[libx264 @ 0x502ec0] broken ffmpeg default settings detected
[libx264 @ 0x502ec0] use an encoding preset (e.g. -vpre medium)
[libx264 @ 0x502ec0] preset usage: -vpre <speed> -vpre <profile>
[libx264 @ 0x502ec0] speed presets are listed in x264 --help
[libx264 @ 0x502ec0] profile is optional; x264 defaults to high
Could not open codec 'libx264': Unspecified error