1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
/*****************************************************************
|
| AP4 - Command Factory
|
| Copyright 2002-2008 Axiomatic Systems, LLC
|
|
| This file is part of Bento4/AP4 (MP4 Atom Processing Library).
|
| Unless you have obtained Bento4 under a difference license,
| this version of Bento4 is Bento4|GPL.
| Bento4|GPL is free software; you can redistribute it and/or modify
| it under the terms of the GNU General Public License as published by
| the Free Software Foundation; either version 2, or (at your option)
| any later version.
|
| Bento4|GPL is distributed in the hope that it will be useful,
| but WITHOUT ANY WARRANTY; without even the implied warranty of
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
| GNU General Public License for more details.
|
| You should have received a copy of the GNU General Public License
| along with Bento4|GPL; see the file COPYING. If not, write to the
| Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
| 02111-1307, USA.
|
****************************************************************/
/*----------------------------------------------------------------------
| includes
+---------------------------------------------------------------------*/
#include "Ap4CommandFactory.h"
#include "Ap4ObjectDescriptor.h"
#include "Ap4Command.h"
#include "Ap4ByteStream.h"
/*----------------------------------------------------------------------
| AP4_CommandFactory::CreateCommandFromStream
+---------------------------------------------------------------------*/
AP4_Result
AP4_CommandFactory::CreateCommandFromStream(AP4_ByteStream& stream,
AP4_Command*& command)
{
AP4_Result result;
// NULL by default
command = NULL;
// remember current stream offset
AP4_Position offset;
stream.Tell(offset);
// read descriptor tag
unsigned char tag;
result = stream.ReadUI08(tag);
if (AP4_FAILED(result)) {
stream.Seek(offset);
return result;
}
// read descriptor size
AP4_UI32 payload_size = 0;
unsigned int header_size = 1;
unsigned int max = 4;
unsigned char ext = 0;
do {
header_size++;
result = stream.ReadUI08(ext);
if (AP4_FAILED(result)) {
stream.Seek(offset);
return result;
}
payload_size = (payload_size<<7) + (ext&0x7F);
} while (--max && (ext&0x80));
// create the command
switch (tag) {
case AP4_COMMAND_TAG_OBJECT_DESCRIPTOR_UPDATE:
case AP4_COMMAND_TAG_IPMP_DESCRIPTOR_UPDATE:
command = new AP4_DescriptorUpdateCommand(stream, tag, header_size, payload_size);
break;
default:
command = new AP4_UnknownCommand(stream, tag, header_size, payload_size);
break;
}
// skip to the end of the descriptor
stream.Seek(offset+header_size+payload_size);
return AP4_SUCCESS;
}
|
