diff options
Diffstat (limited to 'libs/libltc/timecode.c')
-rw-r--r-- | libs/libltc/timecode.c | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/libs/libltc/timecode.c b/libs/libltc/timecode.c new file mode 100644 index 0000000000..83e8e1926b --- /dev/null +++ b/libs/libltc/timecode.c @@ -0,0 +1,451 @@ +/* + libltc - en+decode linear timecode + + Copyright (C) 2006-2012 Robin Gareus <robin@gareus.org> + + This program 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 3 of the + License, or (at your option) any later version. + + This program 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 this library. + If not, see <http://www.gnu.org/licenses/>. +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "ltc/ltc.h" + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +/** + * SMPTE Timezones + */ +struct SMPTETimeZonesStruct { + unsigned char code; //actually 6 bit! + char timezone[6]; +}; + +/** + * SMPTE Timezone codes as per http://www.barney-wol.net/time/timecode.html + */ +static const struct SMPTETimeZonesStruct smpte_time_zones[] = +{ + /* code, timezone (UTC+) //Standard time //Daylight saving */ + { 0x00, "+0000" /* Greenwich */ /* - */ }, + { 0x00, "-0000" /* Greenwich */ /* - */ }, + { 0x01, "-0100" /* Azores */ /* - */ }, + { 0x02, "-0200" /* Mid-Atlantic */ /* - */ }, + { 0x03, "-0300" /* Buenos Aires */ /* Halifax */ }, + { 0x04, "-0400" /* Halifax */ /* New York */ }, + { 0x05, "-0500" /* New York */ /* Chicago */ }, + { 0x06, "-0600" /* Chicago Denver */ /* - */ }, + { 0x07, "-0700" /* Denver */ /* Los Angeles */ }, + { 0x08, "-0800" /* Los Angeles */ /* - */ }, + { 0x09, "-0900" /* Alaska */ /* - */ }, + { 0x10, "-1000" /* Hawaii */ /* - */ }, + { 0x11, "-1100" /* Midway Island */ /* - */ }, + { 0x12, "-1200" /* Kwaialein */ /* - */ }, + { 0x13, "+1300" /* - */ /* New Zealand */ }, + { 0x14, "+1200" /* New Zealand */ /* - */ }, + { 0x15, "+1100" /* Solomon Islands */ /* - */ }, + { 0x16, "+1000" /* Guam */ /* - */ }, + { 0x17, "+0900" /* Tokyo */ /* - */ }, + { 0x18, "+0800" /* Beijing */ /* - */ }, + { 0x19, "+0700" /* Bangkok */ /* - */ }, + { 0x20, "+0600" /* Dhaka */ /* - */ }, + { 0x21, "+0500" /* Islamabad */ /* - */ }, + { 0x22, "+0400" /* Abu Dhabi */ /* - */ }, + { 0x23, "+0300" /* Moscow */ /* - */ }, + { 0x24, "+0200" /* Eastern Europe */ /* - */ }, + { 0x25, "+0100" /* Central Europe */ /* - */ }, +/* { 0x26, "Undefined" Reserved; do not use },*/ +/* { 0x27, "Undefined" Reserved; do not use },*/ + { 0x28, "TP-03" /* Time precision class 3 */ /* - */ }, + { 0x29, "TP-02" /* Time precision class 2 */ /* - */ }, + { 0x30, "TP-01" /* Time precision class 1 */ /* - */ }, + { 0x31, "TP-00" /* Time precision class 0 */ /* - */ }, + { 0x0A, "-0030" /* - */ /* - */ }, + { 0x0B, "-0130" /* - */ /* - */ }, + { 0x0C, "-0230" /* - */ /* Newfoundland */ }, + { 0x0D, "-0330" /* Newfoundland */ /* - */ }, + { 0x0E, "-0430" /* - */ /* - */ }, + { 0x0F, "-0530" /* - */ /* - */ }, + { 0x1A, "-0630" /* - */ /* - */ }, + { 0x1B, "-0730" /* - */ /* - */ }, + { 0x1C, "-0830" /* - */ /* - */ }, + { 0x1D, "-0930" /* Marquesa Islands */ /* - */ }, + { 0x1E, "-1030" /* - */ /* - */ }, + { 0x1F, "-1130" /* - */ /* - */ }, + { 0x2A, "+1130" /* Norfolk Island */ /* - */ }, + { 0x2B, "+1030" /* Lord Howe Is. */ /* - */ }, + { 0x2C, "+0930" /* Darwin */ /* - */ }, + { 0x2D, "+0830" /* - */ /* - */ }, + { 0x2E, "+0730" /* - */ /* - */ }, + { 0x2F, "+0630" /* Rangoon */ /* - */ }, + { 0x3A, "+0530" /* Bombay */ /* - */ }, + { 0x3B, "+0430" /* Kabul */ /* - */ }, + { 0x3C, "+0330" /* Tehran */ /* - */ }, + { 0x3D, "+0230" /* - */ /* - */ }, + { 0x3E, "+0130" /* - */ /* - */ }, + { 0x3F, "+0030" /* - */ /* - */ }, + { 0x32, "+1245" /* Chatham Island */ /* - */ }, +/* { 0x33, "Undefined" Reserved; do not use },*/ +/* { 0x34, "Undefined" Reserved; do not use },*/ +/* { 0x35, "Undefined" Reserved; do not use },*/ +/* { 0x36, "Undefined" Reserved; do not use },*/ +/* { 0x37, "Undefined" Reserved; do not use },*/ + { 0x38, "+XXXX" /* User defined time offset */ /* - */ }, +/* { 0x39, "Undefined" Unknown Unknown },*/ +/* { 0x39, "Undefined" Unknown Unknown },*/ + + { 0xFF, "" /* The End */ } +}; + +static void smpte_set_timezone_string(LTCFrame *frame, SMPTETimecode *stime) { + int i = 0; + + const unsigned char code = frame->user7 + (frame->user8 << 4); + + char timezone[6] = "+0000"; + + for (i = 0 ; smpte_time_zones[i].code != 0xFF ; i++) { + if ( smpte_time_zones[i].code == code ) { + strcpy(timezone, smpte_time_zones[i].timezone); + break; + } + } + strcpy(stime->timezone, timezone); +} + +static void smpte_set_timezone_code(SMPTETimecode *stime, LTCFrame *frame) { + int i = 0; + unsigned char code = 0x00; + + // Find code for timezone string + // Primitive search + for (i=0; smpte_time_zones[i].code != 0xFF; i++) { + if ( (strcmp(smpte_time_zones[i].timezone, stime->timezone)) == 0 ) { + code = smpte_time_zones[i].code; + break; + } + } + + frame->user7 = code & 0x0F; + frame->user8 = (code & 0xF0) >> 4; +} + +/** Drop-frame support function + * We skip the first two frame numbers (0 and 1) at the beginning of each minute, + * except for minutes 0, 10, 20, 30, 40, and 50 + * (i.e. we skip frame numbers at the beginning of minutes for which mins_units is not 0). + */ +static void skip_drop_frames(LTCFrame* frame) { + if ((frame->mins_units != 0) + && (frame->secs_units == 0) + && (frame->secs_tens == 0) + && (frame->frame_units == 0) + && (frame->frame_tens == 0) + ) { + frame->frame_units += 2; + } +} + +void ltc_frame_to_time(SMPTETimecode *stime, LTCFrame *frame, int flags) { + if (!stime) return; + + if (flags & LTC_USE_DATE) { + smpte_set_timezone_string(frame, stime); + + stime->years = frame->user5 + frame->user6*10; + stime->months = frame->user3 + frame->user4*10; + stime->days = frame->user1 + frame->user2*10; + } else { + stime->years = 0; + stime->months = 0; + stime->days = 0; + sprintf(stime->timezone,"+0000"); + } + + stime->hours = frame->hours_units + frame->hours_tens*10; + stime->mins = frame->mins_units + frame->mins_tens*10; + stime->secs = frame->secs_units + frame->secs_tens*10; + stime->frame = frame->frame_units + frame->frame_tens*10; +} + +void ltc_time_to_frame(LTCFrame* frame, SMPTETimecode* stime, enum LTC_TV_STANDARD standard, int flags) { + if (flags & LTC_USE_DATE) { + smpte_set_timezone_code(stime, frame); + frame->user6 = stime->years/10; + frame->user5 = stime->years - frame->user6*10; + frame->user4 = stime->months/10; + frame->user3 = stime->months - frame->user4*10; + frame->user2 = stime->days/10; + frame->user1 = stime->days - frame->user2*10; + } + + frame->hours_tens = stime->hours/10; + frame->hours_units = stime->hours - frame->hours_tens*10; + frame->mins_tens = stime->mins/10; + frame->mins_units = stime->mins - frame->mins_tens*10; + frame->secs_tens = stime->secs/10; + frame->secs_units = stime->secs - frame->secs_tens*10; + frame->frame_tens = stime->frame/10; + frame->frame_units = stime->frame - frame->frame_tens*10; + + // Prevent illegal SMPTE frames + if (frame->dfbit) { + skip_drop_frames(frame); + } + + if ((flags & LTC_NO_PARITY) == 0) { + ltc_frame_set_parity(frame, standard); + } +} + +void ltc_frame_reset(LTCFrame* frame) { + memset(frame, 0, sizeof(LTCFrame)); + // syncword = 0x3FFD +#ifdef __BIG_ENDIAN__ + // mirrored BE bit order: FCBF + frame->sync_word = 0xFCBF; +#else + // mirrored LE bit order: BFFC + frame->sync_word = 0xBFFC; +#endif +} + +int ltc_frame_increment(LTCFrame* frame, int fps, enum LTC_TV_STANDARD standard, int flags) { + int rv = 0; + + frame->frame_units++; + + if (frame->frame_units == 10) + { + frame->frame_units = 0; + frame->frame_tens++; + } + if (fps == frame->frame_units+frame->frame_tens*10) + { + frame->frame_units = 0; + frame->frame_tens = 0; + frame->secs_units++; + if (frame->secs_units == 10) + { + frame->secs_units = 0; + frame->secs_tens++; + if (frame->secs_tens == 6) + { + frame->secs_tens = 0; + frame->mins_units++; + if (frame->mins_units == 10) + { + frame->mins_units = 0; + frame->mins_tens++; + if (frame->mins_tens == 6) + { + frame->mins_tens = 0; + frame->hours_units++; + if (frame->hours_units == 10) + { + frame->hours_units = 0; + frame->hours_tens++; + } + if (frame->hours_units == 4 && frame->hours_tens==2) + { + /* 24h wrap around */ + rv=1; + frame->hours_tens=0; + frame->hours_units = 0; + + if (flags&1) + { + /* wrap date */ + SMPTETimecode stime; + stime.years = frame->user5 + frame->user6*10; + stime.months = frame->user3 + frame->user4*10; + stime.days = frame->user1 + frame->user2*10; + + if (stime.months > 0 && stime.months < 13) + { + unsigned char dpm[12] = {31,28,31,30,31,30,31,31,30,31,30,31}; + /* proper leap-year calc: + * ((stime.years%4)==0 && ( (stime.years%100) != 0 || (stime.years%400) == 0) ) + * simplified since year is 0..99 + */ + if ((stime.years%4)==0 /* && stime.years!=0 */ ) /* year 2000 was a leap-year */ + dpm[1]=29; + stime.days++; + if (stime.days > dpm[stime.months-1]) + { + stime.days=1; + stime.months++; + if (stime.months > 12) { + stime.months=1; + stime.years=(stime.years+1)%100; + } + } + frame->user6 = stime.years/10; + frame->user5 = stime.years%10; + frame->user4 = stime.months/10; + frame->user3 = stime.months%10; + frame->user2 = stime.days/10; + frame->user1 = stime.days%10; + } else { + rv=-1; + } + } + } + } + } + } + } + } + + if (frame->dfbit) { + skip_drop_frames(frame); + } + + if ((flags & LTC_NO_PARITY) == 0) { + ltc_frame_set_parity(frame, standard); + } + + return rv; +} + +int ltc_frame_decrement(LTCFrame* frame, int fps, enum LTC_TV_STANDARD standard, int flags) { + int rv = 0; + + int frames = frame->frame_units + frame->frame_tens * 10; + if (frames > 0) { + frames--; + } else { + frames = fps -1; + } + + frame->frame_units = frames % 10; + frame->frame_tens = frames / 10; + + if (frames == fps -1) { + int secs = frame->secs_units + frame->secs_tens * 10; + if (secs > 0) { + secs--; + } else { + secs = 59; + } + frame->secs_units = secs % 10; + frame->secs_tens = secs / 10; + + if (secs == 59) { + int mins = frame->mins_units + frame->mins_tens * 10; + if (mins > 0) { + mins--; + } else { + mins = 59; + } + frame->mins_units = mins % 10; + frame->mins_tens = mins / 10; + + if (mins == 59) { + int hours = frame->hours_units + frame->hours_tens * 10; + if (hours > 0) { + hours--; + } else { + hours = 23; + } + frame->hours_units = hours % 10; + frame->hours_tens = hours / 10; + + if (hours == 23) { + /* 24h wrap around */ + rv=1; + if (flags<C_USE_DATE) + { + /* wrap date */ + SMPTETimecode stime; + stime.years = frame->user5 + frame->user6*10; + stime.months = frame->user3 + frame->user4*10; + stime.days = frame->user1 + frame->user2*10; + + if (stime.months > 0 && stime.months < 13) + { + unsigned char dpm[12] = {31,28,31,30,31,30,31,31,30,31,30,31}; + /* proper leap-year calc: + * ((stime.years%4)==0 && ( (stime.years%100) != 0 || (stime.years%400) == 0) ) + * simplified since year is 0..99 + */ + if ((stime.years%4)==0 /* && stime.years!=0 */ ) /* year 2000 was a leap-year */ + dpm[1]=29; + // + if (stime.days > 1) { + stime.days--; + } else { + stime.months = 1 + (stime.months + 10)%12; + stime.days = dpm[stime.months-1]; + if (stime.months == 12) { + stime.years=(stime.years+99)%100; // XXX + } + } + + frame->user6 = stime.years/10; + frame->user5 = stime.years%10; + frame->user4 = stime.months/10; + frame->user3 = stime.months%10; + frame->user2 = stime.days/10; + frame->user1 = stime.days%10; + } else { + rv=-1; + } + } + } + } + } + } + + if (frame->dfbit && /* prevent endless recursion */ fps > 2) { + if ((frame->mins_units != 0) + && (frame->secs_units == 0) + && (frame->secs_tens == 0) + && (frame->frame_units == 1) + && (frame->frame_tens == 0) + ) { + ltc_frame_decrement(frame, fps, standard, flags<C_USE_DATE); + ltc_frame_decrement(frame, fps, standard, flags<C_USE_DATE); + } + } + + if ((flags & LTC_NO_PARITY) == 0) { + ltc_frame_set_parity(frame, standard); + } + + return rv; +} + +int parse_bcg_flags(LTCFrame *f, enum LTC_TV_STANDARD standard) { + switch (standard) { + case LTC_TV_625_50: /* 25 fps mode */ + return ( + ((f->binary_group_flag_bit0)?4:0) + | ((f->binary_group_flag_bit1)?2:0) + | ((f->biphase_mark_phase_correction)?1:0) + ); + break; + default: /* 24,30 fps mode */ + return ( + ((f->binary_group_flag_bit2)?4:0) + | ((f->binary_group_flag_bit1)?2:0) + | ((f->binary_group_flag_bit0)?1:0) + ); + break; + } +} |