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comparison lib/libavutil/timecode.h @ 2134:992d2e6f907d

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preparation for libavcodec
author zipi
date Tue, 31 Dec 2013 14:52:14 +0000
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2133:e378232bfd36 2134:992d2e6f907d
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 */