概述
我正在尝试ffmpeg
使用 mingw 从 Windows 上的 src 目录构建一个示例文件,但是我得到了大量对一堆libav*
函数的未定义引用。
我已经看过这个问题和其他几个问题,但没有一个能解决我的问题。具体来说,我不是在构建 C++ 程序,也不是在使用g++
,所以整个extern "C"
事情都不适用(实际上我已经尝试过了,但它没有用)。
细节
我已经下载了 Zeranoe的64 位开发包,并将其解压缩为C:\apps\pf\ffmpeg
. 现在我只是想decoding_encoding.c
在doc/examples
. 我的 CWD 是C:\apps\pf\ffmpeg\doc\examples
,我的命令看起来像这样(续行和添加注释):
#Compile
gcc -o decoding_encoding.obj -c -IC:\apps\pf\ffmpeg\include decoding_encoding.c
#Link
gcc -o decoding_encoding.exe decoding_encoding.obj \
-LC:\apps\pf\ffmpeg\lib -lavformat -lavcodec -lavdevice \
-lavfilter -lavutil -lswscale -lm
编译工作正常,但链接吐出这些错误:
decoding_encoding.obj:decoding_encoding.c:(.text+0xca): undefined reference to `av_get_channel_layout_nb_channels'
decoding_encoding.obj:decoding_encoding.c:(.text+0x131): undefined reference to `avcodec_find_encoder'
decoding_encoding.obj:decoding_encoding.c:(.text+0x179): undefined reference to `avcodec_alloc_context3'
decoding_encoding.obj:decoding_encoding.c:(.text+0x1fa): undefined reference to `av_get_sample_fmt_name'
decoding_encoding.obj:decoding_encoding.c:(.text+0x26c): undefined reference to `av_get_channel_layout_nb_channels'
decoding_encoding.obj:decoding_encoding.c:(.text+0x28f): undefined reference to `avcodec_open2'
decoding_encoding.obj:decoding_encoding.c:(.text+0x313): undefined reference to `avcodec_alloc_frame'
decoding_encoding.obj:decoding_encoding.c:(.text+0x3c8): undefined reference to `av_samples_get_buffer_size'
decoding_encoding.obj:decoding_encoding.c:(.text+0x3d6): undefined reference to `av_malloc'
decoding_encoding.obj:decoding_encoding.c:(.text+0x44f): undefined reference to `avcodec_fill_audio_frame'
decoding_encoding.obj:decoding_encoding.c:(.text+0x4ce): undefined reference to `av_init_packet'
decoding_encoding.obj:decoding_encoding.c:(.text+0x5c2): undefined reference to `avcodec_encode_audio2'
decoding_encoding.obj:decoding_encoding.c:(.text+0x63a): undefined reference to `av_free_packet'
decoding_encoding.obj:decoding_encoding.c:(.text+0x680): undefined reference to `avcodec_encode_audio2'
decoding_encoding.obj:decoding_encoding.c:(.text+0x6f8): undefined reference to `av_free_packet'
decoding_encoding.obj:decoding_encoding.c:(.text+0x722): undefined reference to `av_freep'
decoding_encoding.obj:decoding_encoding.c:(.text+0x72d): undefined reference to `avcodec_free_frame'
decoding_encoding.obj:decoding_encoding.c:(.text+0x738): undefined reference to `avcodec_close'
decoding_encoding.obj:decoding_encoding.c:(.text+0x743): undefined reference to `av_free'
decoding_encoding.obj:decoding_encoding.c:(.text+0x77b): undefined reference to `av_init_packet'
decoding_encoding.obj:decoding_encoding.c:(.text+0x7a1): undefined reference to `avcodec_find_decoder'
decoding_encoding.obj:decoding_encoding.c:(.text+0x7e9): undefined reference to `avcodec_alloc_context3'
decoding_encoding.obj:decoding_encoding.c:(.text+0x840): undefined reference to `avcodec_open2'
decoding_encoding.obj:decoding_encoding.c:(.text+0x8e6): undefined reference to `av_free'
decoding_encoding.obj:decoding_encoding.c:(.text+0x947): undefined reference to `avcodec_alloc_frame'
decoding_encoding.obj:decoding_encoding.c:(.text+0x999): undefined reference to `avcodec_get_frame_defaults'
decoding_encoding.obj:decoding_encoding.c:(.text+0x9c2): undefined reference to `avcodec_decode_audio4'
decoding_encoding.obj:decoding_encoding.c:(.text+0xa44): undefined reference to `av_samples_get_buffer_size'
decoding_encoding.obj:decoding_encoding.c:(.text+0xb7d): undefined reference to `avcodec_close'
decoding_encoding.obj:decoding_encoding.c:(.text+0xb88): undefined reference to `av_free'
decoding_encoding.obj:decoding_encoding.c:(.text+0xb96): undefined reference to `avcodec_free_frame'
decoding_encoding.obj:decoding_encoding.c:(.text+0xbe4): undefined reference to `avcodec_find_encoder'
decoding_encoding.obj:decoding_encoding.c:(.text+0xc2c): undefined reference to `avcodec_alloc_context3'
decoding_encoding.obj:decoding_encoding.c:(.text+0xcee): undefined reference to `av_opt_set'
decoding_encoding.obj:decoding_encoding.c:(.text+0xd08): undefined reference to `avcodec_open2'
decoding_encoding.obj:decoding_encoding.c:(.text+0xd8c): undefined reference to `avcodec_alloc_frame'
decoding_encoding.obj:decoding_encoding.c:(.text+0xe2f): undefined reference to `av_image_alloc'
decoding_encoding.obj:decoding_encoding.c:(.text+0xe83): undefined reference to `av_init_packet'
decoding_encoding.obj:decoding_encoding.c:(.text+0xfd3): undefined reference to `avcodec_encode_video2'
decoding_encoding.obj:decoding_encoding.c:(.text+0x105f): undefined reference to `av_free_packet'
decoding_encoding.obj:decoding_encoding.c:(.text+0x10a9): undefined reference to `avcodec_encode_video2'
decoding_encoding.obj:decoding_encoding.c:(.text+0x1135): undefined reference to `av_free_packet'
decoding_encoding.obj:decoding_encoding.c:(.text+0x117e): undefined reference to `avcodec_close'
decoding_encoding.obj:decoding_encoding.c:(.text+0x1189): undefined reference to `av_free'
decoding_encoding.obj:decoding_encoding.c:(.text+0x1194): undefined reference to `av_freep'
decoding_encoding.obj:decoding_encoding.c:(.text+0x119f): undefined reference to `avcodec_free_frame'
decoding_encoding.obj:decoding_encoding.c:(.text+0x1272): undefined reference to `avcodec_decode_video2'
decoding_encoding.obj:decoding_encoding.c:(.text+0x13b1): undefined reference to `av_init_packet'
decoding_encoding.obj:decoding_encoding.c:(.text+0x13fa): undefined reference to `avcodec_find_decoder'
decoding_encoding.obj:decoding_encoding.c:(.text+0x1442): undefined reference to `avcodec_alloc_context3'
decoding_encoding.obj:decoding_encoding.c:(.text+0x14ba): undefined reference to `avcodec_open2'
decoding_encoding.obj:decoding_encoding.c:(.text+0x153e): undefined reference to `avcodec_alloc_frame'
decoding_encoding.obj:decoding_encoding.c:(.text+0x1674): undefined reference to `avcodec_close'
decoding_encoding.obj:decoding_encoding.c:(.text+0x167f): undefined reference to `av_free'
decoding_encoding.obj:decoding_encoding.c:(.text+0x168a): undefined reference to `avcodec_free_frame'
decoding_encoding.obj:decoding_encoding.c:(.text+0x16ab): undefined reference to `avcodec_register_all'
collect2.exe: error: ld returned 1 exit status