go-ffmpreg

README

go-ffmpreg

empregge- sorry, uh... embedded ffmpeg WASM binary with a small Go library wrapper, using wazero WebAssembly runtime

this provides a singular binary capable of calling into ffmpeg or ffprobe (switches on argv0, like busybox)

ffmpeg version: n5.1.6 (the latest version not reliant on pthreads)

yes, you will have to publicly acknowledge the fact you used ffmpreg as this is GPL

ffmpeg is built with GPLv3 code enabled and with the following external libraries:

• libx264 (for H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 encoding)
• libwebp (for WebP encoding)
• libmp3l*me (for MP3 encoding)
• libopus (for Opus encoding)
• libvpx (for VP8 / VP9 encoding)
• zlib

for a list of what ffmpeg supports (and what it requires external libaries for) see: https://www.ffmpeg.org/general.html#External-libraries

the resulting binary is passed through many wasm-opt optimization passes focusing on a balance of speed and size, such that the embedded binary is ~24MB (uncompressed, before in this is gzip compressed to ~8MB)

usage

see cmd/{ffmpeg,ffprobe,ffmpreg} for examples

ffmpeg may need access to /dev/ and /tmp/ depending on what you are doing, please factor this in when setting up directory mounts

note since wazero runtime is not aware of a "working directory", all paths passed must be absolute relative to filesystem mount

build

podman build --file=build/build.dockerfile

alternatively with far more optimization passes

podman build --file=build/build.dockerfile --build-arg RELEASE=yes

then copy /build/{ffmpeg,ffprobe} from resulting image

the build system itself is separated into scripts found under build/, which are called by build/build.dockerfile. to build ffmpeg with a new external library add a new script for it under build/ that sources build/environ and outputs library header, archive and pkg-config (if any) to /vendor in the build image

hacking

the WebAssembly binary (once uncompressed) under embed/ should be useable under any WebAssembly runtime that supports the following: simd, bulk-memory, nontrapping-float-to-int, mutable-globals, sign-ext, reference-types

on top of the above runtime features, this binary expects exported host functions as defined in the wasi snapshot preview 1, and additionally, setjmp, longjmp

future

• more tests (in particular: ffprobe, 3rd-party libs)

• update ffmpeg to n7.x.x (requires wazero to fully support wasm threads proposal)

• tidy up the ffmpeg patch, in particular add code comments

• build-tagged output with differing 3rd-party library options?

• build with libjxl for JPEG XL, may rely on threads

• build with libx265 for HEVC, may rely on threads

• some form of AV1 encode / decode

further thanks

viviridian for showing me how to modify the ffmpeg build-system to support a new binary!