On 12/06/2018, Zak wrote:
> Dear FFmpeg User Mailing List,
>
> The versions of certain libraries are printed in the banner, such as
> libavcodec.
>
> I am curious how to find information about linked libraries, such as
> libmp3lame, the LAME MP3 encoder. I would like to know:
>
> 1. Was it statically or dynamically linked?
>
> 2. If dynamically linked, where is the libmp3lame.so file?
>
> (I think the answer is /usr/local/libmp3lame.dylib in my case on my Mac,
> but I want FFmpeg to tell me. I am not on Kubuntu right now, but I can
> probably find it on Kubuntu also, and I'm guessing it is an .so and not
> a .dylib file on that OS.)
>
> 3. What is the version of the linked library? Here is how I can ask LAME
> itself, from the LAME CLI front-end for libmp3lame:
>
> bash$ lame --version
>
> LAME 64bits version 3.100 (http://lame.sf.net)
>
> -
>
> Here is my best guess:
>
> bash$ ffmpeg -h encoder=libmp3lame
>
> Encoder libmp3lame [libmp3lame MP3 (MPEG audio layer 3)]:
> General capabilities: delay small
> Threading capabilities: none
> Supported sample rates: 44100 48000 32000 22050 24000 16000 11025
> 12000 8000
> Supported sample formats: s32p fltp s16p
> Supported channel layouts: mono stereo
> libmp3lame encoder AVOptions:
>-reservoir E...A... use bit reservoir (default true)
>-joint_stereo E...A... use joint stereo (default true)
>-abr E...A... use ABR (default false)
>
> This looks promising, but it turns out all of that information is
> hardcoded in this file:
>
> ffmpeg/libavcodec/libmp3lame.c
>
> You can even change this string:
>
> AVCodec ff_libmp3lame_encoder = {
>// ...snip...
>.long_name = "libmp3lame MP3 (MPEG audio layer 3)"
>
> ...and the FFmpeg help will display whatever you type. It is not pulling
> it from the library.
>
> This is intended to be a general question, so I am not going to include
> a specific FFmpeg banner because I use FFmpeg on two operating systems
> (MacOS 10.12 and Kubuntu) and I have multiple versions of FFmpeg.
>
> Thank you,
>
> Zak F.
> ___
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>
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If you're on a Unix-like system (including MacOS and *Ubuntu) use
ldd
where is the path to the executable you want to examine. Example:
$ ldd /usr/local/bin/ffmpeg
linux-vdso.so.1 => (0x7fff279ff000)
libavdevice.so.55 => /usr/local/lib/libavdevice.so.55
(0x2ac9b97e7000)
libavfilter.so.4 => /usr/local/lib/libavfilter.so.4 (0x2ac9b99fe000)
libavformat.so.55 => /usr/local/lib/libavformat.so.55
(0x2ac9b9cdf000)
libavcodec.so.55 => /usr/local/lib/libavcodec.so.55 (0x2ac9ba085000)
libswresample.so.0 => /usr/local/lib/libswresample.so.0
(0x2ac9bb1f)
libswscale.so.2 => /usr/local/lib/libswscale.so.2 (0x2ac9bb407000)
libavutil.so.52 => /usr/local/lib/libavutil.so.52 (0x2ac9bb67d000)
libX11.so.6 => /usr/lib/libX11.so.6 (0x2ac9bb8d3000)
libpthread.so.0 => /lib/libpthread.so.0 (0x2ac9bbcb1000)
libm.so.6 => /lib/libm.so.6 (0x2ac9bbecd000)
libvdpau.so.1 => /usr/lib/libvdpau.so.1 (0x2ac9bc15)
libc.so.6 => /lib/libc.so.6 (0x2ac9bc351000)
libXv.so.1 => /usr/lib/libXv.so.1 (0x2ac9bc6b3000)
libXext.so.6 => /usr/lib/libXext.so.6 (0x2ac9bc8b9000)
libjack.so.0 => /usr/lib/libjack.so.0 (0x2ac9bcacb000)
libasound.so.2 => /usr/lib/libasound.so.2 (0x2ac9bcd0e000)
libSDL-1.2.so.0 => /usr/lib/libSDL-1.2.so.0 (0x2ac9bcff4000)
libdc1394.so.22 => /usr/lib/libdc1394.so.22 (0x2ac9bd2ad000)
libssl.so.0.9.8 => /usr/lib/libssl.so.0.9.8 (0x2ac9bd522000)
libcrypto.so.0.9.8 => /usr/lib/libcrypto.so.0.9.8 (0x2ac9bd778000)
libbz2.so.1.0 => /lib/libbz2.so.1.0 (0x2ac9bdb19000)
libz.so.1 => /usr/lib/libz.so.1 (0x2ac9bdd29000)
libva.so.1 => /usr/lib/libva.so.1 (0x2ac9bdf4)
libvorbisenc.so.2 => /usr/lib/libvorbisenc.so.2 (0x2ac9be146000)
libvorbis.so.0 => /usr/lib/libvorbis.so.0 (0x2ac9be416000)
libtheoraenc.so.1 => /usr/lib/libtheoraenc.so.1 (0x2ac9be447000)
libtheoradec.so.1 => /usr/lib/libtheoradec.so.1 (0x2ac9be686000)
libspeex.so.1 => /usr/lib/libspeex.so.1 (0x2ac9be89f000)
libschroedinger-1.0.so.0 => /usr/lib/libschroedinger-1.0.so.0
(0x2ac9beab9000)
libopenjpeg.so.2 => /usr/lib/libopenjpeg.so.2 (0x2ac9bed63000)
libgsm.so.1 => /usr/lib/libgsm.so.1 (0x2ac9bef83000)
librt.so.1 => /lib/librt.so.1 (0x2ac9bf191000)
libxcb.so.1 => /usr/lib/libxcb.so.1 (0x2ac9bf399000)
libdl.so.2 => /lib/libdl.so.2
