tkslan / ffmpegout

A Unity plugin to export videos with using FFmpeg.

FFmpegOut

FFmpegOut is a Unity plugin that records and exports rendered frames in Unity to a video file by using FFmpeg as a video encoder.

The main scope of FFmpegOut is to reduce rendering time when using Unity for pre-rendering. It greatly reduces the amount of file I/O compared to exporting raw image sequences, so that it can be an effective solution when the bandwidth is the most significant bottleneck. On the other hand, FFmpegOut is not optimized for real-time capturing. It's not strongly recommended to use it in an interactive application.

System Requirements

• Unity 5.6.0 or later

FFmpegOut only supports desktop platforms (Windows/macOS/Linux).

How to Use

Download the latest package from the Releases page and import it to the project. Then, add the CameraCapture component (Add Component -> FFmpegOut -> Camera Capture) to a camera that is used to render frames to be exported.

The CameraCapture component has a few settings.

• The size of frames can be changed with the Set Resolution properties. This is handy for exporting videos in a specific format.
• The frame rate of an exported video is determined from the Frame Rate value rather than the actual application frame rate. The Allow Slow Down switch is useful to keep the frame rate of the exported video stable. It fixes the delta time between frames and stops the application from syncing with real time (wall-clock time). In most cases it makes the application runs slower than real time speed.

Encoding Presets

H.264 Default (MP4)

Highly optimized encoder with a moderate quality and a mid-level bit rate. Recemmended for general use.

H.264 Lossless 420 (MP4)

Not actually lossless but the quality is high enough for most use cases. Recommended for pre-rendering use.

H.264 Lossless 444 (MP4)

The highest quality preset. Most software can't decode videos encoded with this preset (e.g. Premiere crashes when importing them).

ProRes 422 (QuickTime)

ProRes is an intra-frame codec that is gradually phased out but still widely used in video editing. The ProRes codec used in FFmpeg is not aggressively optimized so that it tends to be slower than other codecs.

ProRes 4444 (QuickTime)

Only this preset supports alpha channel. Use this when you needs alpha channel for composition in editing software (Premiere, After Effects, etc.).

VP8 (WebM)

Very low bit rate encoding, optimized for web browser use.

Troubleshooting: Win32Exception

Sometimes on macOS and Linux, FFmpegOut throws Win32Exception and fails to start recording. This is caused because ffmpeg binary doesn't have the executable permission. To solve the problem, the executable permission should be given to ffmpeg (e.g. chmod a+x ffmpeg).

TIPS

• Some codecs don't support arbitrary resolutions and cause errors when capturing the game view in free aspect mode. It's recommended to use the Set Resolution properties in such a case.

Using This Repository

The binary executables of FFmpeg are not included in this repository because they're too large to be included. They have to be added manually after cloning the repository.

Any recent versions of FFmpeg would work, but it's recommended to use KeatsPeeks' static-linked executables because they're used for testing.

• Windows: https://github.com/KeatsPeeks/ffmpeg-static/blob/master/bin/win32/x64/ffmpeg.exe

• macOS: https://github.com/KeatsPeeks/ffmpeg-static/blob/master/bin/darwin/x64/ffmpeg

• Linux: https://github.com/KeatsPeeks/ffmpeg-static/tree/master/bin/linux/x64/ffmpeg

Download these files and copy them into Assets/StreamingAssets/FFmpegOut/(platform name)/.

License

MIT

Note that FFmpeg itself is not placed under this license. For instance, the FFmpeg binaries included in the release packages are depending on some GPL libraries. This should be taken into account when distributing them within a product. See the FFmpeg License page for futher details.