FFmpeg: libavcodec/tak.c Source File

FFmpeg
tak.c
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1 /*
2  * TAK common code
3  * Copyright (c) 2012 Paul B Mahol
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 #include "libavutil/crc.h"
23 #include "libavutil/intreadwrite.h"
24 #include "tak.h"
25 
26  static const int64_t tak_channel_layouts[] = {
27  0,
28  AV_CH_FRONT_LEFT,
29  AV_CH_FRONT_RIGHT,
30  AV_CH_FRONT_CENTER,
31  AV_CH_LOW_FREQUENCY,
32  AV_CH_BACK_LEFT,
33  AV_CH_BACK_RIGHT,
34  AV_CH_FRONT_LEFT_OF_CENTER,
35  AV_CH_FRONT_RIGHT_OF_CENTER,
36  AV_CH_BACK_CENTER,
37  AV_CH_SIDE_LEFT,
38  AV_CH_SIDE_RIGHT,
39  AV_CH_TOP_CENTER,
40  AV_CH_TOP_FRONT_LEFT,
41  AV_CH_TOP_FRONT_CENTER,
42  AV_CH_TOP_FRONT_RIGHT,
43  AV_CH_TOP_BACK_LEFT,
44  AV_CH_TOP_BACK_CENTER,
45  AV_CH_TOP_BACK_RIGHT,
46 };
47 
48  static const uint16_t frame_duration_type_quants[] = {
49  3, 4, 6, 8, 4096, 8192, 16384, 512, 1024, 2048,
50 };
51 
52  static int tak_get_nb_samples(int sample_rate, enum TAKFrameSizeType type)
53 {
54  int nb_samples, max_nb_samples;
55 
56  if (type <= TAK_FST_250ms) {
57  nb_samples = sample_rate * frame_duration_type_quants[type] >>
58  TAK_FRAME_DURATION_QUANT_SHIFT;
59  max_nb_samples = 16384;
60  } else if (type < FF_ARRAY_ELEMS(frame_duration_type_quants)) {
61  nb_samples = frame_duration_type_quants[type];
62  max_nb_samples = sample_rate *
63  frame_duration_type_quants[TAK_FST_250ms] >>
64  TAK_FRAME_DURATION_QUANT_SHIFT;
65  } else {
66  return AVERROR_INVALIDDATA;
67  }
68 
69  if (nb_samples <= 0 || nb_samples > max_nb_samples)
70  return AVERROR_INVALIDDATA;
71 
72  return nb_samples;
73 }
74 
75  int ff_tak_check_crc(const uint8_t *buf, unsigned int buf_size)
76 {
77  uint32_t crc, CRC;
78 
79  if (buf_size < 4)
80  return AVERROR_INVALIDDATA;
81  buf_size -= 3;
82 
83  CRC = AV_RB24(buf + buf_size);
84  crc = av_crc(av_crc_get_table(AV_CRC_24_IEEE), 0xCE04B7U, buf, buf_size);
85  if (CRC != crc)
86  return AVERROR_INVALIDDATA;
87 
88  return 0;
89 }
90 
91  void avpriv_tak_parse_streaminfo(GetBitContext *gb, TAKStreamInfo *s)
92 {
93  uint64_t channel_mask = 0;
94  int frame_type, i;
95 
96  s->codec = get_bits(gb, TAK_ENCODER_CODEC_BITS);
97  skip_bits(gb, TAK_ENCODER_PROFILE_BITS);
98 
99  frame_type = get_bits(gb, TAK_SIZE_FRAME_DURATION_BITS);
100  s->samples = get_bits64(gb, TAK_SIZE_SAMPLES_NUM_BITS);
101 
102  s->data_type = get_bits(gb, TAK_FORMAT_DATA_TYPE_BITS);
103  s->sample_rate = get_bits(gb, TAK_FORMAT_SAMPLE_RATE_BITS) +
104  TAK_SAMPLE_RATE_MIN;
105  s->bps = get_bits(gb, TAK_FORMAT_BPS_BITS) +
106  TAK_BPS_MIN;
107  s->channels = get_bits(gb, TAK_FORMAT_CHANNEL_BITS) +
108  TAK_CHANNELS_MIN;
109 
110  if (get_bits1(gb)) {
111  skip_bits(gb, TAK_FORMAT_VALID_BITS);
112  if (get_bits1(gb)) {
113  for (i = 0; i < s->channels; i++) {
114  int value = get_bits(gb, TAK_FORMAT_CH_LAYOUT_BITS);
115 
116  if (value < FF_ARRAY_ELEMS(tak_channel_layouts))
117  channel_mask |= tak_channel_layouts[value];
118  }
119  }
120  }
121 
122  s->ch_layout = channel_mask;
123  s->frame_samples = tak_get_nb_samples(s->sample_rate, frame_type);
124 }
125 
126  int ff_tak_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
127  TAKStreamInfo *ti, int log_level_offset)
128 {
129  if (get_bits(gb, TAK_FRAME_HEADER_SYNC_ID_BITS) != TAK_FRAME_HEADER_SYNC_ID) {
130  av_log(avctx, AV_LOG_ERROR + log_level_offset, "missing sync id\n");
131  return AVERROR_INVALIDDATA;
132  }
133 
134  ti->flags = get_bits(gb, TAK_FRAME_HEADER_FLAGS_BITS);
135  ti->frame_num = get_bits(gb, TAK_FRAME_HEADER_NO_BITS);
136 
137  if (ti->flags & TAK_FRAME_FLAG_IS_LAST) {
138  ti->last_frame_samples = get_bits(gb, TAK_FRAME_HEADER_SAMPLE_COUNT_BITS) + 1;
139  skip_bits(gb, 2);
140  } else {
141  ti->last_frame_samples = 0;
142  }
143 
144  if (ti->flags & TAK_FRAME_FLAG_HAS_INFO) {
145  avpriv_tak_parse_streaminfo(gb, ti);
146 
147  if (get_bits(gb, 6))
148  skip_bits(gb, 25);
149  align_get_bits(gb);
150  }
151 
152  if (ti->flags & TAK_FRAME_FLAG_HAS_METADATA)
153  return AVERROR_INVALIDDATA;
154 
155  skip_bits(gb, 24);
156 
157  return 0;
158 }
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