1 /*
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>
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 /**
23 * @file
24 * Timecode helpers
25 * @see https://en.wikipedia.org/wiki/SMPTE_time_code
26 * @see http://www.dropframetimecode.org
27 */
28
29 #include <stdio.h>
30 #include "timecode.h"
31 #include "log.h"
32 #include "error.h"
33
av_timecode_adjust_ntsc_framenum2(int framenum,int fps)34 int av_timecode_adjust_ntsc_framenum2(int framenum, int fps)
35 {
36 /* only works for multiples of NTSC 29.97 */
37 int drop_frames = 0;
38 int d, m, frames_per_10mins;
39
40 if (fps && fps % 30 == 0) {
41 drop_frames = fps / 30 * 2;
42 frames_per_10mins = fps / 30 * 17982;
43 } else
44 return framenum;
45
46 d = framenum / frames_per_10mins;
47 m = framenum % frames_per_10mins;
48
49 return framenum + 9U * drop_frames * d + drop_frames * ((m - drop_frames) / (frames_per_10mins / 10));
50 }
51
av_timecode_get_smpte_from_framenum(const AVTimecode * tc,int framenum)52 uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum)
53 {
54 unsigned fps = tc->fps;
55 int drop = !!(tc->flags & AV_TIMECODE_FLAG_DROPFRAME);
56 int hh, mm, ss, ff;
57
58 framenum += tc->start;
59 if (drop)
60 framenum = av_timecode_adjust_ntsc_framenum2(framenum, tc->fps);
61 ff = framenum % fps;
62 ss = framenum / fps % 60;
63 mm = framenum / (fps*60) % 60;
64 hh = framenum / (fps*3600) % 24;
65 return av_timecode_get_smpte(tc->rate, drop, hh, mm, ss, ff);
66 }
67
av_timecode_get_smpte(AVRational rate,int drop,int hh,int mm,int ss,int ff)68 uint32_t av_timecode_get_smpte(AVRational rate, int drop, int hh, int mm, int ss, int ff)
69 {
70 uint32_t tc = 0;
71
72 /* For SMPTE 12-M timecodes, frame count is a special case if > 30 FPS.
73 See SMPTE ST 12-1:2014 Sec 12.1 for more info. */
74 if (av_cmp_q(rate, (AVRational) {30, 1}) == 1) {
75 if (ff % 2 == 1) {
76 if (av_cmp_q(rate, (AVRational) {50, 1}) == 0)
77 tc |= (1 << 7);
78 else
79 tc |= (1 << 23);
80 }
81 ff /= 2;
82 }
83
84 hh = hh % 24;
85 mm = av_clip(mm, 0, 59);
86 ss = av_clip(ss, 0, 59);
87 ff = ff % 40;
88
89 tc |= drop << 30;
90 tc |= (ff / 10) << 28;
91 tc |= (ff % 10) << 24;
92 tc |= (ss / 10) << 20;
93 tc |= (ss % 10) << 16;
94 tc |= (mm / 10) << 12;
95 tc |= (mm % 10) << 8;
96 tc |= (hh / 10) << 4;
97 tc |= (hh % 10);
98
99 return tc;
100 }
101
av_timecode_make_string(const AVTimecode * tc,char * buf,int framenum)102 char *av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum)
103 {
104 int fps = tc->fps;
105 int drop = tc->flags & AV_TIMECODE_FLAG_DROPFRAME;
106 int hh, mm, ss, ff, neg = 0;
107
108 framenum += tc->start;
109 if (drop)
110 framenum = av_timecode_adjust_ntsc_framenum2(framenum, fps);
111 if (framenum < 0) {
112 framenum = -framenum;
113 neg = tc->flags & AV_TIMECODE_FLAG_ALLOWNEGATIVE;
114 }
115 ff = framenum % fps;
116 ss = framenum / fps % 60;
117 mm = framenum / (fps*60LL) % 60;
118 hh = framenum / (fps*3600LL);
119 if (tc->flags & AV_TIMECODE_FLAG_24HOURSMAX)
120 hh = hh % 24;
121 snprintf(buf, AV_TIMECODE_STR_SIZE, "%s%02d:%02d:%02d%c%02d",
122 neg ? "-" : "",
123 hh, mm, ss, drop ? ';' : ':', ff);
124 return buf;
125 }
126
bcd2uint(uint8_t bcd)127 static unsigned bcd2uint(uint8_t bcd)
128 {
129 unsigned low = bcd & 0xf;
130 unsigned high = bcd >> 4;
131 if (low > 9 || high > 9)
132 return 0;
133 return low + 10*high;
134 }
135
av_timecode_make_smpte_tc_string2(char * buf,AVRational rate,uint32_t tcsmpte,int prevent_df,int skip_field)136 char *av_timecode_make_smpte_tc_string2(char *buf, AVRational rate, uint32_t tcsmpte, int prevent_df, int skip_field)
137 {
138 unsigned hh = bcd2uint(tcsmpte & 0x3f); // 6-bit hours
139 unsigned mm = bcd2uint(tcsmpte>>8 & 0x7f); // 7-bit minutes
140 unsigned ss = bcd2uint(tcsmpte>>16 & 0x7f); // 7-bit seconds
141 unsigned ff = bcd2uint(tcsmpte>>24 & 0x3f); // 6-bit frames
142 unsigned drop = tcsmpte & 1<<30 && !prevent_df; // 1-bit drop if not arbitrary bit
143
144 if (av_cmp_q(rate, (AVRational) {30, 1}) == 1) {
145 ff <<= 1;
146 if (!skip_field) {
147 if (av_cmp_q(rate, (AVRational) {50, 1}) == 0)
148 ff += !!(tcsmpte & 1 << 7);
149 else
150 ff += !!(tcsmpte & 1 << 23);
151 }
152 }
153
154 snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u",
155 hh, mm, ss, drop ? ';' : ':', ff);
156 return buf;
157
158 }
159
av_timecode_make_smpte_tc_string(char * buf,uint32_t tcsmpte,int prevent_df)160 char *av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df)
161 {
162 return av_timecode_make_smpte_tc_string2(buf, (AVRational){30, 1}, tcsmpte, prevent_df, 1);
163 }
164
av_timecode_make_mpeg_tc_string(char * buf,uint32_t tc25bit)165 char *av_timecode_make_mpeg_tc_string(char *buf, uint32_t tc25bit)
166 {
167 snprintf(buf, AV_TIMECODE_STR_SIZE,
168 "%02"PRIu32":%02"PRIu32":%02"PRIu32"%c%02"PRIu32,
169 tc25bit>>19 & 0x1f, // 5-bit hours
170 tc25bit>>13 & 0x3f, // 6-bit minutes
171 tc25bit>>6 & 0x3f, // 6-bit seconds
172 tc25bit & 1<<24 ? ';' : ':', // 1-bit drop flag
173 tc25bit & 0x3f); // 6-bit frames
174 return buf;
175 }
176
check_fps(int fps)177 static int check_fps(int fps)
178 {
179 int i;
180 static const int supported_fps[] = {
181 24, 25, 30, 48, 50, 60, 100, 120, 150,
182 };
183
184 for (i = 0; i < FF_ARRAY_ELEMS(supported_fps); i++)
185 if (fps == supported_fps[i])
186 return 0;
187 return -1;
188 }
189
check_timecode(void * log_ctx,AVTimecode * tc)190 static int check_timecode(void *log_ctx, AVTimecode *tc)
191 {
192 if ((int)tc->fps <= 0) {
193 av_log(log_ctx, AV_LOG_ERROR, "Valid timecode frame rate must be specified. Minimum value is 1\n");
194 return AVERROR(EINVAL);
195 }
196 if ((tc->flags & AV_TIMECODE_FLAG_DROPFRAME) && tc->fps % 30 != 0) {
197 av_log(log_ctx, AV_LOG_ERROR, "Drop frame is only allowed with multiples of 30000/1001 FPS\n");
198 return AVERROR(EINVAL);
199 }
200 if (check_fps(tc->fps) < 0) {
201 av_log(log_ctx, AV_LOG_WARNING, "Using non-standard frame rate %d/%d\n",
202 tc->rate.num, tc->rate.den);
203 }
204 return 0;
205 }
206
fps_from_frame_rate(AVRational rate)207 static int fps_from_frame_rate(AVRational rate)
208 {
209 if (!rate.den || !rate.num)
210 return -1;
211 return (rate.num + rate.den/2) / rate.den;
212 }
213
av_timecode_check_frame_rate(AVRational rate)214 int av_timecode_check_frame_rate(AVRational rate)
215 {
216 return check_fps(fps_from_frame_rate(rate));
217 }
218
av_timecode_init(AVTimecode * tc,AVRational rate,int flags,int frame_start,void * log_ctx)219 int av_timecode_init(AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx)
220 {
221 memset(tc, 0, sizeof(*tc));
222 tc->start = frame_start;
223 tc->flags = flags;
224 tc->rate = rate;
225 tc->fps = fps_from_frame_rate(rate);
226 return check_timecode(log_ctx, tc);
227 }
228
av_timecode_init_from_components(AVTimecode * tc,AVRational rate,int flags,int hh,int mm,int ss,int ff,void * log_ctx)229 int av_timecode_init_from_components(AVTimecode *tc, AVRational rate, int flags, int hh, int mm, int ss, int ff, void *log_ctx)
230 {
231 int ret;
232
233 memset(tc, 0, sizeof(*tc));
234 tc->flags = flags;
235 tc->rate = rate;
236 tc->fps = fps_from_frame_rate(rate);
237
238 ret = check_timecode(log_ctx, tc);
239 if (ret < 0)
240 return ret;
241
242 tc->start = (hh*3600 + mm*60 + ss) * tc->fps + ff;
243 if (tc->flags & AV_TIMECODE_FLAG_DROPFRAME) { /* adjust frame number */
244 int tmins = 60*hh + mm;
245 tc->start -= (tc->fps / 30 * 2) * (tmins - tmins/10);
246 }
247 return 0;
248 }
249
av_timecode_init_from_string(AVTimecode * tc,AVRational rate,const char * str,void * log_ctx)250 int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx)
251 {
252 char c;
253 int hh, mm, ss, ff, flags;
254
255 if (sscanf(str, "%d:%d:%d%c%d", &hh, &mm, &ss, &c, &ff) != 5) {
256 av_log(log_ctx, AV_LOG_ERROR, "Unable to parse timecode, "
257 "syntax: hh:mm:ss[:;.]ff\n");
258 return AVERROR_INVALIDDATA;
259 }
260 flags = c != ':' ? AV_TIMECODE_FLAG_DROPFRAME : 0; // drop if ';', '.', ...
261
262 return av_timecode_init_from_components(tc, rate, flags, hh, mm, ss, ff, log_ctx);
263 }
264