In some cases, you may want to have more control over the encoding parameters. This section describes the advanced features of the Export settings panel.
Gyroflow uses ffmpeg for the rendering process. There are a lot of different encoders, parameters and cases, depending on the file type, operating system and your graphic card. For most cases, the defaults are fine, but if you want to pass an additional setting to the encoder, you can use the Custom encoder options field and enter the parameters as you would to the ffmpeg command line. For example:
-preset hq -profile rext.
The list of accepted parameters is available by clicking the Info icon, next to the text field. You can google the parameter names + ffmpeg for specific explanations.
Note that Gyroflow doesn't use the ffmpeg command line (CLI), but rather the C API directly, so not all options that can be passed to the ffmpeg CLI, can be used here. This field is for the video encoder parameters only.
Additional supported options are: -hwaccel_device, -qscale and -pix_fmt.
When using H.264 or H.265, you can specify the keyframe distance - it's the interval for every I-frame (a fully encoded frame independent of other frames). For detailed explanation what it is read this Wikipedia article. It has nothing to do with parameter keyframing in Gyroflow, it's a video encoder parameter.
Some video files contain additional tracks, like timecode, subtitles, motion data etc. By default, Gyroflow discards these tracks and only renders one video and one audio track. In order to preserve them and copy directly to the stabilized file, you can check this option and use the .mov file extension.
You can't use the trim range with this option (i.e. you need to render the full file), because Gyroflow doesn't know how to cut arbitrary binary tracks.
When using the trim range, the rendered file will only be the selected trim section of the original file. However in some cases, it is desirable to render only a fragment of the file, but retain full original length of the file. A common case is when using a video editor and having the edit already done. If you then replace the clip with a shorter one, the edit will fall apart. But if you replace the clip with one with the exact same duration, everything will work fine.
When you check this option, Gyroflow will render black frames outside the trim range, and actual stabilized video inside the trim range. This allows the video codec to compress the black frames, so the file size will still be small, while retaining the full original video duration. This can also be useful when combined with the Preserve other tracks option.
Gyroflow renders all audio as AAC with the same bitrate as the input file. There is currently no option to change the audio format.
Gyroflow always exports the video file with the same frame rate as the original video file. There is currently no option to change the frame rate.
Some computers or laptops have more than one GPU and usually one is more powerful that the other (e.g. integrated GPU vs. the dedicated GPU). You can choose the preferred device used for video encoding here.
There's also a second selector in the Advanced section which controls the device used for the stabilization process itself. These processes are separate and you can process on one GPU and render on the other GPU.
Some devices support more encoding formats and some devices don't support GPU video encoding at all, so make sure you select the correct (and more powerful) device here.
When exporting a project file, you have 3 options:
- Project file - This is the smallest project file which can be used when your video file contains internal motion data. The motion data will always be in the original video file, so there's no need to save it separately in the project. This project contains all stabilization parameters and the file path of the video.
- Project file (with gyro data) - If your motion data is from external source or is in a separate file (like .gcsv), then this project file will embed the entire motion data inside the project file, so there's no need to keep the separate gyro file around. This can be useful when you're using a GoPro as a logger, or when you want to export a project file for the video editor plugins. The default shortcut to save project file (Ctrl+S) is saving with gyro data, as it's the safe default for all cases.
- Project file (with processed gyro data) - This option is similar to the previous one, but it also contains additional motion data processed by Gyroflow - it is useful in combination with external scripts like Gyroflow-to-CSV. Video editor plugins don't need this option, the
(with gyro data)one is enough.