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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 
25 #define BITSTREAM_READER_LE
26 #include "tak.h"
27 
28 static const int64_t tak_channel_layouts[] = {
29     0,
30     AV_CH_FRONT_LEFT,
31     AV_CH_FRONT_RIGHT,
32     AV_CH_FRONT_CENTER,
33     AV_CH_LOW_FREQUENCY,
34     AV_CH_BACK_LEFT,
35     AV_CH_BACK_RIGHT,
36     AV_CH_FRONT_LEFT_OF_CENTER,
37     AV_CH_FRONT_RIGHT_OF_CENTER,
38     AV_CH_BACK_CENTER,
39     AV_CH_SIDE_LEFT,
40     AV_CH_SIDE_RIGHT,
41     AV_CH_TOP_CENTER,
42     AV_CH_TOP_FRONT_LEFT,
43     AV_CH_TOP_FRONT_CENTER,
44     AV_CH_TOP_FRONT_RIGHT,
45     AV_CH_TOP_BACK_LEFT,
46     AV_CH_TOP_BACK_CENTER,
47     AV_CH_TOP_BACK_RIGHT,
48 };
49 
50 static const uint16_t frame_duration_type_quants[] = {
51     3, 4, 6, 8, 4096, 8192, 16384, 512, 1024, 2048,
52 };
53 
tak_get_nb_samples(int sample_rate,enum TAKFrameSizeType type)54 static int tak_get_nb_samples(int sample_rate, enum TAKFrameSizeType type)
55 {
56     int nb_samples, max_nb_samples;
57 
58     if (type <= TAK_FST_250ms) {
59         nb_samples     = sample_rate * frame_duration_type_quants[type] >>
60                          TAK_FRAME_DURATION_QUANT_SHIFT;
61         max_nb_samples = 16384;
62     } else if (type < FF_ARRAY_ELEMS(frame_duration_type_quants)) {
63         nb_samples     = frame_duration_type_quants[type];
64         max_nb_samples = sample_rate *
65                          frame_duration_type_quants[TAK_FST_250ms] >>
66                          TAK_FRAME_DURATION_QUANT_SHIFT;
67     } else {
68         return AVERROR_INVALIDDATA;
69     }
70 
71     if (nb_samples <= 0 || nb_samples > max_nb_samples)
72         return AVERROR_INVALIDDATA;
73 
74     return nb_samples;
75 }
76 
ff_tak_check_crc(const uint8_t * buf,unsigned int buf_size)77 int ff_tak_check_crc(const uint8_t *buf, unsigned int buf_size)
78 {
79     uint32_t crc, CRC;
80 
81     if (buf_size < 4)
82         return AVERROR_INVALIDDATA;
83     buf_size -= 3;
84 
85     CRC = AV_RB24(buf + buf_size);
86     crc = av_crc(av_crc_get_table(AV_CRC_24_IEEE), 0xCE04B7U, buf, buf_size);
87     if (CRC != crc)
88         return AVERROR_INVALIDDATA;
89 
90     return 0;
91 }
92 
ff_tak_parse_streaminfo(TAKStreamInfo * s,GetBitContext * gb)93 void ff_tak_parse_streaminfo(TAKStreamInfo *s, GetBitContext *gb)
94 {
95     uint64_t channel_mask = 0;
96     int frame_type, i;
97 
98     s->codec = get_bits(gb, TAK_ENCODER_CODEC_BITS);
99     skip_bits(gb, TAK_ENCODER_PROFILE_BITS);
100 
101     frame_type = get_bits(gb, TAK_SIZE_FRAME_DURATION_BITS);
102     s->samples = get_bits64(gb, TAK_SIZE_SAMPLES_NUM_BITS);
103 
104     s->data_type   = get_bits(gb, TAK_FORMAT_DATA_TYPE_BITS);
105     s->sample_rate = get_bits(gb, TAK_FORMAT_SAMPLE_RATE_BITS) +
106                      TAK_SAMPLE_RATE_MIN;
107     s->bps         = get_bits(gb, TAK_FORMAT_BPS_BITS) +
108                      TAK_BPS_MIN;
109     s->channels    = get_bits(gb, TAK_FORMAT_CHANNEL_BITS) +
110                      TAK_CHANNELS_MIN;
111 
112     if (get_bits1(gb)) {
113         skip_bits(gb, TAK_FORMAT_VALID_BITS);
114         if (get_bits1(gb)) {
115             for (i = 0; i < s->channels; i++) {
116                 int value = get_bits(gb, TAK_FORMAT_CH_LAYOUT_BITS);
117 
118                 if (value < FF_ARRAY_ELEMS(tak_channel_layouts))
119                     channel_mask |= tak_channel_layouts[value];
120             }
121         }
122     }
123 
124     s->ch_layout     = channel_mask;
125     s->frame_samples = tak_get_nb_samples(s->sample_rate, frame_type);
126 }
127 
avpriv_tak_parse_streaminfo(TAKStreamInfo * s,const uint8_t * buf,int size)128 int avpriv_tak_parse_streaminfo(TAKStreamInfo *s, const uint8_t *buf, int size)
129 {
130     GetBitContext gb;
131     int ret = init_get_bits8(&gb, buf, size);
132 
133     if (ret < 0)
134         return AVERROR_INVALIDDATA;
135 
136     ff_tak_parse_streaminfo(s, &gb);
137 
138     return 0;
139 }
140 
ff_tak_decode_frame_header(AVCodecContext * avctx,GetBitContext * gb,TAKStreamInfo * ti,int log_level_offset)141 int ff_tak_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
142                                TAKStreamInfo *ti, int log_level_offset)
143 {
144     if (get_bits(gb, TAK_FRAME_HEADER_SYNC_ID_BITS) != TAK_FRAME_HEADER_SYNC_ID) {
145         av_log(avctx, AV_LOG_ERROR + log_level_offset, "missing sync id\n");
146         return AVERROR_INVALIDDATA;
147     }
148 
149     ti->flags     = get_bits(gb, TAK_FRAME_HEADER_FLAGS_BITS);
150     ti->frame_num = get_bits(gb, TAK_FRAME_HEADER_NO_BITS);
151 
152     if (ti->flags & TAK_FRAME_FLAG_IS_LAST) {
153         ti->last_frame_samples = get_bits(gb, TAK_FRAME_HEADER_SAMPLE_COUNT_BITS) + 1;
154         skip_bits(gb, 2);
155     } else {
156         ti->last_frame_samples = 0;
157     }
158 
159     if (ti->flags & TAK_FRAME_FLAG_HAS_INFO) {
160         ff_tak_parse_streaminfo(ti, gb);
161 
162         if (get_bits(gb, 6))
163             skip_bits(gb, 25);
164         align_get_bits(gb);
165     }
166 
167     if (ti->flags & TAK_FRAME_FLAG_HAS_METADATA)
168         return AVERROR_INVALIDDATA;
169 
170     skip_bits(gb, 24);
171 
172     return 0;
173 }
174