FFmpeg
timecode.h
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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 23
34 
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  * See SMPTE ST 314M-2005 Sec 4.4.2.2.1 "Time code pack (TC)"
66  * the format description as follows:
67  * bits 0-5: hours, in BCD(6bits)
68  * bits 6: BGF1
69  * bits 7: BGF2 (NTSC) or FIELD (PAL)
70  * bits 8-14: minutes, in BCD(7bits)
71  * bits 15: BGF0 (NTSC) or BGF2 (PAL)
72  * bits 16-22: seconds, in BCD(7bits)
73  * bits 23: FIELD (NTSC) or BGF0 (PAL)
74  * bits 24-29: frames, in BCD(6bits)
75  * bits 30: drop frame flag (0: non drop, 1: drop)
76  * bits 31: color frame flag (0: unsync mode, 1: sync mode)
77  * @note BCD numbers (6 or 7 bits): 4 or 5 lower bits for units, 2 higher bits for tens.
78  * @note Frame number adjustment is automatically done in case of drop timecode,
79  * you do NOT have to call av_timecode_adjust_ntsc_framenum2().
80  * @note The frame number is relative to tc->start.
81  * @note Color frame (CF) and binary group flags (BGF) bits are set to zero.
82  */
83 uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum);
84 
85 /**
86  * Convert sei info to SMPTE 12M binary representation.
87  *
88  * @param rate frame rate in rational form
89  * @param drop drop flag
90  * @param hh hour
91  * @param mm minute
92  * @param ss second
93  * @param ff frame number
94  * @return the SMPTE binary representation
95  */
96 uint32_t av_timecode_get_smpte(AVRational rate, int drop, int hh, int mm, int ss, int ff);
97 
98 /**
99  * Load timecode string in buf.
100  *
101  * @param buf destination buffer, must be at least AV_TIMECODE_STR_SIZE long
102  * @param tc timecode data correctly initialized
103  * @param framenum frame number
104  * @return the buf parameter
105  *
106  * @note Timecode representation can be a negative timecode and have more than
107  * 24 hours, but will only be honored if the flags are correctly set.
108  * @note The frame number is relative to tc->start.
109  */
110 char *av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum);
111 
112 /**
113  * Get the timecode string from the SMPTE timecode format.
114  *
115  * In contrast to av_timecode_make_smpte_tc_string this function supports 50/60
116  * fps timecodes by using the field bit.
117  *
118  * @param buf destination buffer, must be at least AV_TIMECODE_STR_SIZE long
119  * @param rate frame rate of the timecode
120  * @param tcsmpte the 32-bit SMPTE timecode
121  * @param prevent_df prevent the use of a drop flag when it is known the DF bit
122  * is arbitrary
123  * @param skip_field prevent the use of a field flag when it is known the field
124  * bit is arbitrary (e.g. because it is used as PC flag)
125  * @return the buf parameter
126  */
127 char *av_timecode_make_smpte_tc_string2(char *buf, AVRational rate, uint32_t tcsmpte, int prevent_df, int skip_field);
128 
129 /**
130  * Get the timecode string from the SMPTE timecode format.
131  *
132  * @param buf destination buffer, must be at least AV_TIMECODE_STR_SIZE long
133  * @param tcsmpte the 32-bit SMPTE timecode
134  * @param prevent_df prevent the use of a drop flag when it is known the DF bit
135  * is arbitrary
136  * @return the buf parameter
137  */
138 char *av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df);
139 
140 /**
141  * Get the timecode string from the 25-bit timecode format (MPEG GOP format).
142  *
143  * @param buf destination buffer, must be at least AV_TIMECODE_STR_SIZE long
144  * @param tc25bit the 25-bits timecode
145  * @return the buf parameter
146  */
147 char *av_timecode_make_mpeg_tc_string(char *buf, uint32_t tc25bit);
148 
149 /**
150  * Init a timecode struct with the passed parameters.
151  *
152  * @param log_ctx a pointer to an arbitrary struct of which the first field
153  * is a pointer to an AVClass struct (used for av_log)
154  * @param tc pointer to an allocated AVTimecode
155  * @param rate frame rate in rational form
156  * @param flags miscellaneous flags such as drop frame, +24 hours, ...
157  * (see AVTimecodeFlag)
158  * @param frame_start the first frame number
159  * @return 0 on success, AVERROR otherwise
160  */
161 int av_timecode_init(AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx);
162 
163 /**
164  * Parse timecode representation (hh:mm:ss[:;.]ff).
165  *
166  * @param log_ctx a pointer to an arbitrary struct of which the first field is a
167  * pointer to an AVClass struct (used for av_log).
168  * @param tc pointer to an allocated AVTimecode
169  * @param rate frame rate in rational form
170  * @param str timecode string which will determine the frame start
171  * @return 0 on success, AVERROR otherwise
172  */
173 int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx);
174 
175 /**
176  * Check if the timecode feature is available for the given frame rate
177  *
178  * @return 0 if supported, <0 otherwise
179  */
181 
182 #endif /* AVUTIL_TIMECODE_H */
#define tc
Definition: regdef.h:69
uint32_t av_timecode_get_smpte(AVRational rate, int drop, int hh, int mm, int ss, int ff)
Convert sei info to SMPTE 12M binary representation.
Definition: timecode.c:71
timecode is drop frame
Definition: timecode.h:36
char * av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum)
Load timecode string in buf.
Definition: timecode.c:105
int start
timecode frame start (first base frame number)
Definition: timecode.h:42
int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx)
Parse timecode representation (hh:mm:ss[:;.
Definition: timecode.c:232
AVTimecodeFlag
Definition: timecode.h:35
char * av_timecode_make_smpte_tc_string2(char *buf, AVRational rate, uint32_t tcsmpte, int prevent_df, int skip_field)
Get the timecode string from the SMPTE timecode format.
Definition: timecode.c:139
unsigned fps
frame per second; must be consistent with the rate field
Definition: timecode.h:45
#define ss(width, name, subs,...)
Definition: cbs_vp9.c:261
timecode wraps after 24 hours
Definition: timecode.h:37
int av_timecode_adjust_ntsc_framenum2(int framenum, int fps)
Adjust frame number for NTSC drop frame time code.
Definition: timecode.c:34
AVRational rate
frame rate in rational form
Definition: timecode.h:44
int av_timecode_init(AVTimecode *tc, AVRational rate, int flags, int frame_start, void *log_ctx)
Init a timecode struct with the passed parameters.
Definition: timecode.c:222
static int frame_start(MpegEncContext *s)
Rational number (pair of numerator and denominator).
Definition: rational.h:58
int av_timecode_check_frame_rate(AVRational rate)
Check if the timecode feature is available for the given frame rate.
Definition: timecode.c:217
#define flags(name, subs,...)
Definition: cbs_av1.c:560
negative time values are allowed
Definition: timecode.h:38
char * av_timecode_make_smpte_tc_string(char *buf, uint32_t tcsmpte, int prevent_df)
Get the timecode string from the SMPTE timecode format.
Definition: timecode.c:163
char * av_timecode_make_mpeg_tc_string(char *buf, uint32_t tc25bit)
Get the timecode string from the 25-bit timecode format (MPEG GOP format).
Definition: timecode.c:168
Utilties for rational number calculation.
uint32_t av_timecode_get_smpte_from_framenum(const AVTimecode *tc, int framenum)
Convert frame number to SMPTE 12M binary representation.
Definition: timecode.c:55
uint32_t flags
flags such as drop frame, +24 hours support, ...
Definition: timecode.h:43