timecode.c (8328B)
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 "common.h" 31 #include "timecode.h" 32 #include "log.h" 33 #include "error.h" 34 35 int av_timecode_adjust_ntsc_framenum2(int framenum, int fps) 36 { 37 /* only works for multiples of NTSC 29.97 */ 38 int drop_frames = 0; 39 int d, m, frames_per_10mins; 40 41 if (fps && fps % 30 == 0) { 42 drop_frames = fps / 30 * 2; 43 frames_per_10mins = fps / 30 * 17982; 44 } else 45 return framenum; 46 47 d = framenum / frames_per_10mins; 48 m = framenum % frames_per_10mins; 49 50 return framenum + 9U * drop_frames * d + drop_frames * ((m - drop_frames) / (frames_per_10mins / 10)); 51 } 52 53 uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum) 54 { 55 unsigned fps = tc->fps; 56 int drop = !!(tc->flags & AV_TIMECODE_FLAG_DROPFRAME); 57 int hh, mm, ss, ff; 58 59 framenum += tc->start; 60 if (drop) 61 framenum = av_timecode_adjust_ntsc_framenum2(framenum, tc->fps); 62 ff = framenum % fps; 63 ss = framenum / fps % 60; 64 mm = framenum / (fps*60LL) % 60; 65 hh = framenum / (fps*3600LL) % 24; 66 return av_timecode_get_smpte(tc->rate, drop, hh, mm, ss, ff); 67 } 68 69 uint32_t av_timecode_get_smpte(AVRational rate, int drop, int hh, int mm, int ss, int ff) 70 { 71 uint32_t tc = 0; 72 73 /* For SMPTE 12-M timecodes, frame count is a special case if > 30 FPS. 74 See SMPTE ST 12-1:2014 Sec 12.1 for more info. */ 75 if (av_cmp_q(rate, (AVRational) {30, 1}) == 1) { 76 if (ff % 2 == 1) { 77 if (av_cmp_q(rate, (AVRational) {50, 1}) == 0) 78 tc |= (1 << 7); 79 else 80 tc |= (1 << 23); 81 } 82 ff /= 2; 83 } 84 85 hh = hh % 24; 86 mm = av_clip(mm, 0, 59); 87 ss = av_clip(ss, 0, 59); 88 ff = ff % 40; 89 90 tc |= drop << 30; 91 tc |= (ff / 10) << 28; 92 tc |= (ff % 10) << 24; 93 tc |= (ss / 10) << 20; 94 tc |= (ss % 10) << 16; 95 tc |= (mm / 10) << 12; 96 tc |= (mm % 10) << 8; 97 tc |= (hh / 10) << 4; 98 tc |= (hh % 10); 99 100 return tc; 101 } 102 103 char *av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum_arg) 104 { 105 int fps = tc->fps; 106 int drop = tc->flags & AV_TIMECODE_FLAG_DROPFRAME; 107 int hh, mm, ss, ff, ff_len, neg = 0; 108 int64_t framenum = framenum_arg; 109 110 framenum += tc->start; 111 if (drop) 112 framenum = av_timecode_adjust_ntsc_framenum2(framenum, fps); 113 if (framenum < 0) { 114 framenum = -framenum; 115 neg = tc->flags & AV_TIMECODE_FLAG_ALLOWNEGATIVE; 116 } 117 ff = framenum % fps; 118 ss = framenum / fps % 60; 119 mm = framenum / (fps*60LL) % 60; 120 hh = framenum / (fps*3600LL); 121 if (tc->flags & AV_TIMECODE_FLAG_24HOURSMAX) 122 hh = hh % 24; 123 ff_len = fps > 10000 ? 5 : fps > 1000 ? 4 : fps > 100 ? 3 : fps > 10 ? 2 : 1; 124 snprintf(buf, AV_TIMECODE_STR_SIZE, "%s%02d:%02d:%02d%c%0*d", 125 neg ? "-" : "", 126 hh, mm, ss, drop ? ';' : ':', ff_len, ff); 127 return buf; 128 } 129 130 static unsigned bcd2uint(uint8_t bcd) 131 { 132 unsigned low = bcd & 0xf; 133 unsigned high = bcd >> 4; 134 if (low > 9 || high > 9) 135 return 0; 136 return low + 10*high; 137 } 138 139 char *av_timecode_make_smpte_tc_string2(char *buf, AVRational rate, uint32_t tcsmpte, int prevent_df, int skip_field) 140 { 141 unsigned hh = bcd2uint(tcsmpte & 0x3f); // 6-bit hours 142 unsigned mm = bcd2uint(tcsmpte>>8 & 0x7f); // 7-bit minutes 143 unsigned ss = bcd2uint(tcsmpte>>16 & 0x7f); // 7-bit seconds 144 unsigned ff = bcd2uint(tcsmpte>>24 & 0x3f); // 6-bit frames 145 unsigned drop = tcsmpte & 1<<30 && !prevent_df; // 1-bit drop if not arbitrary bit 146 147 if (av_cmp_q(rate, (AVRational) {30, 1}) == 1) { 148 ff <<= 1; 149 if (!skip_field) { 150 if (av_cmp_q(rate, (AVRational) {50, 1}) == 0) 151 ff += !!(tcsmpte & 1 << 7); 152 else 153 ff += !!(tcsmpte & 1 << 23); 154 } 155 } 156 157 snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u", 158 hh, mm, ss, drop ? ';' : ':', ff); 159 return buf; 160 161 } 162 163 char *av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df) 164 { 165 return av_timecode_make_smpte_tc_string2(buf, (AVRational){30, 1}, tcsmpte, prevent_df, 1); 166 } 167 168 char *av_timecode_make_mpeg_tc_string(char *buf, uint32_t tc25bit) 169 { 170 snprintf(buf, AV_TIMECODE_STR_SIZE, 171 "%02"PRIu32":%02"PRIu32":%02"PRIu32"%c%02"PRIu32, 172 tc25bit>>19 & 0x1f, // 5-bit hours 173 tc25bit>>13 & 0x3f, // 6-bit minutes 174 tc25bit>>6 & 0x3f, // 6-bit seconds 175 tc25bit & 1<<24 ? ';' : ':', // 1-bit drop flag 176 tc25bit & 0x3f); // 6-bit frames 177 return buf; 178 } 179 180 static int check_fps(int fps) 181 { 182 int i; 183 static const int supported_fps[] = { 184 24, 25, 30, 48, 50, 60, 100, 120, 150, 185 }; 186 187 for (i = 0; i < FF_ARRAY_ELEMS(supported_fps); i++) 188 if (fps == supported_fps[i]) 189 return 0; 190 return -1; 191 } 192 193 static int check_timecode(void *log_ctx, AVTimecode *tc) 194 { 195 if ((int)tc->fps <= 0) { 196 av_log(log_ctx, AV_LOG_ERROR, "Valid timecode frame rate must be specified. Minimum value is 1\n"); 197 return AVERROR(EINVAL); 198 } 199 if ((tc->flags & AV_TIMECODE_FLAG_DROPFRAME) && tc->fps % 30 != 0) { 200 av_log(log_ctx, AV_LOG_ERROR, "Drop frame is only allowed with multiples of 30000/1001 FPS\n"); 201 return AVERROR(EINVAL); 202 } 203 if (check_fps(tc->fps) < 0) { 204 av_log(log_ctx, AV_LOG_WARNING, "Using non-standard frame rate %d/%d\n", 205 tc->rate.num, tc->rate.den); 206 } 207 return 0; 208 } 209 210 static int fps_from_frame_rate(AVRational rate) 211 { 212 if (!rate.den || !rate.num) 213 return -1; 214 return (rate.num + rate.den/2LL) / rate.den; 215 } 216 217 int av_timecode_check_frame_rate(AVRational rate) 218 { 219 return check_fps(fps_from_frame_rate(rate)); 220 } 221 222 int av_timecode_init(AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx) 223 { 224 memset(tc, 0, sizeof(*tc)); 225 tc->start = frame_start; 226 tc->flags = flags; 227 tc->rate = rate; 228 tc->fps = fps_from_frame_rate(rate); 229 return check_timecode(log_ctx, tc); 230 } 231 232 int av_timecode_init_from_components(AVTimecode *tc, AVRational rate, int flags, int hh, int mm, int ss, int ff, void *log_ctx) 233 { 234 int ret; 235 236 memset(tc, 0, sizeof(*tc)); 237 tc->flags = flags; 238 tc->rate = rate; 239 tc->fps = fps_from_frame_rate(rate); 240 241 ret = check_timecode(log_ctx, tc); 242 if (ret < 0) 243 return ret; 244 245 tc->start = (hh*3600 + mm*60 + ss) * tc->fps + ff; 246 if (tc->flags & AV_TIMECODE_FLAG_DROPFRAME) { /* adjust frame number */ 247 int tmins = 60*hh + mm; 248 tc->start -= (tc->fps / 30 * 2) * (tmins - tmins/10); 249 } 250 return 0; 251 } 252 253 int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx) 254 { 255 char c; 256 int hh, mm, ss, ff, flags; 257 258 if (sscanf(str, "%d:%d:%d%c%d", &hh, &mm, &ss, &c, &ff) != 5) { 259 av_log(log_ctx, AV_LOG_ERROR, "Unable to parse timecode, " 260 "syntax: hh:mm:ss[:;.]ff\n"); 261 return AVERROR_INVALIDDATA; 262 } 263 flags = c != ':' ? AV_TIMECODE_FLAG_DROPFRAME : 0; // drop if ';', '.', ... 264 265 return av_timecode_init_from_components(tc, rate, flags, hh, mm, ss, ff, log_ctx); 266 }