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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 "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 * 8 / 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 
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 
89 
90  for (i = 0; i < avctx->channels; i++)
91  memset(s->dsdctx[i].buf, 0x69, sizeof(s->dsdctx[i].buf));
92 
94 
95  return 0;
96 }
97 
98 static int read_map(GetBitContext *gb, Table *t, unsigned int map[DST_MAX_CHANNELS], int channels)
99 {
100  int ch;
101  t->elements = 1;
102  map[0] = 0;
103  if (!get_bits1(gb)) {
104  for (ch = 1; ch < channels; ch++) {
105  int bits = av_log2(t->elements) + 1;
106  map[ch] = get_bits(gb, bits);
107  if (map[ch] == t->elements) {
108  t->elements++;
109  if (t->elements >= DST_MAX_ELEMENTS)
110  return AVERROR_INVALIDDATA;
111  } else if (map[ch] > t->elements) {
112  return AVERROR_INVALIDDATA;
113  }
114  }
115  } else {
116  memset(map, 0, sizeof(*map) * DST_MAX_CHANNELS);
117  }
118  return 0;
119 }
120 
121 static av_always_inline int get_sr_golomb_dst(GetBitContext *gb, unsigned int k)
122 {
123  int v = get_ur_golomb(gb, k, get_bits_left(gb), 0);
124  if (v && get_bits1(gb))
125  v = -v;
126  return v;
127 }
128 
129 static void read_uncoded_coeff(GetBitContext *gb, int *dst, unsigned int elements,
130  int coeff_bits, int is_signed, int offset)
131 {
132  int i;
133 
134  for (i = 0; i < elements; i++) {
135  dst[i] = (is_signed ? get_sbits(gb, coeff_bits) : get_bits(gb, coeff_bits)) + offset;
136  }
137 }
138 
139 static int read_table(GetBitContext *gb, Table *t, const int8_t code_pred_coeff[3][3],
140  int length_bits, int coeff_bits, int is_signed, int offset)
141 {
142  unsigned int i, j, k;
143  for (i = 0; i < t->elements; i++) {
144  t->length[i] = get_bits(gb, length_bits) + 1;
145  if (!get_bits1(gb)) {
146  read_uncoded_coeff(gb, t->coeff[i], t->length[i], coeff_bits, is_signed, offset);
147  } else {
148  int method = get_bits(gb, 2), lsb_size;
149  if (method == 3)
150  return AVERROR_INVALIDDATA;
151 
152  read_uncoded_coeff(gb, t->coeff[i], method + 1, coeff_bits, is_signed, offset);
153 
154  lsb_size = get_bits(gb, 3);
155  for (j = method + 1; j < t->length[i]; j++) {
156  int c, x = 0;
157  for (k = 0; k < method + 1; k++)
158  x += code_pred_coeff[method][k] * t->coeff[i][j - k - 1];
159  c = get_sr_golomb_dst(gb, lsb_size);
160  if (x >= 0)
161  c -= (x + 4) / 8;
162  else
163  c += (-x + 3) / 8;
164  t->coeff[i][j] = c;
165  }
166  }
167  }
168  return 0;
169 }
170 
171 static void ac_init(ArithCoder *ac, GetBitContext *gb)
172 {
173  ac->a = 4095;
174  ac->c = get_bits(gb, 12);
175 }
176 
177 static av_always_inline void ac_get(ArithCoder *ac, GetBitContext *gb, int p, int *e)
178 {
179  unsigned int k = (ac->a >> 8) | ((ac->a >> 7) & 1);
180  unsigned int q = k * p;
181  unsigned int a_q = ac->a - q;
182 
183  *e = ac->c < a_q;
184  if (*e) {
185  ac->a = a_q;
186  } else {
187  ac->a = q;
188  ac->c -= a_q;
189  }
190 
191  if (ac->a < 2048) {
192  int n = 11 - av_log2(ac->a);
193  ac->a <<= n;
194  ac->c = (ac->c << n) | get_bits(gb, n);
195  }
196 }
197 
199 {
200  return (ff_reverse[c & 127] >> 1) + 1;
201 }
202 
203 static void build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets)
204 {
205  int i, j, k, l;
206 
207  for (i = 0; i < fsets->elements; i++) {
208  int length = fsets->length[i];
209 
210  for (j = 0; j < 16; j++) {
211  int total = av_clip(length - j * 8, 0, 8);
212 
213  for (k = 0; k < 256; k++) {
214  int v = 0;
215 
216  for (l = 0; l < total; l++)
217  v += (((k >> l) & 1) * 2 - 1) * fsets->coeff[i][j * 8 + l];
218  table[i][j][k] = v;
219  }
220  }
221  }
222 }
223 
224 static int decode_frame(AVCodecContext *avctx, void *data,
225  int *got_frame_ptr, AVPacket *avpkt)
226 {
227  unsigned samples_per_frame = DST_SAMPLES_PER_FRAME(avctx->sample_rate);
228  unsigned map_ch_to_felem[DST_MAX_CHANNELS];
229  unsigned map_ch_to_pelem[DST_MAX_CHANNELS];
230  unsigned i, ch, same_map, dst_x_bit;
231  unsigned half_prob[DST_MAX_CHANNELS];
232  const int channels = avctx->channels;
233  DSTContext *s = avctx->priv_data;
234  GetBitContext *gb = &s->gb;
235  ArithCoder *ac = &s->ac;
236  AVFrame *frame = data;
237  uint8_t *dsd;
238  float *pcm;
239  int ret;
240 
241  if (avpkt->size <= 1)
242  return AVERROR_INVALIDDATA;
243 
244  frame->nb_samples = samples_per_frame / 8;
245  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
246  return ret;
247  dsd = frame->data[0];
248  pcm = (float *)frame->data[0];
249 
250  if ((ret = init_get_bits8(gb, avpkt->data, avpkt->size)) < 0)
251  return ret;
252 
253  if (!get_bits1(gb)) {
254  skip_bits1(gb);
255  if (get_bits(gb, 6))
256  return AVERROR_INVALIDDATA;
257  memcpy(frame->data[0], avpkt->data + 1, FFMIN(avpkt->size - 1, frame->nb_samples * avctx->channels));
258  goto dsd;
259  }
260 
261  /* Segmentation (10.4, 10.5, 10.6) */
262 
263  if (!get_bits1(gb)) {
264  avpriv_request_sample(avctx, "Not Same Segmentation");
265  return AVERROR_PATCHWELCOME;
266  }
267 
268  if (!get_bits1(gb)) {
269  avpriv_request_sample(avctx, "Not Same Segmentation For All Channels");
270  return AVERROR_PATCHWELCOME;
271  }
272 
273  if (!get_bits1(gb)) {
274  avpriv_request_sample(avctx, "Not End Of Channel Segmentation");
275  return AVERROR_PATCHWELCOME;
276  }
277 
278  /* Mapping (10.7, 10.8, 10.9) */
279 
280  same_map = get_bits1(gb);
281 
282  if ((ret = read_map(gb, &s->fsets, map_ch_to_felem, avctx->channels)) < 0)
283  return ret;
284 
285  if (same_map) {
286  s->probs.elements = s->fsets.elements;
287  memcpy(map_ch_to_pelem, map_ch_to_felem, sizeof(map_ch_to_felem));
288  } else {
289  avpriv_request_sample(avctx, "Not Same Mapping");
290  if ((ret = read_map(gb, &s->probs, map_ch_to_pelem, avctx->channels)) < 0)
291  return ret;
292  }
293 
294  /* Half Probability (10.10) */
295 
296  for (ch = 0; ch < avctx->channels; ch++)
297  half_prob[ch] = get_bits1(gb);
298 
299  /* Filter Coef Sets (10.12) */
300 
301  read_table(gb, &s->fsets, fsets_code_pred_coeff, 7, 9, 1, 0);
302 
303  /* Probability Tables (10.13) */
304 
305  read_table(gb, &s->probs, probs_code_pred_coeff, 6, 7, 0, 1);
306 
307  /* Arithmetic Coded Data (10.11) */
308 
309  if (get_bits1(gb))
310  return AVERROR_INVALIDDATA;
311  ac_init(ac, gb);
312 
313  build_filter(s->filter, &s->fsets);
314 
315  memset(s->status, 0xAA, sizeof(s->status));
316  memset(dsd, 0, frame->nb_samples * 4 * avctx->channels);
317 
318  ac_get(ac, gb, prob_dst_x_bit(s->fsets.coeff[0][0]), &dst_x_bit);
319 
320  for (i = 0; i < samples_per_frame; i++) {
321  for (ch = 0; ch < channels; ch++) {
322  const unsigned felem = map_ch_to_felem[ch];
323  int16_t (*filter)[256] = s->filter[felem];
324  uint8_t *status = s->status[ch];
325  int prob, residual, v;
326 
327 #define F(x) filter[(x)][status[(x)]]
328  const int16_t predict = F( 0) + F( 1) + F( 2) + F( 3) +
329  F( 4) + F( 5) + F( 6) + F( 7) +
330  F( 8) + F( 9) + F(10) + F(11) +
331  F(12) + F(13) + F(14) + F(15);
332 #undef F
333 
334  if (!half_prob[ch] || i >= s->fsets.length[felem]) {
335  unsigned pelem = map_ch_to_pelem[ch];
336  unsigned index = FFABS(predict) >> 3;
337  prob = s->probs.coeff[pelem][FFMIN(index, s->probs.length[pelem] - 1)];
338  } else {
339  prob = 128;
340  }
341 
342  ac_get(ac, gb, prob, &residual);
343  v = ((predict >> 15) ^ residual) & 1;
344  dsd[((i >> 3) * channels + ch) << 2] |= v << (7 - (i & 0x7 ));
345 
346  AV_WN64A(status + 8, (AV_RN64A(status + 8) << 1) | ((AV_RN64A(status) >> 63) & 1));
347  AV_WN64A(status, (AV_RN64A(status) << 1) | v);
348  }
349  }
350 
351 dsd:
352  for (i = 0; i < avctx->channels; i++) {
353  ff_dsd2pcm_translate(&s->dsdctx[i], frame->nb_samples, 0,
354  frame->data[0] + i * 4,
355  avctx->channels * 4, pcm + i, avctx->channels);
356  }
357 
358  *got_frame_ptr = 1;
359 
360  return avpkt->size;
361 }
362 
364  .name = "dst",
365  .long_name = NULL_IF_CONFIG_SMALL("DST (Digital Stream Transfer)"),
366  .type = AVMEDIA_TYPE_AUDIO,
367  .id = AV_CODEC_ID_DST,
368  .priv_data_size = sizeof(DSTContext),
369  .init = decode_init,
370  .decode = decode_frame,
371  .capabilities = AV_CODEC_CAP_DR1,
372  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
374 };
const char * s
Definition: avisynth_c.h:631
#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:121
This structure describes decoded (raw) audio or video data.
Definition: frame.h:184
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:247
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
#define DST_MAX_CHANNELS
Definition: dstdec.c:37
int size
Definition: avcodec.h:1581
int av_log2(unsigned v)
Definition: intmath.c:26
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:53
Table fsets
Definition: dstdec.c:72
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:98
static av_always_inline void predict(PredictorState *ps, float *coef, int output_enable)
Definition: aacdec.c:174
AVCodec.
Definition: avcodec.h:3542
static int get_sbits(GetBitContext *s, int n)
Definition: get_bits.h:232
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: dstdec.c:224
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
uint8_t bits
Definition: crc.c:296
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2418
uint8_t
#define av_cold
Definition: attributes.h:82
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:171
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, uint8_t clip)
Definition: cfhd.c:80
static AVFrame * frame
uint8_t * data
Definition: avcodec.h:1580
Table probs
Definition: dstdec.c:72
bitstream reader API header.
static int get_ur_golomb(GetBitContext *gb, int k, int limit, int esc_len)
read unsigned golomb rice code (ffv1).
Definition: golomb.h:270
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:568
static void read_uncoded_coeff(GetBitContext *gb, int *dst, unsigned int elements, int coeff_bits, int is_signed, int offset)
Definition: dstdec.c:129
int16_t filter[DST_MAX_ELEMENTS][16][256]
Definition: dstdec.c:74
static const struct endianess table[]
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
const uint8_t ff_reverse[256]
Definition: reverse.c:23
simple assert() macros that are a bit more flexible than ISO C assert().
GLsizei GLsizei * length
Definition: opengl_enc.c:115
const char * name
Name of the codec implementation.
Definition: avcodec.h:3549
static const uint8_t offset[127][2]
Definition: vf_spp.c:92
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
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
void ff_dsd2pcm_translate(DSDContext *s, size_t samples, int lsbf, const unsigned char *src, ptrdiff_t src_stride, float *dst, ptrdiff_t dst_stride)
Definition: dsd.c:55
int n
Definition: avisynth_c.h:547
unsigned int length[DST_MAX_ELEMENTS]
Definition: dstdec.c:63
AVCodec ff_dst_decoder
Definition: dstdec.c:363
#define AV_WN64A(p, v)
Definition: intreadwrite.h:542
#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:2410
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:437
static uint8_t prob_dst_x_bit(int c)
Definition: dstdec.c:198
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:177
main external API structure.
Definition: avcodec.h:1649
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:928
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:299
static void skip_bits1(GetBitContext *s)
Definition: get_bits.h:324
Describe the class of an AVClass context structure.
Definition: log.h:67
int index
Definition: gxfenc.c:89
const VDPAUPixFmtMap * map
unsigned char buf[FIFOSIZE]
Definition: dsd.h:43
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:198
unsigned int elements
Definition: dstdec.c:62
static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)
Definition: ccaption_dec.c:722
common internal api header.
if(ret< 0)
Definition: vf_mcdeint.c:282
static void build_filter(int16_t table[DST_MAX_ELEMENTS][16][256], const Table *fsets)
Definition: dstdec.c:203
static double c[64]
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:1691
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:139
int channels
number of audio channels
Definition: avcodec.h:2411
#define F(x)
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:701
#define av_always_inline
Definition: attributes.h:39
#define AV_RN64A(p)
Definition: intreadwrite.h:530
exp golomb vlc stuff
This structure stores compressed data.
Definition: avcodec.h:1557
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:241
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:956
GetBitContext gb
Definition: dstdec.c:70