1 /* Gstreamer
2  * Copyright (C) <2011> Intel
3  * Copyright (C) <2011> Collabora Ltd.
4  * Copyright (C) <2011> Thibault Saunier <thibault.saunier@collabora.com>
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Library General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Library General Public License for more details.
15  *
16  * You should have received a copy of the GNU Library General Public
17  * License along with this library; if not, write to the
18  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19  * Boston, MA 02110-1301, USA.
20  */
21 
22 #ifndef __PARSER_UTILS__
23 #define __PARSER_UTILS__
24 
25 #include <gst/gst.h>
26 #include <gst/base/gstbitreader.h>
27 
28 /* Parsing utils */
29 #define GET_BITS(b, num, bits) G_STMT_START {        \
30   if (!gst_bit_reader_get_bits_uint32(b, bits, num)) \
31     goto failed;                                     \
32   GST_TRACE ("parsed %d bits: %d", num, *(bits));    \
33 } G_STMT_END
34 
35 #define CHECK_ALLOWED(val, min, max) G_STMT_START { \
36   if (val < min || val > max) { \
37     GST_WARNING ("value not in allowed range. value: %d, range %d-%d", \
38                      val, min, max); \
39     goto failed; \
40   } \
41 } G_STMT_END
42 
43 #define READ_UINT8(reader, val, nbits) G_STMT_START { \
44   if (!gst_bit_reader_get_bits_uint8 (reader, &val, nbits)) { \
45     GST_WARNING ("failed to read uint8, nbits: %d", nbits); \
46     goto failed; \
47   } \
48 } G_STMT_END
49 
50 #define READ_UINT16(reader, val, nbits) G_STMT_START { \
51   if (!gst_bit_reader_get_bits_uint16 (reader, &val, nbits)) { \
52     GST_WARNING ("failed to read uint16, nbits: %d", nbits); \
53     goto failed; \
54   } \
55 } G_STMT_END
56 
57 #define READ_UINT32(reader, val, nbits) G_STMT_START { \
58   if (!gst_bit_reader_get_bits_uint32 (reader, &val, nbits)) { \
59     GST_WARNING ("failed to read uint32, nbits: %d", nbits); \
60     goto failed; \
61   } \
62 } G_STMT_END
63 
64 #define READ_UINT64(reader, val, nbits) G_STMT_START { \
65   if (!gst_bit_reader_get_bits_uint64 (reader, &val, nbits)) { \
66     GST_WARNING ("failed to read uint64, nbits: %d", nbits); \
67     goto failed; \
68   } \
69 } G_STMT_END
70 
71 
72 #define U_READ_UINT8(reader, val, nbits) G_STMT_START { \
73   val = gst_bit_reader_get_bits_uint8_unchecked (reader, nbits); \
74 } G_STMT_END
75 
76 #define U_READ_UINT16(reader, val, nbits) G_STMT_START { \
77   val = gst_bit_reader_get_bits_uint16_unchecked (reader, nbits); \
78 } G_STMT_END
79 
80 #define U_READ_UINT32(reader, val, nbits) G_STMT_START { \
81   val = gst_bit_reader_get_bits_uint32_unchecked (reader, nbits); \
82 } G_STMT_END
83 
84 #define U_READ_UINT64(reader, val, nbits) G_STMT_START { \
85   val = gst_bit_reader_get_bits_uint64_unchecked (reader, nbits); \
86 } G_STMT_END
87 
88 #define SKIP(reader, nbits) G_STMT_START { \
89   if (!gst_bit_reader_skip (reader, nbits)) { \
90     GST_WARNING ("failed to skip nbits: %d", nbits); \
91     goto failed; \
92   } \
93 } G_STMT_END
94 
95 typedef struct _VLCTable VLCTable;
96 
97 struct _VLCTable
98 {
99   guint value;
100   guint cword;
101   guint cbits;
102 };
103 
104 G_GNUC_INTERNAL gboolean
105 decode_vlc (GstBitReader * br, guint * res, const VLCTable * table,
106     guint length);
107 
108 #endif /* __PARSER_UTILS__ */
109