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
* (www.true-audio.com or tta.corecodec.org)
26
* @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;
70
static inline int shift_1(int i)
75
return 0x80000000; // 16 << 31
78
static inline int shift_16(int i)
83
return 0x80000000; // 16 << 27
86
static const uint32_t shift_1[] = {
87
0x00000001, 0x00000002, 0x00000004, 0x00000008,
88
0x00000010, 0x00000020, 0x00000040, 0x00000080,
89
0x00000100, 0x00000200, 0x00000400, 0x00000800,
90
0x00001000, 0x00002000, 0x00004000, 0x00008000,
91
0x00010000, 0x00020000, 0x00040000, 0x00080000,
92
0x00100000, 0x00200000, 0x00400000, 0x00800000,
93
0x01000000, 0x02000000, 0x04000000, 0x08000000,
94
0x10000000, 0x20000000, 0x40000000, 0x80000000,
95
0x80000000, 0x80000000, 0x80000000, 0x80000000,
96
0x80000000, 0x80000000, 0x80000000, 0x80000000
99
static const uint32_t * const shift_16 = shift_1 + 4;
102
static const int32_t ttafilter_configs[4][2] = {
109
static void ttafilter_init(TTAFilter *c, int32_t shift, int32_t mode) {
110
memset(c, 0, sizeof(TTAFilter));
112
c->round = shift_1[shift-1];
113
// c->round = 1 << (shift - 1);
117
// FIXME: copy paste from original
118
static inline void memshl(register int32_t *a, register int32_t *b) {
129
// FIXME: copy paste from original
130
// mode=1 encoder, mode=0 decoder
131
static inline void ttafilter_process(TTAFilter *c, int32_t *in, int32_t mode) {
132
register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round;
135
sum += *dl++ * *qm, qm++;
136
sum += *dl++ * *qm, qm++;
137
sum += *dl++ * *qm, qm++;
138
sum += *dl++ * *qm, qm++;
139
sum += *dl++ * *qm, qm++;
140
sum += *dl++ * *qm, qm++;
141
sum += *dl++ * *qm, qm++;
142
sum += *dl++ * *qm, qm++;
144
} else if(c->error < 0) {
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++;
150
sum += *dl++ * (*qm -= *dx++), qm++;
151
sum += *dl++ * (*qm -= *dx++), qm++;
152
sum += *dl++ * (*qm -= *dx++), qm++;
154
sum += *dl++ * (*qm += *dx++), qm++;
155
sum += *dl++ * (*qm += *dx++), qm++;
156
sum += *dl++ * (*qm += *dx++), qm++;
157
sum += *dl++ * (*qm += *dx++), qm++;
158
sum += *dl++ * (*qm += *dx++), qm++;
159
sum += *dl++ * (*qm += *dx++), qm++;
160
sum += *dl++ * (*qm += *dx++), qm++;
161
sum += *dl++ * (*qm += *dx++), qm++;
164
*(dx-0) = ((*(dl-1) >> 30) | 1) << 2;
165
*(dx-1) = ((*(dl-2) >> 30) | 1) << 1;
166
*(dx-2) = ((*(dl-3) >> 30) | 1) << 1;
167
*(dx-3) = ((*(dl-4) >> 30) | 1);
172
*in -= (sum >> c->shift);
176
*in += (sum >> c->shift);
181
*(dl-1) = *dl - *(dl-1);
182
*(dl-2) = *(dl-1) - *(dl-2);
183
*(dl-3) = *(dl-2) - *(dl-3);
186
memshl(c->dl, c->dl + 1);
187
memshl(c->dx, c->dx + 1);
190
static void rice_init(TTARice *c, uint32_t k0, uint32_t k1)
194
c->sum0 = shift_16[k0];
195
c->sum1 = shift_16[k1];
198
static int tta_get_unary(GetBitContext *gb)
208
static av_cold int tta_decode_init(AVCodecContext * avctx)
210
TTAContext *s = avctx->priv_data;
215
// 30bytes includes a seektable with one frame
216
if (avctx->extradata_size < 30)
219
init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size);
220
if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
223
skip_bits(&s->gb, 32);
224
// if (get_bits_long(&s->gb, 32) != av_bswap32(AV_RL32("TTA1"))) {
225
// av_log(s->avctx, AV_LOG_ERROR, "Missing magic\n");
229
s->flags = get_bits(&s->gb, 16);
230
if (s->flags != 1 && s->flags != 3)
232
av_log(s->avctx, AV_LOG_ERROR, "Invalid flags\n");
235
s->is_float = (s->flags == FORMAT_FLOAT);
236
avctx->channels = s->channels = get_bits(&s->gb, 16);
237
avctx->bits_per_coded_sample = get_bits(&s->gb, 16);
238
s->bps = (avctx->bits_per_coded_sample + 7) / 8;
239
avctx->sample_rate = get_bits_long(&s->gb, 32);
240
if(avctx->sample_rate > 1000000){ //prevent FRAME_TIME * avctx->sample_rate from overflowing and sanity check
241
av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
244
s->data_length = get_bits_long(&s->gb, 32);
245
skip_bits(&s->gb, 32); // CRC32 of header
249
avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
250
av_log_ask_for_sample(s->avctx, "Unsupported sample format.\n");
253
else switch(s->bps) {
254
// case 1: avctx->sample_fmt = AV_SAMPLE_FMT_U8; break;
255
case 2: avctx->sample_fmt = AV_SAMPLE_FMT_S16; break;
256
// case 3: avctx->sample_fmt = AV_SAMPLE_FMT_S24; break;
257
case 4: avctx->sample_fmt = AV_SAMPLE_FMT_S32; break;
259
av_log_ask_for_sample(s->avctx,
260
"Invalid/unsupported sample format.\n");
264
// FIXME: horribly broken, but directly from reference source
265
#define FRAME_TIME 1.04489795918367346939
266
s->frame_length = (int)(FRAME_TIME * avctx->sample_rate);
268
s->last_frame_length = s->data_length % s->frame_length;
269
s->total_frames = s->data_length / s->frame_length +
270
(s->last_frame_length ? 1 : 0);
272
av_log(s->avctx, AV_LOG_DEBUG, "flags: %x chans: %d bps: %d rate: %d block: %d\n",
273
s->flags, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate,
275
av_log(s->avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
276
s->data_length, s->frame_length, s->last_frame_length, s->total_frames);
279
for (i = 0; i < s->total_frames; i++)
280
skip_bits(&s->gb, 32);
281
skip_bits(&s->gb, 32); // CRC32 of seektable
283
if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
284
av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
288
s->decode_buffer = av_mallocz(sizeof(int32_t)*s->frame_length*s->channels);
289
s->ch_ctx = av_malloc(avctx->channels * sizeof(*s->ch_ctx));
291
return AVERROR(ENOMEM);
293
av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
300
static int tta_decode_frame(AVCodecContext *avctx,
301
void *data, int *data_size,
304
const uint8_t *buf = avpkt->data;
305
int buf_size = avpkt->size;
306
TTAContext *s = avctx->priv_data;
309
init_get_bits(&s->gb, buf, buf_size*8);
311
int cur_chan = 0, framelen = s->frame_length;
314
if (*data_size < (framelen * s->channels * 2)) {
315
av_log(avctx, AV_LOG_ERROR, "Output buffer size is too small.\n");
320
if (!s->total_frames && s->last_frame_length)
321
framelen = s->last_frame_length;
323
// init per channel states
324
for (i = 0; i < s->channels; i++) {
325
s->ch_ctx[i].predictor = 0;
326
ttafilter_init(&s->ch_ctx[i].filter, ttafilter_configs[s->bps-1][0], ttafilter_configs[s->bps-1][1]);
327
rice_init(&s->ch_ctx[i].rice, 10, 10);
330
for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
331
int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
332
TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
333
TTARice *rice = &s->ch_ctx[cur_chan].rice;
334
uint32_t unary, depth, k;
337
unary = tta_get_unary(&s->gb);
348
if (get_bits_left(&s->gb) < k)
352
if (k > MIN_CACHE_BITS)
354
value = (unary << k) + get_bits(&s->gb, k);
358
// FIXME: copy paste from original
361
rice->sum1 += value - (rice->sum1 >> 4);
362
if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
364
else if(rice->sum1 > shift_16[rice->k1 + 1])
366
value += shift_1[rice->k0];
368
rice->sum0 += value - (rice->sum0 >> 4);
369
if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
371
else if(rice->sum0 > shift_16[rice->k0 + 1])
375
// extract coded value
376
#define UNFOLD(x) (((x)&1) ? (++(x)>>1) : (-(x)>>1))
380
ttafilter_process(filter, p, 0);
382
// fixed order prediction
383
#define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k)
385
case 1: *p += PRED(*predictor, 4); break;
387
case 3: *p += PRED(*predictor, 5); break;
388
case 4: *p += *predictor; break;
393
// extract 32bit float from last two int samples
394
if (s->is_float && ((p - data) & 1)) {
395
uint32_t neg = *p & 0x80000000;
396
uint32_t hi = *(p - 1);
397
uint32_t lo = abs(*p) - 1;
399
hi += (hi || lo) ? 0x3f80 : 0;
400
// SWAP16: swap all the 16 bits
401
*(p - 1) = (hi << 16) | SWAP16(lo) | neg;
405
/*if ((get_bits_count(&s->gb)+7)/8 > buf_size)
407
av_log(NULL, AV_LOG_INFO, "overread!!\n");
412
if (cur_chan < (s->channels-1))
415
// decorrelate in case of stereo integer
416
if (!s->is_float && (s->channels > 1)) {
418
for (*p += *r / 2; r > p - s->channels; r--)
425
if (get_bits_left(&s->gb) < 32)
427
skip_bits(&s->gb, 32); // frame crc
429
// convert to output buffer
432
uint16_t *samples = data;
433
for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
434
// *samples++ = (unsigned char)*p;
435
// *samples++ = (unsigned char)(*p >> 8);
438
*data_size = (uint8_t *)samples - (uint8_t *)data;
442
av_log(s->avctx, AV_LOG_ERROR, "Error, only 16bit samples supported!\n");
446
// return get_bits_count(&s->gb)+7)/8;
450
static av_cold int tta_decode_close(AVCodecContext *avctx) {
451
TTAContext *s = avctx->priv_data;
453
av_free(s->decode_buffer);
454
av_freep(&s->ch_ctx);
459
AVCodec ff_tta_decoder = {
468
.long_name = NULL_IF_CONFIG_SMALL("True Audio (TTA)"),