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 ALT_BITSTREAM_READER_LE
37 #define FORMAT_FLOAT 3
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;
61 int flags, channels, bps, is_float, data_length;
62 int frame_length, last_frame_length, total_frames;
64 int32_t *decode_buffer;
69 static const uint32_t shift_1[] = {
70 0x00000001, 0x00000002, 0x00000004, 0x00000008,
71 0x00000010, 0x00000020, 0x00000040, 0x00000080,
72 0x00000100, 0x00000200, 0x00000400, 0x00000800,
73 0x00001000, 0x00002000, 0x00004000, 0x00008000,
74 0x00010000, 0x00020000, 0x00040000, 0x00080000,
75 0x00100000, 0x00200000, 0x00400000, 0x00800000,
76 0x01000000, 0x02000000, 0x04000000, 0x08000000,
77 0x10000000, 0x20000000, 0x40000000, 0x80000000,
78 0x80000000, 0x80000000, 0x80000000, 0x80000000,
79 0x80000000, 0x80000000, 0x80000000, 0x80000000
82 static const uint32_t * const shift_16 = shift_1 + 4;
84 static const int32_t ttafilter_configs[4][2] = {
91 static void ttafilter_init(TTAFilter *c, int32_t shift, int32_t mode) {
92 memset(c, 0, sizeof(TTAFilter));
94 c->round = shift_1[shift-1];
95 // c->round = 1 << (shift - 1);
99 // FIXME: copy paste from original
100 static inline void memshl(register int32_t *a, register int32_t *b) {
111 // FIXME: copy paste from original
112 // mode=1 encoder, mode=0 decoder
113 static inline void ttafilter_process(TTAFilter *c, int32_t *in, int32_t mode) {
114 register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round;
117 sum += *dl++ * *qm, qm++;
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++;
126 } else if(c->error < 0) {
127 sum += *dl++ * (*qm -= *dx++), qm++;
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++;
136 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++;
146 *(dx-0) = ((*(dl-1) >> 30) | 1) << 2;
147 *(dx-1) = ((*(dl-2) >> 30) | 1) << 1;
148 *(dx-2) = ((*(dl-3) >> 30) | 1) << 1;
149 *(dx-3) = ((*(dl-4) >> 30) | 1);
154 *in -= (sum >> c->shift);
158 *in += (sum >> c->shift);
163 *(dl-1) = *dl - *(dl-1);
164 *(dl-2) = *(dl-1) - *(dl-2);
165 *(dl-3) = *(dl-2) - *(dl-3);
168 memshl(c->dl, c->dl + 1);
169 memshl(c->dx, c->dx + 1);
172 static void rice_init(TTARice *c, uint32_t k0, uint32_t k1)
176 c->sum0 = shift_16[k0];
177 c->sum1 = shift_16[k1];
180 static int tta_get_unary(GetBitContext *gb)
190 static av_cold int tta_decode_init(AVCodecContext * avctx)
192 TTAContext *s = avctx->priv_data;
197 // 30bytes includes a seektable with one frame
198 if (avctx->extradata_size < 30)
201 init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size);
202 if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
205 skip_bits(&s->gb, 32);
206 // if (get_bits_long(&s->gb, 32) != av_bswap32(AV_RL32("TTA1"))) {
207 // av_log(s->avctx, AV_LOG_ERROR, "Missing magic\n");
211 s->flags = get_bits(&s->gb, 16);
212 if (s->flags != 1 && s->flags != 3)
214 av_log(s->avctx, AV_LOG_ERROR, "Invalid flags\n");
217 s->is_float = (s->flags == FORMAT_FLOAT);
218 avctx->channels = s->channels = get_bits(&s->gb, 16);
219 avctx->bits_per_coded_sample = get_bits(&s->gb, 16);
220 s->bps = (avctx->bits_per_coded_sample + 7) / 8;
221 avctx->sample_rate = get_bits_long(&s->gb, 32);
222 if(avctx->sample_rate > 1000000){ //prevent FRAME_TIME * avctx->sample_rate from overflowing and sanity check
223 av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
226 s->data_length = get_bits_long(&s->gb, 32);
227 skip_bits(&s->gb, 32); // CRC32 of header
231 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
232 av_log_ask_for_sample(s->avctx, "Unsupported sample format.\n");
235 else switch(s->bps) {
236 // case 1: avctx->sample_fmt = AV_SAMPLE_FMT_U8; break;
237 case 2: avctx->sample_fmt = AV_SAMPLE_FMT_S16; break;
238 // case 3: avctx->sample_fmt = AV_SAMPLE_FMT_S24; break;
239 case 4: avctx->sample_fmt = AV_SAMPLE_FMT_S32; break;
241 av_log_ask_for_sample(s->avctx,
242 "Invalid/unsupported sample format.\n");
246 // FIXME: horribly broken, but directly from reference source
247 #define FRAME_TIME 1.04489795918367346939
248 s->frame_length = (int)(FRAME_TIME * avctx->sample_rate);
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, "flags: %x chans: %d bps: %d rate: %d block: %d\n",
255 s->flags, 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");
270 s->decode_buffer = av_mallocz(sizeof(int32_t)*s->frame_length*s->channels);
271 s->ch_ctx = av_malloc(avctx->channels * sizeof(*s->ch_ctx));
273 return AVERROR(ENOMEM);
275 av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
282 static int tta_decode_frame(AVCodecContext *avctx,
283 void *data, int *data_size,
286 const uint8_t *buf = avpkt->data;
287 int buf_size = avpkt->size;
288 TTAContext *s = avctx->priv_data;
291 init_get_bits(&s->gb, buf, buf_size*8);
293 int cur_chan = 0, framelen = s->frame_length;
296 if (*data_size < (framelen * s->channels * 2)) {
297 av_log(avctx, AV_LOG_ERROR, "Output buffer size is too small.\n");
302 if (!s->total_frames && s->last_frame_length)
303 framelen = s->last_frame_length;
305 // init per channel states
306 for (i = 0; i < s->channels; i++) {
307 s->ch_ctx[i].predictor = 0;
308 ttafilter_init(&s->ch_ctx[i].filter, ttafilter_configs[s->bps-1][0], ttafilter_configs[s->bps-1][1]);
309 rice_init(&s->ch_ctx[i].rice, 10, 10);
312 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
313 int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
314 TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
315 TTARice *rice = &s->ch_ctx[cur_chan].rice;
316 uint32_t unary, depth, k;
319 unary = tta_get_unary(&s->gb);
330 if (get_bits_left(&s->gb) < k)
334 if (k > MIN_CACHE_BITS)
336 value = (unary << k) + get_bits(&s->gb, k);
340 // FIXME: copy paste from original
343 rice->sum1 += value - (rice->sum1 >> 4);
344 if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
346 else if(rice->sum1 > shift_16[rice->k1 + 1])
348 value += shift_1[rice->k0];
350 rice->sum0 += value - (rice->sum0 >> 4);
351 if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
353 else if(rice->sum0 > shift_16[rice->k0 + 1])
357 // extract coded value
358 #define UNFOLD(x) (((x)&1) ? (++(x)>>1) : (-(x)>>1))
362 ttafilter_process(filter, p, 0);
364 // fixed order prediction
365 #define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k)
367 case 1: *p += PRED(*predictor, 4); break;
369 case 3: *p += PRED(*predictor, 5); break;
370 case 4: *p += *predictor; break;
374 /*if ((get_bits_count(&s->gb)+7)/8 > buf_size)
376 av_log(NULL, AV_LOG_INFO, "overread!!\n");
381 if (cur_chan < (s->channels-1))
384 // decorrelate in case of stereo integer
385 if (!s->is_float && (s->channels > 1)) {
387 for (*p += *r / 2; r > p - s->channels; r--)
394 if (get_bits_left(&s->gb) < 32)
396 skip_bits(&s->gb, 32); // frame crc
398 // convert to output buffer
401 uint16_t *samples = data;
402 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
403 // *samples++ = (unsigned char)*p;
404 // *samples++ = (unsigned char)(*p >> 8);
407 *data_size = (uint8_t *)samples - (uint8_t *)data;
411 av_log(s->avctx, AV_LOG_ERROR, "Error, only 16bit samples supported!\n");
415 // return get_bits_count(&s->gb)+7)/8;
419 static av_cold int tta_decode_close(AVCodecContext *avctx) {
420 TTAContext *s = avctx->priv_data;
422 av_free(s->decode_buffer);
423 av_freep(&s->ch_ctx);
428 AVCodec ff_tta_decoder = {
430 .type = AVMEDIA_TYPE_AUDIO,
432 .priv_data_size = sizeof(TTAContext),
433 .init = tta_decode_init,
434 .close = tta_decode_close,
435 .decode = tta_decode_frame,
436 .long_name = NULL_IF_CONFIG_SMALL("True Audio (TTA)"),