FFmpeg license
Remotion distributes a compiled FFmpeg binary under the GPLv2+ license. The source and build scripts are publicly available.
x264 and x265
x264 and x265 are licensed under the GPL, not the LGPL. Therefore, Remotion's FFmpeg binary cannot be distributed under the LGPL.
fdk-aac
Remotion does not use the official fdk-aac distribution. The build script shows that Remotion's FFmpeg binary uses the free fdk-aac-free variant, which has no licensing concerns.
Other components
No other components in Remotion's FFmpeg binary should raise licensing concerns.
Remotion has carefully verified the licensing information on this page. Concerns can be sent to hi@remotion.dev.
Patents
This page is about copyright licenses only. Copyright licenses do not include patent licenses, and some codecs are covered by patents that are licensed separately in some jurisdictions.
Whether you need a patent license or have to pay royalties depends on your use case and jurisdiction and is not covered by a Remotion license. See "Third-party rights" in the Terms and Conditions.