/*
 * 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 "common.h"
#include "timecode.h"
#include "log.h"
#include "error.h"

int av_timecode_adjust_ntsc_framenum2(int framenum, int fps)
{
 /* only works for multiples of NTSC 29.97 */
 int drop_frames = 0;
 int d, m, frames_per_10mins;

 if (fps && fps % 30 == 0) {
 drop_frames = fps / 30 * 2;
 frames_per_10mins = fps / 30 * 17982;
 } else
 return framenum;

 d = framenum / frames_per_10mins;
 m = framenum % frames_per_10mins;

 return framenum + 9U * drop_frames * d + drop_frames * ((m - drop_frames) / (frames_per_10mins / 10));
}

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 av_timecode_get_smpte(tc->rate, drop, hh, mm, ss, ff);
}

uint32_t av_timecode_get_smpte(AVRational rate, int drop, int hh, int mm, int ss, int ff)
{
 uint32_t tc = 0;

 /* For SMPTE 12-M timecodes, frame count is a special case if > 30 FPS.
 See SMPTE ST 12-1:2014 Sec 12.1 for more info. */
 if (av_cmp_q(rate, (AVRational) {30, 1}) == 1) {
 if (ff % 2 == 1) {
 if (av_cmp_q(rate, (AVRational) {50, 1}) == 0)
 tc |= (1 << 7);
 else
 tc |= (1 << 23);
 }
 ff /= 2;
 }

 hh = hh % 24;
 mm = av_clip(mm, 0, 59);
 ss = av_clip(ss, 0, 59);
 ff = ff % 40;

 tc |= drop << 30;
 tc |= (ff / 10) << 28;
 tc |= (ff % 10) << 24;
 tc |= (ss / 10) << 20;
 tc |= (ss % 10) << 16;
 tc |= (mm / 10) << 12;
 tc |= (mm % 10) << 8;
 tc |= (hh / 10) << 4;
 tc |= (hh % 10);

 return tc;
}

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, ff_len, 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*60LL) % 60;
 hh = framenum / (fps*3600LL);
 if (tc->flags & AV_TIMECODE_FLAG_24HOURSMAX)
 hh = hh % 24;
 ff_len = fps > 10000 ? 5 : fps > 1000 ? 4 : fps > 100 ? 3 : fps > 10 ? 2 : 1;
 snprintf(buf, AV_TIMECODE_STR_SIZE, "%s%02d:%02d:%02d%c%0*d",
 neg ? "-" : "",
 hh, mm, ss, drop ? ';' : ':', ff_len, 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_string2(char *buf, AVRational rate, uint32_t tcsmpte, int prevent_df, int skip_field)
{
 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

 if (av_cmp_q(rate, (AVRational) {30, 1}) == 1) {
 ff <<= 1;
 if (!skip_field) {
 if (av_cmp_q(rate, (AVRational) {50, 1}) == 0)
 ff += !!(tcsmpte & 1 << 7);
 else
 ff += !!(tcsmpte & 1 << 23);
 }
 }

 snprintf(buf, AV_TIMECODE_STR_SIZE, "%02u:%02u:%02u%c%02u",
 hh, mm, ss, drop ? ';' : ':', ff);
 return buf;

}

char *av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df)
{
 return av_timecode_make_smpte_tc_string2(buf, (AVRational){30, 1}, tcsmpte, prevent_df, 1);
}

char *av_timecode_make_mpeg_tc_string(char *buf, uint32_t tc25bit)
{
 snprintf(buf, AV_TIMECODE_STR_SIZE,
 "%02"PRIu32":%02"PRIu32":%02"PRIu32"%c%02"PRIu32,
 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, 48, 50, 60, 100, 120, 150,
 };

 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 ((int)tc->fps <= 0) {
 av_log(log_ctx, AV_LOG_ERROR, "Valid timecode frame rate must be specified. Minimum value is 1\n");
 return AVERROR(EINVAL);
 }
 if ((tc->flags & AV_TIMECODE_FLAG_DROPFRAME) && tc->fps % 30 != 0) {
 av_log(log_ctx, AV_LOG_ERROR, "Drop frame is only allowed with multiples of 30000/1001 FPS\n");
 return AVERROR(EINVAL);
 }
 if (check_fps(tc->fps) < 0) {
 av_log(log_ctx, AV_LOG_WARNING, "Using non-standard frame rate %d/%d\n",
 tc->rate.num, tc->rate.den);
 }
 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_components(AVTimecode *tc, AVRational rate, int flags, int hh, int mm, int ss, int ff, void *log_ctx)
{
 int ret;

 memset(tc, 0, sizeof(*tc));
 tc->flags = flags;
 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 -= (tc->fps / 30 * 2) * (tmins - tmins/10);
 }
 return 0;
}

int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx)
{
 char c;
 int hh, mm, ss, ff, flags;

 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;
 }
 flags = c != ':' ? AV_TIMECODE_FLAG_DROPFRAME : 0; // drop if ';', '.', ...

 return av_timecode_init_from_components(tc, rate, flags, hh, mm, ss, ff, log_ctx);
}