As of the current episode of RPG Maker Channel, it is confirmed that MV supports MP4 and WebM video formats.

RPG Maker software has had movie support in the past. RPG Maker 2000 and 2003 supported AVI and MPG video; RPG Maker XP did not support movie playback unfortunately; VX Ace supported OGV.

It has also been confirmed that MV will support OGG and (possibly WAV), which is strange, since XP and VX Ace supported MP3 audio files. The excuse is related to licensing, which is ridiculous to me. Fortunately, creating OGG music files is simple compared to making OGV video files.

It's also been confirmed that the side-view battlers are not restricted to the 48x48 sprites, which is really cool if one wanted to use Urimas' MLP sprites for battlers.

So who's psyched for RMMV?

It's got mp4 support finally? Awesome. Any idea on the particular mp4 codecs one must use for RPG Maker MV?

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H264 is the supported codec.