How to enable libx264 in ffmpeg

Question

I am trying to encode with libx264 in ffmpeg

ffmpeg -f image2 -r 25 -i frames/%03d.bmp -vcodec libx264  out.mp4

However, i get the following error message:

Unknown encoder 'libx264'

If us type ffmpeg in the console, it shows under configuration --disable-libx264, so I guess that is the reason.

How can I enable this? I found in some other questions that it can be done by reinstalling with this option, but there where two things I could not find:

1. Is it possible to change the configuration without reinstalling?
2. If not, how do I pass options while reinstalling?

Solution

Is it possible to change the configuration without reinstalling?

The --disable-libx264 flag is a bit misleading. This is not an option that disables the h264 codec during installation, but is a compile flag during creation of your binary/executable. To change that flag, you either need to recompile it yourself, or install a version which had it enabled during compilation. This comes down to the repository you are downloading it from. I can confirm h264 is available on the native x64 Ubuntu version in 18.04.

If not, how do I pass options while reinstalling?

You need to get ffmpeg from a different source which did not disable it. The native windows version installed by chocolatey has the flag enabled on my system. It might be that WSL uses a separate repository which disabled it.

As for how to proceed:

• Use the native windows version of ffmpeg
• Try a different Ubuntu version, e.g. 18.04 LTS
• Download ffmpeg from a different source, example
• Compile ffmpeg from source

Comments

[MMM]

Which OS are you trying this on? Some distributions of ffmpeg don't include the x264 encoders because of hollywood reasons. You can check your available codecs using the -codecs argument.

[user3053216]

@MMM I am using ubuntu 20.04 within windows subsystem for linux. I think the x264 encoder is not there, but i tried to install it with sudo apt install libx264-dev

[Elisa Cha Cha]

Where did you get this ffmpeg? The version from the repo supports libx264. Why not just use that?

[user3053216]

Thanks for the reply. I checked the compilation guide earlier and found that i should run sudo apt install libx264-dev to install the x264, but this seems to be not enough.

[boots]

You'd still need to compile ffmpeg with the switch --enable-libx264. see here trac.ffmpeg.org/wiki/CompilationGuide/Ubuntu about 2/3 the way down. However, most versions you find already compiled will have it enabled by default. It is only the non-free option for the codecs where the licence prohibits binary sharing that are generally omitted. i.e. I use MINT and their version has x264 enabled as do the windows binaries from the ffmpeg distribution.