2 * Copyright (c) 2006 Smartjog S.A.S, Baptiste Coudurier <baptiste.coudurier@gmail.com>
3 * Copyright (c) 2011-2012 Smartjog S.A.S, Clément Bœsch <clement.boesch@smartjog.com>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 * @see https://en.wikipedia.org/wiki/SMPTE_time_code
26 * @see http://www.dropframetimecode.org
34 int av_timecode_adjust_ntsc_framenum(int framenum)
36 /* only works for NTSC 29.97 */
37 int d = framenum / 17982;
38 int m = framenum % 17982;
39 //if (m < 2) m += 2; /* not needed since -2,-1 / 1798 in C returns 0 */
40 return framenum + 18 * d + 2 * ((m - 2) / 1798);
43 uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum)
45 unsigned fps = tc->fps;
46 int drop = !!(tc->flags & AV_TIMECODE_FLAG_DROPFRAME);
49 framenum += tc->start;
51 framenum = av_timecode_adjust_ntsc_framenum(framenum);
53 ss = framenum / fps % 60;
54 mm = framenum / (fps*60) % 60;
55 hh = framenum / (fps*3600) % 24;
56 return 0 << 31 | // color frame flag (0: unsync mode, 1: sync mode)
57 drop << 30 | // drop frame flag (0: non drop, 1: drop)
58 (ff / 10) << 28 | // tens of frames
59 (ff % 10) << 24 | // units of frames
60 0 << 23 | // PC (NTSC) or BGF0 (PAL)
61 (ss / 10) << 20 | // tens of seconds
62 (ss % 10) << 16 | // units of seconds
63 0 << 15 | // BGF0 (NTSC) or BGF2 (PAL)
64 (mm / 10) << 12 | // tens of minutes
65 (mm % 10) << 8 | // units of minutes
66 0 << 7 | // BGF2 (NTSC) or PC (PAL)
68 (hh / 10) << 4 | // tens of hours
69 (hh % 10); // units of hours
72 char *av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum)
75 int drop = tc->flags & AV_TIMECODE_FLAG_DROPFRAME;
76 int hh, mm, ss, ff, neg = 0;
78 framenum += tc->start;
80 framenum = av_timecode_adjust_ntsc_framenum(framenum);
83 neg = tc->flags & AV_TIMECODE_FLAG_ALLOWNEGATIVE;
86 ss = framenum / fps % 60;
87 mm = framenum / (fps*60) % 60;
88 hh = framenum / (fps*3600);
89 if (tc->flags & AV_TIMECODE_FLAG_24HOURSMAX)
91 snprintf(buf, AV_TIMECODE_STR_SIZE, "%s%02d:%02d:%02d%c%02d",
93 hh, mm, ss, drop ? ';' : ':', ff);
97 static unsigned bcd2uint(uint8_t bcd)
99 unsigned low = bcd & 0xf;
100 unsigned high = bcd >> 4;
101 if (low > 9 || high > 9)
103 return low + 10*high;
106 char *av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df)
108 unsigned hh = bcd2uint(tcsmpte & 0x3f); // 6-bit hours
109 unsigned mm = bcd2uint(tcsmpte>>8 & 0x7f); // 7-bit minutes
110 unsigned ss = bcd2uint(tcsmpte>>16 & 0x7f); // 7-bit seconds
111 unsigned ff = bcd2uint(tcsmpte>>24 & 0x3f); // 6-bit frames
112 unsigned drop = tcsmpte & 1<<30 && !prevent_df; // 1-bit drop if not arbitrary bit
113 snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u",
114 hh, mm, ss, drop ? ';' : ':', ff);
118 char *av_timecode_make_mpeg_tc_string(char *buf, uint32_t tc25bit)
120 snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u",
121 tc25bit>>19 & 0x1f, // 5-bit hours
122 tc25bit>>13 & 0x3f, // 6-bit minutes
123 tc25bit>>6 & 0x3f, // 6-bit seconds
124 tc25bit & 1<<24 ? ';' : ':', // 1-bit drop flag
125 tc25bit & 0x3f); // 6-bit frames
129 static int check_timecode(void *log_ctx, AVTimecode *tc)
132 av_log(log_ctx, AV_LOG_ERROR, "Timecode frame rate must be specified\n");
133 return AVERROR(EINVAL);
135 if ((tc->flags & AV_TIMECODE_FLAG_DROPFRAME) && tc->fps != 30) {
136 av_log(log_ctx, AV_LOG_ERROR, "Drop frame is only allowed with 30000/1001 FPS\n");
137 return AVERROR(EINVAL);
145 av_log(log_ctx, AV_LOG_ERROR, "Timecode frame rate not supported\n");
146 return AVERROR_PATCHWELCOME;
150 static int fps_from_frame_rate(AVRational rate)
152 if (!rate.den || !rate.num)
154 return (rate.num + rate.den/2) / rate.den;
157 int av_timecode_init(AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx)
159 memset(tc, 0, sizeof(*tc));
160 tc->start = frame_start;
163 tc->fps = fps_from_frame_rate(rate);
164 return check_timecode(log_ctx, tc);
167 int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx)
170 int hh, mm, ss, ff, ret;
172 if (sscanf(str, "%d:%d:%d%c%d", &hh, &mm, &ss, &c, &ff) != 5) {
173 av_log(log_ctx, AV_LOG_ERROR, "Unable to parse timecode, "
174 "syntax: hh:mm:ss[:;.]ff\n");
175 return AVERROR_INVALIDDATA;
178 memset(tc, 0, sizeof(*tc));
179 tc->flags = c != ':' ? AV_TIMECODE_FLAG_DROPFRAME : 0; // drop if ';', '.', ...
181 tc->fps = fps_from_frame_rate(rate);
183 ret = check_timecode(log_ctx, tc);
187 tc->start = (hh*3600 + mm*60 + ss) * tc->fps + ff;
188 if (tc->flags & AV_TIMECODE_FLAG_DROPFRAME) { /* adjust frame number */
189 int tmins = 60*hh + mm;
190 tc->start -= 2 * (tmins - tmins/10);