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-rw-r--r--libavutil/timecode.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/libavutil/timecode.c b/libavutil/timecode.c
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+++ b/libavutil/timecode.c
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+/*
+ * Copyright (c) 2006 Smartjog S.A.S, Baptiste Coudurier <baptiste.coudurier@gmail.com>
+ * Copyright (c) 2011-2012 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
+ * @see https://en.wikipedia.org/wiki/SMPTE_time_code
+ * @see http://www.dropframetimecode.org
+ */
+
+#include <stdio.h>
+#include "timecode.h"
+#include "log.h"
+#include "error.h"
+
+int av_timecode_adjust_ntsc_framenum2(int framenum, int fps)
+{
+ /* only works for NTSC 29.97 and 59.94 */
+ int drop_frames = 0;
+ int d = framenum / 17982;
+ int m = framenum % 17982;
+
+ if (fps == 30)
+ drop_frames = 2;
+ else if (fps == 60)
+ drop_frames = 4;
+ else
+ return framenum;
+
+ //if (m < 2) m += 2; /* not needed since -2,-1 / 1798 in C returns 0 */
+ return framenum + 9 * drop_frames * d + drop_frames * ((m - 2) / 1798);
+}
+
+uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum)
+{
+ unsigned fps = tc->fps;
+ int drop = !!(tc->flags & AV_TIMECODE_FLAG_DROPFRAME);
+ int hh, mm, ss, ff;
+
+ framenum += tc->start;
+ if (drop)
+ framenum = av_timecode_adjust_ntsc_framenum2(framenum, tc->fps);
+ ff = framenum % fps;
+ ss = framenum / fps % 60;
+ mm = framenum / (fps*60) % 60;
+ hh = framenum / (fps*3600) % 24;
+ return 0 << 31 | // color frame flag (0: unsync mode, 1: sync mode)
+ drop << 30 | // drop frame flag (0: non drop, 1: drop)
+ (ff / 10) << 28 | // tens of frames
+ (ff % 10) << 24 | // units of frames
+ 0 << 23 | // PC (NTSC) or BGF0 (PAL)
+ (ss / 10) << 20 | // tens of seconds
+ (ss % 10) << 16 | // units of seconds
+ 0 << 15 | // BGF0 (NTSC) or BGF2 (PAL)
+ (mm / 10) << 12 | // tens of minutes
+ (mm % 10) << 8 | // units of minutes
+ 0 << 7 | // BGF2 (NTSC) or PC (PAL)
+ 0 << 6 | // BGF1
+ (hh / 10) << 4 | // tens of hours
+ (hh % 10); // units of hours
+}
+
+char *av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum)
+{
+ int fps = tc->fps;
+ int drop = tc->flags & AV_TIMECODE_FLAG_DROPFRAME;
+ int hh, mm, ss, ff, neg = 0;
+
+ framenum += tc->start;
+ if (drop)
+ framenum = av_timecode_adjust_ntsc_framenum2(framenum, fps);
+ if (framenum < 0) {
+ framenum = -framenum;
+ neg = tc->flags & AV_TIMECODE_FLAG_ALLOWNEGATIVE;
+ }
+ ff = framenum % fps;
+ ss = framenum / fps % 60;
+ mm = framenum / (fps*60) % 60;
+ hh = framenum / (fps*3600);
+ if (tc->flags & AV_TIMECODE_FLAG_24HOURSMAX)
+ hh = hh % 24;
+ snprintf(buf, AV_TIMECODE_STR_SIZE, "%s%02d:%02d:%02d%c%02d",
+ neg ? "-" : "",
+ hh, mm, ss, drop ? ';' : ':', ff);
+ return buf;
+}
+
+static unsigned bcd2uint(uint8_t bcd)
+{
+ unsigned low = bcd & 0xf;
+ unsigned high = bcd >> 4;
+ if (low > 9 || high > 9)
+ return 0;
+ return low + 10*high;
+}
+
+char *av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df)
+{
+ unsigned hh = bcd2uint(tcsmpte & 0x3f); // 6-bit hours
+ unsigned mm = bcd2uint(tcsmpte>>8 & 0x7f); // 7-bit minutes
+ unsigned ss = bcd2uint(tcsmpte>>16 & 0x7f); // 7-bit seconds
+ unsigned ff = bcd2uint(tcsmpte>>24 & 0x3f); // 6-bit frames
+ unsigned drop = tcsmpte & 1<<30 && !prevent_df; // 1-bit drop if not arbitrary bit
+ snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u",
+ hh, mm, ss, drop ? ';' : ':', ff);
+ return buf;
+}
+
+char *av_timecode_make_mpeg_tc_string(char *buf, uint32_t tc25bit)
+{
+ snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u",
+ tc25bit>>19 & 0x1f, // 5-bit hours
+ tc25bit>>13 & 0x3f, // 6-bit minutes
+ tc25bit>>6 & 0x3f, // 6-bit seconds
+ tc25bit & 1<<24 ? ';' : ':', // 1-bit drop flag
+ tc25bit & 0x3f); // 6-bit frames
+ return buf;
+}
+
+static int check_fps(int fps)
+{
+ int i;
+ static const int supported_fps[] = {24, 25, 30, 50, 60};
+
+ for (i = 0; i < FF_ARRAY_ELEMS(supported_fps); i++)
+ if (fps == supported_fps[i])
+ return 0;
+ return -1;
+}
+
+static int check_timecode(void *log_ctx, AVTimecode *tc)
+{
+ if (tc->fps <= 0) {
+ av_log(log_ctx, AV_LOG_ERROR, "Timecode frame rate must be specified\n");
+ return AVERROR(EINVAL);
+ }
+ if ((tc->flags & AV_TIMECODE_FLAG_DROPFRAME) && tc->fps != 30) {
+ av_log(log_ctx, AV_LOG_ERROR, "Drop frame is only allowed with 30000/1001 FPS\n");
+ return AVERROR(EINVAL);
+ }
+ if (check_fps(tc->fps) < 0) {
+ av_log(log_ctx, AV_LOG_ERROR, "Timecode frame rate %d/%d not supported\n",
+ tc->rate.num, tc->rate.den);
+ return AVERROR_PATCHWELCOME;
+ }
+ return 0;
+}
+
+static int fps_from_frame_rate(AVRational rate)
+{
+ if (!rate.den || !rate.num)
+ return -1;
+ return (rate.num + rate.den/2) / rate.den;
+}
+
+int av_timecode_check_frame_rate(AVRational rate)
+{
+ return check_fps(fps_from_frame_rate(rate));
+}
+
+int av_timecode_init(AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx)
+{
+ memset(tc, 0, sizeof(*tc));
+ tc->start = frame_start;
+ tc->flags = flags;
+ tc->rate = rate;
+ tc->fps = fps_from_frame_rate(rate);
+ return check_timecode(log_ctx, tc);
+}
+
+int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx)
+{
+ char c;
+ int hh, mm, ss, ff, ret;
+
+ if (sscanf(str, "%d:%d:%d%c%d", &hh, &mm, &ss, &c, &ff) != 5) {
+ av_log(log_ctx, AV_LOG_ERROR, "Unable to parse timecode, "
+ "syntax: hh:mm:ss[:;.]ff\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ memset(tc, 0, sizeof(*tc));
+ tc->flags = c != ':' ? AV_TIMECODE_FLAG_DROPFRAME : 0; // drop if ';', '.', ...
+ tc->rate = rate;
+ tc->fps = fps_from_frame_rate(rate);
+
+ ret = check_timecode(log_ctx, tc);
+ if (ret < 0)
+ return ret;
+
+ tc->start = (hh*3600 + mm*60 + ss) * tc->fps + ff;
+ if (tc->flags & AV_TIMECODE_FLAG_DROPFRAME) { /* adjust frame number */
+ int tmins = 60*hh + mm;
+ tc->start -= 2 * (tmins - tmins/10);
+ }
+ return 0;
+}
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