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
|
#include "seektable.h"
#include "demuxer.h"
static int GetStreamNumber(uint32_t id)
{
char *stream_data = (char *)(&id);
if (!isxdigit(stream_data[0]) || !isxdigit(stream_data[1]))
return -1;
stream_data[2] = 0;
int stream_number = strtoul(stream_data, 0, 16);
return stream_number;
}
nsavi::SeekTable::SeekTable(int stream_number, bool require_keyframes, const nsavi::HeaderList *header_list)
: header_list(header_list), stream_number(stream_number), require_keyframes(require_keyframes), super_index(0), indices_processed(0), super_index_duration(0)
{
stream = header_list->stream_list[stream_number].stream_header;
const nsavi::INDX *index = header_list->stream_list[stream_number].stream_index;
if (index)
{
if (index->index_type == nsavi::indx_type_master)
{
super_index = (nsavi::AVISUPERINDEX *)index;
}
else if (index->index_type == nsavi::indx_type_chunk)
{
AddIndex(index, 0);
}
}
}
nsavi::SeekTable::~SeekTable()
{
}
const nsavi::SeekEntry *nsavi::SeekTable::GetSeekPoint(int ×tamp_ms, int current_ms, int seek_direction)
{
int last_time = 0;
const nsavi::SeekEntry *last_entry = 0;
// TODO: binary search
for (SeekEntries::iterator itr=seek_entries.begin();itr!=seek_entries.end();itr++)
{
if (itr->first > timestamp_ms)
{
if (seek_direction == SEEK_FORWARD && current_ms >= last_time)
{
itr++;
if (itr != seek_entries.end())
{
last_entry = &itr->second;
last_time = itr->first;
}
else
{
return 0;
}
}
timestamp_ms = last_time;
return last_entry;
}
last_entry = &itr->second;
last_time = itr->first;
}
if (seek_direction == SEEK_FORWARD && current_ms >= last_time)
{
return 0;
}
else
{
timestamp_ms = last_time;
return last_entry;
}
}
void nsavi::SeekTable::AddIndex(const IDX1 *index)
{
// TODO: calculate total bytes at the same time, so we can get a more accurate bitrate
data_processed[index] = true;
uint64_t total_time = 0;
uint64_t stream_rate = (uint64_t)stream->rate;
//if (!require_keyframes)
// seek_entries.reserve(seek_entries.size() + index->index_count);
for (uint32_t i=0;i!=index->index_count;i++)
{
const nsavi::IDX1_INDEX &this_index = index->indices[i];
int this_stream_number = GetStreamNumber(this_index.chunk_id);
if (this_stream_number == stream_number && (!require_keyframes || this_index.flags & nsavi::idx1_flags_keyframe))
{
int timestamp = (int)(total_time * 1000ULL / stream_rate);
SeekEntry &entry = seek_entries[timestamp];
#ifdef SEEK_TABLE_STORE_CHUNK_HEADER
entry.chunk_id = this_index.chunk_id;
entry.chunk_size = this_index.chunk_size;
#endif
entry.file_position = this_index.offset;
entry.stream_time = total_time;
entry.timestamp = timestamp;
entry.absolute = false;
}
if (this_stream_number == stream_number && !(this_index.flags & nsavi::idx1_flags_no_duration))
{
if (stream->sample_size)
{
uint64_t samples = this_index.chunk_size / stream->sample_size;
total_time += stream->scale * samples;
}
else
total_time += stream->scale;
}
}
}
void nsavi::SeekTable::AddIndex(const INDX *index, uint64_t start_time)
{
if (index->index_type == nsavi::indx_type_chunk)
{
const nsavi::AVISTDINDEX *chunk_index = (nsavi::AVISTDINDEX *)index;
//if (!require_keyframes)
// seek_entries.reserve(seek_entries.size() + chunk_index->indx.number_of_entries);
start_time *= stream->scale;
uint64_t stream_rate = (uint64_t)stream->rate;
for (uint32_t i=0;i!=chunk_index->indx.number_of_entries;i++)
{
const INDX_CHUNK_ENTRY &this_index = chunk_index->entries[i];
if (!require_keyframes || !(this_index.size & 0x80000000))
{
int timestamp = (int)(start_time * 1000ULL / stream_rate);
SeekEntry &entry = seek_entries[timestamp];
#ifdef SEEK_TABLE_STORE_CHUNK_HEADER
entry.chunk_id = chunk_index->indx.chunk_id;
entry.chunk_size = this_index.size & ~0x80000000;
#endif
entry.file_position = chunk_index->base_offset + this_index.offset;
entry.stream_time = start_time;
entry.timestamp = timestamp;
entry.absolute = true;
}
if (stream->sample_size)
{
uint64_t samples = this_index.size / stream->sample_size;
start_time += stream->scale * samples;
}
else
start_time += stream->scale;
}
}
}
bool nsavi::SeekTable::GetIndexLocation(int timestamp, uint64_t *position, uint64_t *start_time)
{
// TODO: use timestamp more effectively
if (super_index)
{
for (uint32_t i=indices_processed;i!=super_index->indx.number_of_entries;i++)
{
indices_processed++;
*start_time = super_index_duration;
super_index_duration += super_index->entries[i].duration;
*position = super_index->entries[i].offset;
return true;
}
}
return false;
}
|
