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
|
/*
* Copyright (c) 2006 Smartjog S.A.S, Baptiste Coudurier <baptiste.coudurier@gmail.com>
* Copyright (c) 2011-2012 Smartjog S.A.S, Clément Bœsch <clement.boesch@smartjog.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Timecode helpers
* @see https://en.wikipedia.org/wiki/SMPTE_time_code
* @see http://www.dropframetimecode.org
*/
#include <stdio.h>
#include "timecode.h"
#include "log.h"
#include "error.h"
int av_timecode_adjust_ntsc_framenum2(int framenum, int fps)
{
/* only works for NTSC 29.97 and 59.94 */
int drop_frames = 0;
int d, m, frames_per_10mins;
if (fps == 30) {
drop_frames = 2;
frames_per_10mins = 17982;
} else if (fps == 60) {
drop_frames = 4;
frames_per_10mins = 35964;
} else
return framenum;
d = framenum / frames_per_10mins;
m = framenum % frames_per_10mins;
return framenum + 9U * drop_frames * d + drop_frames * ((m - drop_frames) / (frames_per_10mins / 10));
}
uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum)
{
unsigned fps = tc->fps;
int drop = !!(tc->flags & AV_TIMECODE_FLAG_DROPFRAME);
int hh, mm, ss, ff;
framenum += tc->start;
if (drop)
framenum = av_timecode_adjust_ntsc_framenum2(framenum, tc->fps);
ff = framenum % fps;
ss = framenum / fps % 60;
mm = framenum / (fps*60) % 60;
hh = framenum / (fps*3600) % 24;
return 0 << 31 | // color frame flag (0: unsync mode, 1: sync mode)
drop << 30 | // drop frame flag (0: non drop, 1: drop)
(ff / 10) << 28 | // tens of frames
(ff % 10) << 24 | // units of frames
0 << 23 | // PC (NTSC) or BGF0 (PAL)
(ss / 10) << 20 | // tens of seconds
(ss % 10) << 16 | // units of seconds
0 << 15 | // BGF0 (NTSC) or BGF2 (PAL)
(mm / 10) << 12 | // tens of minutes
(mm % 10) << 8 | // units of minutes
0 << 7 | // BGF2 (NTSC) or PC (PAL)
0 << 6 | // BGF1
(hh / 10) << 4 | // tens of hours
(hh % 10); // units of hours
}
char *av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum)
{
int fps = tc->fps;
int drop = tc->flags & AV_TIMECODE_FLAG_DROPFRAME;
int hh, mm, ss, ff, neg = 0;
framenum += tc->start;
if (drop)
framenum = av_timecode_adjust_ntsc_framenum2(framenum, fps);
if (framenum < 0) {
framenum = -framenum;
neg = tc->flags & AV_TIMECODE_FLAG_ALLOWNEGATIVE;
}
ff = framenum % fps;
ss = framenum / fps % 60;
mm = framenum / (fps*60) % 60;
hh = framenum / (fps*3600);
if (tc->flags & AV_TIMECODE_FLAG_24HOURSMAX)
hh = hh % 24;
snprintf(buf, AV_TIMECODE_STR_SIZE, "%s%02d:%02d:%02d%c%02d",
neg ? "-" : "",
hh, mm, ss, drop ? ';' : ':', ff);
return buf;
}
static unsigned bcd2uint(uint8_t bcd)
{
unsigned low = bcd & 0xf;
unsigned high = bcd >> 4;
if (low > 9 || high > 9)
return 0;
return low + 10*high;
}
char *av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df)
{
unsigned hh = bcd2uint(tcsmpte & 0x3f); // 6-bit hours
unsigned mm = bcd2uint(tcsmpte>>8 & 0x7f); // 7-bit minutes
unsigned ss = bcd2uint(tcsmpte>>16 & 0x7f); // 7-bit seconds
unsigned ff = bcd2uint(tcsmpte>>24 & 0x3f); // 6-bit frames
unsigned drop = tcsmpte & 1<<30 && !prevent_df; // 1-bit drop if not arbitrary bit
snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u",
hh, mm, ss, drop ? ';' : ':', ff);
return buf;
}
char *av_timecode_make_mpeg_tc_string(char *buf, uint32_t tc25bit)
{
snprintf(buf, AV_TIMECODE_STR_SIZE,
"%02"PRIu32":%02"PRIu32":%02"PRIu32"%c%02"PRIu32,
tc25bit>>19 & 0x1f, // 5-bit hours
tc25bit>>13 & 0x3f, // 6-bit minutes
tc25bit>>6 & 0x3f, // 6-bit seconds
tc25bit & 1<<24 ? ';' : ':', // 1-bit drop flag
tc25bit & 0x3f); // 6-bit frames
return buf;
}
static int check_fps(int fps)
{
int i;
static const int supported_fps[] = {
24, 25, 30, 48, 50, 60, 100, 120, 150,
};
for (i = 0; i < FF_ARRAY_ELEMS(supported_fps); i++)
if (fps == supported_fps[i])
return 0;
return -1;
}
static int check_timecode(void *log_ctx, AVTimecode *tc)
{
if ((int)tc->fps <= 0) {
av_log(log_ctx, AV_LOG_ERROR, "Timecode frame rate must be specified\n");
return AVERROR(EINVAL);
}
if ((tc->flags & AV_TIMECODE_FLAG_DROPFRAME) && tc->fps != 30 && tc->fps != 60) {
av_log(log_ctx, AV_LOG_ERROR, "Drop frame is only allowed with 30000/1001 or 60000/1001 FPS\n");
return AVERROR(EINVAL);
}
if (check_fps(tc->fps) < 0) {
av_log(log_ctx, AV_LOG_WARNING, "Using non-standard frame rate %d/%d\n",
tc->rate.num, tc->rate.den);
}
return 0;
}
static int fps_from_frame_rate(AVRational rate)
{
if (!rate.den || !rate.num)
return -1;
return (rate.num + rate.den/2) / rate.den;
}
int av_timecode_check_frame_rate(AVRational rate)
{
return check_fps(fps_from_frame_rate(rate));
}
int av_timecode_init(AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx)
{
memset(tc, 0, sizeof(*tc));
tc->start = frame_start;
tc->flags = flags;
tc->rate = rate;
tc->fps = fps_from_frame_rate(rate);
return check_timecode(log_ctx, tc);
}
int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx)
{
char c;
int hh, mm, ss, ff, ret;
if (sscanf(str, "%d:%d:%d%c%d", &hh, &mm, &ss, &c, &ff) != 5) {
av_log(log_ctx, AV_LOG_ERROR, "Unable to parse timecode, "
"syntax: hh:mm:ss[:;.]ff\n");
return AVERROR_INVALIDDATA;
}
memset(tc, 0, sizeof(*tc));
tc->flags = c != ':' ? AV_TIMECODE_FLAG_DROPFRAME : 0; // drop if ';', '.', ...
tc->rate = rate;
tc->fps = fps_from_frame_rate(rate);
ret = check_timecode(log_ctx, tc);
if (ret < 0)
return ret;
tc->start = (hh*3600 + mm*60 + ss) * tc->fps + ff;
if (tc->flags & AV_TIMECODE_FLAG_DROPFRAME) { /* adjust frame number */
int tmins = 60*hh + mm;
tc->start -= 2 * (tmins - tmins/10);
}
return 0;
}
|
