# WebAssembly port of FFmpeg

This repository hosts scripts and commands to build WebAssembly port of FFmpeg powering [**wide.video** | Free Online Video Editor](https://wide.video) and [**ffmpeg.wide.video** | FFmpeg Online](https://ffmpeg.wide.video).

## Build

Default build procedure using docker will produce multiple (gpl, lgpl, simd) artifacts in `./wasm` folder:

```shell
./scripts/docker-run.sh
	./scripts/docker-init.sh    # execute in container shell
	./scripts/release.sh        # execute in container shell
```

Alternatively, non-container build can be executed similarly:

```shell
sudo -s
./scripts/release.sh
```

Release script further executes configuration and build of each submodule, which can be called manually as follows:

```shell
sudo -s
export FFMPEG_LGPL=true                  # release.sh
export FFMPEG_SKIP_LIBS=false            # release.sh
./scripts/clean.sh                       # release.sh
./scripts/build.sh                       # release.sh
	source scripts/init-emscripten.sh    # build.sh
	./scripts/build-zlib.sh              # build.sh
	./scripts/configure-ffmpeg.sh        # build.sh
	./scripts/build-ffmpeg.sh            # build.sh
	./scripts/customize-ffmpeg.sh        # build.sh
```

## Docker Reattach

Reattach stdin for exited container:

```shell
docker ps -q -l              # find container ID (or discover via Docker desktop)
docker start dd3dbe04a7e5    # restart in the background
docker attach dd3dbe04a7e5   # reattach the terminal & stdin
```

## Known Issues

- Google shell [Encountered a section with no Package: header](https://github.com/hashicorp/consul/issues/11162) can be resolved by calling `sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 467B942D3A79BD29`
- [Single thread version is not buildable](https://trac.ffmpeg.org/ticket/10009) as FFmpeg [depends upon threading](http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=760ce4bc0bd11f74f0851c0a662dd5cae888df83).
- [Openh264 not buildable with emscripten >= 3.1.33](https://github.com/cisco/openh264/issues/3666)