diff options
Diffstat (limited to 'libavcodec/timecode.c')
| -rw-r--r-- | libavcodec/timecode.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/libavcodec/timecode.c b/libavcodec/timecode.c new file mode 100644 index 0000000..7f3b1d5 --- /dev/null +++ b/libavcodec/timecode.c @@ -0,0 +1,83 @@ +/* + * Copyright (C) 2006 Smartjog S.A.S, Baptiste Coudurier <baptiste.coudurier@gmail.com> + * Copyright (C) 2011 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 + */ + +#include <stdio.h> +#include "timecode.h" +#include "libavutil/log.h" + +int ff_framenum_to_drop_timecode(int frame_num) +{ + /* only works for NTSC 29.97 */ + int d = frame_num / 17982; + int m = frame_num % 17982; + //if (m < 2) m += 2; /* not needed since -2,-1 / 1798 in C returns 0 */ + return frame_num + 18 * d + 2 * ((m - 2) / 1798); +} + +uint32_t ff_framenum_to_smtpe_timecode(unsigned frame, int fps, int drop) +{ + return (0 << 31) | // color frame flag + (drop << 30) | // drop frame flag + ( ((frame % fps) / 10) << 28) | // tens of frames + ( ((frame % fps) % 10) << 24) | // units of frames + (0 << 23) | // field phase (NTSC), b0 (PAL) + ((((frame / fps) % 60) / 10) << 20) | // tens of seconds + ((((frame / fps) % 60) % 10) << 16) | // units of seconds + (0 << 15) | // b0 (NTSC), b2 (PAL) + ((((frame / (fps * 60)) % 60) / 10) << 12) | // tens of minutes + ((((frame / (fps * 60)) % 60) % 10) << 8) | // units of minutes + (0 << 7) | // b1 + (0 << 6) | // b2 (NTSC), field phase (PAL) + ((((frame / (fps * 3600) % 24)) / 10) << 4) | // tens of hours + ( (frame / (fps * 3600) % 24)) % 10; // units of hours +} + +int ff_init_smtpe_timecode(void *avcl, struct ff_timecode *tc) +{ + int hh, mm, ss, ff, fps; + char c; + + if (sscanf(tc->str, "%d:%d:%d%c%d", &hh, &mm, &ss, &c, &ff) != 5) { + av_log(avcl, AV_LOG_ERROR, "unable to parse timecode, " + "syntax: hh:mm:ss[:;.]ff\n"); + return -1; + } + + fps = (tc->rate.num + tc->rate.den/2) / tc->rate.den; + tc->start = (hh*3600 + mm*60 + ss) * fps + ff; + tc->drop = c != ':'; // drop if ';', '.', ... + + if (tc->drop) { /* adjust frame number */ + int tmins = 60*hh + mm; + if (tc->rate.den != 1001 || fps != 30) { + av_log(avcl, AV_LOG_ERROR, "error: drop frame is only allowed with" + "30000/1001 FPS"); + return -2; + } + tc->start -= 2 * (tmins - tmins/10); + } + return 0; +} |
