FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/dtsdec.c
Date: 2022-11-26 13:19:19
Exec Total Coverage
Lines: 54 66 81.8%
Branches: 39 62 62.9%

Line Branch Exec Source
1 /*
2 * RAW DTS demuxer
3 * Copyright (c) 2008 Benjamin Larsson
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
24 #include "libavcodec/bytestream.h"
25 #include "libavcodec/dca.h"
26 #include "libavcodec/dca_syncwords.h"
27 #include "libavcodec/get_bits.h"
28
29 #include "avformat.h"
30 #include "rawdec.h"
31
32 6780 static int dts_probe(const AVProbeData *p)
33 {
34 const uint8_t *buf, *bufp;
35 6780 uint32_t state = -1;
36 6780 int markers[4*16] = {0};
37 6780 int exss_markers = 0, exss_nextpos = 0;
38 int sum, max, pos, ret, i;
39 6780 int64_t diff = 0;
40 6780 int diffcount = 1;
41 6780 uint8_t hdr[DCA_CORE_FRAME_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 };
42
43
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59410623 for (pos = FFMIN(4096, p->buf_size); pos < p->buf_size - 2; pos += 2) {
44 int marker, wide_hdr, hdr_size, framesize;
45 DCACoreFrameHeader h;
46 GetBitContext gb;
47
48 59403843 bufp = buf = p->buf + pos;
49 59403843 state = (state << 16) | bytestream_get_be16(&bufp);
50
51
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59403843 if (pos >= 4) {
52
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59403843 if (AV_RL16(buf) || AV_RL16(buf-4)) {
53
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57679862 diff += FFABS(((int16_t)AV_RL16(buf)) - (int16_t)AV_RL16(buf-4));
54 57679862 diffcount ++;
55 }
56 }
57
58 /* extension substream (EXSS) */
59
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59403843 if (state == DCA_SYNCWORD_SUBSTREAM) {
60
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28 if (pos < exss_nextpos)
61 59403789 continue;
62
63 28 init_get_bits(&gb, buf - 2, 96);
64 28 skip_bits_long(&gb, 42);
65
66 28 wide_hdr = get_bits1(&gb);
67 28 hdr_size = get_bits(&gb, 8 + 4 * wide_hdr) + 1;
68 28 framesize = get_bits(&gb, 16 + 4 * wide_hdr) + 1;
69
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28 if (hdr_size & 3 || framesize & 3)
70 continue;
71
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28 if (hdr_size < 16 || framesize < hdr_size)
72 continue;
73
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28 if (pos - 2 + hdr_size > p->buf_size)
74 continue;
75
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28 if (av_crc(av_crc_get_table(AV_CRC_16_CCITT), 0xffff, buf + 3, hdr_size - 5))
76 continue;
77
78
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28 if (pos == exss_nextpos)
79 exss_markers++;
80 else
81 28 exss_markers = FFMAX(1, exss_markers - 1);
82 28 exss_nextpos = pos + framesize;
83 28 continue;
84 }
85
86 /* regular bitstream */
87
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59403815 if (state == DCA_SYNCWORD_CORE_BE &&
88
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50 (bytestream_get_be16(&bufp) & 0xFC00) == 0xFC00)
89 50 marker = 0;
90
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59403765 else if (state == DCA_SYNCWORD_CORE_LE &&
91
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4 (bytestream_get_be16(&bufp) & 0x00FC) == 0x00FC)
92 4 marker = 1;
93
94 /* 14 bits big-endian bitstream */
95
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59403761 else if (state == DCA_SYNCWORD_CORE_14B_BE &&
96 (bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0)
97 marker = 2;
98
99 /* 14 bits little-endian bitstream */
100
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59403761 else if (state == DCA_SYNCWORD_CORE_14B_LE &&
101 (bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007)
102 marker = 3;
103 else
104 59403761 continue;
105
106
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54 if ((ret = avpriv_dca_convert_bitstream(buf - 2, DCA_CORE_FRAME_HEADER_SIZE,
107 hdr, DCA_CORE_FRAME_HEADER_SIZE)) < 0)
108 continue;
109
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54 if (avpriv_dca_parse_core_frame_header(&h, hdr, ret) < 0)
110 continue;
111
112 54 marker += 4 * h.sr_code;
113
114 54 markers[marker] ++;
115 }
116
117
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6780 if (exss_markers > 3)
118 return AVPROBE_SCORE_EXTENSION + 1;
119
120 6780 sum = max = 0;
121
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440700 for (i=0; i<FF_ARRAY_ELEMS(markers); i++) {
122 433920 sum += markers[i];
123
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433920 if (markers[max] < markers[i])
124 16 max = i;
125 }
126
127
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6780 if (markers[max] > 3 && p->buf_size / markers[max] < 32*1024 &&
128
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7 markers[max] * 4 > sum * 3 &&
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7 diff / diffcount > 600)
130 7 return AVPROBE_SCORE_EXTENSION + 1;
131
132 6773 return 0;
133 }
134
135 const AVInputFormat ff_dts_demuxer = {
136 .name = "dts",
137 .long_name = NULL_IF_CONFIG_SMALL("raw DTS"),
138 .read_probe = dts_probe,
139 .read_header = ff_raw_audio_read_header,
140 .read_packet = ff_raw_read_partial_packet,
141 .flags = AVFMT_GENERIC_INDEX,
142 .extensions = "dts",
143 .raw_codec_id = AV_CODEC_ID_DTS,
144 .priv_data_size = sizeof(FFRawDemuxerContext),
145 .priv_class = &ff_raw_demuxer_class,
146 };
147