3 * Copyright (c) 2008 Benjamin Larsson
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavcodec/bytestream.h"
23 #include "libavcodec/get_bits.h"
24 #include "libavcodec/dca.h"
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
33 static int dts_probe(AVProbeData
*p
)
35 const uint8_t *buf
, *bufp
;
37 int markers
[4*16] = {0};
40 uint8_t hdr
[12 + FF_INPUT_BUFFER_PADDING_SIZE
] = { 0 };
42 buf
= p
->buf
+ FFMIN(4096, p
->buf_size
);
44 for(; buf
< (p
->buf
+p
->buf_size
)-2; buf
+=2) {
45 int marker
, sample_blocks
, sample_rate
, sr_code
, framesize
;
50 state
= (state
<< 16) | bytestream_get_be16(&bufp
);
52 if (buf
- p
->buf
>= 4)
53 diff
+= FFABS(((int16_t)AV_RL16(buf
)) - (int16_t)AV_RL16(buf
-4));
55 /* regular bitstream */
56 if (state
== DCA_MARKER_RAW_BE
)
58 else if (state
== DCA_MARKER_RAW_LE
)
61 /* 14 bits big-endian bitstream */
62 else if (state
== DCA_MARKER_14B_BE
&&
63 (bytestream_get_be16(&bufp
) & 0xFFF0) == 0x07F0)
66 /* 14 bits little-endian bitstream */
67 else if (state
== DCA_MARKER_14B_LE
&&
68 (bytestream_get_be16(&bufp
) & 0xF0FF) == 0xF007)
73 if (avpriv_dca_convert_bitstream(buf
-2, 12, hdr
, 12) < 0)
76 init_get_bits(&gb
, hdr
, 96);
77 skip_bits_long(&gb
, 39);
79 sample_blocks
= get_bits(&gb
, 7) + 1;
80 if (sample_blocks
< 8)
83 framesize
= get_bits(&gb
, 14) + 1;
88 sr_code
= get_bits(&gb
, 4);
89 sample_rate
= avpriv_dca_sample_rates
[sr_code
];
97 skip_bits_long(&gb
, 9);
98 lfe
= get_bits(&gb
, 2);
102 marker
+= 4* sr_code
;
108 for (i
=0; i
<FF_ARRAY_ELEMS(markers
); i
++) {
110 if (markers
[max
] < markers
[i
])
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;
122 AVInputFormat ff_dts_demuxer
= {
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
,
130 .raw_codec_id
= AV_CODEC_ID_DTS
,