编译FFmpeg时踩的那些坑
作者：互联网
编译FFmpeg过程中遇到如下报错：
1号坑：error: 'ERROR_NOT_ENOUGH_MEMORY' undeclared
libavformat/options.c:77:5: warning: 'av_oformat_next' is deprecated [-Wdeprecated-declarations]
while (ofmt = av_oformat_next(ofmt))
^~~~~
In file included from libavformat/options.c:20:0:
libavformat/avformat.h:2095:17: note: declared here
AVOutputFormat *av_oformat_next(const AVOutputFormat *f);
^~~~~~~~~~~~~~~
CC libavformat/os_support.o
In file included from libavformat/os_support.h:115:0,
from libavformat/os_support.c:29:
libavformat/os_support.c: In function 'ff_gai_strerror':
libavformat/os_support.c:194:10: error: 'ERROR_NOT_ENOUGH_MEMORY' undeclared (first use in this function)
case EAI_MEMORY:
^
libavformat/os_support.c:194:10: note: each undeclared identifier is reported only once for each function it appears in
make: *** [libavformat/os_support.o] Error 1
or
make: [ffbuild/.config] Error 127 (ignored)
WARNING: libavdevice/alldevices.c libavfilter/allfilters.c libavformat/allformats.c libavcodec/allcodecs.c libavcodec/bitstream_filters.c libavcodec/parsers.c libavformat/protocols.c newer than config.h, rerun configure
make: [ffbuild/.config] Error 127 (ignored)
CC libavformat/os_support.o
In file included from libavformat/os_support.h:115:0,
from libavformat/os_support.c:29:
libavformat/os_support.c: In function 'ff_gai_strerror':
libavformat/os_support.c:194:10: error: 'ERROR_NOT_ENOUGH_MEMORY' undeclared (first use in this function)
case EAI_MEMORY:
^
libavformat/os_support.c:194:10: note: each undeclared identifier is reported only once for each function it appears in
make: *** [libavformat/os_support.o] Error 1
解决：
在os_support.h中增加winerror.h头文件的引用：
2号坑：error: 'ENOTCONN' undeclared
make: [ffbuild/.config] Error 127 (ignored)
WARNING: libavdevice/alldevices.c libavfilter/allfilters.c libavformat/allformats.c libavcodec/allcodecs.c libavcodec/bitstream_filters.c libavcodec/parsers.c libavformat/protocols.c newer than config.h, rerun configure
make: [ffbuild/.config] Error 127 (ignored)
CC libavformat/rtsp.o
libavformat/rtsp.c: In function 'rtsp_send_cmd_with_content_async':
libavformat/rtsp.c:1322:16: error: 'ENOTCONN' undeclared (first use in this function)
return ENOTCONN;
^~~~~~~~
libavformat/rtsp.c:1322:16: note: each undeclared identifier is reported only once for each function it appears in
解决：
可以配置引用宏 ENOTCONN 的头文件，因为 ENOTCONN 其实对应着126这个值，最简单的做法就是直接修改为126。
3号坑：ffmpeg 由于找不到libiconv-2.dll 无法继续执行代码。重新安装程序可能会解决此问题。
运行编译出来的ffmpeg.exe文件，报错：
原本以为自己编译的ffmpeg.exe必须依赖libiconv-2.dll库，就把libiconv-2.dll拷贝到同级目录，再运行依然报错：
看来是自己想简单了！
搜遍了网络资源也没有找到解决办法，自己就经过两个小时的尝试，终于找到了解决方法。
一、 拷贝libiconv-2.dll库到msys.bat脚本依赖的bin目录下，如图：
二、运行如下命令注册libiconv-2.dll库到系统中。
regsvr32 libiconv-2.dll /s
如果没有报错，表示注册成功。
三、configure配置项增加“--disable-iconv”。
完成上述三步，再运行./configure && make 进行编译。
终于，这次编译出来的ffmpeg.exe可以正常使用了。
赶紧使用如下命令测试一下：
./ffmpeg.exe -h
如果ffmpeg.exe正常可用，会得到如下结果：
$ ./ffmpeg.exe -h
ffmpeg version n4.2.2-9-g393eff8 Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 6.3.0 (MinGW.org GCC-6.3.0-1)
configuration: --disable-everything --disable-x86asm --enable-encoder=aac --disable-iconv
libavutil 56. 31.100 / 56. 31.100
libavcodec 58. 54.100 / 58. 54.100
libavformat 58. 29.100 / 58. 29.100
libavdevice 58. 8.100 / 58. 8.100
libavfilter 7. 57.100 / 7. 57.100
libswscale 5. 5.100 / 5. 5.100
libswresample 3. 5.100 / 3. 5.100
Hyper fast Audio and Video encoder
usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...
Getting help:
-h -- print basic options
-h long -- print more options
-h full -- print all options (including all format and codec specific options, very long)
-h type=name -- print all options for the named decoder/encoder/demuxer/muxer/filter/bsf
See man ffmpeg for detailed description of the options.
Print help / information / capabilities:
-L show license
-h topic show help
-? topic show help
-help topic show help
--help topic show help
-version show version
-buildconf show build configuration
-formats show available formats
-muxers show available muxers
-demuxers show available demuxers
-devices show available devices
-codecs show available codecs
-decoders show available decoders
-encoders show available encoders
-bsfs show available bit stream filters
-protocols show available protocols
-filters show available filters
-pix_fmts show available pixel formats
-layouts show standard channel layouts
-sample_fmts show available audio sample formats
-colors show available color names
-sources device list sources of the input device
-sinks device list sinks of the output device
-hwaccels show available HW acceleration methods
Global options (affect whole program instead of just one file:
-loglevel loglevel set logging level
-v loglevel set logging level
-report generate a report
-max_alloc bytes set maximum size of a single allocated block
-y overwrite output files
-n never overwrite output files
-ignore_unknown Ignore unknown stream types
-filter_threads number of non-complex filter threads
-filter_complex_threads number of threads for -filter_complex
-stats print progress report during encoding
-max_error_rate maximum error rate ratio of errors (0.0: no errors, 1.0: 100% errors) above which ffmpeg returns an error instead of success.
-bits_per_raw_sample number set the number of bits per raw sample
-vol volume change audio volume (256=normal)
Per-file main options:
-f fmt force format
-c codec codec name
-codec codec codec name
-pre preset preset name
-map_metadata outfile[,metadata]:infile[,metadata] set metadata information of outfile from infile
-t duration record or transcode "duration" seconds of audio/video
-to time_stop record or transcode stop time
-fs limit_size set the limit file size in bytes
-ss time_off set the start time offset
-sseof time_off set the start time offset relative to EOF
-seek_timestamp enable/disable seeking by timestamp with -ss
-timestamp time set the recording timestamp ('now' to set the current time)
-metadata string=string add metadata
-program title=string:st=number... add program with specified streams
-target type specify target file type ("vcd", "svcd", "dvd", "dv" or "dv50" with optional prefixes "pal-", "ntsc-" or "film-")
-apad audio pad
-frames number set the number of frames to output
-filter filter_graph set stream filtergraph
-filter_script filename read stream filtergraph description from a file
-reinit_filter reinit filtergraph on input parameter changes
-discard discard
-disposition disposition
Video options:
-vframes number set the number of video frames to output
-r rate set frame rate (Hz value, fraction or abbreviation)
-s size set frame size (WxH or abbreviation)
-aspect aspect set aspect ratio (4:3, 16:9 or 1.3333, 1.7777)
-bits_per_raw_sample number set the number of bits per raw sample
-vn disable video
-vcodec codec force video codec ('copy' to copy stream)
-timecode hh:mm:ss[:;.]ff set initial TimeCode value.
-pass n select the pass number (1 to 3)
-vf filter_graph set video filters
-ab bitrate audio bitrate (please use -b:a)
-b bitrate video bitrate (please use -b:v)
-dn disable data
Audio options:
-aframes number set the number of audio frames to output
-aq quality set audio quality (codec-specific)
-ar rate set audio sampling rate (in Hz)
-ac channels set number of audio channels
-an disable audio
-acodec codec force audio codec ('copy' to copy stream)
-vol volume change audio volume (256=normal)
-af filter_graph set audio filters
Subtitle options:
-s size set frame size (WxH or abbreviation)
-sn disable subtitle
-scodec codec force subtitle codec ('copy' to copy stream)
-stag fourcc/tag force subtitle tag/fourcc
-fix_sub_duration fix subtitles duration
-canvas_size size set canvas size (WxH or abbreviation)
-spre preset set the subtitle options to the indicated preset
至此，终于把FFmpeg最新的4.2.2版本在windows上编译过了。不容易，windows系统坑太多。相比较macOS，复杂繁琐了不少。
上边的几个问题，是编译过程中比较容易遇到的，希望对你有所帮助！
了解本专栏 订阅专栏 解锁全文标签：set,FFmpeg,libavformat,show,number,那些,编译,os,options 来源： https://blog.csdn.net/liuzehn/article/details/106520787