FFmpeg  4.3.8
dstdec.c
Go to the documentation of this file.
1 /*
2  * Direct Stream Transfer (DST) decoder
3  * Copyright (c) 2014 Peter Ross <pross@xvid.org>
4  *
5  * This file is part of FFmpeg.
6  *
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.
11  *
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.
16  *
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
20  */
21 
22 /**
23  * @file
24  * Direct Stream Transfer (DST) decoder
25  * ISO/IEC 14496-3 Part 3 Subpart 10: Technical description of lossless coding of oversampled audio
26  */
27 
28 #include "libavutil/avassert.h"
29 #include "libavutil/intreadwrite.h"
30 #include "internal.h"
31 #include "get_bits.h"
32 #include "avcodec.h"
33 #include "golomb.h"
34 #include "mathops.h"
35 #include "dsd.h"
36 
37 #define DST_MAX_CHANNELS 6
38 #define DST_MAX_ELEMENTS (2 * DST_MAX_CHANNELS)
39 
40 #define DSD_FS44(sample_rate) (sample_rate * 8LL / 44100)
41 
42 #define DST_SAMPLES_PER_FRAME(sample_rate) (588 * DSD_FS44(sample_rate))
43 
44 static const int8_t fsets_code_pred_coeff[3][3] = {
45  { -8 },
46  { -16, 8 },
47  { -9, -5, 6 },
48 };
49 
50 static const int8_t probs_code_pred_coeff[3][3] = {
51  { -8 },
52  { -16, 8 },
53  { -24, 24, -8 },
54 };
55 
56 typedef struct ArithCoder {
57  unsigned int a;
58  unsigned int c;
59 } ArithCoder;
60 
61 typedef struct Table {
62  unsigned int elements;
63  unsigned int length[DST_MAX_ELEMENTS];
65 } Table;
66 
67 typedef struct DSTContext {
68  AVClass *class;
69 
72  Table fsets, probs;
74  DECLARE_ALIGNED(16, int16_t, filter)[DST_MAX_ELEMENTS][16][256];
76 } DSTContext;
77 
79 {
80  DSTContext *s = avctx->priv_data;
81  int i;
82 
83  if (avctx->channels > DST_MAX_CHANNELS) {
84  avpriv_request_sample(avctx, "Channel count %d", avctx->channels);
85  return AVERROR_PATCHWELCOME;
86  }
87 
88  // the sample rate is only allowed to be 64,128,256 * 44100 by ISO/IEC 14496-3:2005(E)
89  // We are a bit more tolerant here, but this check is needed to bound the size and duration
90  if (avctx->sample_rate > 512 * 44100)
91  return AVERROR_INVALIDDATA;
92 
93 
94  if (DST_SAMPLES_PER_FRAME(avctx->sample_rate) & 7) {
95  return AVERROR_PATCHWELCOME;
96  }
97 
99 
100  for (i = 0; i < avctx->channels; i++)
101  memset(s->dsdctx[i].buf, 0x69, sizeof(s->dsdctx[i].buf));
102 
104 
105  return 0;
106 }
107 
108 static int read_map(GetBitContext *gb, Table *t, unsigned int map[DST_MAX_CHANNELS], int channels)
109 {
110  int ch;
111  t->elements = 1;
112  map[0] = 0;
113  if (!get_bits1(gb)) {
114  for (ch = 1; ch < channels; ch++) {
115  int bits = av_log2(t->elements) + 1;
116  map[ch] = get_bits(gb, bits);
117  if (map[ch] == t->elements) {
118  t->elements++;
119  if (t->elements >= DST_MAX_ELEMENTS)
120  return AVERROR_INVALIDDATA;
121  } else if (map[ch] > t->elements) {
122  return AVERROR_INVALIDDATA;
123  }
124  }
125  } else {
126  memset(map, 0, sizeof(*map) * DST_MAX_CHANNELS);
127  }
128  return 0;
129 }
130 
132 {
133  int v = get_ur_golomb_jpegls(gb, k, get_bits_left(gb), 0);
134  if (v && get_bits1(gb))
135  v = -v;
136  return v;
137 }
138 
139 static void read_uncoded_coeff(GetBitContext *gb, int *dst, unsigned int elements,
140  int coeff_bits, int is_signed, int offset)
141 {
142  int i;
143 
144  for (i = 0; i < elements; i++) {
145  dst[i] = (is_signed ? get_sbits(gb, coeff_bits) : get_bits(gb, coeff_bits)) + offset;
146  }
147 }
148 
149 static int read_table(GetBitContext *gb, Table *t, const int8_t code_pred_coeff[3][3],
150  int length_bits, int coeff_bits, int is_signed, int offset)
151 {
152  unsigned int i, j, k;
153  for (i = 0; i < t->elements; i++) {
154  t->length[i] = get_bits(gb, length_bits) + 1;
155  if (!get_bits1(gb)) {
156  read_uncoded_coeff(gb, t->coeff[i], t->length[i], coeff_bits, is_signed, offset);
157  } else {
158  int method = get_bits(gb, 2), lsb_size;
159  if (method == 3)
160  return AVERROR_INVALIDDATA;
161 
162  read_uncoded_coeff(gb, t->coeff[i], method + 1, coeff_bits, is_signed, offset);
163 
164  lsb_size = get_bits(gb, 3);
165  for (j = method + 1; j < t->length[i]; j++) {
166  int c, x = 0;
167  for (k = 0; k < method + 1; k++)
168  x += code_pred_coeff[method][k] * (unsigned)t->coeff[i][j - k - 1];
169  c = get_sr_golomb_dst(gb, lsb_size);
170  if (x >= 0)
171  c -= (x + 4) / 8;
172  else
173  c += (-x + 3) / 8;
174  if (!is_signed) {
175  if (c < offset || c >= offset + (1<<coeff_bits))
176  return AVERROR_INVALIDDATA;
177  }
178  t->coeff[i][j] = c;
179  }
180  }
181  }
182  return 0;
183 }
184 
185 static void ac_init(ArithCoder *ac, GetBitContext *gb)
186 {
187  ac->a = 4095;
188  ac->c = get_bits(gb, 12);
189 }
190 
191 static av_always_inline void ac_get(ArithCoder *ac, GetBitContext *gb, int p, int *e)
192 {
193  unsigned int k = (ac->a >> 8) | ((ac->a >> 7) & 1);
194  unsigned int q = k * p;
195  unsigned int a_q = ac->a - q;
196 
197  *e = ac->c < a_q;
198  if (*e) {
199  ac->a = a_q;
200  } else {
201  ac->a = q;
202  ac->c -= a_q;
203  }
204 
205  if (ac->a < 2048) {
206  int n = 11 - av_log2(ac->a);
207  ac->a <<= n;
208  ac->c = (ac->c << n) | get_bits(gb, n);
209  }
210 }
211 
213 {
214  return (ff_reverse[c & 127] >> 1) + 1;
215 }
216 
217 static int build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets)
218 {
219  int i, j, k, l;
220 
221  for (i = 0; i < fsets->elements; i++) {
222  int length = fsets->length[i];
223 
224  for (j = 0; j < 16; j++) {
225  int total = av_clip(length - j * 8, 0, 8);
226 
227  for (k = 0; k < 256; k++) {
228  int64_t v = 0;
229 
230  for (l = 0; l < total; l++)
231  v += (((k >> l) & 1) * 2 - 1) * fsets->coeff[i][j * 8 + l];
232  if ((int16_t)v != v)
233  return AVERROR_INVALIDDATA;
234  table[i][j][k] = v;
235  }
236  }
237  }
238  return 0;
239 }
240 
241 static int decode_frame(AVCodecContext *avctx, void *data,
242  int *got_frame_ptr, AVPacket *avpkt)
243 {
244  unsigned samples_per_frame = DST_SAMPLES_PER_FRAME(avctx->sample_rate);
245  unsigned map_ch_to_felem[DST_MAX_CHANNELS];
246  unsigned map_ch_to_pelem[DST_MAX_CHANNELS];
247  unsigned i, ch, same_map, dst_x_bit;
248  unsigned half_prob[DST_MAX_CHANNELS];
249  const int channels = avctx->channels;
250  DSTContext *s = avctx->priv_data;
251  GetBitContext *gb = &s->gb;
252  ArithCoder *ac = &s->ac;
253  AVFrame *frame = data;
254  uint8_t *dsd;
255  float *pcm;
256  int ret;
257 
258  if (avpkt->size <= 1)
259  return AVERROR_INVALIDDATA;
260 
261  frame->nb_samples = samples_per_frame / 8;
262  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
263  return ret;
264  dsd = frame->data[0];
265  pcm = (float *)frame->data[0];
266 
267  if ((ret = init_get_bits8(gb, avpkt->data, avpkt->size)) < 0)
268  return ret;
269 
270  if (!get_bits1(gb)) {
271  skip_bits1(gb);
272  if (get_bits(gb, 6))
273  return AVERROR_INVALIDDATA;
274  memcpy(frame->data[0], avpkt->data + 1, FFMIN(avpkt->size - 1, frame->nb_samples * channels));
275  goto dsd;
276  }
277 
278  /* Segmentation (10.4, 10.5, 10.6) */
279 
280  if (!get_bits1(gb)) {
281  avpriv_request_sample(avctx, "Not Same Segmentation");
282  return AVERROR_PATCHWELCOME;
283  }
284 
285  if (!get_bits1(gb)) {
286  avpriv_request_sample(avctx, "Not Same Segmentation For All Channels");
287  return AVERROR_PATCHWELCOME;
288  }
289 
290  if (!get_bits1(gb)) {
291  avpriv_request_sample(avctx, "Not End Of Channel Segmentation");
292  return AVERROR_PATCHWELCOME;
293  }
294 
295  /* Mapping (10.7, 10.8, 10.9) */
296 
297  same_map = get_bits1(gb);
298 
299  if ((ret = read_map(gb, &s->fsets, map_ch_to_felem, channels)) < 0)
300  return ret;
301 
302  if (same_map) {
303  s->probs.elements = s->fsets.elements;
304  memcpy(map_ch_to_pelem, map_ch_to_felem, sizeof(map_ch_to_felem));
305  } else {
306  avpriv_request_sample(avctx, "Not Same Mapping");
307  if ((ret = read_map(gb, &s->probs, map_ch_to_pelem, channels)) < 0)
308  return ret;
309  }
310 
311  /* Half Probability (10.10) */
312 
313  for (ch = 0; ch < channels; ch++)
314  half_prob[ch] = get_bits1(gb);
315 
316  /* Filter Coef Sets (10.12) */
317 
318  ret = read_table(gb, &s->fsets, fsets_code_pred_coeff, 7, 9, 1, 0);
319  if (ret < 0)
320  return ret;
321 
322  /* Probability Tables (10.13) */
323 
324  ret = read_table(gb, &s->probs, probs_code_pred_coeff, 6, 7, 0, 1);
325  if (ret < 0)
326  return ret;
327 
328  /* Arithmetic Coded Data (10.11) */
329 
330  if (get_bits1(gb))
331  return AVERROR_INVALIDDATA;
332  ac_init(ac, gb);
333 
334  ret = build_filter(s->filter, &s->fsets);
335  if (ret < 0)
336  return ret;
337 
338  memset(s->status, 0xAA, sizeof(s->status));
339  memset(dsd, 0, frame->nb_samples * 4 * channels);
340 
341  ac_get(ac, gb, prob_dst_x_bit(s->fsets.coeff[0][0]), &dst_x_bit);
342 
343  for (i = 0; i < samples_per_frame; i++) {
344  for (ch = 0; ch < channels; ch++) {
345  const unsigned felem = map_ch_to_felem[ch];
346  int16_t (*filter)[256] = s->filter[felem];
347  uint8_t *status = s->status[ch];
348  int prob, residual, v;
349 
350 #define F(x) filter[(x)][status[(x)]]
351  const int16_t predict = F( 0) + F( 1) + F( 2) + F( 3) +
352  F( 4) + F( 5) + F( 6) + F( 7) +
353  F( 8) + F( 9) + F(10) + F(11) +
354  F(12) + F(13) + F(14) + F(15);
355 #undef F
356 
357  if (!half_prob[ch] || i >= s->fsets.length[felem]) {
358  unsigned pelem = map_ch_to_pelem[ch];
359  unsigned index = FFABS(predict) >> 3;
360  prob = s->probs.coeff[pelem][FFMIN(index, s->probs.length[pelem] - 1)];
361  } else {
362  prob = 128;
363  }
364 
365  ac_get(ac, gb, prob, &residual);
366  v = ((predict >> 15) ^ residual) & 1;
367  dsd[((i >> 3) * channels + ch) << 2] |= v << (7 - (i & 0x7 ));
368 
369  AV_WL64A(status + 8, (AV_RL64A(status + 8) << 1) | ((AV_RL64A(status) >> 63) & 1));
370  AV_WL64A(status, (AV_RL64A(status) << 1) | v);
371  }
372  }
373 
374 dsd:
375  for (i = 0; i < channels; i++) {
376  ff_dsd2pcm_translate(&s->dsdctx[i], frame->nb_samples, 0,
377  frame->data[0] + i * 4,
378  channels * 4, pcm + i, channels);
379  }
380 
381  *got_frame_ptr = 1;
382 
383  return avpkt->size;
384 }
385 
387  .name = "dst",
388  .long_name = NULL_IF_CONFIG_SMALL("DST (Digital Stream Transfer)"),
389  .type = AVMEDIA_TYPE_AUDIO,
390  .id = AV_CODEC_ID_DST,
391  .priv_data_size = sizeof(DSTContext),
392  .init = decode_init,
393  .decode = decode_frame,
394  .capabilities = AV_CODEC_CAP_DR1,
395  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
397 };
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static av_always_inline int get_sr_golomb_dst(GetBitContext *gb, unsigned int k)
Definition: dstdec.c:131
This structure describes decoded (raw) audio or video data.
Definition: frame.h:300
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
Definition: dstdec.c:61
unsigned int a
Definition: dstdec.c:57
#define DST_MAX_ELEMENTS
Definition: dstdec.c:38
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
const uint8_t ff_reverse[256]
Definition: reverse.c:23
#define avpriv_request_sample(...)
#define DST_MAX_CHANNELS
Definition: dstdec.c:37
int size
Definition: packet.h:356
Table fsets
Definition: dstdec.c:72
static int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len)
read unsigned golomb rice code (jpegls).
Definition: golomb.h:431
av_cold void ff_init_dsd_data(void)
Definition: dsd.c:46
static int read_map(GetBitContext *gb, Table *t, unsigned int map[DST_MAX_CHANNELS], int channels)
Definition: dstdec.c:108
static av_always_inline void predict(PredictorState *ps, float *coef, int output_enable)
Definition: aacdec.c:174
AVCodec.
Definition: codec.h:190
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:359
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: dstdec.c:241
static void filter(int16_t *output, ptrdiff_t out_stride, int16_t *low, ptrdiff_t low_stride, int16_t *high, ptrdiff_t high_stride, int len, int clip)
Definition: cfhd.c:196
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1194
uint8_t
#define av_cold
Definition: attributes.h:88
void ff_dsd2pcm_translate(DSDContext *s, size_t samples, int lsbf, const uint8_t *src, ptrdiff_t src_stride, float *dst, ptrdiff_t dst_stride)
Definition: dsd.c:55
static const int8_t fsets_code_pred_coeff[3][3]
Definition: dstdec.c:44
static void ac_init(ArithCoder *ac, GetBitContext *gb)
Definition: dstdec.c:185
static AVFrame * frame
const char data[16]
Definition: mxf.c:91
#define DECLARE_ALIGNED(n, t, v)
Declare a variable that is aligned in memory.
Definition: mem.h:112
uint8_t * data
Definition: packet.h:355
Table probs
Definition: dstdec.c:72
bitstream reader API header.
channels
Definition: aptx.h:33
static const uint16_t table[]
Definition: prosumer.c:206
#define prob(name, subs,...)
Definition: cbs_vp9.c:373
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:849
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
static void read_uncoded_coeff(GetBitContext *gb, int *dst, unsigned int elements, int coeff_bits, int is_signed, int offset)
Definition: dstdec.c:139
int16_t filter[DST_MAX_ELEMENTS][16][256]
Definition: dstdec.c:74
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:188
#define AV_RL64A(p)
Definition: intreadwrite.h:554
simple assert() macros that are a bit more flexible than ISO C assert().
const char * name
Name of the codec implementation.
Definition: codec.h:197
uint8_t bits
Definition: vp3data.h:202
static const uint8_t offset[127][2]
Definition: vf_spp.c:93
static av_cold int decode_init(AVCodecContext *avctx)
Definition: dstdec.c:78
static const int8_t probs_code_pred_coeff[3][3]
Definition: dstdec.c:50
#define FFMIN(a, b)
Definition: common.h:96
static const ElemCat * elements[ELEMENT_COUNT]
Definition: signature.h:566
ArithCoder ac
Definition: dstdec.c:71
Per-channel buffer.
Definition: dsd.h:42
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
#define s(width, name)
Definition: cbs_vp9.c:257
unsigned int length[DST_MAX_ELEMENTS]
Definition: dstdec.c:63
AVCodec ff_dst_decoder
Definition: dstdec.c:386
#define av_log2
Definition: intmath.h:83
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
unsigned int c
Definition: dstdec.c:58
Libavcodec external API header.
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
int sample_rate
samples per second
Definition: avcodec.h:1186
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:677
static uint8_t prob_dst_x_bit(int c)
Definition: dstdec.c:212
int coeff[DST_MAX_ELEMENTS][128]
Definition: dstdec.c:64
static av_always_inline void ac_get(ArithCoder *ac, GetBitContext *gb, int p, int *e)
Definition: dstdec.c:191
main external API structure.
Definition: avcodec.h:526
long long int64_t
Definition: coverity.c:34
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1854
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
static void skip_bits1(GetBitContext *s)
Definition: get_bits.h:538
Describe the class of an AVClass context structure.
Definition: log.h:67
int index
Definition: gxfenc.c:89
static int build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets)
Definition: dstdec.c:217
const VDPAUPixFmtMap * map
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:314
unsigned int elements
Definition: dstdec.c:62
uint8_t buf[FIFOSIZE]
Definition: dsd.h:43
common internal api header.
if(ret< 0)
Definition: vf_mcdeint.c:279
uint8_t status[DST_MAX_CHANNELS][16]
Definition: dstdec.c:73
#define DST_SAMPLES_PER_FRAME(sample_rate)
Definition: dstdec.c:42
DSDContext dsdctx[DST_MAX_CHANNELS]
Definition: dstdec.c:75
void * priv_data
Definition: avcodec.h:553
static int read_table(GetBitContext *gb, Table *t, const int8_t code_pred_coeff[3][3], int length_bits, int coeff_bits, int is_signed, int offset)
Definition: dstdec.c:149
int channels
number of audio channels
Definition: avcodec.h:1187
#define F(x)
static const double coeff[2][5]
Definition: vf_owdenoise.c:72
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:731
#define av_always_inline
Definition: attributes.h:45
GetBitContext * gb
Definition: mss12.h:53
exp golomb vlc stuff
This structure stores compressed data.
Definition: packet.h:332
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:366
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:50
GetBitContext gb
Definition: dstdec.c:70
#define AV_WL64A(p, v)
Definition: intreadwrite.h:557