2 * TTA (The Lossless True Audio) decoder
3 * Copyright (c) 2006 Alex Beregszaszi
5 * This file is part of Libav.
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.
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.
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
24 * TTA (The Lossless True Audio) decoder
25 * @see http://www.true-audio.com/
26 * @see http://tta.corecodec.org/
27 * @author Alex Beregszaszi
30 #define BITSTREAM_READER_LE
35 #include "libavutil/crc.h"
37 #define FORMAT_SIMPLE 1
38 #define FORMAT_ENCRYPTED 2
41 typedef struct TTAFilter {
42 int32_t shift, round, error;
43 int32_t qm[MAX_ORDER];
44 int32_t dx[MAX_ORDER];
45 int32_t dl[MAX_ORDER];
48 typedef struct TTARice {
49 uint32_t k0, k1, sum0, sum1;
52 typedef struct TTAChannel {
58 typedef struct TTAContext {
59 AVCodecContext *avctx;
62 const AVCRC *crc_table;
64 int format, channels, bps;
66 int frame_length, last_frame_length, total_frames;
68 int32_t *decode_buffer;
73 static const uint32_t shift_1[] = {
74 0x00000001, 0x00000002, 0x00000004, 0x00000008,
75 0x00000010, 0x00000020, 0x00000040, 0x00000080,
76 0x00000100, 0x00000200, 0x00000400, 0x00000800,
77 0x00001000, 0x00002000, 0x00004000, 0x00008000,
78 0x00010000, 0x00020000, 0x00040000, 0x00080000,
79 0x00100000, 0x00200000, 0x00400000, 0x00800000,
80 0x01000000, 0x02000000, 0x04000000, 0x08000000,
81 0x10000000, 0x20000000, 0x40000000, 0x80000000,
82 0x80000000, 0x80000000, 0x80000000, 0x80000000,
83 0x80000000, 0x80000000, 0x80000000, 0x80000000
86 static const uint32_t * const shift_16 = shift_1 + 4;
88 static const int32_t ttafilter_configs[4] = {
95 static void ttafilter_init(TTAFilter *c, int32_t shift) {
96 memset(c, 0, sizeof(TTAFilter));
98 c->round = shift_1[shift-1];
99 // c->round = 1 << (shift - 1);
102 // FIXME: copy paste from original
103 static inline void memshl(register int32_t *a, register int32_t *b) {
114 static inline void ttafilter_process(TTAFilter *c, int32_t *in)
116 register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round;
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 sum += *dl++ * *qm, qm++;
128 } else if(c->error < 0) {
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 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 sum += *dl++ * (*qm += *dx++), qm++;
148 *(dx-0) = ((*(dl-1) >> 30) | 1) << 2;
149 *(dx-1) = ((*(dl-2) >> 30) | 1) << 1;
150 *(dx-2) = ((*(dl-3) >> 30) | 1) << 1;
151 *(dx-3) = ((*(dl-4) >> 30) | 1);
154 *in += (sum >> c->shift);
157 *(dl-1) = *dl - *(dl-1);
158 *(dl-2) = *(dl-1) - *(dl-2);
159 *(dl-3) = *(dl-2) - *(dl-3);
161 memshl(c->dl, c->dl + 1);
162 memshl(c->dx, c->dx + 1);
165 static void rice_init(TTARice *c, uint32_t k0, uint32_t k1)
169 c->sum0 = shift_16[k0];
170 c->sum1 = shift_16[k1];
173 static int tta_get_unary(GetBitContext *gb)
178 while (get_bits_left(gb) > 0 && get_bits1(gb))
183 static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
187 CRC = AV_RL32(buf + buf_size);
188 crc = av_crc(s->crc_table, 0xFFFFFFFFU, buf, buf_size);
189 if (CRC != (crc ^ 0xFFFFFFFFU)) {
190 av_log(s->avctx, AV_LOG_ERROR, "CRC error\n");
191 return AVERROR_INVALIDDATA;
197 static av_cold int tta_decode_init(AVCodecContext * avctx)
199 TTAContext *s = avctx->priv_data;
203 // 30bytes includes a seektable with one frame
204 if (avctx->extradata_size < 30)
207 init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size * 8);
208 if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
210 if (avctx->err_recognition & AV_EF_CRCCHECK) {
211 s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
212 tta_check_crc(s, avctx->extradata, 18);
216 skip_bits_long(&s->gb, 32);
218 s->format = get_bits(&s->gb, 16);
220 av_log(s->avctx, AV_LOG_ERROR, "Invalid format\n");
223 if (s->format == FORMAT_ENCRYPTED) {
224 av_log_missing_feature(s->avctx, "Encrypted TTA", 0);
225 return AVERROR(EINVAL);
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
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;
244 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
245 avctx->bits_per_raw_sample = 16;
248 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
249 avctx->bits_per_raw_sample = 24;
252 av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported sample format.\n");
253 return AVERROR_INVALIDDATA;
257 if (avctx->sample_rate > 0x7FFFFFu) {
258 av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
259 return AVERROR(EINVAL);
261 s->frame_length = 256 * avctx->sample_rate / 245;
263 s->last_frame_length = s->data_length % s->frame_length;
264 s->total_frames = s->data_length / s->frame_length +
265 (s->last_frame_length ? 1 : 0);
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,
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, s->total_frames);
274 if (avctx->extradata_size <= 26 || s->total_frames > INT_MAX / 4 ||
275 avctx->extradata_size - 26 < s->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 if (tta_check_crc(s, avctx->extradata + 22, s->total_frames * 4))
279 return AVERROR_INVALIDDATA;
281 skip_bits_long(&s->gb, 32 * s->total_frames);
282 skip_bits_long(&s->gb, 32); // CRC32 of seektable
284 if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
285 av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
290 s->decode_buffer = av_mallocz(sizeof(int32_t)*s->frame_length*s->channels);
291 if (!s->decode_buffer)
292 return AVERROR(ENOMEM);
294 s->ch_ctx = av_malloc(avctx->channels * sizeof(*s->ch_ctx));
296 av_freep(&s->decode_buffer);
297 return AVERROR(ENOMEM);
300 av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
304 avcodec_get_frame_defaults(&s->frame);
305 avctx->coded_frame = &s->frame;
310 static int tta_decode_frame(AVCodecContext *avctx, void *data,
311 int *got_frame_ptr, AVPacket *avpkt)
313 const uint8_t *buf = avpkt->data;
314 int buf_size = avpkt->size;
315 TTAContext *s = avctx->priv_data;
317 int cur_chan = 0, framelen = s->frame_length;
320 if (avctx->err_recognition & AV_EF_CRCCHECK) {
321 if (buf_size < 4 || tta_check_crc(s, buf, buf_size - 4))
322 return AVERROR_INVALIDDATA;
325 init_get_bits(&s->gb, buf, buf_size*8);
329 if (!s->total_frames && s->last_frame_length)
330 framelen = s->last_frame_length;
332 /* get output buffer */
333 s->frame.nb_samples = framelen;
334 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
335 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
339 // decode directly to output buffer for 24-bit sample format
341 s->decode_buffer = (int32_t *)s->frame.data[0];
343 // init per channel states
344 for (i = 0; i < s->channels; i++) {
345 s->ch_ctx[i].predictor = 0;
346 ttafilter_init(&s->ch_ctx[i].filter, ttafilter_configs[s->bps-1]);
347 rice_init(&s->ch_ctx[i].rice, 10, 10);
350 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
351 int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
352 TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
353 TTARice *rice = &s->ch_ctx[cur_chan].rice;
354 uint32_t unary, depth, k;
357 unary = tta_get_unary(&s->gb);
368 if (get_bits_left(&s->gb) < k) {
369 ret = AVERROR_INVALIDDATA;
374 if (k > MIN_CACHE_BITS) {
375 ret = AVERROR_INVALIDDATA;
378 value = (unary << k) + get_bits(&s->gb, k);
382 // FIXME: copy paste from original
385 rice->sum1 += value - (rice->sum1 >> 4);
386 if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
388 else if(rice->sum1 > shift_16[rice->k1 + 1])
390 value += shift_1[rice->k0];
392 rice->sum0 += value - (rice->sum0 >> 4);
393 if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
395 else if(rice->sum0 > shift_16[rice->k0 + 1])
399 // extract coded value
400 *p = 1 + ((value >> 1) ^ ((value & 1) - 1));
403 ttafilter_process(filter, p);
405 // fixed order prediction
406 #define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k)
408 case 1: *p += PRED(*predictor, 4); break;
410 case 3: *p += PRED(*predictor, 5); break;
411 case 4: *p += *predictor; break;
416 if (cur_chan < (s->channels-1))
419 // decorrelate in case of stereo integer
420 if (s->channels > 1) {
422 for (*p += *r / 2; r > p - s->channels; r--)
429 if (get_bits_left(&s->gb) < 32) {
430 ret = AVERROR_INVALIDDATA;
433 skip_bits_long(&s->gb, 32); // frame crc
435 // convert to output buffer
437 int16_t *samples = (int16_t *)s->frame.data[0];
438 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
441 // shift samples for 24-bit sample format
442 int32_t *samples = (int32_t *)s->frame.data[0];
443 for (i = 0; i < framelen * s->channels; i++)
445 // reset decode buffer
446 s->decode_buffer = NULL;
450 *(AVFrame *)data = s->frame;
454 // reset decode buffer
456 s->decode_buffer = NULL;
460 static av_cold int tta_decode_close(AVCodecContext *avctx) {
461 TTAContext *s = avctx->priv_data;
463 av_free(s->decode_buffer);
464 av_freep(&s->ch_ctx);
469 AVCodec ff_tta_decoder = {
471 .type = AVMEDIA_TYPE_AUDIO,
473 .priv_data_size = sizeof(TTAContext),
474 .init = tta_decode_init,
475 .close = tta_decode_close,
476 .decode = tta_decode_frame,
477 .capabilities = CODEC_CAP_DR1,
478 .long_name = NULL_IF_CONFIG_SMALL("True Audio (TTA)"),