ffmpeg.libavutil.timecode source code

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 module ffmpeg.libavutil.timecode;
28 
29 import ffmpeg.libavutil.rational;
30 
31 extern (C):
32 import ffmpeg; @nogc nothrow:
33 
34 enum AV_TIMECODE_STR_SIZE = 23;
35 
36 enum AVTimecodeFlag
37 {
38     AV_TIMECODE_FLAG_DROPFRAME = 1 << 0, ///< timecode is drop frame
39     AV_TIMECODE_FLAG_24HOURSMAX = 1 << 1, ///< timecode wraps after 24 hours
40     AV_TIMECODE_FLAG_ALLOWNEGATIVE = 1 << 2 ///< negative time values are allowed
41 }
42 
43 struct AVTimecode
44 {
45     int start; ///< timecode frame start (first base frame number)
46     uint flags; ///< flags such as drop frame, +24 hours support, ...
47     AVRational rate; ///< frame rate in rational form
48     uint fps; ///< frame per second; must be consistent with the rate field
49 }
50 
51 /**
52  * Adjust frame number for NTSC drop frame time code.
53  *
54  * @param framenum frame number to adjust
55  * @param fps      frame per second, 30 or 60
56  * @return         adjusted frame number
57  * @warning        adjustment is only valid in NTSC 29.97 and 59.94
58  */
59 int av_timecode_adjust_ntsc_framenum2 (int framenum, int fps);
60 
61 /**
62  * Convert frame number to SMPTE 12M binary representation.
63  *
64  * @param tc       timecode data correctly initialized
65  * @param framenum frame number
66  * @return         the SMPTE binary representation
67  *
68  * @note Frame number adjustment is automatically done in case of drop timecode,
69  *       you do NOT have to call av_timecode_adjust_ntsc_framenum2().
70  * @note The frame number is relative to tc->start.
71  * @note Color frame (CF), binary group flags (BGF) and biphase mark polarity
72  *       correction (PC) bits are set to zero.
73  */
74 uint av_timecode_get_smpte_from_framenum (const(AVTimecode)* tc, int framenum);
75 
76 /**
77  * Load timecode string in buf.
78  *
79  * @param buf      destination buffer, must be at least AV_TIMECODE_STR_SIZE long
80  * @param tc       timecode data correctly initialized
81  * @param framenum frame number
82  * @return         the buf parameter
83  *
84  * @note Timecode representation can be a negative timecode and have more than
85  *       24 hours, but will only be honored if the flags are correctly set.
86  * @note The frame number is relative to tc->start.
87  */
88 char* av_timecode_make_string (const(AVTimecode)* tc, char* buf, int framenum);
89 
90 /**
91  * Get the timecode string from the SMPTE timecode format.
92  *
93  * @param buf        destination buffer, must be at least AV_TIMECODE_STR_SIZE long
94  * @param tcsmpte    the 32-bit SMPTE timecode
95  * @param prevent_df prevent the use of a drop flag when it is known the DF bit
96  *                   is arbitrary
97  * @return           the buf parameter
98  */
99 char* av_timecode_make_smpte_tc_string (char* buf, uint tcsmpte, int prevent_df);
100 
101 /**
102  * Get the timecode string from the 25-bit timecode format (MPEG GOP format).
103  *
104  * @param buf     destination buffer, must be at least AV_TIMECODE_STR_SIZE long
105  * @param tc25bit the 25-bits timecode
106  * @return        the buf parameter
107  */
108 char* av_timecode_make_mpeg_tc_string (char* buf, uint tc25bit);
109 
110 /**
111  * Init a timecode struct with the passed parameters.
112  *
113  * @param log_ctx     a pointer to an arbitrary struct of which the first field
114  *                    is a pointer to an AVClass struct (used for av_log)
115  * @param tc          pointer to an allocated AVTimecode
116  * @param rate        frame rate in rational form
117  * @param flags       miscellaneous flags such as drop frame, +24 hours, ...
118  *                    (see AVTimecodeFlag)
119  * @param frame_start the first frame number
120  * @return            0 on success, AVERROR otherwise
121  */
122 int av_timecode_init (AVTimecode* tc, AVRational rate, int flags, int frame_start, void* log_ctx);
123 
124 /**
125  * Parse timecode representation (hh:mm:ss[:;.]ff).
126  *
127  * @param log_ctx a pointer to an arbitrary struct of which the first field is a
128  *                pointer to an AVClass struct (used for av_log).
129  * @param tc      pointer to an allocated AVTimecode
130  * @param rate    frame rate in rational form
131  * @param str     timecode string which will determine the frame start
132  * @return        0 on success, AVERROR otherwise
133  */
134 int av_timecode_init_from_string (AVTimecode* tc, AVRational rate, const(char)* str, void* log_ctx);
135 
136 /**
137  * Check if the timecode feature is available for the given frame rate
138  *
139  * @return 0 if supported, <0 otherwise
140  */
141 int av_timecode_check_frame_rate (AVRational rate);
142 
143 /* AVUTIL_TIMECODE_H */