FFmpeg  4.4.6
sbcdec.c
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1 /*
2  * Bluetooth low-complexity, subband codec (SBC)
3  *
4  * Copyright (C) 2017 Aurelien Jacobs <aurel@gnuage.org>
5  * Copyright (C) 2012-2013 Intel Corporation
6  * Copyright (C) 2008-2010 Nokia Corporation
7  * Copyright (C) 2004-2010 Marcel Holtmann <marcel@holtmann.org>
8  * Copyright (C) 2004-2005 Henryk Ploetz <henryk@ploetzli.ch>
9  * Copyright (C) 2005-2008 Brad Midgley <bmidgley@xmission.com>
10  *
11  * This file is part of FFmpeg.
12  *
13  * FFmpeg is free software; you can redistribute it and/or
14  * modify it under the terms of the GNU Lesser General Public
15  * License as published by the Free Software Foundation; either
16  * version 2.1 of the License, or (at your option) any later version.
17  *
18  * FFmpeg is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21  * Lesser General Public License for more details.
22  *
23  * You should have received a copy of the GNU Lesser General Public
24  * License along with FFmpeg; if not, write to the Free Software
25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26  */
27 
28 /**
29  * @file
30  * SBC decoder implementation
31  */
32 
33 #include "avcodec.h"
34 #include "internal.h"
35 #include "libavutil/intreadwrite.h"
36 #include "libavutil/mem_internal.h"
37 #include "sbc.h"
38 #include "sbcdec_data.h"
39 
41  int32_t V[2][170];
42  int offset[2][16];
43 };
44 
45 typedef struct SBCDecContext {
46  AVClass *class;
50 
51 /*
52  * Unpacks a SBC frame at the beginning of the stream in data,
53  * which has at most len bytes into frame.
54  * Returns the length in bytes of the packed frame, or a negative
55  * value on error. The error codes are:
56  *
57  * -1 Data stream too short
58  * -2 Sync byte incorrect
59  * -3 CRC8 incorrect
60  * -4 Bitpool value out of bounds
61  */
62 static int sbc_unpack_frame(const uint8_t *data, struct sbc_frame *frame,
63  size_t len)
64 {
65  unsigned int consumed;
66  /* Will copy the parts of the header that are relevant to crc
67  * calculation here */
68  uint8_t crc_header[11] = { 0 };
69  int crc_pos;
70  int32_t temp;
71 
72  uint32_t audio_sample;
73  int ch, sb, blk, bit; /* channel, subband, block and bit standard
74  counters */
75  int bits[2][8]; /* bits distribution */
76  uint32_t levels[2][8]; /* levels derived from that */
77 
78  if (len < 4)
79  return -1;
80 
81  if (data[0] == MSBC_SYNCWORD) {
82  if (data[1] != 0)
83  return -2;
84  if (data[2] != 0)
85  return -2;
86 
87  frame->frequency = SBC_FREQ_16000;
88  frame->blocks = MSBC_BLOCKS;
89  frame->allocation = LOUDNESS;
90  frame->mode = MONO;
91  frame->channels = 1;
92  frame->subbands = 8;
93  frame->bitpool = 26;
94  } else if (data[0] == SBC_SYNCWORD) {
95  frame->frequency = (data[1] >> 6) & 0x03;
96  frame->blocks = 4 * ((data[1] >> 4) & 0x03) + 4;
97  frame->mode = (data[1] >> 2) & 0x03;
98  frame->channels = frame->mode == MONO ? 1 : 2;
99  frame->allocation = (data[1] >> 1) & 0x01;
100  frame->subbands = data[1] & 0x01 ? 8 : 4;
101  frame->bitpool = data[2];
102 
103  if ((frame->mode == MONO || frame->mode == DUAL_CHANNEL) &&
104  frame->bitpool > 16 * frame->subbands)
105  return -4;
106 
107  if ((frame->mode == STEREO || frame->mode == JOINT_STEREO) &&
108  frame->bitpool > 32 * frame->subbands)
109  return -4;
110  } else
111  return -2;
112 
113  consumed = 32;
114  crc_header[0] = data[1];
115  crc_header[1] = data[2];
116  crc_pos = 16;
117 
118  if (frame->mode == JOINT_STEREO) {
119  if (len * 8 < consumed + frame->subbands)
120  return -1;
121 
122  frame->joint = 0x00;
123  for (sb = 0; sb < frame->subbands - 1; sb++)
124  frame->joint |= ((data[4] >> (7 - sb)) & 0x01) << sb;
125  if (frame->subbands == 4)
126  crc_header[crc_pos / 8] = data[4] & 0xf0;
127  else
128  crc_header[crc_pos / 8] = data[4];
129 
130  consumed += frame->subbands;
131  crc_pos += frame->subbands;
132  }
133 
134  if (len * 8 < consumed + (4 * frame->subbands * frame->channels))
135  return -1;
136 
137  for (ch = 0; ch < frame->channels; ch++) {
138  for (sb = 0; sb < frame->subbands; sb++) {
139  /* FIXME assert(consumed % 4 == 0); */
140  frame->scale_factor[ch][sb] =
141  (data[consumed >> 3] >> (4 - (consumed & 0x7))) & 0x0F;
142  crc_header[crc_pos >> 3] |=
143  frame->scale_factor[ch][sb] << (4 - (crc_pos & 0x7));
144 
145  consumed += 4;
146  crc_pos += 4;
147  }
148  }
149 
150  if (data[3] != ff_sbc_crc8(frame->crc_ctx, crc_header, crc_pos))
151  return -3;
152 
154 
155  for (ch = 0; ch < frame->channels; ch++) {
156  for (sb = 0; sb < frame->subbands; sb++)
157  levels[ch][sb] = (1 << bits[ch][sb]) - 1;
158  }
159 
160  for (blk = 0; blk < frame->blocks; blk++) {
161  for (ch = 0; ch < frame->channels; ch++) {
162  for (sb = 0; sb < frame->subbands; sb++) {
163  uint32_t shift;
164 
165  if (levels[ch][sb] == 0) {
166  frame->sb_sample[blk][ch][sb] = 0;
167  continue;
168  }
169 
170  shift = frame->scale_factor[ch][sb] +
172 
173  audio_sample = 0;
174  for (bit = 0; bit < bits[ch][sb]; bit++) {
175  if (consumed > len * 8)
176  return -1;
177 
178  if ((data[consumed >> 3] >> (7 - (consumed & 0x7))) & 0x01)
179  audio_sample |= 1 << (bits[ch][sb] - bit - 1);
180 
181  consumed++;
182  }
183 
184  frame->sb_sample[blk][ch][sb] = (int32_t)
185  (((((uint64_t) audio_sample << 1) | 1) << shift) /
186  levels[ch][sb]) - (1 << shift);
187  }
188  }
189  }
190 
191  if (frame->mode == JOINT_STEREO) {
192  for (blk = 0; blk < frame->blocks; blk++) {
193  for (sb = 0; sb < frame->subbands; sb++) {
194  if (frame->joint & (0x01 << sb)) {
195  temp = frame->sb_sample[blk][0][sb] +
196  frame->sb_sample[blk][1][sb];
197  frame->sb_sample[blk][1][sb] =
198  frame->sb_sample[blk][0][sb] -
199  frame->sb_sample[blk][1][sb];
200  frame->sb_sample[blk][0][sb] = temp;
201  }
202  }
203  }
204  }
205 
206  if ((consumed & 0x7) != 0)
207  consumed += 8 - (consumed & 0x7);
208 
209  return consumed >> 3;
210 }
211 
212 static inline void sbc_synthesize_four(struct sbc_decoder_state *state,
213  struct sbc_frame *frame,
214  int ch, int blk, AVFrame *output_frame)
215 {
216  int i, k, idx;
217  int32_t *v = state->V[ch];
218  int *offset = state->offset[ch];
219 
220  for (i = 0; i < 8; i++) {
221  /* Shifting */
222  offset[i]--;
223  if (offset[i] < 0) {
224  offset[i] = 79;
225  memcpy(v + 80, v, 9 * sizeof(*v));
226  }
227 
228  /* Distribute the new matrix value to the shifted position */
229  v[offset[i]] =
230  (int)( (unsigned)ff_synmatrix4[i][0] * frame->sb_sample[blk][ch][0] +
231  (unsigned)ff_synmatrix4[i][1] * frame->sb_sample[blk][ch][1] +
232  (unsigned)ff_synmatrix4[i][2] * frame->sb_sample[blk][ch][2] +
233  (unsigned)ff_synmatrix4[i][3] * frame->sb_sample[blk][ch][3] ) >> 15;
234  }
235 
236  /* Compute the samples */
237  for (idx = 0, i = 0; i < 4; i++, idx += 5) {
238  k = (i + 4) & 0xf;
239 
240  /* Store in output, Q0 */
241  AV_WN16A(&output_frame->data[ch][blk * 8 + i * 2], av_clip_int16(
242  (int)( (unsigned)v[offset[i] + 0] * ff_sbc_proto_4_40m0[idx + 0] +
243  (unsigned)v[offset[k] + 1] * ff_sbc_proto_4_40m1[idx + 0] +
244  (unsigned)v[offset[i] + 2] * ff_sbc_proto_4_40m0[idx + 1] +
245  (unsigned)v[offset[k] + 3] * ff_sbc_proto_4_40m1[idx + 1] +
246  (unsigned)v[offset[i] + 4] * ff_sbc_proto_4_40m0[idx + 2] +
247  (unsigned)v[offset[k] + 5] * ff_sbc_proto_4_40m1[idx + 2] +
248  (unsigned)v[offset[i] + 6] * ff_sbc_proto_4_40m0[idx + 3] +
249  (unsigned)v[offset[k] + 7] * ff_sbc_proto_4_40m1[idx + 3] +
250  (unsigned)v[offset[i] + 8] * ff_sbc_proto_4_40m0[idx + 4] +
251  (unsigned)v[offset[k] + 9] * ff_sbc_proto_4_40m1[idx + 4] ) >> 15));
252  }
253 }
254 
255 static inline void sbc_synthesize_eight(struct sbc_decoder_state *state,
256  struct sbc_frame *frame,
257  int ch, int blk, AVFrame *output_frame)
258 {
259  int i, k, idx;
260  int32_t *v = state->V[ch];
261  int *offset = state->offset[ch];
262 
263  for (i = 0; i < 16; i++) {
264  /* Shifting */
265  offset[i]--;
266  if (offset[i] < 0) {
267  offset[i] = 159;
268  memcpy(v + 160, v, 9 * sizeof(*v));
269  }
270 
271  /* Distribute the new matrix value to the shifted position */
272  v[offset[i]] =
273  (int)( (unsigned)ff_synmatrix8[i][0] * frame->sb_sample[blk][ch][0] +
274  (unsigned)ff_synmatrix8[i][1] * frame->sb_sample[blk][ch][1] +
275  (unsigned)ff_synmatrix8[i][2] * frame->sb_sample[blk][ch][2] +
276  (unsigned)ff_synmatrix8[i][3] * frame->sb_sample[blk][ch][3] +
277  (unsigned)ff_synmatrix8[i][4] * frame->sb_sample[blk][ch][4] +
278  (unsigned)ff_synmatrix8[i][5] * frame->sb_sample[blk][ch][5] +
279  (unsigned)ff_synmatrix8[i][6] * frame->sb_sample[blk][ch][6] +
280  (unsigned)ff_synmatrix8[i][7] * frame->sb_sample[blk][ch][7] ) >> 15;
281  }
282 
283  /* Compute the samples */
284  for (idx = 0, i = 0; i < 8; i++, idx += 5) {
285  k = (i + 8) & 0xf;
286 
287  /* Store in output, Q0 */
288  AV_WN16A(&output_frame->data[ch][blk * 16 + i * 2], av_clip_int16(
289  (int)( (unsigned)v[offset[i] + 0] * ff_sbc_proto_8_80m0[idx + 0] +
290  (unsigned)v[offset[k] + 1] * ff_sbc_proto_8_80m1[idx + 0] +
291  (unsigned)v[offset[i] + 2] * ff_sbc_proto_8_80m0[idx + 1] +
292  (unsigned)v[offset[k] + 3] * ff_sbc_proto_8_80m1[idx + 1] +
293  (unsigned)v[offset[i] + 4] * ff_sbc_proto_8_80m0[idx + 2] +
294  (unsigned)v[offset[k] + 5] * ff_sbc_proto_8_80m1[idx + 2] +
295  (unsigned)v[offset[i] + 6] * ff_sbc_proto_8_80m0[idx + 3] +
296  (unsigned)v[offset[k] + 7] * ff_sbc_proto_8_80m1[idx + 3] +
297  (unsigned)v[offset[i] + 8] * ff_sbc_proto_8_80m0[idx + 4] +
298  (unsigned)v[offset[k] + 9] * ff_sbc_proto_8_80m1[idx + 4] ) >> 15));
299  }
300 }
301 
304 {
305  int ch, blk;
306 
307  switch (frame->subbands) {
308  case 4:
309  for (ch = 0; ch < frame->channels; ch++)
310  for (blk = 0; blk < frame->blocks; blk++)
312  break;
313 
314  case 8:
315  for (ch = 0; ch < frame->channels; ch++)
316  for (blk = 0; blk < frame->blocks; blk++)
318  break;
319  }
320 }
321 
322 static int sbc_decode_init(AVCodecContext *avctx)
323 {
324  SBCDecContext *sbc = avctx->priv_data;
325  int i, ch;
326 
328 
330 
331  memset(sbc->dsp.V, 0, sizeof(sbc->dsp.V));
332  for (ch = 0; ch < 2; ch++)
333  for (i = 0; i < FF_ARRAY_ELEMS(sbc->dsp.offset[0]); i++)
334  sbc->dsp.offset[ch][i] = (10 * i + 10);
335  return 0;
336 }
337 
339  void *data, int *got_frame_ptr,
340  AVPacket *avpkt)
341 {
342  SBCDecContext *sbc = avctx->priv_data;
343  AVFrame *frame = data;
344  int ret, frame_length;
345 
346  if (!sbc)
347  return AVERROR(EIO);
348 
349  frame_length = sbc_unpack_frame(avpkt->data, &sbc->frame, avpkt->size);
350  if (frame_length <= 0)
351  return frame_length;
352 
353  avctx->channels = sbc->frame.channels;
354 
355  frame->nb_samples = sbc->frame.blocks * sbc->frame.subbands;
356  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
357  return ret;
358 
359  sbc_synthesize_audio(&sbc->dsp, &sbc->frame, frame);
360 
361  *got_frame_ptr = 1;
362 
363  return frame_length;
364 }
365 
367  .name = "sbc",
368  .long_name = NULL_IF_CONFIG_SMALL("SBC (low-complexity subband codec)"),
369  .type = AVMEDIA_TYPE_AUDIO,
370  .id = AV_CODEC_ID_SBC,
371  .priv_data_size = sizeof(SBCDecContext),
375  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
376  .channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_MONO,
378  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
380  .supported_samplerates = (const int[]) { 16000, 32000, 44100, 48000, 0 },
381 };
#define JOINT_STEREO
Definition: atrac3.c:58
uint8_t
int32_t
Libavcodec external API header.
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
#define bit(string, value)
Definition: cbs_mpeg2.c:58
static struct @321 state
#define av_clip_int16
Definition: common.h:137
#define STEREO
Definition: cook.c:62
#define MONO
Definition: cook.c:61
static const uint16_t channel_layouts[7]
Definition: dca_lbr.c:114
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1900
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
static AVFrame * frame
#define LOUDNESS(energy)
Definition: f_ebur128.c:478
int
#define AV_CH_LAYOUT_MONO
#define AV_CH_LAYOUT_STEREO
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
#define AV_CODEC_CAP_CHANNEL_CONF
Codec should fill in channel configuration and samplerate instead of container.
Definition: codec.h:104
@ AV_CODEC_ID_SBC
Definition: codec_id.h:512
const AVCRC * av_crc_get_table(AVCRCId crc_id)
Get an initialized standard CRC table.
Definition: crc.c:374
@ AV_CRC_8_EBU
Definition: crc.h:57
#define AVERROR(e)
Definition: error.h:43
#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_S16P
signed 16 bits, planar
Definition: samplefmt.h:67
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:59
int i
Definition: input.c:407
#define AV_WN16A(p, v)
Definition: intreadwrite.h:534
static int output_frame(H264Context *h, AVFrame *dst, H264Picture *srcp)
Definition: h264dec.c:828
#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
static int sbc_unpack_frame(const uint8_t *data, struct sbc_frame *frame, size_t len)
Definition: sbcdec.c:62
AVCodec ff_sbc_decoder
Definition: sbcdec.c:366
static void sbc_synthesize_four(struct sbc_decoder_state *state, struct sbc_frame *frame, int ch, int blk, AVFrame *output_frame)
Definition: sbcdec.c:212
static void sbc_synthesize_audio(struct sbc_decoder_state *state, struct sbc_frame *frame, AVFrame *output_frame)
Definition: sbcdec.c:302
static void sbc_synthesize_eight(struct sbc_decoder_state *state, struct sbc_frame *frame, int ch, int blk, AVFrame *output_frame)
Definition: sbcdec.c:255
static int sbc_decode_init(AVCodecContext *avctx)
Definition: sbcdec.c:322
static int sbc_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: sbcdec.c:338
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 char data[16]
Definition: mxf.c:142
uint8_t ff_sbc_crc8(const AVCRC *ctx, const uint8_t *data, size_t len)
Definition: sbc.c:55
void ff_sbc_calculate_bits(const struct sbc_frame *frame, int(*bits)[8])
Definition: sbc.c:79
SBC common definitions for the encoder and decoder.
#define SBC_ALIGN
Definition: sbc.h:79
#define SBCDEC_FIXED_EXTRA_BITS
Definition: sbc.h:73
#define MSBC_BLOCKS
Definition: sbc.h:40
#define SBC_SYNCWORD
Definition: sbc.h:69
#define SBC_FREQ_16000
Definition: sbc.h:43
#define MSBC_SYNCWORD
Definition: sbc.h:70
const int32_t ff_synmatrix4[8][4]
Definition: sbcdec_data.c:83
const int32_t ff_sbc_proto_8_80m1[]
Definition: sbcdec_data.c:70
const int32_t ff_sbc_proto_4_40m0[]
Definition: sbcdec_data.c:41
const int32_t ff_synmatrix8[16][8]
Definition: sbcdec_data.c:94
const int32_t ff_sbc_proto_8_80m0[]
Definition: sbcdec_data.c:57
const int32_t ff_sbc_proto_4_40m1[]
Definition: sbcdec_data.c:49
SBC decoder tables.
#define blk(i)
Definition: sha.c:185
#define FF_ARRAY_ELEMS(a)
static int shift(int a, int b)
Definition: sonic.c:82
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 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
int channels
number of audio channels, only used for audio.
Definition: frame.h:624
This structure stores compressed data.
Definition: packet.h:346
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
struct sbc_decoder_state dsp
Definition: sbcdec.c:48
struct sbc_frame frame
Definition: sbcdec.c:47
int32_t V[2][170]
Definition: sbcdec.c:41
int offset[2][16]
Definition: sbcdec.c:42
Definition: sbc.h:83
uint8_t channels
Definition: sbc.h:92
const AVCRC * crc_ctx
Definition: sbc.h:113
uint8_t subbands
Definition: sbc.h:97
uint8_t blocks
Definition: sbc.h:85
else temp
Definition: vf_mcdeint.c:259
static const uint8_t offset[127][2]
Definition: vf_spp.c:107
int len
uint8_t bits
Definition: vp3data.h:141