA;
82  }
83 
84  return 0;
85 }
86 
87 static uint64_t tta_check_crc64(uint8_t *pass)
88 {
89  uint64_t crc = UINT64_MAX, poly = 0x42F0E1EBA9EA3693U;
90  uint8_t *end = pass + strlen(pass);
91  int i;
92 
93  while (pass < end) {
94  crc ^= (uint64_t)*pass++ << 56;
95  for (i = 0; i < 8; i++)
96  crc = (crc << 1) ^ (poly & (((int64_t) crc) >> 63));
97  }
98 
99  return crc ^ UINT64_MAX;
100 }
101 
103 {
104  TTAContext *s = avctx->priv_data;
105 
106  if (s->bps < 3) {
108  if (!s->decode_buffer)
109  return AVERROR(ENOMEM);
110  } else
111  s->decode_buffer = NULL;
112  s->ch_ctx = av_malloc_array(avctx->channels, sizeof(*s->ch_ctx));
113  if (!s->ch_ctx) {
114  av_freep(&s->decode_buffer);
115  return AVERROR(ENOMEM);
116  }
117 
118  return 0;
119 }
120 
122 {
123  TTAContext *s = avctx->priv_data;
124  GetBitContext gb;
125  int total_frames;
126 
127  s->avctx = avctx;
128 
129  // 30bytes includes TTA1 header
130  if (avctx->extradata_size < 22)
131  return AVERROR_INVALIDDATA;
132 
134  init_get_bits8(&gb, avctx->extradata, avctx->extradata_size);
135  if (show_bits_long(&gb, 32) == AV_RL32("TTA1")) {
136  /* signature */
137  skip_bits_long(&gb, 32);
138 
139  s->format = get_bits(&gb, 16);
140  if (s->format > 2) {
141  av_log(avctx, AV_LOG_ERROR, "Invalid format\n");
142  return AVERROR_INVALIDDATA;
143  }
144  if (s->format == FORMAT_ENCRYPTED) {
145  if (!s->pass) {
146  av_log(avctx, AV_LOG_ERROR, "Missing password for encrypted stream. Please use the -password option\n");
147  return AVERROR(EINVAL);
148  }
150  }
151  avctx->channels = s->channels = get_bits(&gb, 16);
152  if (s->channels > 1 && s->channels < 9)
154  avctx->bits_per_raw_sample = get_bits(&gb, 16);
155  s->bps = (avctx->bits_per_raw_sample + 7) / 8;
156  avctx->sample_rate = get_bits_long(&gb, 32);
157  s->data_length = get_bits_long(&gb, 32);
158  skip_bits_long(&gb, 32); // CRC32 of header
159 
160  if (s->channels == 0) {
161  av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
162  return AVERROR_INVALIDDATA;
163  } else if (avctx->sample_rate == 0) {
164  av_log(avctx, AV_LOG_ERROR, "Invalid samplerate\n");
165  return AVERROR_INVALIDDATA;
166  }
167 
168  switch(s->bps) {
169  case 1: avctx->sample_fmt = AV_SAMPLE_FMT_U8; break;
170  case 2:
171  avctx->sample_fmt = AV_SAMPLE_FMT_S16;
172  break;
173  case 3:
174  avctx->sample_fmt = AV_SAMPLE_FMT_S32;
175  break;
176  //case 4: avctx->sample_fmt = AV_SAMPLE_FMT_S32; break;
177  default:
178  av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported sample format.\n");
179  return AVERROR_INVALIDDATA;
180  }
181 
182  // prevent overflow
183  if (avctx->sample_rate > 0x7FFFFFu) {
184  av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
185  return AVERROR(EINVAL);
186  }
187  s->frame_length = 256 * avctx->sample_rate / 245;
188 
190  total_frames = s->data_length / s->frame_length +
191  (s->last_frame_length ? 1 : 0);
192 
193  av_log(avctx, AV_LOG_DEBUG, "format: %d chans: %d bps: %d rate: %d block: %d\n",
194  s->format, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate,
195  avctx->block_align);
196  av_log(avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
197  s->data_length, s->frame_length, s->last_frame_length, total_frames);
198 
199  if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
200  av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
201  return AVERROR_INVALIDDATA;
202  }
203  } else {
204  av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
205  return AVERROR_INVALIDDATA;
206  }
207 
208  ff_ttadsp_init(&s->dsp);
209 
210  return allocate_buffers(avctx);
211 }
212 
213 static int tta_decode_frame(AVCodecContext *avctx, void *data,
214  int *got_frame_ptr, AVPacket *avpkt)
215 {
216  AVFrame *frame = data;
217  ThreadFrame tframe = { .f = data };
218  const uint8_t *buf = avpkt->data;
219  int buf_size = avpkt->size;
220  TTAContext *s = avctx->priv_data;
221  GetBitContext gb;
222  int i, ret;
223  int cur_chan = 0, framelen = s->frame_length;
224  int32_t *p;
225 
226  if (avctx->err_recognition & AV_EF_CRCCHECK) {
227  if (buf_size < 4 ||
228  (tta_check_crc(s, buf, buf_size - 4) && avctx->err_recognition & AV_EF_EXPLODE))
229  return AVERROR_INVALIDDATA;
230  }
231 
232  if ((ret = init_get_bits8(&gb, avpkt->data, avpkt->size)) < 0)
233  return ret;
234 
235  /* get output buffer */
236  frame->nb_samples = framelen;
237  if ((ret = ff_thread_get_buffer(avctx, &tframe, 0)) < 0)
238  return ret;
239 
240  // decode directly to output buffer for 24-bit sample format
241  if (s->bps == 3)
242  s->decode_buffer = (int32_t *)frame->data[0];
243 
244  // init per channel states
245  for (i = 0; i < s->channels; i++) {
246  TTAFilter *filter = &s->ch_ctx[i].filter;
247  s->ch_ctx[i].predictor = 0;
249  if (s->format == FORMAT_ENCRYPTED) {
250  int i;
251  for (i = 0; i < 8; i++)
252  filter->qm[i] = sign_extend(s->crc_pass[i], 8);
253  }
254  ff_tta_rice_init(&s->ch_ctx[i].rice, 10, 10);
255  }
256 
257  i = 0;
258  for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
259  int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
260  TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
261  TTARice *rice = &s->ch_ctx[cur_chan].rice;
262  uint32_t unary, depth, k;
263  int32_t value;
264 
265  unary = get_unary(&gb, 0, get_bits_left(&gb));
266 
267  if (unary == 0) {
268  depth = 0;
269  k = rice->k0;
270  } else {
271  depth = 1;
272  k = rice->k1;
273  unary--;
274  }
275 
276  if (get_bits_left(&gb) < k) {
277  ret = AVERROR_INVALIDDATA;
278  goto error;
279  }
280 
281  if (k) {
282  if (k > MIN_CACHE_BITS) {
283  ret = AVERROR_INVALIDDATA;
284  goto error;
285  }
286  value = (unary << k) + get_bits(&gb, k);
287  } else
288  value = unary;
289 
290  // FIXME: copy paste from original
291  switch (depth) {
292  case 1:
293  rice->sum1 += value - (rice->sum1 >> 4);
294  if (rice->k1 > 0 && rice->sum1 < ff_tta_shift_16[rice->k1])
295  rice->k1--;
296  else if(rice->sum1 > ff_tta_shift_16[rice->k1 + 1])
297  rice->k1++;
298  value += ff_tta_shift_1[rice->k0];
299  default:
300  rice->sum0 += value - (rice->sum0 >> 4);
301  if (rice->k0 > 0 && rice->sum0 < ff_tta_shift_16[rice->k0])
302  rice->k0--;
303  else if(rice->sum0 > ff_tta_shift_16[rice->k0 + 1])
304  rice->k0++;
305  }
306 
307  // extract coded value
308  *p = 1 + ((value >> 1) ^ ((value & 1) - 1));
309 
310  // run hybrid filter
311  s->dsp.ttafilter_process_dec(filter->qm, filter->dx, filter->dl, &filter->error, p,
312  filter->shift, filter->round);
313 
314  // fixed order prediction
315 #define PRED(x, k) (int32_t)((((uint64_t)(x) << (k)) - (x)) >> (k))
316  switch (s->bps) {
317  case 1: *p += PRED(*predictor, 4); break;
318  case 2:
319  case 3: *p += PRED(*predictor, 5); break;
320  case 4: *p += *predictor; break;
321  }
322  *predictor = *p;
323 
324  // flip channels
325  if (cur_chan < (s->channels-1))
326  cur_chan++;
327  else {
328  // decorrelate in case of multiple channels
329  if (s->channels > 1) {
330  int32_t *r = p - 1;
331  for (*p += *r / 2; r > p - s->channels; r--)
332  *r = *(r + 1) - *r;
333  }
334  cur_chan = 0;
335  i++;
336  // check for last frame
337  if (i == s->last_frame_length && get_bits_left(&gb) / 8 == 4) {
338  frame->nb_samples = framelen = s->last_frame_length;
339  break;
340  }
341  }
342  }
343 
344  align_get_bits(&gb);
345  if (get_bits_left(&gb) < 32) {
346  ret = AVERROR_INVALIDDATA;
347  goto error;
348  }
349  skip_bits_long(&gb, 32); // frame crc
350 
351  // convert to output buffer
352  switch (s->bps) {
353  case 1: {
354  uint8_t *samples = (uint8_t *)frame->data[0];
355  for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
356  *samples++ = *p + 0x80;
357  break;
358  }
359  case 2: {
360  int16_t *samples = (int16_t *)frame->data[0];
361  for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
362  *samples++ = *p;
363  break;
364  }
365  case 3: {
366  // shift samples for 24-bit sample format
367  int32_t *samples = (int32_t *)frame->data[0];
368  for (i = 0; i < framelen * s->channels; i++)
369  *samples++ <<= 8;
370  // reset decode buffer
371  s->decode_buffer = NULL;
372  break;
373  }
374  }
375 
376  *got_frame_ptr = 1;
377 
378  return buf_size;
379 error:
380  // reset decode buffer
381  if (s->bps == 3)
382  s->decode_buffer = NULL;
383  return ret;
384 }
385 
387 {
388  TTAContext *s = avctx->priv_data;
389  s->avctx = avctx;
390  return allocate_buffers(avctx);
391 }
392 
394  TTAContext *s = avctx->priv_data;
395 
396  if (s->bps < 3)
398  s->decode_buffer = NULL;
399  av_freep(&s->ch_ctx);
400 
401  return 0;
402 }
403 
404 #define OFFSET(x) offsetof(TTAContext, x)
405 #define DEC (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM)
406 static const AVOption options[] = {
407  { "password", "Set decoding password", OFFSET(pass), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, DEC },
408  { NULL },
409 };
410 
411 static const AVClass tta_decoder_class = {
412  .class_name = "TTA Decoder",
413  .item_name = av_default_item_name,
414  .option = options,
415  .version = LIBAVUTIL_VERSION_INT,
416 };
417 
419  .name = "tta",
420  .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
421  .type = AVMEDIA_TYPE_AUDIO,
422  .id = AV_CODEC_ID_TTA,
423  .priv_data_size = sizeof(TTAContext),
428  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,
429  .priv_class = &tta_decoder_class,
430 };