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2ba45a60 DM |
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 "libavcodec/bytestream.h" | |
23 | #include "libavcodec/get_bits.h" | |
24 | #include "libavcodec/dca.h" | |
25 | #include "avformat.h" | |
26 | #include "rawdec.h" | |
27 | ||
28 | #define DCA_MARKER_14B_BE 0x1FFFE800 | |
29 | #define DCA_MARKER_14B_LE 0xFF1F00E8 | |
30 | #define DCA_MARKER_RAW_BE 0x7FFE8001 | |
31 | #define DCA_MARKER_RAW_LE 0xFE7F0180 | |
32 | ||
33 | static int dts_probe(AVProbeData *p) | |
34 | { | |
35 | const uint8_t *buf, *bufp; | |
36 | uint32_t state = -1; | |
f6fa7814 | 37 | int markers[4*16] = {0}; |
2ba45a60 DM |
38 | int sum, max, i; |
39 | int64_t diff = 0; | |
40 | uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 }; | |
41 | ||
42 | buf = p->buf + FFMIN(4096, p->buf_size); | |
43 | ||
44 | for(; buf < (p->buf+p->buf_size)-2; buf+=2) { | |
45 | int marker, sample_blocks, sample_rate, sr_code, framesize; | |
f6fa7814 | 46 | int lfe; |
2ba45a60 DM |
47 | GetBitContext gb; |
48 | ||
49 | bufp = buf; | |
50 | state = (state << 16) | bytestream_get_be16(&bufp); | |
51 | ||
52 | if (buf - p->buf >= 4) | |
53 | diff += FFABS(((int16_t)AV_RL16(buf)) - (int16_t)AV_RL16(buf-4)); | |
54 | ||
55 | /* regular bitstream */ | |
56 | if (state == DCA_MARKER_RAW_BE) | |
57 | marker = 0; | |
58 | else if (state == DCA_MARKER_RAW_LE) | |
59 | marker = 1; | |
60 | ||
61 | /* 14 bits big-endian bitstream */ | |
62 | else if (state == DCA_MARKER_14B_BE && | |
63 | (bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0) | |
64 | marker = 2; | |
65 | ||
66 | /* 14 bits little-endian bitstream */ | |
67 | else if (state == DCA_MARKER_14B_LE && | |
68 | (bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007) | |
69 | marker = 3; | |
70 | else | |
71 | continue; | |
72 | ||
73 | if (avpriv_dca_convert_bitstream(buf-2, 12, hdr, 12) < 0) | |
74 | continue; | |
75 | ||
76 | init_get_bits(&gb, hdr, 96); | |
77 | skip_bits_long(&gb, 39); | |
78 | ||
79 | sample_blocks = get_bits(&gb, 7) + 1; | |
80 | if (sample_blocks < 8) | |
81 | continue; | |
82 | ||
83 | framesize = get_bits(&gb, 14) + 1; | |
84 | if (framesize < 95) | |
85 | continue; | |
86 | ||
87 | skip_bits(&gb, 6); | |
88 | sr_code = get_bits(&gb, 4); | |
89 | sample_rate = avpriv_dca_sample_rates[sr_code]; | |
90 | if (sample_rate == 0) | |
91 | continue; | |
92 | ||
f6fa7814 DM |
93 | get_bits(&gb, 5); |
94 | if (get_bits(&gb, 1)) | |
95 | continue; | |
96 | ||
97 | skip_bits_long(&gb, 9); | |
98 | lfe = get_bits(&gb, 2); | |
99 | if (lfe > 2) | |
100 | continue; | |
101 | ||
102 | marker += 4* sr_code; | |
103 | ||
2ba45a60 DM |
104 | markers[marker] ++; |
105 | } | |
f6fa7814 DM |
106 | |
107 | sum = max = 0; | |
108 | for (i=0; i<FF_ARRAY_ELEMS(markers); i++) { | |
109 | sum += markers[i]; | |
2ba45a60 DM |
110 | if (markers[max] < markers[i]) |
111 | max = i; | |
f6fa7814 DM |
112 | } |
113 | ||
2ba45a60 DM |
114 | if (markers[max] > 3 && p->buf_size / markers[max] < 32*1024 && |
115 | markers[max] * 4 > sum * 3 && | |
116 | diff / p->buf_size > 200) | |
117 | return AVPROBE_SCORE_EXTENSION + 1; | |
118 | ||
119 | return 0; | |
120 | } | |
121 | ||
122 | AVInputFormat ff_dts_demuxer = { | |
123 | .name = "dts", | |
124 | .long_name = NULL_IF_CONFIG_SMALL("raw DTS"), | |
125 | .read_probe = dts_probe, | |
126 | .read_header = ff_raw_audio_read_header, | |
127 | .read_packet = ff_raw_read_partial_packet, | |
128 | .flags = AVFMT_GENERIC_INDEX, | |
129 | .extensions = "dts", | |
130 | .raw_codec_id = AV_CODEC_ID_DTS, | |
131 | }; |