ffmpeg_cli is a Nim library for interfacing with the FFmpeg CLI to start, observe and terminate encode jobs with an intuitive API.
You can use an argument builder for programmatic CLI argument construction, or pass your own arguments directly.
Media files can be probed with FFprobe, and the probe result can be accessed from a serialized object.
The startFfmpegProcess proc spawns a process manager thread and then immediately returns an FfmpegProcess object with an attached Future. No blocking I/O is performed on the caller's thread, and the caller may choose to asynchronously await the Future, or use waitFor to block the thread until the process is complete, or fails.
The probeFile proc is blocking, and immediately returns the probe result or raises an error. A version that is run in a worker thread is provided for convenience as probeFileAsync, but note that spawning the thread that runs it is expensive, and you may be better off running the blocking version on a thread pool.
Errors returned by FFmpeg and FFprobe are raised as Nim exceptions, and can be handled normally.
When an FFmpeg error occurs, an FfmpegError will be raised, and the exact process exit code and error message can be accessed from it.
This library was tested with FFmpeg version n5.1.2 on ArchLinux, and was compiled with the following flags:
--prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librav1e --enable-librsvg --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-nvdec --enable-nvenc --enable-opencl --enable-opengl --enable-shared --enable-version3 --enable-vulkan
Arguments generated with FfmpegJob should work with any relatively recent FFmpeg build (assuming the correct flags are enabled), and running FFmpeg processes without using the argument builder should work on virtually all FFmpeg versions, regardless of flags.
You must have a relatively recent version of FFmpeg installed and available on your system's PATH for tests to be run. Output files from testing will be written to your system's temp path.