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
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
|
/*****************************************************************
|
| AP4 - stts Atoms
|
| 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 "Ap4SttsAtom.h"
#include "Ap4AtomFactory.h"
#include "Ap4Utils.h"
/*----------------------------------------------------------------------
| dynamic cast support
+---------------------------------------------------------------------*/
AP4_DEFINE_DYNAMIC_CAST_ANCHOR(AP4_SttsAtom)
/*----------------------------------------------------------------------
| AP4_SttsAtom::Create
+---------------------------------------------------------------------*/
AP4_SttsAtom*
AP4_SttsAtom::Create(AP4_Size size, AP4_ByteStream& stream)
{
AP4_UI08 version;
AP4_UI32 flags;
if (AP4_FAILED(AP4_Atom::ReadFullHeader(stream, version, flags))) return NULL;
if (version != 0) return NULL;
return new AP4_SttsAtom(size, version, flags, stream);
}
/*----------------------------------------------------------------------
| AP4_SttsAtom::AP4_SttsAtom
+---------------------------------------------------------------------*/
AP4_SttsAtom::AP4_SttsAtom() :
AP4_Atom(AP4_ATOM_TYPE_STTS, AP4_FULL_ATOM_HEADER_SIZE+4, 0, 0)
{
m_LookupCache.entry_index = 0;
m_LookupCache.sample = 0;
m_LookupCache.dts = 0;
}
/*----------------------------------------------------------------------
| AP4_SttsAtom::AP4_SttsAtom
+---------------------------------------------------------------------*/
AP4_SttsAtom::AP4_SttsAtom(AP4_UI32 size,
AP4_UI08 version,
AP4_UI32 flags,
AP4_ByteStream& stream) :
AP4_Atom(AP4_ATOM_TYPE_STTS, size, version, flags)
{
m_LookupCache.entry_index = 0;
m_LookupCache.sample = 0;
m_LookupCache.dts = 0;
AP4_UI32 entry_count;
stream.ReadUI32(entry_count);
while (entry_count--) {
AP4_UI32 sample_count;
AP4_UI32 sample_duration;
if (stream.ReadUI32(sample_count) == AP4_SUCCESS &&
stream.ReadUI32(sample_duration) == AP4_SUCCESS) {
m_Entries.Append(AP4_SttsTableEntry(sample_count,
sample_duration));
}
}
}
/*----------------------------------------------------------------------
| AP4_SttsAtom::GetDts
+---------------------------------------------------------------------*/
AP4_Result
AP4_SttsAtom::GetDts(AP4_Ordinal sample, AP4_UI64& dts, AP4_UI32* duration)
{
// default value
dts = 0;
if (duration) *duration = 0;
// sample indexes start at 1
if (sample == 0) return AP4_ERROR_OUT_OF_RANGE;
--sample;
// check the lookup cache
AP4_Ordinal lookup_start = 0;
AP4_Ordinal sample_start = 0;
AP4_UI64 dts_start = 0;
if (sample >= m_LookupCache.sample) {
// start from the cached entry
lookup_start = m_LookupCache.entry_index;
sample_start = m_LookupCache.sample;
dts_start = m_LookupCache.dts;
}
// look from the last known point
for (AP4_Ordinal i = lookup_start; i < m_Entries.ItemCount(); i++) {
AP4_SttsTableEntry& entry = m_Entries[i];
// check if we have reached the sample
if (sample < sample_start+entry.m_SampleCount) {
// we are within the sample range for the current entry
dts = dts_start + (AP4_UI64)(sample - sample_start) * (AP4_UI64)entry.m_SampleDuration;
if (duration) *duration = entry.m_SampleDuration;
// update the lookup cache
m_LookupCache.entry_index = i;
m_LookupCache.sample = sample_start;
m_LookupCache.dts = dts_start;
return AP4_SUCCESS;
}
// update the sample and dts bases
sample_start += entry.m_SampleCount;
dts_start += entry.m_SampleCount*entry.m_SampleDuration;
}
// sample is greater than the number of samples
return AP4_ERROR_OUT_OF_RANGE;
}
/*----------------------------------------------------------------------
| AP4_SttsAtom::AddEntry
+---------------------------------------------------------------------*/
AP4_Result
AP4_SttsAtom::AddEntry(AP4_UI32 sample_count, AP4_UI32 sample_duration)
{
m_Entries.Append(AP4_SttsTableEntry(sample_count, sample_duration));
m_Size32 += 8;
return AP4_SUCCESS;
}
/*----------------------------------------------------------------------
| AP4_SttsAtom::WriteFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_SttsAtom::WriteFields(AP4_ByteStream& stream)
{
AP4_Result result;
// write the entry count
AP4_Cardinal entry_count = m_Entries.ItemCount();
result = stream.WriteUI32(entry_count);
if (AP4_FAILED(result)) return result;
// write the entries
for (AP4_Ordinal i=0; i<entry_count; i++) {
// sample count
result = stream.WriteUI32(m_Entries[i].m_SampleCount);
if (AP4_FAILED(result)) return result;
// time offset
result = stream.WriteUI32(m_Entries[i].m_SampleDuration);
if (AP4_FAILED(result)) return result;
}
return AP4_SUCCESS;
}
/*----------------------------------------------------------------------
| AP4_SttsAtom::GetSampleIndexForTimeStamp
+---------------------------------------------------------------------*/
AP4_Result
AP4_SttsAtom::GetSampleIndexForTimeStamp(AP4_UI64 ts,
AP4_Ordinal& sample_index)
{
// init
AP4_Cardinal entry_count = m_Entries.ItemCount();
AP4_UI64 accumulated = 0;
sample_index = 0;
for (AP4_Ordinal i=0; i<entry_count; i++) {
AP4_UI64 next_accumulated =
accumulated +
(AP4_UI64)m_Entries[i].m_SampleCount *
(AP4_UI64)m_Entries[i].m_SampleDuration;
// check if the ts is in the range of this entry
if (ts < next_accumulated) {
sample_index += (AP4_UI32)((ts - accumulated) / m_Entries[i].m_SampleDuration);
return AP4_SUCCESS;
}
// update accumulated and sample
accumulated = next_accumulated;
sample_index += m_Entries[i].m_SampleCount;
}
// ts not in range of the table
return AP4_FAILURE;
}
/*----------------------------------------------------------------------
| AP4_SttsAtom::InspectFields
+---------------------------------------------------------------------*/
AP4_Result
AP4_SttsAtom::InspectFields(AP4_AtomInspector& inspector)
{
inspector.AddField("entry_count", m_Entries.ItemCount());
if (inspector.GetVerbosity() >= 1) {
char header[32];
char value[256];
for (AP4_Ordinal i=0; i<m_Entries.ItemCount(); i++) {
AP4_FormatString(header, sizeof(header), "entry %8d", i);
AP4_FormatString(value, sizeof(value),
"sample_count=%d, sample_duration=%d",
m_Entries[i].m_SampleCount,
m_Entries[i].m_SampleDuration);
inspector.AddField(header, value);
}
}
return AP4_SUCCESS;
}
|
