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, total_frames;
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;
182 // 30bytes includes a seektable with one frame
183 if (avctx->extradata_size < 30)
184 return AVERROR_INVALIDDATA;
186 init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size * 8);
187 if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
189 if (avctx->err_recognition & AV_EF_CRCCHECK) {
190 s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
191 tta_check_crc(s, avctx->extradata, 18);
195 skip_bits_long(&s->gb, 32);
197 s->format = get_bits(&s->gb, 16);
199 av_log(s->avctx, AV_LOG_ERROR, "Invalid format\n");
200 return AVERROR_INVALIDDATA;
202 if (s->format == FORMAT_ENCRYPTED) {
203 av_log_missing_feature(s->avctx, "Encrypted TTA", 0);
204 return AVERROR_PATCHWELCOME;
206 avctx->channels = s->channels = get_bits(&s->gb, 16);
207 if (s->channels > 1 && s->channels < 9)
208 avctx->channel_layout = tta_channel_layouts[s->channels-2];
209 avctx->bits_per_raw_sample = get_bits(&s->gb, 16);
210 s->bps = (avctx->bits_per_raw_sample + 7) / 8;
211 avctx->sample_rate = get_bits_long(&s->gb, 32);
212 s->data_length = get_bits_long(&s->gb, 32);
213 skip_bits_long(&s->gb, 32); // CRC32 of header
215 if (s->channels == 0) {
216 av_log(s->avctx, AV_LOG_ERROR, "Invalid number of channels\n");
217 return AVERROR_INVALIDDATA;
218 } else if (avctx->sample_rate == 0) {
219 av_log(s->avctx, AV_LOG_ERROR, "Invalid samplerate\n");
220 return AVERROR_INVALIDDATA;
224 case 1: avctx->sample_fmt = AV_SAMPLE_FMT_U8; break;
226 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
229 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
231 //case 4: avctx->sample_fmt = AV_SAMPLE_FMT_S32; break;
233 av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported sample format.\n");
234 return AVERROR_INVALIDDATA;
238 if (avctx->sample_rate > 0x7FFFFFu) {
239 av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
240 return AVERROR(EINVAL);
242 s->frame_length = 256 * avctx->sample_rate / 245;
244 s->last_frame_length = s->data_length % s->frame_length;
245 s->total_frames = s->data_length / s->frame_length +
246 (s->last_frame_length ? 1 : 0);
248 av_log(s->avctx, AV_LOG_DEBUG, "format: %d chans: %d bps: %d rate: %d block: %d\n",
249 s->format, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate,
251 av_log(s->avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
252 s->data_length, s->frame_length, s->last_frame_length, s->total_frames);
254 if (s->total_frames < 0)
255 return AVERROR_INVALIDDATA;
258 if (avctx->extradata_size <= 26 || s->total_frames > INT_MAX / 4 ||
259 avctx->extradata_size - 26 < s->total_frames * 4)
260 av_log(avctx, AV_LOG_WARNING, "Seek table missing or too small\n");
261 else if (avctx->err_recognition & AV_EF_CRCCHECK) {
262 if (avctx->extradata_size < 26 + s->total_frames * 4 || tta_check_crc(s, avctx->extradata + 22, s->total_frames * 4))
263 return AVERROR_INVALIDDATA;
265 skip_bits_long(&s->gb, 32 * s->total_frames);
266 skip_bits_long(&s->gb, 32); // CRC32 of seektable
268 if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
269 av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
270 return AVERROR_INVALIDDATA;
274 s->decode_buffer = av_mallocz(sizeof(int32_t)*s->frame_length*s->channels);
275 if (!s->decode_buffer)
276 return AVERROR(ENOMEM);
278 s->decode_buffer = NULL;
279 s->ch_ctx = av_malloc(avctx->channels * sizeof(*s->ch_ctx));
281 av_freep(&s->decode_buffer);
282 return AVERROR(ENOMEM);
285 av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
286 return AVERROR_INVALIDDATA;
289 avcodec_get_frame_defaults(&s->frame);
290 avctx->coded_frame = &s->frame;
295 static int tta_decode_frame(AVCodecContext *avctx, void *data,
296 int *got_frame_ptr, AVPacket *avpkt)
298 const uint8_t *buf = avpkt->data;
299 int buf_size = avpkt->size;
300 TTAContext *s = avctx->priv_data;
302 int cur_chan = 0, framelen = s->frame_length;
305 if (avctx->err_recognition & AV_EF_CRCCHECK) {
306 if (buf_size < 4 || tta_check_crc(s, buf, buf_size - 4))
307 return AVERROR_INVALIDDATA;
310 init_get_bits(&s->gb, buf, buf_size*8);
314 if (!s->total_frames && s->last_frame_length)
315 framelen = s->last_frame_length;
317 /* get output buffer */
318 s->frame.nb_samples = framelen;
319 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
320 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
324 // decode directly to output buffer for 24-bit sample format
326 s->decode_buffer = (int32_t *)s->frame.data[0];
328 // init per channel states
329 for (i = 0; i < s->channels; i++) {
330 s->ch_ctx[i].predictor = 0;
331 ttafilter_init(&s->ch_ctx[i].filter, ttafilter_configs[s->bps-1]);
332 rice_init(&s->ch_ctx[i].rice, 10, 10);
335 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
336 int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
337 TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
338 TTARice *rice = &s->ch_ctx[cur_chan].rice;
339 uint32_t unary, depth, k;
342 unary = tta_get_unary(&s->gb);
353 if (get_bits_left(&s->gb) < k) {
354 ret = AVERROR_INVALIDDATA;
359 if (k > MIN_CACHE_BITS) {
360 ret = AVERROR_INVALIDDATA;
363 value = (unary << k) + get_bits(&s->gb, k);
367 // FIXME: copy paste from original
370 rice->sum1 += value - (rice->sum1 >> 4);
371 if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
373 else if(rice->sum1 > shift_16[rice->k1 + 1])
375 value += shift_1[rice->k0];
377 rice->sum0 += value - (rice->sum0 >> 4);
378 if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
380 else if(rice->sum0 > shift_16[rice->k0 + 1])
384 // extract coded value
385 *p = 1 + ((value >> 1) ^ ((value & 1) - 1));
388 ttafilter_process(filter, p);
390 // fixed order prediction
391 #define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k)
393 case 1: *p += PRED(*predictor, 4); break;
395 case 3: *p += PRED(*predictor, 5); break;
396 case 4: *p += *predictor; break;
401 if (cur_chan < (s->channels-1))
404 // decorrelate in case of multiple channels
405 if (s->channels > 1) {
407 for (*p += *r / 2; r > p - s->channels; r--)
414 if (get_bits_left(&s->gb) < 32) {
415 ret = AVERROR_INVALIDDATA;
418 skip_bits_long(&s->gb, 32); // frame crc
420 // convert to output buffer
423 uint8_t *samples = (uint8_t *)s->frame.data[0];
424 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
425 *samples++ = *p + 0x80;
429 int16_t *samples = (int16_t *)s->frame.data[0];
430 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
435 // shift samples for 24-bit sample format
436 int32_t *samples = (int32_t *)s->frame.data[0];
437 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
439 // reset decode buffer
440 s->decode_buffer = NULL;
446 *(AVFrame *)data = s->frame;
450 // reset decode buffer
452 s->decode_buffer = NULL;
456 static av_cold int tta_decode_close(AVCodecContext *avctx) {
457 TTAContext *s = avctx->priv_data;
460 av_free(s->decode_buffer);
461 s->decode_buffer = NULL;
462 av_freep(&s->ch_ctx);
467 AVCodec ff_tta_decoder = {
469 .type = AVMEDIA_TYPE_AUDIO,
470 .id = AV_CODEC_ID_TTA,
471 .priv_data_size = sizeof(TTAContext),
472 .init = tta_decode_init,
473 .close = tta_decode_close,
474 .decode = tta_decode_frame,
475 .capabilities = CODEC_CAP_DR1,
476 .long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),