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
36 #define FORMAT_SIMPLE 1
37 #define FORMAT_ENCRYPTED 2
40 typedef struct TTAFilter {
41 int32_t shift, round, error, mode;
42 int32_t qm[MAX_ORDER];
43 int32_t dx[MAX_ORDER];
44 int32_t dl[MAX_ORDER];
47 typedef struct TTARice {
48 uint32_t k0, k1, sum0, sum1;
51 typedef struct TTAChannel {
57 typedef struct TTAContext {
58 AVCodecContext *avctx;
62 int format, channels, bps, data_length;
63 int frame_length, last_frame_length, total_frames;
65 int32_t *decode_buffer;
70 static const uint32_t shift_1[] = {
71 0x00000001, 0x00000002, 0x00000004, 0x00000008,
72 0x00000010, 0x00000020, 0x00000040, 0x00000080,
73 0x00000100, 0x00000200, 0x00000400, 0x00000800,
74 0x00001000, 0x00002000, 0x00004000, 0x00008000,
75 0x00010000, 0x00020000, 0x00040000, 0x00080000,
76 0x00100000, 0x00200000, 0x00400000, 0x00800000,
77 0x01000000, 0x02000000, 0x04000000, 0x08000000,
78 0x10000000, 0x20000000, 0x40000000, 0x80000000,
79 0x80000000, 0x80000000, 0x80000000, 0x80000000,
80 0x80000000, 0x80000000, 0x80000000, 0x80000000
83 static const uint32_t * const shift_16 = shift_1 + 4;
85 static const int32_t ttafilter_configs[4][2] = {
92 static void ttafilter_init(TTAFilter *c, int32_t shift, int32_t mode) {
93 memset(c, 0, sizeof(TTAFilter));
95 c->round = shift_1[shift-1];
96 // c->round = 1 << (shift - 1);
100 // FIXME: copy paste from original
101 static inline void memshl(register int32_t *a, register int32_t *b) {
112 // FIXME: copy paste from original
113 // mode=1 encoder, mode=0 decoder
114 static inline void ttafilter_process(TTAFilter *c, int32_t *in, int32_t mode) {
115 register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round;
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++;
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++;
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++;
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);
155 *in -= (sum >> c->shift);
159 *in += (sum >> c->shift);
164 *(dl-1) = *dl - *(dl-1);
165 *(dl-2) = *(dl-1) - *(dl-2);
166 *(dl-3) = *(dl-2) - *(dl-3);
169 memshl(c->dl, c->dl + 1);
170 memshl(c->dx, c->dx + 1);
173 static void rice_init(TTARice *c, uint32_t k0, uint32_t k1)
177 c->sum0 = shift_16[k0];
178 c->sum1 = shift_16[k1];
181 static int tta_get_unary(GetBitContext *gb)
186 while (get_bits_left(gb) > 0 && get_bits1(gb))
191 static av_cold int tta_decode_init(AVCodecContext * avctx)
193 TTAContext *s = avctx->priv_data;
198 // 30bytes includes a seektable with one frame
199 if (avctx->extradata_size < 30)
202 init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size * 8);
203 if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
206 skip_bits(&s->gb, 32);
208 s->format = get_bits(&s->gb, 16);
210 av_log(s->avctx, AV_LOG_ERROR, "Invalid format\n");
213 if (s->format == FORMAT_ENCRYPTED) {
214 av_log_missing_feature(s->avctx, "Encrypted TTA", 0);
215 return AVERROR(EINVAL);
217 avctx->channels = s->channels = get_bits(&s->gb, 16);
218 avctx->bits_per_coded_sample = get_bits(&s->gb, 16);
219 s->bps = (avctx->bits_per_coded_sample + 7) / 8;
220 avctx->sample_rate = get_bits_long(&s->gb, 32);
221 s->data_length = get_bits_long(&s->gb, 32);
222 skip_bits(&s->gb, 32); // CRC32 of header
224 if (s->channels == 0) {
225 av_log(s->avctx, AV_LOG_ERROR, "Invalid number of channels\n");
226 return AVERROR_INVALIDDATA;
231 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
232 avctx->bits_per_raw_sample = 16;
235 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
236 avctx->bits_per_raw_sample = 24;
239 av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported sample format.\n");
240 return AVERROR_INVALIDDATA;
244 if (avctx->sample_rate > 0x7FFFFF) {
245 av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
246 return AVERROR(EINVAL);
248 s->frame_length = 256 * avctx->sample_rate / 245;
250 s->last_frame_length = s->data_length % s->frame_length;
251 s->total_frames = s->data_length / s->frame_length +
252 (s->last_frame_length ? 1 : 0);
254 av_log(s->avctx, AV_LOG_DEBUG, "format: %d chans: %d bps: %d rate: %d block: %d\n",
255 s->format, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate,
257 av_log(s->avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
258 s->data_length, s->frame_length, s->last_frame_length, s->total_frames);
261 for (i = 0; i < s->total_frames; i++)
262 skip_bits(&s->gb, 32);
263 skip_bits(&s->gb, 32); // CRC32 of seektable
265 if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
266 av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
271 s->decode_buffer = av_mallocz(sizeof(int32_t)*s->frame_length*s->channels);
272 if (!s->decode_buffer)
273 return AVERROR(ENOMEM);
275 s->ch_ctx = av_malloc(avctx->channels * sizeof(*s->ch_ctx));
277 av_freep(&s->decode_buffer);
278 return AVERROR(ENOMEM);
281 av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
285 avcodec_get_frame_defaults(&s->frame);
286 avctx->coded_frame = &s->frame;
291 static int tta_decode_frame(AVCodecContext *avctx, void *data,
292 int *got_frame_ptr, AVPacket *avpkt)
294 const uint8_t *buf = avpkt->data;
295 int buf_size = avpkt->size;
296 TTAContext *s = avctx->priv_data;
298 int cur_chan = 0, framelen = s->frame_length;
301 init_get_bits(&s->gb, buf, buf_size*8);
305 if (!s->total_frames && s->last_frame_length)
306 framelen = s->last_frame_length;
308 /* get output buffer */
309 s->frame.nb_samples = framelen;
310 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
311 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
315 // decode directly to output buffer for 24-bit sample format
317 s->decode_buffer = data;
319 // init per channel states
320 for (i = 0; i < s->channels; i++) {
321 s->ch_ctx[i].predictor = 0;
322 ttafilter_init(&s->ch_ctx[i].filter, ttafilter_configs[s->bps-1][0], ttafilter_configs[s->bps-1][1]);
323 rice_init(&s->ch_ctx[i].rice, 10, 10);
326 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
327 int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
328 TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
329 TTARice *rice = &s->ch_ctx[cur_chan].rice;
330 uint32_t unary, depth, k;
333 unary = tta_get_unary(&s->gb);
344 if (get_bits_left(&s->gb) < k)
348 if (k > MIN_CACHE_BITS)
350 value = (unary << k) + get_bits(&s->gb, k);
354 // FIXME: copy paste from original
357 rice->sum1 += value - (rice->sum1 >> 4);
358 if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
360 else if(rice->sum1 > shift_16[rice->k1 + 1])
362 value += shift_1[rice->k0];
364 rice->sum0 += value - (rice->sum0 >> 4);
365 if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
367 else if(rice->sum0 > shift_16[rice->k0 + 1])
371 // extract coded value
372 #define UNFOLD(x) (((x)&1) ? (++(x)>>1) : (-(x)>>1))
376 ttafilter_process(filter, p, 0);
378 // fixed order prediction
379 #define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k)
381 case 1: *p += PRED(*predictor, 4); break;
383 case 3: *p += PRED(*predictor, 5); break;
384 case 4: *p += *predictor; break;
389 if (cur_chan < (s->channels-1))
392 // decorrelate in case of stereo integer
393 if (s->channels > 1) {
395 for (*p += *r / 2; r > p - s->channels; r--)
402 if (get_bits_left(&s->gb) < 32)
404 skip_bits(&s->gb, 32); // frame crc
406 // convert to output buffer
408 int16_t *samples = (int16_t *)s->frame.data[0];
409 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
412 // shift samples for 24-bit sample format
413 int32_t *samples = (int32_t *)s->frame.data[0];
414 for (i = 0; i < framelen * s->channels; i++)
416 // reset decode buffer
417 s->decode_buffer = NULL;
421 *(AVFrame *)data = s->frame;
426 static av_cold int tta_decode_close(AVCodecContext *avctx) {
427 TTAContext *s = avctx->priv_data;
429 av_free(s->decode_buffer);
430 av_freep(&s->ch_ctx);
435 AVCodec ff_tta_decoder = {
437 .type = AVMEDIA_TYPE_AUDIO,
439 .priv_data_size = sizeof(TTAContext),
440 .init = tta_decode_init,
441 .close = tta_decode_close,
442 .decode = tta_decode_frame,
443 .capabilities = CODEC_CAP_DR1,
444 .long_name = NULL_IF_CONFIG_SMALL("True Audio (TTA)"),