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 #include <limits.h>
31
32 #include "libavutil/crc.h"
33 #include "libavutil/intreadwrite.h"
34 #include "libavutil/opt.h"
35
36 #define BITSTREAM_READER_LE
37 #include "ttadata.h"
38 #include "ttadsp.h"
39 #include "avcodec.h"
40 #include "get_bits.h"
41 #include "thread.h"
42 #include "unary.h"
43 #include "internal.h"
44
45 #define FORMAT_SIMPLE 1
46 #define FORMAT_ENCRYPTED 2
47
48 typedef struct TTAContext {
49 AVClass *class;
50 AVCodecContext *avctx;
51 const AVCRC *crc_table;
52
53 int format, channels, bps;
54 unsigned data_length;
55 int frame_length, last_frame_length;
56
57 int32_t *decode_buffer;
58
59 uint8_t crc_pass[8];
60 uint8_t *pass;
61 TTAChannel *ch_ctx;
62 TTADSPContext dsp;
63 } TTAContext;
64
65 static const int64_t tta_channel_layouts[7] = {
66 AV_CH_LAYOUT_STEREO,
67 AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
68 AV_CH_LAYOUT_QUAD,
69 0,
70 AV_CH_LAYOUT_5POINT1_BACK,
71 AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER,
72 AV_CH_LAYOUT_7POINT1_WIDE
73 };
74
tta_check_crc(TTAContext * s,const uint8_t * buf,int buf_size)75 static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
76 {
77 uint32_t crc, CRC;
78
79 CRC = AV_RL32(buf + buf_size);
80 crc = av_crc(s->crc_table, 0xFFFFFFFFU, buf, buf_size);
81 if (CRC != (crc ^ 0xFFFFFFFFU)) {
82 av_log(s->avctx, AV_LOG_ERROR, "CRC error\n");
83 return AVERROR_INVALIDDATA;
84 }
85
86 return 0;
87 }
88
tta_check_crc64(uint8_t * pass)89 static uint64_t tta_check_crc64(uint8_t *pass)
90 {
91 uint64_t crc = UINT64_MAX, poly = 0x42F0E1EBA9EA3693U;
92 uint8_t *end = pass + strlen(pass);
93 int i;
94
95 while (pass < end) {
96 crc ^= (uint64_t)*pass++ << 56;
97 for (i = 0; i < 8; i++)
98 crc = (crc << 1) ^ (poly & (((int64_t) crc) >> 63));
99 }
100
101 return crc ^ UINT64_MAX;
102 }
103
allocate_buffers(AVCodecContext * avctx)104 static int allocate_buffers(AVCodecContext *avctx)
105 {
106 TTAContext *s = avctx->priv_data;
107
108 if (s->bps < 3) {
109 s->decode_buffer = av_mallocz_array(sizeof(int32_t)*s->frame_length, s->channels);
110 if (!s->decode_buffer)
111 return AVERROR(ENOMEM);
112 } else
113 s->decode_buffer = NULL;
114 s->ch_ctx = av_malloc_array(avctx->channels, sizeof(*s->ch_ctx));
115 if (!s->ch_ctx) {
116 av_freep(&s->decode_buffer);
117 return AVERROR(ENOMEM);
118 }
119
120 return 0;
121 }
122
tta_decode_init(AVCodecContext * avctx)123 static av_cold int tta_decode_init(AVCodecContext * avctx)
124 {
125 TTAContext *s = avctx->priv_data;
126 GetBitContext gb;
127 int total_frames;
128 int ret;
129
130 s->avctx = avctx;
131
132 // 22 bytes for a TTA1 header
133 if (avctx->extradata_size < 22)
134 return AVERROR_INVALIDDATA;
135
136 s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
137 ret = init_get_bits8(&gb, avctx->extradata, avctx->extradata_size);
138 if (ret < 0)
139 return ret;
140
141 if (show_bits_long(&gb, 32) == AV_RL32("TTA1")) {
142 /* signature */
143 skip_bits_long(&gb, 32);
144
145 s->format = get_bits(&gb, 16);
146 if (s->format > 2) {
147 av_log(avctx, AV_LOG_ERROR, "Invalid format\n");
148 return AVERROR_INVALIDDATA;
149 }
150 if (s->format == FORMAT_ENCRYPTED) {
151 if (!s->pass) {
152 av_log(avctx, AV_LOG_ERROR, "Missing password for encrypted stream. Please use the -password option\n");
153 return AVERROR(EINVAL);
154 }
155 AV_WL64(s->crc_pass, tta_check_crc64(s->pass));
156 }
157 avctx->channels = s->channels = get_bits(&gb, 16);
158 if (s->channels > 1 && s->channels < 9)
159 avctx->channel_layout = tta_channel_layouts[s->channels-2];
160 avctx->bits_per_raw_sample = get_bits(&gb, 16);
161 s->bps = (avctx->bits_per_raw_sample + 7) / 8;
162 avctx->sample_rate = get_bits_long(&gb, 32);
163 s->data_length = get_bits_long(&gb, 32);
164 skip_bits_long(&gb, 32); // CRC32 of header
165
166 if (s->channels == 0 || s->channels > 16) {
167 av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
168 return AVERROR_INVALIDDATA;
169 } else if (avctx->sample_rate == 0) {
170 av_log(avctx, AV_LOG_ERROR, "Invalid samplerate\n");
171 return AVERROR_INVALIDDATA;
172 }
173
174 switch(s->bps) {
175 case 1: avctx->sample_fmt = AV_SAMPLE_FMT_U8; break;
176 case 2:
177 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
178 break;
179 case 3:
180 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
181 break;
182 //case 4: avctx->sample_fmt = AV_SAMPLE_FMT_S32; break;
183 default:
184 av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported sample format.\n");
185 return AVERROR_INVALIDDATA;
186 }
187
188 // prevent overflow
189 if (avctx->sample_rate > 0x7FFFFFu) {
190 av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
191 return AVERROR(EINVAL);
192 }
193 s->frame_length = 256 * avctx->sample_rate / 245;
194
195 s->last_frame_length = s->data_length % s->frame_length;
196 total_frames = s->data_length / s->frame_length +
197 (s->last_frame_length ? 1 : 0);
198
199 av_log(avctx, AV_LOG_DEBUG, "format: %d chans: %d bps: %d rate: %d block: %d\n",
200 s->format, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate,
201 avctx->block_align);
202 av_log(avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
203 s->data_length, s->frame_length, s->last_frame_length, total_frames);
204
205 if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
206 av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
207 return AVERROR_INVALIDDATA;
208 }
209 } else {
210 av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
211 return AVERROR_INVALIDDATA;
212 }
213
214 ff_ttadsp_init(&s->dsp);
215
216 return allocate_buffers(avctx);
217 }
218
tta_decode_frame(AVCodecContext * avctx,void * data,int * got_frame_ptr,AVPacket * avpkt)219 static int tta_decode_frame(AVCodecContext *avctx, void *data,
220 int *got_frame_ptr, AVPacket *avpkt)
221 {
222 AVFrame *frame = data;
223 ThreadFrame tframe = { .f = data };
224 const uint8_t *buf = avpkt->data;
225 int buf_size = avpkt->size;
226 TTAContext *s = avctx->priv_data;
227 GetBitContext gb;
228 int i, ret;
229 int cur_chan = 0, framelen = s->frame_length;
230 uint32_t *p;
231
232 if (avctx->err_recognition & AV_EF_CRCCHECK) {
233 if (buf_size < 4 ||
234 (tta_check_crc(s, buf, buf_size - 4) && avctx->err_recognition & AV_EF_EXPLODE))
235 return AVERROR_INVALIDDATA;
236 }
237
238 if ((ret = init_get_bits8(&gb, avpkt->data, avpkt->size)) < 0)
239 return ret;
240
241 /* get output buffer */
242 frame->nb_samples = framelen;
243 if ((ret = ff_thread_get_buffer(avctx, &tframe, 0)) < 0)
244 return ret;
245
246 // decode directly to output buffer for 24-bit sample format
247 if (s->bps == 3)
248 s->decode_buffer = (int32_t *)frame->data[0];
249
250 // init per channel states
251 for (i = 0; i < s->channels; i++) {
252 TTAFilter *filter = &s->ch_ctx[i].filter;
253 s->ch_ctx[i].predictor = 0;
254 ff_tta_filter_init(filter, ff_tta_filter_configs[s->bps-1]);
255 if (s->format == FORMAT_ENCRYPTED) {
256 int i;
257 for (i = 0; i < 8; i++)
258 filter->qm[i] = sign_extend(s->crc_pass[i], 8);
259 }
260 ff_tta_rice_init(&s->ch_ctx[i].rice, 10, 10);
261 }
262
263 i = 0;
264 for (p = s->decode_buffer; (int32_t*)p < s->decode_buffer + (framelen * s->channels); p++) {
265 int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
266 TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
267 TTARice *rice = &s->ch_ctx[cur_chan].rice;
268 uint32_t unary, depth, k;
269 int32_t value;
270
271 unary = get_unary(&gb, 0, get_bits_left(&gb));
272
273 if (unary == 0) {
274 depth = 0;
275 k = rice->k0;
276 } else {
277 depth = 1;
278 k = rice->k1;
279 unary--;
280 }
281
282 if (get_bits_left(&gb) < k) {
283 ret = AVERROR_INVALIDDATA;
284 goto error;
285 }
286
287 if (k) {
288 if (k > MIN_CACHE_BITS || unary > INT32_MAX >> k) {
289 ret = AVERROR_INVALIDDATA;
290 goto error;
291 }
292 value = (unary << k) + get_bits(&gb, k);
293 } else
294 value = unary;
295
296 // FIXME: copy paste from original
297 switch (depth) {
298 case 1:
299 rice->sum1 += value - (rice->sum1 >> 4);
300 if (rice->k1 > 0 && rice->sum1 < ff_tta_shift_16[rice->k1])
301 rice->k1--;
302 else if(rice->sum1 > ff_tta_shift_16[rice->k1 + 1])
303 rice->k1++;
304 value += ff_tta_shift_1[rice->k0];
305 default:
306 rice->sum0 += value - (rice->sum0 >> 4);
307 if (rice->k0 > 0 && rice->sum0 < ff_tta_shift_16[rice->k0])
308 rice->k0--;
309 else if(rice->sum0 > ff_tta_shift_16[rice->k0 + 1])
310 rice->k0++;
311 }
312
313 // extract coded value
314 *p = 1 + ((value >> 1) ^ ((value & 1) - 1));
315
316 // run hybrid filter
317 s->dsp.filter_process(filter->qm, filter->dx, filter->dl, &filter->error, p,
318 filter->shift, filter->round);
319
320 // fixed order prediction
321 #define PRED(x, k) (int32_t)((((uint64_t)(x) << (k)) - (x)) >> (k))
322 switch (s->bps) {
323 case 1: *p += PRED(*predictor, 4); break;
324 case 2:
325 case 3: *p += PRED(*predictor, 5); break;
326 case 4: *p += *predictor; break;
327 }
328 *predictor = *p;
329
330 // flip channels
331 if (cur_chan < (s->channels-1))
332 cur_chan++;
333 else {
334 // decorrelate in case of multiple channels
335 if (s->channels > 1) {
336 int32_t *r = p - 1;
337 for (*p += *r / 2; r > (int32_t*)p - s->channels; r--)
338 *r = *(r + 1) - *r;
339 }
340 cur_chan = 0;
341 i++;
342 // check for last frame
343 if (i == s->last_frame_length && get_bits_left(&gb) / 8 == 4) {
344 frame->nb_samples = framelen = s->last_frame_length;
345 break;
346 }
347 }
348 }
349
350 align_get_bits(&gb);
351 if (get_bits_left(&gb) < 32) {
352 ret = AVERROR_INVALIDDATA;
353 goto error;
354 }
355 skip_bits_long(&gb, 32); // frame crc
356
357 // convert to output buffer
358 switch (s->bps) {
359 case 1: {
360 uint8_t *samples = (uint8_t *)frame->data[0];
361 for (p = s->decode_buffer; (int32_t*)p < s->decode_buffer + (framelen * s->channels); p++)
362 *samples++ = *p + 0x80;
363 break;
364 }
365 case 2: {
366 int16_t *samples = (int16_t *)frame->data[0];
367 for (p = s->decode_buffer; (int32_t*)p < s->decode_buffer + (framelen * s->channels); p++)
368 *samples++ = *p;
369 break;
370 }
371 case 3: {
372 // shift samples for 24-bit sample format
373 int32_t *samples = (int32_t *)frame->data[0];
374 for (i = 0; i < framelen * s->channels; i++)
375 *samples++ *= 256;
376 // reset decode buffer
377 s->decode_buffer = NULL;
378 break;
379 }
380 }
381
382 *got_frame_ptr = 1;
383
384 return buf_size;
385 error:
386 // reset decode buffer
387 if (s->bps == 3)
388 s->decode_buffer = NULL;
389 return ret;
390 }
391
tta_decode_close(AVCodecContext * avctx)392 static av_cold int tta_decode_close(AVCodecContext *avctx) {
393 TTAContext *s = avctx->priv_data;
394
395 if (s->bps < 3)
396 av_freep(&s->decode_buffer);
397 s->decode_buffer = NULL;
398 av_freep(&s->ch_ctx);
399
400 return 0;
401 }
402
403 #define OFFSET(x) offsetof(TTAContext, x)
404 #define DEC (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM)
405 static const AVOption options[] = {
406 { "password", "Set decoding password", OFFSET(pass), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, DEC },
407 { NULL },
408 };
409
410 static const AVClass tta_decoder_class = {
411 .class_name = "TTA Decoder",
412 .item_name = av_default_item_name,
413 .option = options,
414 .version = LIBAVUTIL_VERSION_INT,
415 };
416
417 AVCodec ff_tta_decoder = {
418 .name = "tta",
419 .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
420 .type = AVMEDIA_TYPE_AUDIO,
421 .id = AV_CODEC_ID_TTA,
422 .priv_data_size = sizeof(TTAContext),
423 .init = tta_decode_init,
424 .close = tta_decode_close,
425 .decode = tta_decode_frame,
426 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_CHANNEL_CONF,
427 .priv_class = &tta_decoder_class,
428 };
429