timecode.h (5325B)
1 /* 2 * Copyright (c) 2006 Smartjog S.A.S, Baptiste Coudurier <baptiste.coudurier@gmail.com> 3 * Copyright (c) 2011-2012 Smartjog S.A.S, Clément Bœsch <clement.boesch@smartjog.com> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22 /** 23 * @file 24 * Timecode helpers header 25 */ 26 27 #ifndef AVUTIL_TIMECODE_H 28 #define AVUTIL_TIMECODE_H 29 30 #include <stdint.h> 31 #include "rational.h" 32 33 #define AV_TIMECODE_STR_SIZE 16 34 35 enum AVTimecodeFlag { 36 AV_TIMECODE_FLAG_DROPFRAME = 1<<0, ///< timecode is drop frame 37 AV_TIMECODE_FLAG_24HOURSMAX = 1<<1, ///< timecode wraps after 24 hours 38 AV_TIMECODE_FLAG_ALLOWNEGATIVE = 1<<2, ///< negative time values are allowed 39 }; 40 41 typedef struct { 42 int start; ///< timecode frame start (first base frame number) 43 uint32_t flags; ///< flags such as drop frame, +24 hours support, ... 44 AVRational rate; ///< frame rate in rational form 45 unsigned fps; ///< frame per second; must be consistent with the rate field 46 } AVTimecode; 47 48 /** 49 * Adjust frame number for NTSC drop frame time code. 50 * 51 * @param framenum frame number to adjust 52 * @param fps frame per second, 30 or 60 53 * @return adjusted frame number 54 * @warning adjustment is only valid in NTSC 29.97 and 59.94 55 */ 56 int av_timecode_adjust_ntsc_framenum2(int framenum, int fps); 57 58 /** 59 * Convert frame number to SMPTE 12M binary representation. 60 * 61 * @param tc timecode data correctly initialized 62 * @param framenum frame number 63 * @return the SMPTE binary representation 64 * 65 * @note Frame number adjustment is automatically done in case of drop timecode, 66 * you do NOT have to call av_timecode_adjust_ntsc_framenum2(). 67 * @note The frame number is relative to tc->start. 68 * @note Color frame (CF), binary group flags (BGF) and biphase mark polarity 69 * correction (PC) bits are set to zero. 70 */ 71 uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum); 72 73 /** 74 * Load timecode string in buf. 75 * 76 * @param buf destination buffer, must be at least AV_TIMECODE_STR_SIZE long 77 * @param tc timecode data correctly initialized 78 * @param framenum frame number 79 * @return the buf parameter 80 * 81 * @note Timecode representation can be a negative timecode and have more than 82 * 24 hours, but will only be honored if the flags are correctly set. 83 * @note The frame number is relative to tc->start. 84 */ 85 char *av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum); 86 87 /** 88 * Get the timecode string from the SMPTE timecode format. 89 * 90 * @param buf destination buffer, must be at least AV_TIMECODE_STR_SIZE long 91 * @param tcsmpte the 32-bit SMPTE timecode 92 * @param prevent_df prevent the use of a drop flag when it is known the DF bit 93 * is arbitrary 94 * @return the buf parameter 95 */ 96 char *av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df); 97 98 /** 99 * Get the timecode string from the 25-bit timecode format (MPEG GOP format). 100 * 101 * @param buf destination buffer, must be at least AV_TIMECODE_STR_SIZE long 102 * @param tc25bit the 25-bits timecode 103 * @return the buf parameter 104 */ 105 char *av_timecode_make_mpeg_tc_string(char *buf, uint32_t tc25bit); 106 107 /** 108 * Init a timecode struct with the passed parameters. 109 * 110 * @param log_ctx a pointer to an arbitrary struct of which the first field 111 * is a pointer to an AVClass struct (used for av_log) 112 * @param tc pointer to an allocated AVTimecode 113 * @param rate frame rate in rational form 114 * @param flags miscellaneous flags such as drop frame, +24 hours, ... 115 * (see AVTimecodeFlag) 116 * @param frame_start the first frame number 117 * @return 0 on success, AVERROR otherwise 118 */ 119 int av_timecode_init(AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx); 120 121 /** 122 * Parse timecode representation (hh:mm:ss[:;.]ff). 123 * 124 * @param log_ctx a pointer to an arbitrary struct of which the first field is a 125 * pointer to an AVClass struct (used for av_log). 126 * @param tc pointer to an allocated AVTimecode 127 * @param rate frame rate in rational form 128 * @param str timecode string which will determine the frame start 129 * @return 0 on success, AVERROR otherwise 130 */ 131 int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx); 132 133 /** 134 * Check if the timecode feature is available for the given frame rate 135 * 136 * @return 0 if supported, <0 otherwise 137 */ 138 int av_timecode_check_frame_rate(AVRational rate); 139 140 #endif /* AVUTIL_TIMECODE_H */