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
35 #include "libavutil/crc.h"
37 #define FORMAT_SIMPLE 1
38 #define FORMAT_ENCRYPTED 2
41 typedef struct TTAFilter {
42 int32_t shift, round, error;
43 int32_t qm[MAX_ORDER];
44 int32_t dx[MAX_ORDER];
45 int32_t dl[MAX_ORDER];
48 typedef struct TTARice {
49 uint32_t k0, k1, sum0, sum1;
52 typedef struct TTAChannel {
58 typedef struct TTAContext {
59 AVCodecContext *avctx;
62 const AVCRC *crc_table;
64 int format, channels, bps;
66 int frame_length, last_frame_length, total_frames;
68 int32_t *decode_buffer;
73 static const uint32_t shift_1[] = {
74 0x00000001, 0x00000002, 0x00000004, 0x00000008,
75 0x00000010, 0x00000020, 0x00000040, 0x00000080,
76 0x00000100, 0x00000200, 0x00000400, 0x00000800,
77 0x00001000, 0x00002000, 0x00004000, 0x00008000,
78 0x00010000, 0x00020000, 0x00040000, 0x00080000,
79 0x00100000, 0x00200000, 0x00400000, 0x00800000,
80 0x01000000, 0x02000000, 0x04000000, 0x08000000,
81 0x10000000, 0x20000000, 0x40000000, 0x80000000,
82 0x80000000, 0x80000000, 0x80000000, 0x80000000,
83 0x80000000, 0x80000000, 0x80000000, 0x80000000
86 static const uint32_t * const shift_16 = shift_1 + 4;
88 static const int32_t ttafilter_configs[4] = {
95 static void ttafilter_init(TTAFilter *c, int32_t shift) {
96 memset(c, 0, sizeof(TTAFilter));
98 c->round = shift_1[shift-1];
99 // c->round = 1 << (shift - 1);
102 static inline void ttafilter_process(TTAFilter *c, int32_t *in)
104 register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round;
107 qm[0] -= dx[0]; qm[1] -= dx[1]; qm[2] -= dx[2]; qm[3] -= dx[3];
108 qm[4] -= dx[4]; qm[5] -= dx[5]; qm[6] -= dx[6]; qm[7] -= dx[7];
109 } else if (c->error > 0) {
110 qm[0] += dx[0]; qm[1] += dx[1]; qm[2] += dx[2]; qm[3] += dx[3];
111 qm[4] += dx[4]; qm[5] += dx[5]; qm[6] += dx[6]; qm[7] += dx[7];
114 sum += dl[0] * qm[0] + dl[1] * qm[1] + dl[2] * qm[2] + dl[3] * qm[3] +
115 dl[4] * qm[4] + dl[5] * qm[5] + dl[6] * qm[6] + dl[7] * qm[7];
117 dx[0] = dx[1]; dx[1] = dx[2]; dx[2] = dx[3]; dx[3] = dx[4];
118 dl[0] = dl[1]; dl[1] = dl[2]; dl[2] = dl[3]; dl[3] = dl[4];
120 dx[4] = ((dl[4] >> 30) | 1);
121 dx[5] = ((dl[5] >> 30) | 2) & ~1;
122 dx[6] = ((dl[6] >> 30) | 2) & ~1;
123 dx[7] = ((dl[7] >> 30) | 4) & ~3;
126 *in += (sum >> c->shift);
128 dl[4] = -dl[5]; dl[5] = -dl[6];
129 dl[6] = *in - dl[7]; dl[7] = *in;
130 dl[5] += dl[6]; dl[4] += dl[5];
133 static void rice_init(TTARice *c, uint32_t k0, uint32_t k1)
137 c->sum0 = shift_16[k0];
138 c->sum1 = shift_16[k1];
141 static int tta_get_unary(GetBitContext *gb)
146 while (get_bits_left(gb) > 0 && get_bits1(gb))
151 static const int64_t tta_channel_layouts[7] = {
153 AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
156 AV_CH_LAYOUT_5POINT1_BACK,
157 AV_CH_LAYOUT_5POINT1_BACK|AV_CH_BACK_CENTER,
158 AV_CH_LAYOUT_7POINT1_WIDE
161 static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
165 CRC = AV_RL32(buf + buf_size);
166 crc = av_crc(s->crc_table, 0xFFFFFFFFU, buf, buf_size);
167 if (CRC != (crc ^ 0xFFFFFFFFU)) {
168 av_log(s->avctx, AV_LOG_ERROR, "CRC error\n");
169 return AVERROR_INVALIDDATA;
175 static av_cold int tta_decode_init(AVCodecContext * avctx)
177 TTAContext *s = avctx->priv_data;
181 // 30bytes includes a seektable with one frame
182 if (avctx->extradata_size < 30)
185 init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size * 8);
186 if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
188 if (avctx->err_recognition & AV_EF_CRCCHECK) {
189 s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
190 tta_check_crc(s, avctx->extradata, 18);
194 skip_bits_long(&s->gb, 32);
196 s->format = get_bits(&s->gb, 16);
198 av_log(s->avctx, AV_LOG_ERROR, "Invalid format\n");
201 if (s->format == FORMAT_ENCRYPTED) {
202 av_log_missing_feature(s->avctx, "Encrypted TTA", 0);
203 return AVERROR(EINVAL);
205 avctx->channels = s->channels = get_bits(&s->gb, 16);
206 if (s->channels > 1 && s->channels < 9)
207 avctx->channel_layout = tta_channel_layouts[s->channels-2];
208 avctx->bits_per_coded_sample = get_bits(&s->gb, 16);
209 s->bps = (avctx->bits_per_coded_sample + 7) / 8;
210 avctx->sample_rate = get_bits_long(&s->gb, 32);
211 s->data_length = get_bits_long(&s->gb, 32);
212 skip_bits_long(&s->gb, 32); // CRC32 of header
214 if (s->channels == 0) {
215 av_log(s->avctx, AV_LOG_ERROR, "Invalid number of channels\n");
216 return AVERROR_INVALIDDATA;
217 } else if (avctx->sample_rate == 0) {
218 av_log(s->avctx, AV_LOG_ERROR, "Invalid samplerate\n");
219 return AVERROR_INVALIDDATA;
223 case 1: avctx->sample_fmt = AV_SAMPLE_FMT_U8; break;
225 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
226 avctx->bits_per_raw_sample = 16;
229 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
230 avctx->bits_per_raw_sample = 24;
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 s->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, s->total_frames);
255 if (s->total_frames < 0)
256 return AVERROR_INVALIDDATA;
259 if (avctx->extradata_size <= 26 || s->total_frames > INT_MAX / 4 ||
260 avctx->extradata_size - 26 < s->total_frames * 4)
261 av_log(avctx, AV_LOG_WARNING, "Seek table missing or too small\n");
262 else if (avctx->err_recognition & AV_EF_CRCCHECK) {
263 if (avctx->extradata_size < 26 + s->total_frames * 4 || tta_check_crc(s, avctx->extradata + 22, s->total_frames * 4))
264 return AVERROR_INVALIDDATA;
266 skip_bits_long(&s->gb, 32 * s->total_frames);
267 skip_bits_long(&s->gb, 32); // CRC32 of seektable
269 if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
270 av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
275 s->decode_buffer = av_mallocz(sizeof(int32_t)*s->frame_length*s->channels);
276 if (!s->decode_buffer)
277 return AVERROR(ENOMEM);
279 s->decode_buffer = NULL;
280 s->ch_ctx = av_malloc(avctx->channels * sizeof(*s->ch_ctx));
282 av_freep(&s->decode_buffer);
283 return AVERROR(ENOMEM);
286 av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
290 avcodec_get_frame_defaults(&s->frame);
291 avctx->coded_frame = &s->frame;
296 static int tta_decode_frame(AVCodecContext *avctx, void *data,
297 int *got_frame_ptr, AVPacket *avpkt)
299 const uint8_t *buf = avpkt->data;
300 int buf_size = avpkt->size;
301 TTAContext *s = avctx->priv_data;
303 int cur_chan = 0, framelen = s->frame_length;
306 if (avctx->err_recognition & AV_EF_CRCCHECK) {
307 if (buf_size < 4 || tta_check_crc(s, buf, buf_size - 4))
308 return AVERROR_INVALIDDATA;
311 init_get_bits(&s->gb, buf, buf_size*8);
315 if (!s->total_frames && s->last_frame_length)
316 framelen = s->last_frame_length;
318 /* get output buffer */
319 s->frame.nb_samples = framelen;
320 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
321 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
325 // decode directly to output buffer for 24-bit sample format
327 s->decode_buffer = (int32_t *)s->frame.data[0];
329 // init per channel states
330 for (i = 0; i < s->channels; i++) {
331 s->ch_ctx[i].predictor = 0;
332 ttafilter_init(&s->ch_ctx[i].filter, ttafilter_configs[s->bps-1]);
333 rice_init(&s->ch_ctx[i].rice, 10, 10);
336 for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
337 int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
338 TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
339 TTARice *rice = &s->ch_ctx[cur_chan].rice;
340 uint32_t unary, depth, k;
343 unary = tta_get_unary(&s->gb);
354 if (get_bits_left(&s->gb) < k) {
355 ret = AVERROR_INVALIDDATA;
360 if (k > MIN_CACHE_BITS) {
361 ret = AVERROR_INVALIDDATA;
364 value = (unary << k) + get_bits(&s->gb, k);
368 // FIXME: copy paste from original
371 rice->sum1 += value - (rice->sum1 >> 4);
372 if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
374 else if(rice->sum1 > shift_16[rice->k1 + 1])
376 value += shift_1[rice->k0];
378 rice->sum0 += value - (rice->sum0 >> 4);
379 if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
381 else if(rice->sum0 > shift_16[rice->k0 + 1])
385 // extract coded value
386 *p = 1 + ((value >> 1) ^ ((value & 1) - 1));
389 ttafilter_process(filter, p);
391 // fixed order prediction
392 #define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k)
394 case 1: *p += PRED(*predictor, 4); break;
396 case 3: *p += PRED(*predictor, 5); break;
397 case 4: *p += *predictor; break;
402 if (cur_chan < (s->channels-1))
405 // decorrelate in case of multiple channels
406 if (s->channels > 1) {
408 for (*p += *r / 2; r > p - s->channels; r--)
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 uint16_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,
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("True Audio (TTA)"),