I'm in the Windows version of Aximmetry DE and I'm using the Record_3-Audio compound to render a video to my disk. I click on the RECORDER panel and configure the video format to H.264/MP4 (5) and when I click on the record button, I get this message:
Started recording into "Studio_0003.mp4"
Failed to initialize video codec for "Studio_0003.mp4"
Failed to create video file "Studio_0003.mp4"
Stopped recording into "Studio_0003.mp4"
No video file was made. If I use WMV, DNxHD, Cineform, it render the video file just fine.
Probably you do not run Aximmetry on an NVidia card.
Aximmetry uses the NVidia NVENC GPU-based codec for H.264/.265.