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
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 #include "libavutil/crc.h"
38 #define FORMAT_SIMPLE 1
39 #define FORMAT_ENCRYPTED 2
42 typedef struct TTAFilter {
43 int32_t shift, round, error;
44 int32_t qm[MAX_ORDER];
45 int32_t dx[MAX_ORDER];
46 int32_t dl[MAX_ORDER];
49 typedef struct TTARice {
50 uint32_t k0, k1, sum0, sum1;
53 typedef struct TTAChannel {
59 typedef struct TTAContext {
60 AVCodecContext *avctx;
63 const AVCRC *crc_table;
65 int format, channels, bps;
67 int frame_length, last_frame_length;
69 int32_t *decode_buffer;
74 static const uint32_t shift_1[] = {
75 0x00000001, 0x00000002, 0x00000004, 0x00000008,
76 0x00000010, 0x00000020, 0x00000040, 0x00000080,
77 0x00000100, 0x00000200, 0x00000400, 0x00000800,
78 0x00001000, 0x00002000, 0x00004000, 0x00008000,
79 0x00010000, 0x00020000, 0x00040000, 0x00080000,
80 0x00100000, 0x00200000, 0x00400000, 0x00800000,
81 0x01000000, 0x02000000, 0x04000000, 0x08000000,
82 0x10000000, 0x20000000, 0x40000000, 0x80000000,
83 0x80000000, 0x80000000, 0x80000000, 0x80000000,
84 0x80000000, 0x80000000, 0x80000000, 0x80000000
87 static const uint32_t * const shift_16 = shift_1 + 4;
89 static const int32_t ttafilter_configs[4] = {
96 static void ttafilter_init(TTAFilter *c, int32_t shift) {
97 memset(c, 0, sizeof(TTAFilter));
99 c->round = shift_1[shift-1];
100 // c->round = 1 << (shift - 1);
103 static inline void ttafilter_process(TTAFilter *c, int32_t *in)
105 register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round;
108 qm[0] -= dx[0]; qm[1] -= dx[1]; qm[2] -= dx[2]; qm[3] -= dx[3];
109 qm[4] -= dx[4]; qm[5] -= dx[5]; qm[6] -= dx[6]; qm[7] -= dx[7];
110 } else if (c->error > 0) {
111 qm[0] += dx[0]; qm[1] += dx[1]; qm[2] += dx[2]; qm[3] += dx[3];
112 qm[4] += dx[4]; qm[5] += dx[5]; qm[6] += dx[6]; qm[7] += dx[7];
115 sum += dl[0] * qm[0] + dl[1] * qm[1] + dl[2] * qm[2] + dl[3] * qm[3] +
116 dl[4] * qm[4] + dl[5] * qm[5] + dl[6] * qm[6] + dl[7] * qm[7];
118 dx[0] = dx[1]; dx[1] = dx[2]; dx[2] = dx[3]; dx[3] = dx[4];
119 dl[0] = dl[1]; dl[1] = dl[2]; dl[2] = dl[3]; dl[3] = dl[4];
121 dx[4] = ((dl[4] >> 30) | 1);
122 dx[5] = ((dl[5] >> 30) | 2) & ~1;
123 dx[6] = ((dl[6] >> 30) | 2) & ~1;
124 dx[7] = ((dl[7] >> 30) | 4) & ~3;
127 *in += (sum >> c->shift);
129 dl[4] = -dl[5]; dl[5] = -dl[6];
130 dl[6] = *in - dl[7]; dl[7] = *in;
131 dl[5] += dl[6]; dl[4] += dl[5];
134 static void rice_init(TTARice *c, uint32_t k0, uint32_t k1)
138 c->sum0 = shift_16[k0];
139 c->sum1 = shift_16[k1];
142 static int tta_get_unary(GetBitContext *gb)
147 while (get_bits_left(gb) > 0 && get_bits1(gb))
152 static const int64_t tta_channel_layouts[7] = {
154 AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
157 AV_CH_LAYOUT_5POINT1_BACK,
158 AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER,
159 AV_CH_LAYOUT_7POINT1_WIDE
162 static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
166 CRC = AV_RL32(buf + buf_size);
167 crc = av_crc(s->crc_table, 0xFFFFFFFFU, buf, buf_size);
168 if (CRC != (crc ^ 0xFFFFFFFFU)) {
169 av_log(s->avctx, AV_LOG_ERROR, "CRC error\n");
170 return AVERROR_INVALIDDATA;
176 static av_cold int tta_decode_init(AVCodecContext * avctx)
178 TTAContext *s = avctx->priv_data;
183 // 30bytes includes a seektable with one frame
184 if (avctx->extradata_size < 30)
185 return AVERROR_INVALIDDATA;
187 init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size * 8);
188 if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
190 if (avctx->err_recognition & AV_EF_CRCCHECK) {
191 s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
192 tta_check_crc(s, avctx->extradata, 18);
196 skip_bits_long(&s->gb, 32);
198 s->format = get_bits(&s->gb, 16);
200 av_log(s->avctx, AV_LOG_ERROR, "Invalid format\n");
201 return AVERROR_INVALIDDATA;
203 if (s->format == FORMAT_ENCRYPTED) {
204 av_log_missing_feature(s->avctx, "Encrypted TTA", 0);
205 return AVERROR_PATCHWELCOME;
207 avctx->channels = s->channels = get_bits(&s->gb, 16);
208 if (s->channels > 1 && s->channels < 9)
209 avctx->channel_layout = tta_channel_layouts[s->channels-2];
210 avctx->bits_per_raw_sample = get_bits(&s->gb, 16);
211 s->bps = (avctx->bits_per_raw_sample + 7) / 8;
212 avctx->sample_rate = get_bits_long(&s->gb, 32);
213 s->data_length = get_bits_long(&s->gb, 32);
214 skip_bits_long(&s->gb, 32); // CRC32 of header
216 if (s->channels == 0) {
217 av_log(s->avctx, AV_LOG_ERROR, "Invalid number of channels\n");
218 return AVERROR_INVALIDDATA;
219 } else if (avctx->sample_rate == 0) {
220 av_log(s->avctx, AV_LOG_ERROR, "Invalid samplerate\n");
221 return AVERROR_INVALIDDATA;
225 case 1: avctx->sample_fmt = AV_SAMPLE_FMT_U8; break;
227 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
230 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
232 //case 4: avctx->sample_fmt = AV_SAMPLE_FMT_S32; break;
234 av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported sample format.\n");
235 return AVERROR_INVALIDDATA;
239 if (avctx->sample_rate > 0x7FFFFFu) {
240 av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
241 return AVERROR(EINVAL);
243 s->frame_length = 256 * avctx->sample_rate / 245;
245 s->last_frame_length = s->data_length % s->frame_length;
246 total_frames = s->data_length / s->frame_length +
247 (s->last_frame_length ? 1 : 0);
249 av_log(s->avctx, AV_LOG_DEBUG, "format: %d chans: %d bps: %d rate: %d block: %d\n",
250 s->format, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate,
252 av_log(s->avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
253 s->data_length, s->frame_length, s->last_frame_length, total_frames);
256 if (avctx->extradata_size <= 26 || total_frames > INT_MAX / 4 ||
257 avctx->extradata_size - 26 < total_frames * 4)
258 av_log(avctx, AV_LOG_WARNING, "Seek table missing or too small\n");
259 else if (avctx->err_recognition & AV_EF_CRCCHECK) {
260 if (tta_check_crc(s, avctx->extradata + 22, total_frames * 4))
261 return AVERROR_INVALIDDATA;
263 skip_bits_long(&s->gb, 32 * total_frames);
264 skip_bits_long(&s->gb, 32); // CRC32 of seektable
266 if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
267 av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
268 return AVERROR_INVALIDDATA;
272 s->decode_buffer = av_mallocz(sizeof(int32_t)*s->frame_length*s->channels);
273 if (!s->decode_buffer)
274 return AVERROR(ENOMEM);
276 s->decode_buffer = NULL;
277 s->ch_ctx = av_malloc(avctx->channels * sizeof(*s->ch_ctx));
279 av_freep(&s->decode_buffer);
280 return AVERROR(ENOMEM);
283 av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
284 return AVERROR_INVALIDDATA;
287 avcodec_get_frame_defaults(&s->frame);
288 avctx->coded_frame = &s->frame;
293 static int tta_decode_frame(AVCodecContext *avctx, void *data,
294 int *got_frame_ptr, AVPacket *avpkt)
296 const uint8_t *buf = avpkt->data;
297 int buf_size = avpkt->size;
298 TTAContext *s = avctx->priv_data;
300 int cur_chan = 0, framelen = s->frame_length;
303 if (avctx->err_recognition & AV_EF_CRCCHECK) {
304 if (buf_size < 4 || tta_check_crc(s, buf, buf_size - 4))
305 return AVERROR_INVALIDDATA;
308 init_get_bits(&s->gb, buf, buf_size*8);
310 /* get output buffer */
311 s->frame.nb_samples = framelen;
312 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
313 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
317 // decode directly to output buffer for 24-bit sample format
319 s->decode_buffer = (int32_t *)s->frame.data[0];
321 // init per channel states
322 for (i = 0; i < s->channels; i++) {
323 s->ch_ctx[i].predictor = 0;
324 ttafilter_init(&s->ch_ctx[i].filter, ttafilter_configs[s->bps-1]);
325 rice_init(&s->ch_ctx[i].rice, 10, 10);
329 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
330 int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
331 TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
332 TTARice *rice = &s->ch_ctx[cur_chan].rice;
333 uint32_t unary, depth, k;
336 unary = tta_get_unary(&s->gb);
347 if (get_bits_left(&s->gb) < k) {
348 ret = AVERROR_INVALIDDATA;
353 if (k > MIN_CACHE_BITS) {
354 ret = AVERROR_INVALIDDATA;
357 value = (unary << k) + get_bits(&s->gb, k);
361 // FIXME: copy paste from original
364 rice->sum1 += value - (rice->sum1 >> 4);
365 if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
367 else if(rice->sum1 > shift_16[rice->k1 + 1])
369 value += shift_1[rice->k0];
371 rice->sum0 += value - (rice->sum0 >> 4);
372 if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
374 else if(rice->sum0 > shift_16[rice->k0 + 1])
378 // extract coded value
379 *p = 1 + ((value >> 1) ^ ((value & 1) - 1));
382 ttafilter_process(filter, p);
384 // fixed order prediction
385 #define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k)
387 case 1: *p += PRED(*predictor, 4); break;
389 case 3: *p += PRED(*predictor, 5); break;
390 case 4: *p += *predictor; break;
395 if (cur_chan < (s->channels-1))
398 // decorrelate in case of multiple channels
399 if (s->channels > 1) {
401 for (*p += *r / 2; r > p - s->channels; r--)
406 // check for last frame
407 if (i == s->last_frame_length && get_bits_left(&s->gb) / 8 == 4) {
408 s->frame.nb_samples = framelen = s->last_frame_length;
414 align_get_bits(&s->gb);
415 if (get_bits_left(&s->gb) < 32) {
416 ret = AVERROR_INVALIDDATA;
419 skip_bits_long(&s->gb, 32); // frame crc
421 // convert to output buffer
424 uint8_t *samples = (uint8_t *)s->frame.data[0];
425 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
426 *samples++ = *p + 0x80;
430 int16_t *samples = (int16_t *)s->frame.data[0];
431 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
436 // shift samples for 24-bit sample format
437 int32_t *samples = (int32_t *)s->frame.data[0];
438 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
440 // reset decode buffer
441 s->decode_buffer = NULL;
447 *(AVFrame *)data = s->frame;
451 // reset decode buffer
453 s->decode_buffer = NULL;
457 static av_cold int tta_decode_close(AVCodecContext *avctx) {
458 TTAContext *s = avctx->priv_data;
461 av_free(s->decode_buffer);
462 s->decode_buffer = NULL;
463 av_freep(&s->ch_ctx);
468 AVCodec ff_tta_decoder = {
470 .type = AVMEDIA_TYPE_AUDIO,
471 .id = AV_CODEC_ID_TTA,
472 .priv_data_size = sizeof(TTAContext),
473 .init = tta_decode_init,
474 .close = tta_decode_close,
475 .decode = tta_decode_frame,
476 .capabilities = CODEC_CAP_DR1,
477 .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),