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
;
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
;
49 state
= (state
<< 16) | bytestream_get_be16(&bufp
);
51 if (buf
- p
->buf
>= 4)
52 diff
+= FFABS(((int16_t)AV_RL16(buf
)) - (int16_t)AV_RL16(buf
-4));
54 /* regular bitstream */
55 if (state
== DCA_MARKER_RAW_BE
)
57 else if (state
== DCA_MARKER_RAW_LE
)
60 /* 14 bits big-endian bitstream */
61 else if (state
== DCA_MARKER_14B_BE
&&
62 (bytestream_get_be16(&bufp
) & 0xFFF0) == 0x07F0)
65 /* 14 bits little-endian bitstream */
66 else if (state
== DCA_MARKER_14B_LE
&&
67 (bytestream_get_be16(&bufp
) & 0xF0FF) == 0xF007)
72 if (avpriv_dca_convert_bitstream(buf
-2, 12, hdr
, 12) < 0)
75 init_get_bits(&gb
, hdr
, 96);
76 skip_bits_long(&gb
, 39);
78 sample_blocks
= get_bits(&gb
, 7) + 1;
79 if (sample_blocks
< 8)
82 framesize
= get_bits(&gb
, 14) + 1;
87 sr_code
= get_bits(&gb
, 4);
88 sample_rate
= avpriv_dca_sample_rates
[sr_code
];
94 sum
= markers
[0] + markers
[1] + markers
[2] + markers
[3];
97 if (markers
[max
] < markers
[i
])
99 if (markers
[max
] > 3 && p
->buf_size
/ markers
[max
] < 32*1024 &&
100 markers
[max
] * 4 > sum
* 3 &&
101 diff
/ p
->buf_size
> 200)
102 return AVPROBE_SCORE_EXTENSION
+ 1;
107 AVInputFormat ff_dts_demuxer
= {
109 .long_name
= NULL_IF_CONFIG_SMALL("raw DTS"),
110 .read_probe
= dts_probe
,
111 .read_header
= ff_raw_audio_read_header
,
112 .read_packet
= ff_raw_read_partial_packet
,
113 .flags
= AVFMT_GENERIC_INDEX
,
115 .raw_codec_id
= AV_CODEC_ID_DTS
,