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error.h
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 /**
20  * @file
21  * error code definitions
22  */
23 
24 #ifndef AVUTIL_ERROR_H
25 #define AVUTIL_ERROR_H
26 
27 #include <errno.h>
28 #include <stddef.h>
29 
30 /**
31  * @addtogroup lavu_error
32  *
33  * @{
34  */
35 
36 
37 /* error handling */
38 #if EDOM > 0
39 #define AVERROR(e) (-(e)) ///< Returns a negative error code from a POSIX error code, to return from library functions.
40 #define AVUNERROR(e) (-(e)) ///< Returns a POSIX error code from a library function error return value.
41 #else
42 /* Some platforms have E* and errno already negated. */
43 #define AVERROR(e) (e)
44 #define AVUNERROR(e) (e)
45 #endif
46 
47 #define FFERRTAG(a, b, c, d) (-(int)MKTAG(a, b, c, d))
48 
49 #define AVERROR_BSF_NOT_FOUND FFERRTAG(0xF8,'B','S','F') ///< Bitstream filter not found
50 #define AVERROR_BUG FFERRTAG( 'B','U','G','!') ///< Internal bug, also see AVERROR_BUG2
51 #define AVERROR_BUFFER_TOO_SMALL FFERRTAG( 'B','U','F','S') ///< Buffer too small
52 #define AVERROR_DECODER_NOT_FOUND FFERRTAG(0xF8,'D','E','C') ///< Decoder not found
53 #define AVERROR_DEMUXER_NOT_FOUND FFERRTAG(0xF8,'D','E','M') ///< Demuxer not found
54 #define AVERROR_ENCODER_NOT_FOUND FFERRTAG(0xF8,'E','N','C') ///< Encoder not found
55 #define AVERROR_EOF FFERRTAG( 'E','O','F',' ') ///< End of file
56 #define AVERROR_EXIT FFERRTAG( 'E','X','I','T') ///< Immediate exit was requested; the called function should not be restarted
57 #define AVERROR_EXTERNAL FFERRTAG( 'E','X','T',' ') ///< Generic error in an external library
58 #define AVERROR_FILTER_NOT_FOUND FFERRTAG(0xF8,'F','I','L') ///< Filter not found
59 #define AVERROR_INVALIDDATA FFERRTAG( 'I','N','D','A') ///< Invalid data found when processing input
60 #define AVERROR_MUXER_NOT_FOUND FFERRTAG(0xF8,'M','U','X') ///< Muxer not found
61 #define AVERROR_OPTION_NOT_FOUND FFERRTAG(0xF8,'O','P','T') ///< Option not found
62 #define AVERROR_PATCHWELCOME FFERRTAG( 'P','A','W','E') ///< Not yet implemented in FFmpeg, patches welcome
63 #define AVERROR_PROTOCOL_NOT_FOUND FFERRTAG(0xF8,'P','R','O') ///< Protocol not found
64 
65 #define AVERROR_STREAM_NOT_FOUND FFERRTAG(0xF8,'S','T','R') ///< Stream not found
66 /**
67  * This is semantically identical to AVERROR_BUG
68  * it has been introduced in Libav after our AVERROR_BUG and with a modified value.
69  */
70 #define AVERROR_BUG2 FFERRTAG( 'B','U','G',' ')
71 #define AVERROR_UNKNOWN FFERRTAG( 'U','N','K','N') ///< Unknown error, typically from an external library
72 #define AVERROR_EXPERIMENTAL (-0x2bb2afa8) ///< Requested feature is flagged experimental. Set strict_std_compliance if you really want to use it.
73 
74 #define AV_ERROR_MAX_STRING_SIZE 64
75 
76 /**
77  * Put a description of the AVERROR code errnum in errbuf.
78  * In case of failure the global variable errno is set to indicate the
79  * error. Even in case of failure av_strerror() will print a generic
80  * error message indicating the errnum provided to errbuf.
81  *
82  * @param errnum error code to describe
83  * @param errbuf buffer to which description is written
84  * @param errbuf_size the size in bytes of errbuf
85  * @return 0 on success, a negative value if a description for errnum
86  * cannot be found
87  */
88 int av_strerror(int errnum, char *errbuf, size_t errbuf_size);
89 
90 /**
91  * Fill the provided buffer with a string containing an error string
92  * corresponding to the AVERROR code errnum.
93  *
94  * @param errbuf a buffer
95  * @param errbuf_size size in bytes of errbuf
96  * @param errnum error code to describe
97  * @return the buffer in input, filled with the error description
98  * @see av_strerror()
99  */
100 static inline char *av_make_error_string(char *errbuf, size_t errbuf_size, int errnum)
101 {
102  av_strerror(errnum, errbuf, errbuf_size);
103  return errbuf;
104 }
105 
106 /**
107  * Convenience macro, the return value should be used only directly in
108  * function arguments but never stand-alone.
109  */
110 #define av_err2str(errnum) \
111  av_make_error_string((char[AV_ERROR_MAX_STRING_SIZE]){0}, AV_ERROR_MAX_STRING_SIZE, errnum)
112 
113 /**
114  * @}
115  */
116 
117 #endif /* AVUTIL_ERROR_H */