FFmpeg
options_table.h
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1 /*
2  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVFORMAT_OPTIONS_TABLE_H
22 #define AVFORMAT_OPTIONS_TABLE_H
23 
24 #include <limits.h>
25 
26 #include "libavutil/opt.h"
27 #include "avformat.h"
28 #include "internal.h"
29 
30 #define OFFSET(x) offsetof(AVFormatContext,x)
31 #define DEFAULT 0 //should be NAN but it does not work as it is not a constant in glibc as required by ANSI/ISO C
32 //these names are too long to be readable
33 #define E AV_OPT_FLAG_ENCODING_PARAM
34 #define D AV_OPT_FLAG_DECODING_PARAM
35 
36 static const AVOption avformat_options[] = {
37 {"avioflags", NULL, OFFSET(avio_flags), AV_OPT_TYPE_FLAGS, {.i64 = DEFAULT }, INT_MIN, INT_MAX, D|E, .unit = "avioflags"},
38 {"direct", "reduce buffering", 0, AV_OPT_TYPE_CONST, {.i64 = AVIO_FLAG_DIRECT }, INT_MIN, INT_MAX, D|E, .unit = "avioflags"},
39 {"probesize", "set probing size", OFFSET(probesize), AV_OPT_TYPE_INT64, {.i64 = 5000000 }, 32, INT64_MAX, D},
40 {"formatprobesize", "number of bytes to probe file format", OFFSET(format_probesize), AV_OPT_TYPE_INT, {.i64 = PROBE_BUF_MAX}, 0, INT_MAX-1, D},
41 {"packetsize", "set packet size", OFFSET(packet_size), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, 0, INT_MAX, E},
42 {"fflags", NULL, OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = AVFMT_FLAG_AUTO_BSF }, INT_MIN, INT_MAX, D|E, .unit = "fflags"},
43 {"flush_packets", "reduce the latency by flushing out packets immediately", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_FLUSH_PACKETS }, INT_MIN, INT_MAX, E, .unit = "fflags"},
44 {"ignidx", "ignore index", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_IGNIDX }, INT_MIN, INT_MAX, D, .unit = "fflags"},
45 {"genpts", "generate pts", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_GENPTS }, INT_MIN, INT_MAX, D, .unit = "fflags"},
46 {"nofillin", "do not fill in missing values that can be exactly calculated", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_NOFILLIN }, INT_MIN, INT_MAX, D, .unit = "fflags"},
47 {"noparse", "disable AVParsers, this needs nofillin too", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_NOPARSE }, INT_MIN, INT_MAX, D, .unit = "fflags"},
48 {"igndts", "ignore dts", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_IGNDTS }, INT_MIN, INT_MAX, D, .unit = "fflags"},
49 {"discardcorrupt", "discard corrupted frames", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_DISCARD_CORRUPT }, INT_MIN, INT_MAX, D, .unit = "fflags"},
50 {"sortdts", "try to interleave outputted packets by dts", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_SORT_DTS }, INT_MIN, INT_MAX, D, .unit = "fflags"},
51 {"fastseek", "fast but inaccurate seeks", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_FAST_SEEK }, INT_MIN, INT_MAX, D, .unit = "fflags"},
52 {"nobuffer", "reduce the latency introduced by optional buffering", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_FLAG_NOBUFFER }, 0, INT_MAX, D, .unit = "fflags"},
53 {"bitexact", "do not write random/volatile data", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_BITEXACT }, 0, 0, E, .unit = "fflags" },
54 #if FF_API_LAVF_SHORTEST
55 {"shortest", "stop muxing with the shortest stream", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_SHORTEST }, 0, 0, E | AV_OPT_FLAG_DEPRECATED, .unit = "fflags" },
56 #endif
57 {"autobsf", "add needed bsfs automatically", 0, AV_OPT_TYPE_CONST, { .i64 = AVFMT_FLAG_AUTO_BSF }, 0, 0, E, .unit = "fflags" },
58 {"seek2any", "allow seeking to non-keyframes on demuxer level when supported", OFFSET(seek2any), AV_OPT_TYPE_BOOL, {.i64 = 0 }, 0, 1, D},
59 {"analyzeduration", "specify how many microseconds are analyzed to probe the input", OFFSET(max_analyze_duration), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, D},
60 {"cryptokey", "decryption key", OFFSET(key), AV_OPT_TYPE_BINARY, {.dbl = 0}, 0, 0, D},
61 {"indexmem", "max memory used for timestamp index (per stream)", OFFSET(max_index_size), AV_OPT_TYPE_INT, {.i64 = 1<<20 }, 0, INT_MAX, D},
62 {"rtbufsize", "max memory used for buffering real-time frames", OFFSET(max_picture_buffer), AV_OPT_TYPE_INT, {.i64 = 3041280 }, 0, INT_MAX, D}, /* defaults to 1s of 15fps 352x288 YUYV422 video */
63 {"fdebug", "print specific debug info", OFFSET(debug), AV_OPT_TYPE_FLAGS, {.i64 = DEFAULT }, 0, INT_MAX, E|D, .unit = "fdebug"},
64 {"ts", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_FDEBUG_TS }, INT_MIN, INT_MAX, E|D, .unit = "fdebug"},
65 {"max_delay", "maximum muxing or demuxing delay in microseconds", OFFSET(max_delay), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, INT_MAX, E|D},
66 {"start_time_realtime", "wall-clock time when stream begins (PTS==0)", OFFSET(start_time_realtime), AV_OPT_TYPE_INT64, {.i64 = AV_NOPTS_VALUE}, INT64_MIN, INT64_MAX, E},
67 {"fpsprobesize", "number of frames used to probe fps", OFFSET(fps_probe_size), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX-1, D},
68 {"audio_preload", "microseconds by which audio packets should be interleaved earlier", OFFSET(audio_preload), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX-1, E},
69 {"chunk_duration", "microseconds for each chunk", OFFSET(max_chunk_duration), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX-1, E},
70 {"chunk_size", "size in bytes for each chunk", OFFSET(max_chunk_size), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX-1, E},
71 /* this is a crutch for avconv, since it cannot deal with identically named options in different contexts.
72  * to be removed when avconv is fixed */
73 {"f_err_detect", "set error detection flags (deprecated; use err_detect, save via avconv)", OFFSET(error_recognition), AV_OPT_TYPE_FLAGS, {.i64 = AV_EF_CRCCHECK }, INT_MIN, INT_MAX, D, .unit = "err_detect"},
74 {"err_detect", "set error detection flags", OFFSET(error_recognition), AV_OPT_TYPE_FLAGS, {.i64 = AV_EF_CRCCHECK }, INT_MIN, INT_MAX, D, .unit = "err_detect"},
75 {"crccheck", "verify embedded CRCs", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_CRCCHECK }, INT_MIN, INT_MAX, D, .unit = "err_detect"},
76 {"bitstream", "detect bitstream specification deviations", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_BITSTREAM }, INT_MIN, INT_MAX, D, .unit = "err_detect"},
77 {"buffer", "detect improper bitstream length", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_BUFFER }, INT_MIN, INT_MAX, D, .unit = "err_detect"},
78 {"explode", "abort decoding on minor error detection", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_EXPLODE }, INT_MIN, INT_MAX, D, .unit = "err_detect"},
79 {"ignore_err", "ignore errors", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_IGNORE_ERR }, INT_MIN, INT_MAX, D, .unit = "err_detect"},
80 {"careful", "consider things that violate the spec, are fast to check and have not been seen in the wild as errors", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_CAREFUL }, INT_MIN, INT_MAX, D, .unit = "err_detect"},
81 {"compliant", "consider all spec non compliancies as errors", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_COMPLIANT | AV_EF_CAREFUL }, INT_MIN, INT_MAX, D, .unit = "err_detect"},
82 {"aggressive", "consider things that a sane encoder shouldn't do as an error", 0, AV_OPT_TYPE_CONST, {.i64 = AV_EF_AGGRESSIVE | AV_EF_COMPLIANT | AV_EF_CAREFUL}, INT_MIN, INT_MAX, D, .unit = "err_detect"},
83 {"use_wallclock_as_timestamps", "use wallclock as timestamps", OFFSET(use_wallclock_as_timestamps), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, D},
84 {"skip_initial_bytes", "set number of bytes to skip before reading header and frames", OFFSET(skip_initial_bytes), AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX-1, D},
85 {"correct_ts_overflow", "correct single timestamp overflows", OFFSET(correct_ts_overflow), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, D},
86 {"flush_packets", "enable flushing of the I/O context after each packet", OFFSET(flush_packets), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, E},
87 {"metadata_header_padding", "set number of bytes to be written as padding in a metadata header", OFFSET(metadata_header_padding), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, E},
88 {"output_ts_offset", "set output timestamp offset", OFFSET(output_ts_offset), AV_OPT_TYPE_DURATION, {.i64 = 0}, -INT64_MAX, INT64_MAX, E},
89 {"max_interleave_delta", "maximum buffering duration for interleaving", OFFSET(max_interleave_delta), AV_OPT_TYPE_INT64, { .i64 = 10000000 }, 0, INT64_MAX, E },
90 {"f_strict", "how strictly to follow the standards (deprecated; use strict, save via avconv)", OFFSET(strict_std_compliance), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX, D|E, .unit = "strict"},
91 {"strict", "how strictly to follow the standards", OFFSET(strict_std_compliance), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX, D|E, .unit = "strict"},
92 {"very", "strictly conform to a older more strict version of the spec or reference software", 0, AV_OPT_TYPE_CONST, {.i64 = FF_COMPLIANCE_VERY_STRICT }, INT_MIN, INT_MAX, D|E, .unit = "strict"},
93 {"strict", "strictly conform to all the things in the spec no matter what the consequences", 0, AV_OPT_TYPE_CONST, {.i64 = FF_COMPLIANCE_STRICT }, INT_MIN, INT_MAX, D|E, .unit = "strict"},
94 {"normal", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_COMPLIANCE_NORMAL }, INT_MIN, INT_MAX, D|E, .unit = "strict"},
95 {"unofficial", "allow unofficial extensions", 0, AV_OPT_TYPE_CONST, {.i64 = FF_COMPLIANCE_UNOFFICIAL }, INT_MIN, INT_MAX, D|E, .unit = "strict"},
96 {"experimental", "allow non-standardized experimental variants", 0, AV_OPT_TYPE_CONST, {.i64 = FF_COMPLIANCE_EXPERIMENTAL }, INT_MIN, INT_MAX, D|E, .unit = "strict"},
97 {"max_ts_probe", "maximum number of packets to read while waiting for the first timestamp", OFFSET(max_ts_probe), AV_OPT_TYPE_INT, { .i64 = 50 }, 0, INT_MAX, D },
98 {"avoid_negative_ts", "shift timestamps so they start at 0", OFFSET(avoid_negative_ts), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 2, E, .unit = "avoid_negative_ts"},
99 {"auto", "enabled when required by target format", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_AVOID_NEG_TS_AUTO }, INT_MIN, INT_MAX, E, .unit = "avoid_negative_ts"},
100 {"disabled", "do not change timestamps", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_AVOID_NEG_TS_DISABLED }, INT_MIN, INT_MAX, E, .unit = "avoid_negative_ts"},
101 {"make_non_negative", "shift timestamps so they are non negative", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE }, INT_MIN, INT_MAX, E, .unit = "avoid_negative_ts"},
102 {"make_zero", "shift timestamps so they start at 0", 0, AV_OPT_TYPE_CONST, {.i64 = AVFMT_AVOID_NEG_TS_MAKE_ZERO }, INT_MIN, INT_MAX, E, .unit = "avoid_negative_ts"},
103 {"dump_separator", "set information dump field separator", OFFSET(dump_separator), AV_OPT_TYPE_STRING, {.str = ", "}, 0, 0, D|E},
104 {"codec_whitelist", "List of decoders that are allowed to be used", OFFSET(codec_whitelist), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D },
105 {"format_whitelist", "List of demuxers that are allowed to be used", OFFSET(format_whitelist), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D },
106 {"protocol_whitelist", "List of protocols that are allowed to be used", OFFSET(protocol_whitelist), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D },
107 {"protocol_blacklist", "List of protocols that are not allowed to be used", OFFSET(protocol_blacklist), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, D },
108 {"max_streams", "maximum number of streams", OFFSET(max_streams), AV_OPT_TYPE_INT, { .i64 = 1000 }, 0, INT_MAX, D },
109 {"skip_estimate_duration_from_pts", "skip duration calculation in estimate_timings_from_pts", OFFSET(skip_estimate_duration_from_pts), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, D},
110 {"max_probe_packets", "Maximum number of packets to probe a codec", OFFSET(max_probe_packets), AV_OPT_TYPE_INT, { .i64 = 2500 }, 0, INT_MAX, D },
111 {"duration_probesize", "Maximum number of bytes to probe the durations of the streams in estimate_timings_from_pts", OFFSET(duration_probesize), AV_OPT_TYPE_INT64, {.i64 = 0 }, 0, INT64_MAX, D},
112 {NULL},
113 };
114 
115 #undef E
116 #undef D
117 #undef DEFAULT
118 #undef OFFSET
119 
120 #endif /* AVFORMAT_OPTIONS_TABLE_H */
AVFMT_FLAG_DISCARD_CORRUPT
#define AVFMT_FLAG_DISCARD_CORRUPT
Discard frames marked corrupted.
Definition: avformat.h:1460
AV_EF_EXPLODE
#define AV_EF_EXPLODE
abort decoding on minor error detection
Definition: defs.h:51
AV_EF_CAREFUL
#define AV_EF_CAREFUL
consider things that violate the spec, are fast to calculate and have not been seen in the wild as er...
Definition: defs.h:54
opt.h
OFFSET
#define OFFSET(x)
Definition: options_table.h:30
FF_FDEBUG_TS
#define FF_FDEBUG_TS
Definition: avformat.h:1579
AV_EF_COMPLIANT
#define AV_EF_COMPLIANT
consider all spec non compliances as errors
Definition: defs.h:55
AVFMT_FLAG_IGNIDX
#define AVFMT_FLAG_IGNIDX
Ignore index.
Definition: avformat.h:1453
AVOption
AVOption.
Definition: opt.h:429
AV_OPT_TYPE_DURATION
@ AV_OPT_TYPE_DURATION
Underlying C type is int64_t.
Definition: opt.h:319
FF_COMPLIANCE_STRICT
#define FF_COMPLIANCE_STRICT
Strictly conform to all the things in the spec no matter what consequences.
Definition: defs.h:59
FF_COMPLIANCE_EXPERIMENTAL
#define FF_COMPLIANCE_EXPERIMENTAL
Allow nonstandardized experimental things.
Definition: defs.h:62
E
#define E
Definition: options_table.h:33
AV_OPT_TYPE_BINARY
@ AV_OPT_TYPE_BINARY
Underlying C type is a uint8_t* that is either NULL or points to an array allocated with the av_mallo...
Definition: opt.h:286
AVFMT_FLAG_AUTO_BSF
#define AVFMT_FLAG_AUTO_BSF
Add bitstream filters as requested by the muxer.
Definition: avformat.h:1474
AV_EF_BITSTREAM
#define AV_EF_BITSTREAM
detect bitstream specification deviations
Definition: defs.h:49
AVFMT_AVOID_NEG_TS_MAKE_ZERO
#define AVFMT_AVOID_NEG_TS_MAKE_ZERO
Shift timestamps so that they start at 0.
Definition: avformat.h:1691
D
#define D
Definition: options_table.h:34
AV_EF_IGNORE_ERR
#define AV_EF_IGNORE_ERR
ignore errors and continue
Definition: defs.h:53
AV_OPT_TYPE_INT64
@ AV_OPT_TYPE_INT64
Underlying C type is int64_t.
Definition: opt.h:263
limits.h
key
const char * key
Definition: hwcontext_opencl.c:189
AVFMT_FLAG_NOPARSE
#define AVFMT_FLAG_NOPARSE
Do not use AVParsers, you also must set AVFMT_FLAG_NOFILLIN as the fillin code works on frames and no...
Definition: avformat.h:1457
internal.h
AVFMT_AVOID_NEG_TS_DISABLED
#define AVFMT_AVOID_NEG_TS_DISABLED
Do not shift timestamps even when they are negative.
Definition: avformat.h:1689
NULL
#define NULL
Definition: coverity.c:32
FF_COMPLIANCE_VERY_STRICT
#define FF_COMPLIANCE_VERY_STRICT
Strictly conform to an older more strict version of the spec or reference software.
Definition: defs.h:58
avformat_options
static const AVOption avformat_options[]
Definition: options_table.h:36
AV_EF_CRCCHECK
#define AV_EF_CRCCHECK
Verify checksums embedded in the bitstream (could be of either encoded or decoded data,...
Definition: defs.h:48
AVFMT_FLAG_NOFILLIN
#define AVFMT_FLAG_NOFILLIN
Do not infer any values from other values, just return what is stored in the container.
Definition: avformat.h:1456
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
AVFMT_FLAG_IGNDTS
#define AVFMT_FLAG_IGNDTS
Ignore DTS on frames that contain both DTS & PTS.
Definition: avformat.h:1455
FF_COMPLIANCE_NORMAL
#define FF_COMPLIANCE_NORMAL
Definition: defs.h:60
FF_COMPLIANCE_UNOFFICIAL
#define FF_COMPLIANCE_UNOFFICIAL
Allow unofficial extensions.
Definition: defs.h:61
PROBE_BUF_MAX
#define PROBE_BUF_MAX
Definition: internal.h:34
AV_OPT_FLAG_DEPRECATED
#define AV_OPT_FLAG_DEPRECATED
Set if option is deprecated, users should refer to AVOption.help text for more information.
Definition: opt.h:386
AVFMT_FLAG_FAST_SEEK
#define AVFMT_FLAG_FAST_SEEK
Enable fast, but inaccurate seeks for some formats.
Definition: avformat.h:1470
AVFMT_FLAG_NOBUFFER
#define AVFMT_FLAG_NOBUFFER
Do not buffer frames when possible.
Definition: avformat.h:1458
AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE
#define AVFMT_AVOID_NEG_TS_MAKE_NON_NEGATIVE
Shift timestamps so they are non negative.
Definition: avformat.h:1690
AVFMT_FLAG_GENPTS
#define AVFMT_FLAG_GENPTS
Generate missing pts even if it requires parsing future frames.
Definition: avformat.h:1452
AVFMT_FLAG_BITEXACT
#define AVFMT_FLAG_BITEXACT
When muxing, try to avoid writing any random/volatile data to the output.
Definition: avformat.h:1468
AV_EF_AGGRESSIVE
#define AV_EF_AGGRESSIVE
consider things that a sane encoder/muxer should not do as an error
Definition: defs.h:56
AVFMT_FLAG_SORT_DTS
#define AVFMT_FLAG_SORT_DTS
try to interleave outputted packets by dts (using this flag can slow demuxing down)
Definition: avformat.h:1469
avformat.h
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Underlying C type is int.
Definition: opt.h:259
AVIO_FLAG_DIRECT
#define AVIO_FLAG_DIRECT
Use direct mode.
Definition: avio.h:644
AV_EF_BUFFER
#define AV_EF_BUFFER
detect improper bitstream length
Definition: defs.h:50
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Underlying C type is int.
Definition: opt.h:327
DEFAULT
#define DEFAULT
Definition: options_table.h:31
AV_OPT_TYPE_FLAGS
@ AV_OPT_TYPE_FLAGS
Underlying C type is unsigned int.
Definition: opt.h:255
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:482
AVFMT_FLAG_FLUSH_PACKETS
#define AVFMT_FLAG_FLUSH_PACKETS
Flush the AVIOContext every packet.
Definition: avformat.h:1461
AVFMT_AVOID_NEG_TS_AUTO
#define AVFMT_AVOID_NEG_TS_AUTO
Enabled when required by target format.
Definition: avformat.h:1688
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Underlying C type is a uint8_t* that is either NULL or points to a C string allocated with the av_mal...
Definition: opt.h:276
AV_OPT_TYPE_CONST
@ AV_OPT_TYPE_CONST
Special option type for declaring named constants.
Definition: opt.h:299