MikuVideo — Free Video Converter for MikuMikuDance

[0:00] Installation. Go to MmdFr.fr menu > MikuVideo and click the download button.

Choose Keep, Keep anyway, and Open. Install for me only. If your computer requires it, it will install Microsoft .NET 8.

Open the video file using the Video AVI button. Choose a video file. You can also search for all files. A list of recent files is displayed under the arrow, or drag and drop from a file explorer. There are two slots, AVI video and audio WAV. The small round button with the arrow allows you to play the slot.

[1:04] Quick tour — the space bar toggles between play and pause. The purple ball allows for fast movement; you can play forward or backward. You can adjust the playback speed using the scroll wheel in the speed zone. With the scroll wheel in the position zone, you switch to frame-by-frame mode and can move forward or backward.

Quick tour on screen — to switch to on-screen control, click once on the screen; otherwise you remain in control of the purple ball. On the screen, use the right or left arrows to switch to frame-by-frame mode. The scroll wheel on the screen zooms in and out. Click and drag to pan the video. Right-click resets zoom and pan. There are other shortcuts — see the help file.

[2:02] Convert to MP4. The video must be in the first slot. If it doesn't start at frame zero, it has no sound — this is an MMD bug. Therefore you need to add the WAV file to the second slot, and you also need to specify the start offset of the WAV file. The Convert button will merge the video and audio tracks and compress them to MP4. This is done using the graphics card, so it's relatively fast. Once the video is converted, the third slot will play automatically.

[2:41] Convert to background video screen. You just downloaded the video — it has a long name with spaces and strange characters. To keep the reference, create a folder with that name, then change the name to "video background." Put the source video in slot one (Video AVI) and select Convert to AVI for background/screen.

The conversion is done by the CPU, which is much slower. It doesn't change the resolution, but it encodes at 30 frames per second. The AVI MMD format is pixelated — you can use 4K with MikuMikuDance, but the resulting video file must be less than 1,000 megabytes, otherwise it will freeze in MMD; in 4K that's less than 60 seconds. This format also works for MikuMikuMoving (MMM) without any size restrictions; however, decoding in MMM is slower, so a lower resolution is recommended there.

With MMD, go to the Background menu and load the background AVI file. With the stage, the background is behind the walls.

To put it on the screen instead, disable Show background AVI file. Load an accessory — the horizontal format 16 by 9 — and send the video to it via the Background menu, mode 03. Set the scale to 5, then position the screen behind the neon lights and in front of the wall. Switch from local to global. Remember to register the accessory at frame zero and save.

[5:13] Convert to background video for motion trace. The name is long, so create a folder with this name to have a trace, and rename the files with a short name. Open the video file to select the correct segment to trace, then convert this segment to AVI. Also convert the audio track — put it in slot one to cut it like the video, since only slot one allows cutting. The conversion is very fast. Everything is ready to be loaded into MMD.

Position the model in camera mode and register it. Then position the video using Shift + zoom icon and the move icon. Switching to camera mode repositions the model and the background video; to move the bones, switch back to model mode.

If you liked it, give it a thumbs up. If you want additional features or want to report a bug, you can do so on the MikuVideo page or on Discord. Have fun with MMD and MikuVideo — see you soon on MmdFr!