Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> vp9 (libvpx-vp9))
Stream #0:1 -> #0:1 (copy)
[libvpx-vp9 @ 000001bd4a5c1540] v1.7.0
[webm @ 000001bd4a417b00] Only VP8 or VP9 or AV1 video and Vorbis or Opus audio and WebVTT subtitles are supported for WebM.
[out#0/webm @ 000001bd4a6753c0] Could not write header (incorrect codec parameters ?): Invalid argument
Error while filtering: Invalid argument
[out#0/webm @ 000001bd4a6753c0] Nothing was written into output file, because at least one of its streams received no packets.
Conversion failed!