Notes on building

Dependencies

On *nix systems, clang, pkg-config and FFmpeg libraries (including development headers) are required.

On macOS:

brew install pkg-config ffmpeg

On Debian-based systems:

apt install -y clang libavcodec-dev libavformat-dev libavutil-dev pkg-config

Other libav*-dev and libsw*-dev packages may be required if you enable the corresponding features, e.g., libavdevice-dev for the device feature.

Compiling against a non-latest FFmpeg version

README contains a table with the supported FFmpeg versions and corresponding feature flags. The appropriate ffmpeg$version feature flag needs to be specified and all feature flags for later versions need to be disabled in order to build against a non-latest FFmpeg version. This usually entails using --no-default-features, then selectively enable other disabled default features in addition to the proper ffmpeg$version feature.

Note that at the moment codec and format have to be enabled to successfully build ffmpeg-sys-next. That is to say, for instance, to build against FFmpeg 4.2, at a minimum we need

cargo build --no-default-features --features ffmpeg42,codec,format

See #16.

Here's a sample Makefile snippet for FFmpeg version detection (up to v4.3):

LIBAVCODEC_VERSION=$(shell pkg-config --modversion libavcodec)
$(info detected lavc $(LIBAVCODEC_VERSION))
LIBAVCODEC_VERSION_MAJOR := $(word 1,$(subst ., ,$(LIBAVCODEC_VERSION)))
LIBAVCODEC_VERSION_MINOR := $(word 2,$(subst ., ,$(LIBAVCODEC_VERSION)))
ifeq ($(LIBAVCODEC_VERSION_MAJOR),)
  $(error cannot determine libavcodec version with pkg-config)
else ifeq ($(shell test $(LIBAVCODEC_VERSION_MAJOR) -gt 58; echo $$?),0)
  $(warning unknown libavcodec version, possibly from FFmpeg >4; use at own risk)
  FEATURES += ffmpeg43
else ifeq ($(LIBAVCODEC_VERSION_MAJOR),58)
  ifeq ($(shell test $(LIBAVCODEC_VERSION_MINOR) -ge 91; echo $$?),0)
    FEATURES += ffmpeg43
  else ifeq ($(shell test $(LIBAVCODEC_VERSION_MINOR) -ge 54; echo $$?),0)
    FEATURES += ffmpeg42
  else ifeq ($(shell test $(LIBAVCODEC_VERSION_MINOR) -ge 35; echo $$?),0)
    FEATURES += ffmpeg41
  else
    FEATURES += ffmpeg4
  endif
endif

Building on Windows

It does work, someone has done it. Not sure if pkg-config is a dead end, but using the FFMPEG_DIR env var should work.

At some point a guide will probably be provided (when I get around to try to build this on Windows myself)... But contributions here are very welcome.

In the meantime, you can find some tips on the issue tracker. See for instance #7 and #9.