| 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 | |
| 34 | int av_timecode_adjust_ntsc_framenum2(int framenum, int fps) |
| 35 | { |
| 36 | /* only works for NTSC 29.97 and 59.94 */ |
| 37 | int drop_frames = 0; |
| 38 | int d, m, frames_per_10mins; |
| 39 | |
| 40 | if (fps == 30) { |
| 41 | drop_frames = 2; |
| 42 | frames_per_10mins = 17982; |
| 43 | } else if (fps == 60) { |
| 44 | drop_frames = 4; |
| 45 | frames_per_10mins = 35964; |
| 46 | } else |
| 47 | return framenum; |
| 48 | |
| 49 | d = framenum / frames_per_10mins; |
| 50 | m = framenum % frames_per_10mins; |
| 51 | |
| 52 | return framenum + 9 * drop_frames * d + drop_frames * ((m - drop_frames) / (frames_per_10mins / 10)); |
| 53 | } |
| 54 | |
| 55 | uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum) |
| 56 | { |
| 57 | unsigned fps = tc->fps; |
| 58 | int drop = !!(tc->flags & AV_TIMECODE_FLAG_DROPFRAME); |
| 59 | int hh, mm, ss, ff; |
| 60 | |
| 61 | framenum += tc->start; |
| 62 | if (drop) |
| 63 | framenum = av_timecode_adjust_ntsc_framenum2(framenum, tc->fps); |
| 64 | ff = framenum % fps; |
| 65 | ss = framenum / fps % 60; |
| 66 | mm = framenum / (fps*60) % 60; |
| 67 | hh = framenum / (fps*3600) % 24; |
| 68 | return 0 << 31 | // color frame flag (0: unsync mode, 1: sync mode) |
| 69 | drop << 30 | // drop frame flag (0: non drop, 1: drop) |
| 70 | (ff / 10) << 28 | // tens of frames |
| 71 | (ff % 10) << 24 | // units of frames |
| 72 | 0 << 23 | // PC (NTSC) or BGF0 (PAL) |
| 73 | (ss / 10) << 20 | // tens of seconds |
| 74 | (ss % 10) << 16 | // units of seconds |
| 75 | 0 << 15 | // BGF0 (NTSC) or BGF2 (PAL) |
| 76 | (mm / 10) << 12 | // tens of minutes |
| 77 | (mm % 10) << 8 | // units of minutes |
| 78 | 0 << 7 | // BGF2 (NTSC) or PC (PAL) |
| 79 | 0 << 6 | // BGF1 |
| 80 | (hh / 10) << 4 | // tens of hours |
| 81 | (hh % 10); // units of hours |
| 82 | } |
| 83 | |
| 84 | char *av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum) |
| 85 | { |
| 86 | int fps = tc->fps; |
| 87 | int drop = tc->flags & AV_TIMECODE_FLAG_DROPFRAME; |
| 88 | int hh, mm, ss, ff, neg = 0; |
| 89 | |
| 90 | framenum += tc->start; |
| 91 | if (drop) |
| 92 | framenum = av_timecode_adjust_ntsc_framenum2(framenum, fps); |
| 93 | if (framenum < 0) { |
| 94 | framenum = -framenum; |
| 95 | neg = tc->flags & AV_TIMECODE_FLAG_ALLOWNEGATIVE; |
| 96 | } |
| 97 | ff = framenum % fps; |
| 98 | ss = framenum / fps % 60; |
| 99 | mm = framenum / (fps*60) % 60; |
| 100 | hh = framenum / (fps*3600); |
| 101 | if (tc->flags & AV_TIMECODE_FLAG_24HOURSMAX) |
| 102 | hh = hh % 24; |
| 103 | snprintf(buf, AV_TIMECODE_STR_SIZE, "%s%02d:%02d:%02d%c%02d", |
| 104 | neg ? "-" : "", |
| 105 | hh, mm, ss, drop ? ';' : ':', ff); |
| 106 | return buf; |
| 107 | } |
| 108 | |
| 109 | static unsigned bcd2uint(uint8_t bcd) |
| 110 | { |
| 111 | unsigned low = bcd & 0xf; |
| 112 | unsigned high = bcd >> 4; |
| 113 | if (low > 9 || high > 9) |
| 114 | return 0; |
| 115 | return low + 10*high; |
| 116 | } |
| 117 | |
| 118 | char *av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df) |
| 119 | { |
| 120 | unsigned hh = bcd2uint(tcsmpte & 0x3f); // 6-bit hours |
| 121 | unsigned mm = bcd2uint(tcsmpte>>8 & 0x7f); // 7-bit minutes |
| 122 | unsigned ss = bcd2uint(tcsmpte>>16 & 0x7f); // 7-bit seconds |
| 123 | unsigned ff = bcd2uint(tcsmpte>>24 & 0x3f); // 6-bit frames |
| 124 | unsigned drop = tcsmpte & 1<<30 && !prevent_df; // 1-bit drop if not arbitrary bit |
| 125 | snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u", |
| 126 | hh, mm, ss, drop ? ';' : ':', ff); |
| 127 | return buf; |
| 128 | } |
| 129 | |
| 130 | char *av_timecode_make_mpeg_tc_string(char *buf, uint32_t tc25bit) |
| 131 | { |
| 132 | snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u", |
| 133 | tc25bit>>19 & 0x1f, // 5-bit hours |
| 134 | tc25bit>>13 & 0x3f, // 6-bit minutes |
| 135 | tc25bit>>6 & 0x3f, // 6-bit seconds |
| 136 | tc25bit & 1<<24 ? ';' : ':', // 1-bit drop flag |
| 137 | tc25bit & 0x3f); // 6-bit frames |
| 138 | return buf; |
| 139 | } |
| 140 | |
| 141 | static int check_fps(int fps) |
| 142 | { |
| 143 | int i; |
| 144 | static const int supported_fps[] = {24, 25, 30, 48, 50, 60}; |
| 145 | |
| 146 | for (i = 0; i < FF_ARRAY_ELEMS(supported_fps); i++) |
| 147 | if (fps == supported_fps[i]) |
| 148 | return 0; |
| 149 | return -1; |
| 150 | } |
| 151 | |
| 152 | static int check_timecode(void *log_ctx, AVTimecode *tc) |
| 153 | { |
| 154 | if (tc->fps <= 0) { |
| 155 | av_log(log_ctx, AV_LOG_ERROR, "Timecode frame rate must be specified\n"); |
| 156 | return AVERROR(EINVAL); |
| 157 | } |
| 158 | if ((tc->flags & AV_TIMECODE_FLAG_DROPFRAME) && tc->fps != 30 && tc->fps != 60) { |
| 159 | av_log(log_ctx, AV_LOG_ERROR, "Drop frame is only allowed with 30000/1001 or 60000/1001 FPS\n"); |
| 160 | return AVERROR(EINVAL); |
| 161 | } |
| 162 | if (check_fps(tc->fps) < 0) { |
| 163 | av_log(log_ctx, AV_LOG_ERROR, "Timecode frame rate %d/%d not supported\n", |
| 164 | tc->rate.num, tc->rate.den); |
| 165 | return AVERROR_PATCHWELCOME; |
| 166 | } |
| 167 | return 0; |
| 168 | } |
| 169 | |
| 170 | static int fps_from_frame_rate(AVRational rate) |
| 171 | { |
| 172 | if (!rate.den || !rate.num) |
| 173 | return -1; |
| 174 | return (rate.num + rate.den/2) / rate.den; |
| 175 | } |
| 176 | |
| 177 | int av_timecode_check_frame_rate(AVRational rate) |
| 178 | { |
| 179 | return check_fps(fps_from_frame_rate(rate)); |
| 180 | } |
| 181 | |
| 182 | int av_timecode_init(AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx) |
| 183 | { |
| 184 | memset(tc, 0, sizeof(*tc)); |
| 185 | tc->start = frame_start; |
| 186 | tc->flags = flags; |
| 187 | tc->rate = rate; |
| 188 | tc->fps = fps_from_frame_rate(rate); |
| 189 | return check_timecode(log_ctx, tc); |
| 190 | } |
| 191 | |
| 192 | int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx) |
| 193 | { |
| 194 | char c; |
| 195 | int hh, mm, ss, ff, ret; |
| 196 | |
| 197 | if (sscanf(str, "%d:%d:%d%c%d", &hh, &mm, &ss, &c, &ff) != 5) { |
| 198 | av_log(log_ctx, AV_LOG_ERROR, "Unable to parse timecode, " |
| 199 | "syntax: hh:mm:ss[:;.]ff\n"); |
| 200 | return AVERROR_INVALIDDATA; |
| 201 | } |
| 202 | |
| 203 | memset(tc, 0, sizeof(*tc)); |
| 204 | tc->flags = c != ':' ? AV_TIMECODE_FLAG_DROPFRAME : 0; // drop if ';', '.', ... |
| 205 | tc->rate = rate; |
| 206 | tc->fps = fps_from_frame_rate(rate); |
| 207 | |
| 208 | ret = check_timecode(log_ctx, tc); |
| 209 | if (ret < 0) |
| 210 | return ret; |
| 211 | |
| 212 | tc->start = (hh*3600 + mm*60 + ss) * tc->fps + ff; |
| 213 | if (tc->flags & AV_TIMECODE_FLAG_DROPFRAME) { /* adjust frame number */ |
| 214 | int tmins = 60*hh + mm; |
| 215 | tc->start -= 2 * (tmins - tmins/10); |
| 216 | } |
| 217 | return 0; |
| 218 | } |