FFmpeg  4.4
dstdec.c
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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 "libavutil/mem_internal.h"
31 #include "internal.h"
32 #include "get_bits.h"
33 #include "avcodec.h"
34 #include "golomb.h"
35 #include "mathops.h"
36 #include "dsd.h"
37 
38 #define DST_MAX_CHANNELS 6
39 #define DST_MAX_ELEMENTS (2 * DST_MAX_CHANNELS)
40 
41 #define DSD_FS44(sample_rate) (sample_rate * 8LL / 44100)
42 
43 #define DST_SAMPLES_PER_FRAME(sample_rate) (588 * DSD_FS44(sample_rate))
44 
45 static const int8_t fsets_code_pred_coeff[3][3] = {
46  { -8 },
47  { -16, 8 },
48  { -9, -5, 6 },
49 };
50 
51 static const int8_t probs_code_pred_coeff[3][3] = {
52  { -8 },
53  { -16, 8 },
54  { -24, 24, -8 },
55 };
56 
57 typedef struct ArithCoder {
58  unsigned int a;
59  unsigned int c;
60 } ArithCoder;
61 
62 typedef struct Table {
63  unsigned int elements;
64  unsigned int length[DST_MAX_ELEMENTS];
66 } Table;
67 
68 typedef struct DSTContext {
69  AVClass *class;
70 
75  DECLARE_ALIGNED(16, int16_t, filter)[DST_MAX_ELEMENTS][16][256];
77 } DSTContext;
78 
80 {
81  DSTContext *s = avctx->priv_data;
82  int i;
83 
84  if (avctx->channels > DST_MAX_CHANNELS) {
85  avpriv_request_sample(avctx, "Channel count %d", avctx->channels);
86  return AVERROR_PATCHWELCOME;
87  }
88 
89  // the sample rate is only allowed to be 64,128,256 * 44100 by ISO/IEC 14496-3:2005(E)
90  // We are a bit more tolerant here, but this check is needed to bound the size and duration
91  if (avctx->sample_rate > 512 * 44100)
92  return AVERROR_INVALIDDATA;
93 
94 
95  if (DST_SAMPLES_PER_FRAME(avctx->sample_rate) & 7) {
96  return AVERROR_PATCHWELCOME;
97  }
98 
100 
101  for (i = 0; i < avctx->channels; i++)
102  memset(s->dsdctx[i].buf, 0x69, sizeof(s->dsdctx[i].buf));
103 
105 
106  return 0;
107 }
108 
109 static int read_map(GetBitContext *gb, Table *t, unsigned int map[DST_MAX_CHANNELS], int channels)
110 {
111  int ch;
112  t->elements = 1;
113  map[0] = 0;
114  if (!get_bits1(gb)) {
115  for (ch = 1; ch < channels; ch++) {
116  int bits = av_log2(t->elements) + 1;
117  map[ch] = get_bits(gb, bits);
118  if (map[ch] == t->elements) {
119  t->elements++;
120  if (t->elements >= DST_MAX_ELEMENTS)
121  return AVERROR_INVALIDDATA;
122  } else if (map[ch] > t->elements) {
123  return AVERROR_INVALIDDATA;
124  }
125  }
126  } else {
127  memset(map, 0, sizeof(*map) * DST_MAX_CHANNELS);
128  }
129  return 0;
130 }
131 
132 static av_always_inline int get_sr_golomb_dst(GetBitContext *gb, unsigned int k)
133 {
134  int v = get_ur_golomb_jpegls(gb, k, get_bits_left(gb), 0);
135  if (v && get_bits1(gb))
136  v = -v;
137  return v;
138 }
139 
140 static void read_uncoded_coeff(GetBitContext *gb, int *dst, unsigned int elements,
141  int coeff_bits, int is_signed, int offset)
142 {
143  int i;
144 
145  for (i = 0; i < elements; i++) {
146  dst[i] = (is_signed ? get_sbits(gb, coeff_bits) : get_bits(gb, coeff_bits)) + offset;
147  }
148 }
149 
150 static int read_table(GetBitContext *gb, Table *t, const int8_t code_pred_coeff[3][3],
151  int length_bits, int coeff_bits, int is_signed, int offset)
152 {
153  unsigned int i, j, k;
154  for (i = 0; i < t->elements; i++) {
155  t->length[i] = get_bits(gb, length_bits) + 1;
156  if (!get_bits1(gb)) {
157  read_uncoded_coeff(gb, t->coeff[i], t->length[i], coeff_bits, is_signed, offset);
158  } else {
159  int method = get_bits(gb, 2), lsb_size;
160  if (method == 3)
161  return AVERROR_INVALIDDATA;
162 
163  read_uncoded_coeff(gb, t->coeff[i], method + 1, coeff_bits, is_signed, offset);
164 
165  lsb_size = get_bits(gb, 3);
166  for (j = method + 1; j < t->length[i]; j++) {
167  int c, x = 0;
168  for (k = 0; k < method + 1; k++)
169  x += code_pred_coeff[method][k] * (unsigned)t->coeff[i][j - k - 1];
170  c = get_sr_golomb_dst(gb, lsb_size);
171  if (x >= 0)
172  c -= (x + 4) / 8;
173  else
174  c += (-x + 3) / 8;
175  if (!is_signed) {
176  if (c < offset || c >= offset + (1<<coeff_bits))
177  return AVERROR_INVALIDDATA;
178  }
179  t->coeff[i][j] = c;
180  }
181  }
182  }
183  return 0;
184 }
185 
186 static void ac_init(ArithCoder *ac, GetBitContext *gb)
187 {
188  ac->a = 4095;
189  ac->c = get_bits(gb, 12);
190 }
191 
192 static av_always_inline void ac_get(ArithCoder *ac, GetBitContext *gb, int p, int *e)
193 {
194  unsigned int k = (ac->a >> 8) | ((ac->a >> 7) & 1);
195  unsigned int q = k * p;
196  unsigned int a_q = ac->a - q;
197 
198  *e = ac->c < a_q;
199  if (*e) {
200  ac->a = a_q;
201  } else {
202  ac->a = q;
203  ac->c -= a_q;
204  }
205 
206  if (ac->a < 2048) {
207  int n = 11 - av_log2(ac->a);
208  ac->a <<= n;
209  ac->c = (ac->c << n) | get_bits(gb, n);
210  }
211 }
212 
214 {
215  return (ff_reverse[c & 127] >> 1) + 1;
216 }
217 
218 static void build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets)
219 {
220  int i, j, k, l;
221 
222  for (i = 0; i < fsets->elements; i++) {
223  int length = fsets->length[i];
224 
225  for (j = 0; j < 16; j++) {
226  int total = av_clip(length - j * 8, 0, 8);
227 
228  for (k = 0; k < 256; k++) {
229  int v = 0;
230 
231  for (l = 0; l < total; l++)
232  v += (((k >> l) & 1) * 2 - 1) * fsets->coeff[i][j * 8 + l];
233  table[i][j][k] = v;
234  }
235  }
236  }
237 }
238 
239 static int decode_frame(AVCodecContext *avctx, void *data,
240  int *got_frame_ptr, AVPacket *avpkt)
241 {
242  unsigned samples_per_frame = DST_SAMPLES_PER_FRAME(avctx->sample_rate);
243  unsigned map_ch_to_felem[DST_MAX_CHANNELS];
244  unsigned map_ch_to_pelem[DST_MAX_CHANNELS];
245  unsigned i, ch, same_map, dst_x_bit;
246  unsigned half_prob[DST_MAX_CHANNELS];
247  const int channels = avctx->channels;
248  DSTContext *s = avctx->priv_data;
249  GetBitContext *gb = &s->gb;
250  ArithCoder *ac = &s->ac;
251  AVFrame *frame = data;
252  uint8_t *dsd;
253  float *pcm;
254  int ret;
255 
256  if (avpkt->size <= 1)
257  return AVERROR_INVALIDDATA;
258 
259  frame->nb_samples = samples_per_frame / 8;
260  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
261  return ret;
262  dsd = frame->data[0];
263  pcm = (float *)frame->data[0];
264 
265  if ((ret = init_get_bits8(gb, avpkt->data, avpkt->size)) < 0)
266  return ret;
267 
268  if (!get_bits1(gb)) {
269  skip_bits1(gb);
270  if (get_bits(gb, 6))
271  return AVERROR_INVALIDDATA;
272  memcpy(frame->data[0], avpkt->data + 1, FFMIN(avpkt->size - 1, frame->nb_samples * channels));
273  goto dsd;
274  }
275 
276  /* Segmentation (10.4, 10.5, 10.6) */
277 
278  if (!get_bits1(gb)) {
279  avpriv_request_sample(avctx, "Not Same Segmentation");
280  return AVERROR_PATCHWELCOME;
281  }
282 
283  if (!get_bits1(gb)) {
284  avpriv_request_sample(avctx, "Not Same Segmentation For All Channels");
285  return AVERROR_PATCHWELCOME;
286  }
287 
288  if (!get_bits1(gb)) {
289  avpriv_request_sample(avctx, "Not End Of Channel Segmentation");
290  return AVERROR_PATCHWELCOME;
291  }
292 
293  /* Mapping (10.7, 10.8, 10.9) */
294 
295  same_map = get_bits1(gb);
296 
297  if ((ret = read_map(gb, &s->fsets, map_ch_to_felem, channels)) < 0)
298  return ret;
299 
300  if (same_map) {
301  s->probs.elements = s->fsets.elements;
302  memcpy(map_ch_to_pelem, map_ch_to_felem, sizeof(map_ch_to_felem));
303  } else {
304  avpriv_request_sample(avctx, "Not Same Mapping");
305  if ((ret = read_map(gb, &s->probs, map_ch_to_pelem, channels)) < 0)
306  return ret;
307  }
308 
309  /* Half Probability (10.10) */
310 
311  for (ch = 0; ch < channels; ch++)
312  half_prob[ch] = get_bits1(gb);
313 
314  /* Filter Coef Sets (10.12) */
315 
316  ret = read_table(gb, &s->fsets, fsets_code_pred_coeff, 7, 9, 1, 0);
317  if (ret < 0)
318  return ret;
319 
320  /* Probability Tables (10.13) */
321 
322  ret = read_table(gb, &s->probs, probs_code_pred_coeff, 6, 7, 0, 1);
323  if (ret < 0)
324  return ret;
325 
326  /* Arithmetic Coded Data (10.11) */
327 
328  if (get_bits1(gb))
329  return AVERROR_INVALIDDATA;
330  ac_init(ac, gb);
331 
332  build_filter(s->filter, &s->fsets);
333 
334  memset(s->status, 0xAA, sizeof(s->status));
335  memset(dsd, 0, frame->nb_samples * 4 * channels);
336 
337  ac_get(ac, gb, prob_dst_x_bit(s->fsets.coeff[0][0]), &dst_x_bit);
338 
339  for (i = 0; i < samples_per_frame; i++) {
340  for (ch = 0; ch < channels; ch++) {
341  const unsigned felem = map_ch_to_felem[ch];
342  int16_t (*filter)[256] = s->filter[felem];
343  uint8_t *status = s->status[ch];
344  int prob, residual, v;
345 
346 #define F(x) filter[(x)][status[(x)]]
347  const int16_t predict = F( 0) + F( 1) + F( 2) + F( 3) +
348  F( 4) + F( 5) + F( 6) + F( 7) +
349  F( 8) + F( 9) + F(10) + F(11) +
350  F(12) + F(13) + F(14) + F(15);
351 #undef F
352 
353  if (!half_prob[ch] || i >= s->fsets.length[felem]) {
354  unsigned pelem = map_ch_to_pelem[ch];
355  unsigned index = FFABS(predict) >> 3;
356  prob = s->probs.coeff[pelem][FFMIN(index, s->probs.length[pelem] - 1)];
357  } else {
358  prob = 128;
359  }
360 
361  ac_get(ac, gb, prob, &residual);
362  v = ((predict >> 15) ^ residual) & 1;
363  dsd[((i >> 3) * channels + ch) << 2] |= v << (7 - (i & 0x7 ));
364 
365  AV_WL64A(status + 8, (AV_RL64A(status + 8) << 1) | ((AV_RL64A(status) >> 63) & 1));
366  AV_WL64A(status, (AV_RL64A(status) << 1) | v);
367  }
368  }
369 
370 dsd:
371  for (i = 0; i < channels; i++) {
372  ff_dsd2pcm_translate(&s->dsdctx[i], frame->nb_samples, 0,
373  frame->data[0] + i * 4,
374  channels * 4, pcm + i, channels);
375  }
376 
377  *got_frame_ptr = 1;
378 
379  return avpkt->size;
380 }
381 
383  .name = "dst",
384  .long_name = NULL_IF_CONFIG_SMALL("DST (Digital Stream Transfer)"),
385  .type = AVMEDIA_TYPE_AUDIO,
386  .id = AV_CODEC_ID_DST,
387  .priv_data_size = sizeof(DSTContext),
388  .init = decode_init,
389  .decode = decode_frame,
390  .capabilities = AV_CODEC_CAP_DR1,
391  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
393  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
394 };
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:925
channels
Definition: aptx.h:33
#define av_always_inline
Definition: attributes.h:45
#define av_cold
Definition: attributes.h:88
uint8_t
simple assert() macros that are a bit more flexible than ISO C assert().
Libavcodec external API header.
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
#define s(width, name)
Definition: cbs_vp9.c:257
#define prob(name, subs,...)
Definition: cbs_vp9.c:373
static av_always_inline void filter(int16_t *output, ptrdiff_t out_stride, const int16_t *low, ptrdiff_t low_stride, const int16_t *high, ptrdiff_t high_stride, int len, int clip)
Definition: cfhddsp.c:27
#define FFMIN(a, b)
Definition: common.h:105
#define av_clip
Definition: common.h:122
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1893
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
static AVFrame * frame
av_cold void ff_init_dsd_data(void)
Definition: dsd.c:47
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:53
static void ac_init(ArithCoder *ac, GetBitContext *gb)
Definition: dstdec.c:186
static av_always_inline void ac_get(ArithCoder *ac, GetBitContext *gb, int p, int *e)
Definition: dstdec.c:192
#define F(x)
static uint8_t prob_dst_x_bit(int c)
Definition: dstdec.c:213
static void build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets)
Definition: dstdec.c:218
static const int8_t fsets_code_pred_coeff[3][3]
Definition: dstdec.c:45
static av_cold int decode_init(AVCodecContext *avctx)
Definition: dstdec.c:79
#define DST_MAX_ELEMENTS
Definition: dstdec.c:39
static void read_uncoded_coeff(GetBitContext *gb, int *dst, unsigned int elements, int coeff_bits, int is_signed, int offset)
Definition: dstdec.c:140
AVCodec ff_dst_decoder
Definition: dstdec.c:382
static av_always_inline int get_sr_golomb_dst(GetBitContext *gb, unsigned int k)
Definition: dstdec.c:132
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:150
static const int8_t probs_code_pred_coeff[3][3]
Definition: dstdec.c:51
#define DST_SAMPLES_PER_FRAME(sample_rate)
Definition: dstdec.c:43
#define DST_MAX_CHANNELS
Definition: dstdec.c:38
static int read_map(GetBitContext *gb, Table *t, unsigned int map[DST_MAX_CHANNELS], int channels)
Definition: dstdec.c:109
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: dstdec.c:239
bitstream reader API header.
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:359
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:849
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:677
static void skip_bits1(GetBitContext *s)
Definition: get_bits.h:538
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
exp golomb vlc stuff
static int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len)
read unsigned golomb rice code (jpegls).
Definition: golomb.h:430
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
@ AV_CODEC_ID_DST
Definition: codec_id.h:506
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define DECLARE_ALIGNED(n, t, v)
Declare a variable that is aligned in memory.
Definition: mem.h:117
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
@ AV_SAMPLE_FMT_FLT
float
Definition: samplefmt.h:63
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:59
int index
Definition: gxfenc.c:89
const VDPAUPixFmtMap * map
int i
Definition: input.c:407
#define av_log2
Definition: intmath.h:83
#define AV_WL64A(p, v)
Definition: intreadwrite.h:557
#define AV_RL64A(p)
Definition: intreadwrite.h:554
static av_always_inline void predict(PredictorState *ps, float *coef, int output_enable)
Definition: aacdec.c:179
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:41
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
const uint8_t ff_reverse[256]
Definition: reverse.c:23
const char data[16]
Definition: mxf.c:142
static const uint16_t table[]
Definition: prosumer.c:206
static const ElemCat * elements[ELEMENT_COUNT]
Definition: signature.h:566
Describe the class of an AVClass context structure.
Definition: log.h:67
main external API structure.
Definition: avcodec.h:536
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1204
int sample_rate
samples per second
Definition: avcodec.h:1196
int channels
number of audio channels
Definition: avcodec.h:1197
void * priv_data
Definition: avcodec.h:563
AVCodec.
Definition: codec.h:197
const char * name
Name of the codec implementation.
Definition: codec.h:204
This structure describes decoded (raw) audio or video data.
Definition: frame.h:318
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:384
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:332
This structure stores compressed data.
Definition: packet.h:346
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
unsigned int a
Definition: dstdec.c:58
unsigned int c
Definition: dstdec.c:59
Per-channel buffer.
Definition: dsd.h:42
uint8_t status[DST_MAX_CHANNELS][16]
Definition: dstdec.c:74
int16_t filter[DST_MAX_ELEMENTS][16][256]
Definition: dstdec.c:75
Table fsets
Definition: dstdec.c:73
Table probs
Definition: dstdec.c:73
GetBitContext gb
Definition: dstdec.c:71
ArithCoder ac
Definition: dstdec.c:72
DSDContext dsdctx[DST_MAX_CHANNELS]
Definition: dstdec.c:76
Definition: dstdec.c:62
unsigned int elements
Definition: dstdec.c:63
int coeff[DST_MAX_ELEMENTS][128]
Definition: dstdec.c:65
unsigned int length[DST_MAX_ELEMENTS]
Definition: dstdec.c:64
#define avpriv_request_sample(...)
if(ret< 0)
Definition: vf_mcdeint.c:282
static const uint8_t offset[127][2]
Definition: vf_spp.c:107
uint8_t bits
Definition: vp3data.h:141
static double c[64]