MacOS: building minimal, audio-only version fails with linker error

[Marcus Ilgner]

In order to build a minimal, audio-decoding-only of ffmpeg I created this longish configure command line. It builds on Linux but strangely enough fails when executing on MacOS 10.8.
First I disable all features, then I add back in everything I actually might need.

./configure --prefix=../../dist --disable-static --enable-shared --disable-programs --disable-doc --disable-everything --enable-decoder=aac --enable-decoder=aac_latm --enable-decoder=mp1 --enable-decoder=mp2 --enable-decoder=mp3 --enable-decoder=mp3float --enable-decoder=mp3adufloat --enable-decoder=mp3adu --enable-decoder=mp3on4 --enable-decoder=mp3on4float --enable-decoder=vorbis --enable-decoder=flac --enable-decoder=wavpack --enable-decoder=wmalossless --enable-decoder=wmapro --enable-decoder=wmav1 --enable-decoder=wmav2 --enable-decoder=pcm_alaw --enable-decoder=pcm_bluray --enable-decoder=pcm_dvd --enable-decoder=pcm_f32be --enable-decoder=pcm_f32le --enable-decoder=pcm_f64be --enable-decoder=pcm_f64le --enable-decoder=pcm_lxf --enable-decoder=pcm_mulaw --enable-decoder=pcm_s16be --enable-decoder=pcm_s16be_planar --enable-decoder=pcm_s16le --enable-decoder=pcm_s16le_planar --enable-decoder=pcm_s24be --enable-decoder=pcm_s24daud --enable-decoder=pcm_s24le --enable-decoder=pcm_s24le_planar --enable-decoder=pcm_s32be --enable-decoder=pcm_s32le --enable-decoder=pcm_s32le_planar --enable-decoder=pcm_s8 --enable-decoder=pcm_s8_planar --enable-decoder=pcm_u16be --enable-decoder=pcm_u16le --enable-decoder=pcm_u24be --enable-decoder=pcm_u24le --enable-decoder=pcm_u32be --enable-decoder=pcm_u32le --enable-decoder=pcm_u8 --enable-bsf=mp3_header_decompress --enable-bsf=aac_adtstoasc --enable-bsf=chomp --enable-bsf=remove_extradata --disable-swscale --enable-swresample --enable-parser=aac --enable-parser=aac_latm --enable-parser=flac --enable-parser=ac3 --enable-parser=vorbis --enable-parser=mpegaudio --enable-demuxer=aac --enable-demuxer=aiff --enable-demuxer=flac --enable-demuxer=latm --enable-demuxer=mp3 --enable-demuxer=ogg --enable-demuxer=pcm_f32be --enable-demuxer=pcm_f32le --enable-demuxer=pcm_f64be --enable-demuxer=pcm_f64le --enable-demuxer=pcm_mulaw --enable-demuxer=pcm_s16be --enable-demuxer=pcm_s16le --enable-demuxer=pcm_s24be --enable-demuxer=pcm_s24le --enable-demuxer=pcm_s32be --enable-demuxer=pcm_s32le --enable-demuxer=pcm_s8 --enable-demuxer=pcm_u16be --enable-demuxer=pcm_u16le --enable-demuxer=pcm_u24be --enable-demuxer=pcm_u24le --enable-demuxer=pcm_u32be --enable-demuxer=pcm_u32le --enable-demuxer=pcm_u8 --enable-demuxer=wav --enable-protocol=file

Attached, find the make output. Also it looks like there are still video components built, like libavcodec/dirac.o, libavfilter/video.o - but I don't mind since it's probably minimal.

[Marcus Ilgner]

Build output

[Carl Eugen Hoyos]

LD      libavfilter/libavfilter.3.dylib
Undefined symbols for architecture x86_64:
  "_av_find_input_format", referenced from:
      _ff_load_image in lavfutils.o

av_find_input_format is defined in libavformat/format.c which is compiled unconditionally so your problem is difficult to understand. Could you confirm that you did make distclean before testing and that no conflicting versions of dynamic FFmpeg libraries are installed on your system?

Also it looks like there are still video components built, like libavcodec/dirac.o

The ogg demuxer relies on dirac.o.

Unrelated: Your configure line will get more readable if you use wildcards and lists:
./configure --disable-demuxers --enable-demuxer=pcm*,flac,latm
(This is supported since a long time.)

--disable-everything originally was a debug option (that contrary to its name does not disable all components of FFmpeg), you may want to try --disable-all. As a side-effect, it will also fix the linking problem you reported (although that does not at all explain it).
(This option is not supported since a long time, it will not work on old versions.)

I don't think you will find pcm_bluray and pcm_dvd in any of the formats for which you enabled demuxers, the following should also work as expected:
./configure --disable-decoders --enable-decoder=pcm* --disable-decoder=pcm_bluray,pcm_dvd

[jamal]

av_find_input_format is defined in libavformat/format.c which is compiled unconditionally so your problem is difficult to understand.

In this build, libavfilter/avcodec.o and libavfilter/lavfutils.o are compiled because of these lines in libavfilter's Makefile:

OBJS-$(CONFIG_AVCODEC)                       += avcodec.o
OBJS-$(CONFIG_AVFORMAT)                      += lavfutils.o

But when linking, neither avcoded or avformat are included in the FFLIBS variable because they are only added when certain filters are built, and all filters were disabled here.

Something like

FFLIBS-$(CONFIG_AVCODEC)  += avcodec
FFLIBS-$(CONFIG_AVFORMAT) += avformat

fixes this, and i think a patch doing this was submitted some time ago but was never committed for some reason.

[Carl Eugen Hoyos]

$ ./configure --disable-everything --enable-shared --disable-static

$ make V=1
gcc -dynamiclib -Wl,-single_module -Wl,-install_name,/usr/local/lib/libavfilter.3.dylib,-current_version,3.82.100,-compatibility_version,3 -Llibavcodec -Llibavdevice -Llibavfilter -Llibavformat -Llibavresample -Llibavutil -Llibpostproc -Llibswscale -Llibswresample -Wl,-dynamic,-search_paths_first -o libavfilter/libavfilter.3.dylib libavfilter/af_aformat.o libavfilter/af_anull.o libavfilter/allfilters.o libavfilter/audio.o libavfilter/avcodec.o libavfilter/avfilter.o libavfilter/avfiltergraph.o libavfilter/buffer.o libavfilter/buffersink.o libavfilter/buffersrc.o libavfilter/drawutils.o libavfilter/fifo.o libavfilter/formats.o libavfilter/graphdump.o libavfilter/graphparser.o libavfilter/lavfutils.o libavfilter/lswsutils.o libavfilter/opencl_allkernels.o libavfilter/pthread.o libavfilter/setpts.o libavfilter/transform.o libavfilter/trim.o libavfilter/vf_format.o libavfilter/vf_null.o libavfilter/video.o -lavutil -liconv -lm -lbz2 -lz
Undefined symbols:
  "_sws_scale", referenced from:
      _ff_scale_image in lswsutils.o
  "_av_read_frame", referenced from:
      _ff_load_image in lavfutils.o
  "_sws_getContext", referenced from:
      _ff_scale_image in lswsutils.o
  "_av_find_input_format", referenced from:
      _ff_load_image in lavfutils.o
  "_avcodec_open2", referenced from:
      _ff_load_image in lavfutils.o
  "_avcodec_close", referenced from:
      _ff_load_image in lavfutils.o
  "_sws_freeContext", referenced from:
      _ff_scale_image in lswsutils.o
  "_avcodec_decode_video2", referenced from:
      _ff_load_image in lavfutils.o
  "_avcodec_find_best_pix_fmt_of_2", referenced from:
      _pick_format in avfiltergraph.o
  "_avformat_close_input", referenced from:
      _ff_load_image in lavfutils.o
  "_avcodec_find_decoder", referenced from:
      _ff_load_image in lavfutils.o
  "_av_register_all", referenced from:
      _ff_load_image in lavfutils.o
  "_avcodec_alloc_frame", referenced from:
      _ff_load_image in lavfutils.o
  "_avformat_open_input", referenced from:
      _ff_load_image in lavfutils.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make: *** [libavfilter/libavfilter.3.dylib] Error 1

[Carl Eugen Hoyos]

Still reproducible:

$ make V=1 ffmpeg
gcc -dynamiclib -Wl,-single_module -Wl,-install_name,/usr/local/lib/libavfilter.3.dylib,-current_version,3.92.100,-compatibility_version,3 -Llibavcodec -Llibavdevice -Llibavfilter -Llibavformat -Llibavresample -Llibavutil -Llibpostproc -Llibswscale -Llibswresample -Wl,-dynamic,-search_paths_first -o libavfilter/libavfilter.3.dylib libavfilter/af_aformat.o libavfilter/af_anull.o libavfilter/allfilters.o libavfilter/audio.o libavfilter/avcodec.o libavfilter/avfilter.o libavfilter/avfiltergraph.o libavfilter/buffer.o libavfilter/buffersink.o libavfilter/buffersrc.o libavfilter/drawutils.o libavfilter/fifo.o libavfilter/formats.o libavfilter/graphdump.o libavfilter/graphparser.o libavfilter/opencl_allkernels.o libavfilter/pthread.o libavfilter/setpts.o libavfilter/transform.o libavfilter/trim.o libavfilter/vf_format.o libavfilter/vf_null.o libavfilter/video.o -lavutil -liconv -lm -lbz2 -lz 
Undefined symbols for architecture x86_64:
  "_avcodec_find_best_pix_fmt_of_2", referenced from:
      _pick_format in avfiltergraph.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [libavfilter/libavfilter.3.dylib] Error 1

[Michael Niedermayer]

Should be fixed by 617e866e25b72fa5d9f9d6bbcbd7e4bd69e63a54