2 * TTA (The Lossless True Audio) decoder
3 * Copyright (c) 2006 Alex Beregszaszi
5 * This file is part of FFmpeg.
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.
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.
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
23 * @file libavcodec/tta.c
24 * TTA (The Lossless True Audio) decoder
25 * (www.true-audio.com or tta.corecodec.org)
26 * @author Alex Beregszaszi
30 #define ALT_BITSTREAM_READER_LE
34 #include "bitstream.h"
37 #define FORMAT_FLOAT 3
39 typedef struct TTAContext {
40 AVCodecContext *avctx;
43 int flags, channels, bps, is_float, data_length;
44 int frame_length, last_frame_length, total_frames;
46 int32_t *decode_buffer;
50 static inline int shift_1(int i)
55 return 0x80000000; // 16 << 31
58 static inline int shift_16(int i)
63 return 0x80000000; // 16 << 27
66 static const uint32_t shift_1[] = {
67 0x00000001, 0x00000002, 0x00000004, 0x00000008,
68 0x00000010, 0x00000020, 0x00000040, 0x00000080,
69 0x00000100, 0x00000200, 0x00000400, 0x00000800,
70 0x00001000, 0x00002000, 0x00004000, 0x00008000,
71 0x00010000, 0x00020000, 0x00040000, 0x00080000,
72 0x00100000, 0x00200000, 0x00400000, 0x00800000,
73 0x01000000, 0x02000000, 0x04000000, 0x08000000,
74 0x10000000, 0x20000000, 0x40000000, 0x80000000,
75 0x80000000, 0x80000000, 0x80000000, 0x80000000,
76 0x80000000, 0x80000000, 0x80000000, 0x80000000
79 static const uint32_t * const shift_16 = shift_1 + 4;
83 typedef struct TTAFilter {
84 int32_t shift, round, error, mode;
85 int32_t qm[MAX_ORDER];
86 int32_t dx[MAX_ORDER];
87 int32_t dl[MAX_ORDER];
90 static const int32_t ttafilter_configs[4][2] = {
97 static void ttafilter_init(TTAFilter *c, int32_t shift, int32_t mode) {
98 memset(c, 0, sizeof(TTAFilter));
100 c->round = shift_1[shift-1];
101 // c->round = 1 << (shift - 1);
105 // FIXME: copy paste from original
106 static inline void memshl(register int32_t *a, register int32_t *b) {
117 // FIXME: copy paste from original
118 // mode=1 encoder, mode=0 decoder
119 static inline void ttafilter_process(TTAFilter *c, int32_t *in, int32_t mode) {
120 register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round;
123 sum += *dl++ * *qm, qm++;
124 sum += *dl++ * *qm, qm++;
125 sum += *dl++ * *qm, qm++;
126 sum += *dl++ * *qm, qm++;
127 sum += *dl++ * *qm, qm++;
128 sum += *dl++ * *qm, qm++;
129 sum += *dl++ * *qm, qm++;
130 sum += *dl++ * *qm, qm++;
132 } else if(c->error < 0) {
133 sum += *dl++ * (*qm -= *dx++), qm++;
134 sum += *dl++ * (*qm -= *dx++), qm++;
135 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++;
142 sum += *dl++ * (*qm += *dx++), qm++;
143 sum += *dl++ * (*qm += *dx++), qm++;
144 sum += *dl++ * (*qm += *dx++), qm++;
145 sum += *dl++ * (*qm += *dx++), qm++;
146 sum += *dl++ * (*qm += *dx++), qm++;
147 sum += *dl++ * (*qm += *dx++), qm++;
148 sum += *dl++ * (*qm += *dx++), qm++;
149 sum += *dl++ * (*qm += *dx++), qm++;
152 *(dx-0) = ((*(dl-1) >> 30) | 1) << 2;
153 *(dx-1) = ((*(dl-2) >> 30) | 1) << 1;
154 *(dx-2) = ((*(dl-3) >> 30) | 1) << 1;
155 *(dx-3) = ((*(dl-4) >> 30) | 1);
160 *in -= (sum >> c->shift);
164 *in += (sum >> c->shift);
169 *(dl-1) = *dl - *(dl-1);
170 *(dl-2) = *(dl-1) - *(dl-2);
171 *(dl-3) = *(dl-2) - *(dl-3);
174 memshl(c->dl, c->dl + 1);
175 memshl(c->dx, c->dx + 1);
178 typedef struct TTARice {
179 uint32_t k0, k1, sum0, sum1;
182 static void rice_init(TTARice *c, uint32_t k0, uint32_t k1)
186 c->sum0 = shift_16[k0];
187 c->sum1 = shift_16[k1];
190 static int tta_get_unary(GetBitContext *gb)
200 static av_cold int tta_decode_init(AVCodecContext * avctx)
202 TTAContext *s = avctx->priv_data;
207 // 30bytes includes a seektable with one frame
208 if (avctx->extradata_size < 30)
211 init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size);
212 if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
215 skip_bits(&s->gb, 32);
216 // if (get_bits_long(&s->gb, 32) != bswap_32(AV_RL32("TTA1"))) {
217 // av_log(s->avctx, AV_LOG_ERROR, "Missing magic\n");
221 s->flags = get_bits(&s->gb, 16);
222 if (s->flags != 1 && s->flags != 3)
224 av_log(s->avctx, AV_LOG_ERROR, "Invalid flags\n");
227 s->is_float = (s->flags == FORMAT_FLOAT);
228 avctx->channels = s->channels = get_bits(&s->gb, 16);
229 avctx->bits_per_coded_sample = get_bits(&s->gb, 16);
230 s->bps = (avctx->bits_per_coded_sample + 7) / 8;
231 avctx->sample_rate = get_bits_long(&s->gb, 32);
232 if(avctx->sample_rate > 1000000){ //prevent FRAME_TIME * avctx->sample_rate from overflowing and sanity check
233 av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
236 s->data_length = get_bits_long(&s->gb, 32);
237 skip_bits(&s->gb, 32); // CRC32 of header
241 avctx->sample_fmt = SAMPLE_FMT_FLT;
242 av_log(s->avctx, AV_LOG_ERROR, "Unsupported sample format. Please contact the developers.\n");
245 else switch(s->bps) {
246 // case 1: avctx->sample_fmt = SAMPLE_FMT_U8; break;
247 case 2: avctx->sample_fmt = SAMPLE_FMT_S16; break;
248 // case 3: avctx->sample_fmt = SAMPLE_FMT_S24; break;
249 case 4: avctx->sample_fmt = SAMPLE_FMT_S32; break;
251 av_log(s->avctx, AV_LOG_ERROR, "Invalid/unsupported sample format. Please contact the developers.\n");
255 // FIXME: horribly broken, but directly from reference source
256 #define FRAME_TIME 1.04489795918367346939
257 s->frame_length = (int)(FRAME_TIME * avctx->sample_rate);
259 s->last_frame_length = s->data_length % s->frame_length;
260 s->total_frames = s->data_length / s->frame_length +
261 (s->last_frame_length ? 1 : 0);
263 av_log(s->avctx, AV_LOG_DEBUG, "flags: %x chans: %d bps: %d rate: %d block: %d\n",
264 s->flags, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate,
266 av_log(s->avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
267 s->data_length, s->frame_length, s->last_frame_length, s->total_frames);
270 for (i = 0; i < s->total_frames; i++)
271 skip_bits(&s->gb, 32);
272 skip_bits(&s->gb, 32); // CRC32 of seektable
274 if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
275 av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
279 s->decode_buffer = av_mallocz(sizeof(int32_t)*s->frame_length*s->channels);
281 av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
288 static int tta_decode_frame(AVCodecContext *avctx,
289 void *data, int *data_size,
290 const uint8_t *buf, int buf_size)
292 TTAContext *s = avctx->priv_data;
295 init_get_bits(&s->gb, buf, buf_size*8);
297 int32_t predictors[s->channels];
298 TTAFilter filters[s->channels];
299 TTARice rices[s->channels];
300 int cur_chan = 0, framelen = s->frame_length;
305 if (!s->total_frames && s->last_frame_length)
306 framelen = s->last_frame_length;
308 // init per channel states
309 for (i = 0; i < s->channels; i++) {
311 ttafilter_init(&(filters[i]), ttafilter_configs[s->bps-1][0], ttafilter_configs[s->bps-1][1]);
312 rice_init(&(rices[i]), 10, 10);
315 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
316 int32_t *predictor = &(predictors[cur_chan]);
317 TTAFilter *filter = &(filters[cur_chan]);
318 TTARice *rice = &(rices[cur_chan]);
319 uint32_t unary, depth, k;
322 unary = tta_get_unary(&s->gb);
334 value = (unary << k) + get_bits(&s->gb, k);
338 // FIXME: copy paste from original
341 rice->sum1 += value - (rice->sum1 >> 4);
342 if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
344 else if(rice->sum1 > shift_16[rice->k1 + 1])
346 value += shift_1[rice->k0];
348 rice->sum0 += value - (rice->sum0 >> 4);
349 if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
351 else if(rice->sum0 > shift_16[rice->k0 + 1])
355 // extract coded value
356 #define UNFOLD(x) (((x)&1) ? (++(x)>>1) : (-(x)>>1))
360 ttafilter_process(filter, p, 0);
362 // fixed order prediction
363 #define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k)
365 case 1: *p += PRED(*predictor, 4); break;
367 case 3: *p += PRED(*predictor, 5); break;
368 case 4: *p += *predictor; break;
373 // extract 32bit float from last two int samples
374 if (s->is_float && ((p - data) & 1)) {
375 uint32_t neg = *p & 0x80000000;
376 uint32_t hi = *(p - 1);
377 uint32_t lo = abs(*p) - 1;
379 hi += (hi || lo) ? 0x3f80 : 0;
380 // SWAP16: swap all the 16 bits
381 *(p - 1) = (hi << 16) | SWAP16(lo) | neg;
385 /*if ((get_bits_count(&s->gb)+7)/8 > buf_size)
387 av_log(NULL, AV_LOG_INFO, "overread!!\n");
392 if (cur_chan < (s->channels-1))
395 // decorrelate in case of stereo integer
396 if (!s->is_float && (s->channels > 1)) {
398 for (*p += *r / 2; r > p - s->channels; r--)
405 skip_bits(&s->gb, 32); // frame crc
407 // convert to output buffer
410 uint16_t *samples = data;
411 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
412 // *samples++ = (unsigned char)*p;
413 // *samples++ = (unsigned char)(*p >> 8);
416 *data_size = (uint8_t *)samples - (uint8_t *)data;
420 av_log(s->avctx, AV_LOG_ERROR, "Error, only 16bit samples supported!\n");
424 // return get_bits_count(&s->gb)+7)/8;
428 static av_cold int tta_decode_close(AVCodecContext *avctx) {
429 TTAContext *s = avctx->priv_data;
431 if (s->decode_buffer)
432 av_free(s->decode_buffer);
437 AVCodec tta_decoder = {
446 .long_name = NULL_IF_CONFIG_SMALL("True Audio (TTA)"),