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/*

 * Copyright (c) 2006 Smartjog S.A.S, Baptiste Coudurier 

 * Copyright (c) 2011-2012 Smartjog S.A.S, Clément Bœsch 

 *

 * 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 

#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, m, frames_per_10mins;

    if (fps == 30) {

        drop_frames = 2;

        frames_per_10mins = 17982;

    } else if (fps == 60) {

        drop_frames = 4;

        frames_per_10mins = 35964;

    } else

        return framenum;

    d = framenum / frames_per_10mins;

    m = framenum % frames_per_10mins;

    return framenum + 9 * 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 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

           (ss / 10) << 20 | // tens  of seconds

           (ss % 10) << 16 | // units of seconds

           (mm / 10) << 12 | // tens  of minutes

           (mm % 10) <<  8 | // units of minutes

           (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 && tc->fps != 60) {

        av_log(log_ctx, AV_LOG_ERROR, "Drop frame is only allowed with 30000/1001 or 60000/1001 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;

}