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/channel_layout.h"
33 #include "libavutil/crc.h"
34 #include "libavutil/intreadwrite.h"
35 #include "libavutil/opt.h"
36
37 #define BITSTREAM_READER_LE
38 #include "ttadata.h"
39 #include "ttadsp.h"
40 #include "avcodec.h"
41 #include "codec_internal.h"
42 #include "get_bits.h"
43 #include "thread.h"
44 #include "unary.h"
45
46 #define FORMAT_SIMPLE 1
47 #define FORMAT_ENCRYPTED 2
48
49 typedef struct TTAContext {
50 AVClass *class;
51 AVCodecContext *avctx;
52 const AVCRC *crc_table;
53
54 int format, channels, bps;
55 unsigned data_length;
56 int frame_length, last_frame_length;
57
58 int32_t *decode_buffer;
59
60 uint8_t crc_pass[8];
61 uint8_t *pass;
62 TTAChannel *ch_ctx;
63 TTADSPContext dsp;
64 } TTAContext;
65
66 static const int64_t tta_channel_layouts[7] = {
67 AV_CH_LAYOUT_STEREO,
68 AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
69 AV_CH_LAYOUT_QUAD,
70 0,
71 AV_CH_LAYOUT_5POINT1_BACK,
72 AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER,
73 AV_CH_LAYOUT_7POINT1_WIDE
74 };
75
tta_check_crc(TTAContext * s,const uint8_t * buf,int buf_size)76 static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
77 {
78 uint32_t crc, CRC;
79
80 CRC = AV_RL32(buf + buf_size);
81 crc = av_crc(s->crc_table, 0xFFFFFFFFU, buf, buf_size);
82 if (CRC != (crc ^ 0xFFFFFFFFU)) {
83 av_log(s->avctx, AV_LOG_ERROR, "CRC error\n");
84 return AVERROR_INVALIDDATA;
85 }
86
87 return 0;
88 }
89
tta_check_crc64(uint8_t * pass)90 static uint64_t tta_check_crc64(uint8_t *pass)
91 {
92 uint64_t crc = UINT64_MAX, poly = 0x42F0E1EBA9EA3693U;
93 uint8_t *end = pass + strlen(pass);
94 int i;
95
96 while (pass < end) {
97 crc ^= (uint64_t)*pass++ << 56;
98 for (i = 0; i < 8; i++)
99 crc = (crc << 1) ^ (poly & (((int64_t) crc) >> 63));
100 }
101
102 return crc ^ UINT64_MAX;
103 }
104
allocate_buffers(AVCodecContext * avctx)105 static int allocate_buffers(AVCodecContext *avctx)
106 {
107 TTAContext *s = avctx->priv_data;
108
109 if (s->bps < 3) {
110 s->decode_buffer = av_calloc(s->frame_length,
111 sizeof(*s->decode_buffer) * s->channels);
112 if (!s->decode_buffer)
113 return AVERROR(ENOMEM);
114 } else
115 s->decode_buffer = NULL;
116 s->ch_ctx = av_malloc_array(avctx->ch_layout.nb_channels, sizeof(*s->ch_ctx));
117 if (!s->ch_ctx)
118 return AVERROR(ENOMEM);
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
158 s->channels = get_bits(&gb, 16);
159
160 av_channel_layout_uninit(&avctx->ch_layout);
161 if (s->channels > 1 && s->channels < 9) {
162 av_channel_layout_from_mask(&avctx->ch_layout, tta_channel_layouts[s->channels-2]);
163 } else {
164 avctx->ch_layout.order = AV_CHANNEL_ORDER_UNSPEC;
165 avctx->ch_layout.nb_channels = s->channels;
166 }
167
168 avctx->bits_per_raw_sample = get_bits(&gb, 16);
169 s->bps = (avctx->bits_per_raw_sample + 7) / 8;
170 avctx->sample_rate = get_bits_long(&gb, 32);
171 s->data_length = get_bits_long(&gb, 32);
172 skip_bits_long(&gb, 32); // CRC32 of header
173
174 if (s->channels == 0 || s->channels > 16) {
175 av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
176 return AVERROR_INVALIDDATA;
177 } else if (avctx->sample_rate == 0) {
178 av_log(avctx, AV_LOG_ERROR, "Invalid samplerate\n");
179 return AVERROR_INVALIDDATA;
180 }
181
182 switch(s->bps) {
183 case 1: avctx->sample_fmt = AV_SAMPLE_FMT_U8; break;
184 case 2:
185 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
186 break;
187 case 3:
188 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
189 break;
190 //case 4: avctx->sample_fmt = AV_SAMPLE_FMT_S32; break;
191 default:
192 av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported sample format.\n");
193 return AVERROR_INVALIDDATA;
194 }
195
196 // prevent overflow
197 if (avctx->sample_rate > 0x7FFFFFu) {
198 av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
199 return AVERROR(EINVAL);
200 }
201 s->frame_length = 256 * avctx->sample_rate / 245;
202
203 s->last_frame_length = s->data_length % s->frame_length;
204 total_frames = s->data_length / s->frame_length +
205 (s->last_frame_length ? 1 : 0);
206
207 av_log(avctx, AV_LOG_DEBUG, "format: %d chans: %d bps: %d rate: %d block: %d\n",
208 s->format, avctx->ch_layout.nb_channels, avctx->bits_per_coded_sample, avctx->sample_rate,
209 avctx->block_align);
210 av_log(avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
211 s->data_length, s->frame_length, s->last_frame_length, total_frames);
212
213 if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
214 av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
215 return AVERROR_INVALIDDATA;
216 }
217 } else {
218 av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
219 return AVERROR_INVALIDDATA;
220 }
221
222 ff_ttadsp_init(&s->dsp);
223
224 return allocate_buffers(avctx);
225 }
226
tta_decode_frame(AVCodecContext * avctx,AVFrame * frame,int * got_frame_ptr,AVPacket * avpkt)227 static int tta_decode_frame(AVCodecContext *avctx, AVFrame *frame,
228 int *got_frame_ptr, AVPacket *avpkt)
229 {
230 const uint8_t *buf = avpkt->data;
231 int buf_size = avpkt->size;
232 TTAContext *s = avctx->priv_data;
233 GetBitContext gb;
234 int i, ret;
235 int cur_chan = 0, framelen = s->frame_length;
236 uint32_t *p;
237
238 if (avctx->err_recognition & AV_EF_CRCCHECK) {
239 if (buf_size < 4 ||
240 (tta_check_crc(s, buf, buf_size - 4) && avctx->err_recognition & AV_EF_EXPLODE))
241 return AVERROR_INVALIDDATA;
242 }
243
244 if ((ret = init_get_bits8(&gb, avpkt->data, avpkt->size)) < 0)
245 return ret;
246
247 /* get output buffer */
248 frame->nb_samples = framelen;
249 if ((ret = ff_thread_get_buffer(avctx, frame, 0)) < 0)
250 return ret;
251
252 // decode directly to output buffer for 24-bit sample format
253 if (s->bps == 3)
254 s->decode_buffer = (int32_t *)frame->data[0];
255
256 // init per channel states
257 for (i = 0; i < s->channels; i++) {
258 TTAFilter *filter = &s->ch_ctx[i].filter;
259 s->ch_ctx[i].predictor = 0;
260 ff_tta_filter_init(filter, ff_tta_filter_configs[s->bps-1]);
261 if (s->format == FORMAT_ENCRYPTED) {
262 int i;
263 for (i = 0; i < 8; i++)
264 filter->qm[i] = sign_extend(s->crc_pass[i], 8);
265 }
266 ff_tta_rice_init(&s->ch_ctx[i].rice, 10, 10);
267 }
268
269 i = 0;
270 for (p = s->decode_buffer; (int32_t*)p < s->decode_buffer + (framelen * s->channels); p++) {
271 int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
272 TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
273 TTARice *rice = &s->ch_ctx[cur_chan].rice;
274 uint32_t unary, depth, k;
275 int32_t value;
276
277 unary = get_unary(&gb, 0, get_bits_left(&gb));
278
279 if (unary == 0) {
280 depth = 0;
281 k = rice->k0;
282 } else {
283 depth = 1;
284 k = rice->k1;
285 unary--;
286 }
287
288 if (get_bits_left(&gb) < k) {
289 ret = AVERROR_INVALIDDATA;
290 goto error;
291 }
292
293 if (k) {
294 if (k > MIN_CACHE_BITS || unary > INT32_MAX >> k) {
295 ret = AVERROR_INVALIDDATA;
296 goto error;
297 }
298 value = (unary << k) + get_bits(&gb, k);
299 } else
300 value = unary;
301
302 // FIXME: copy paste from original
303 switch (depth) {
304 case 1:
305 rice->sum1 += value - (rice->sum1 >> 4);
306 if (rice->k1 > 0 && rice->sum1 < ff_tta_shift_16[rice->k1])
307 rice->k1--;
308 else if(rice->sum1 > ff_tta_shift_16[rice->k1 + 1])
309 rice->k1++;
310 value += ff_tta_shift_1[rice->k0];
311 default:
312 rice->sum0 += value - (rice->sum0 >> 4);
313 if (rice->k0 > 0 && rice->sum0 < ff_tta_shift_16[rice->k0])
314 rice->k0--;
315 else if(rice->sum0 > ff_tta_shift_16[rice->k0 + 1])
316 rice->k0++;
317 }
318
319 // extract coded value
320 *p = 1 + ((value >> 1) ^ ((value & 1) - 1));
321
322 // run hybrid filter
323 s->dsp.filter_process(filter->qm, filter->dx, filter->dl, &filter->error, p,
324 filter->shift, filter->round);
325
326 // fixed order prediction
327 #define PRED(x, k) (int32_t)((((uint64_t)(x) << (k)) - (x)) >> (k))
328 switch (s->bps) {
329 case 1: *p += PRED(*predictor, 4); break;
330 case 2:
331 case 3: *p += PRED(*predictor, 5); break;
332 case 4: *p += *predictor; break;
333 }
334 *predictor = *p;
335
336 // flip channels
337 if (cur_chan < (s->channels-1))
338 cur_chan++;
339 else {
340 // decorrelate in case of multiple channels
341 if (s->channels > 1) {
342 int32_t *r = p - 1;
343 for (*p += *r / 2; r > (int32_t*)p - s->channels; r--)
344 *r = *(r + 1) - (unsigned)*r;
345 }
346 cur_chan = 0;
347 i++;
348 // check for last frame
349 if (i == s->last_frame_length && get_bits_left(&gb) / 8 == 4) {
350 frame->nb_samples = framelen = s->last_frame_length;
351 break;
352 }
353 }
354 }
355
356 align_get_bits(&gb);
357 if (get_bits_left(&gb) < 32) {
358 ret = AVERROR_INVALIDDATA;
359 goto error;
360 }
361 skip_bits_long(&gb, 32); // frame crc
362
363 // convert to output buffer
364 switch (s->bps) {
365 case 1: {
366 uint8_t *samples = (uint8_t *)frame->data[0];
367 for (p = s->decode_buffer; (int32_t*)p < s->decode_buffer + (framelen * s->channels); p++)
368 *samples++ = *p + 0x80;
369 break;
370 }
371 case 2: {
372 int16_t *samples = (int16_t *)frame->data[0];
373 for (p = s->decode_buffer; (int32_t*)p < s->decode_buffer + (framelen * s->channels); p++)
374 *samples++ = *p;
375 break;
376 }
377 case 3: {
378 // shift samples for 24-bit sample format
379 int32_t *samples = (int32_t *)frame->data[0];
380 int overflow = 0;
381
382 for (i = 0; i < framelen * s->channels; i++) {
383 int scaled = *samples * 256U;
384 overflow += (scaled >> 8 != *samples);
385 *samples++ = scaled;
386 }
387 if (overflow)
388 av_log(avctx, AV_LOG_WARNING, "%d overflows occurred on 24bit upscale\n", overflow);
389 // reset decode buffer
390 s->decode_buffer = NULL;
391 break;
392 }
393 }
394
395 *got_frame_ptr = 1;
396
397 return buf_size;
398 error:
399 // reset decode buffer
400 if (s->bps == 3)
401 s->decode_buffer = NULL;
402 return ret;
403 }
404
tta_decode_close(AVCodecContext * avctx)405 static av_cold int tta_decode_close(AVCodecContext *avctx) {
406 TTAContext *s = avctx->priv_data;
407
408 if (s->bps < 3)
409 av_freep(&s->decode_buffer);
410 s->decode_buffer = NULL;
411 av_freep(&s->ch_ctx);
412
413 return 0;
414 }
415
416 #define OFFSET(x) offsetof(TTAContext, x)
417 #define DEC (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM)
418 static const AVOption options[] = {
419 { "password", "Set decoding password", OFFSET(pass), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, DEC },
420 { NULL },
421 };
422
423 static const AVClass tta_decoder_class = {
424 .class_name = "TTA Decoder",
425 .item_name = av_default_item_name,
426 .option = options,
427 .version = LIBAVUTIL_VERSION_INT,
428 };
429
430 const FFCodec ff_tta_decoder = {
431 .p.name = "tta",
432 .p.long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
433 .p.type = AVMEDIA_TYPE_AUDIO,
434 .p.id = AV_CODEC_ID_TTA,
435 .priv_data_size = sizeof(TTAContext),
436 .init = tta_decode_init,
437 .close = tta_decode_close,
438 FF_CODEC_DECODE_CB(tta_decode_frame),
439 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_CHANNEL_CONF,
440 .p.priv_class = &tta_decoder_class,
441 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
442 };
443