Free online USM to MKV converter

Game cutscenes stored as USM files often cannot be opened by standard video editors or media players. Converting the extracted video and audio into MKV makes the footage easier to play, archive, and edit.

What the USM format is

USM is a proprietary container used by CRI Middleware's CRI Movie system, commonly in Japanese and console PC games for pre-rendered cutscenes. Games and packaging tools may create USM files containing H.264 or MPEG video plus ADX or HCA audio; some releases also encrypt the streams or use game-specific variants.

You usually encounter files such as movie.usm inside a game's data, archive, or movie directory. A normal video player may not recognize them because USM is not a general-purpose container and FFmpeg does not provide a universal USM demuxer.

What the MKV format is

MKV, formally Matroska, is an open container that can hold video, multiple audio tracks, subtitles, chapters, attachments, and metadata. It is suitable for playback in VLC, mpv, Kodi, and many desktop media players, and it preserves separate streams without requiring them to be compressed into one track.

MKV is useful when the extracted USM streams need multiple language tracks, subtitles, chapter markers, or lossless remuxing. The container itself does not reduce quality; quality depends on whether the streams are copied or re-encoded.

How to actually convert USM to MKV

There is no single universal converter for every USM variant. First make a backup of the original file, then use a USM extractor or decryptor that supports the game-specific CRI Movie version. VGMToolbox may extract supported CRI USM files; other releases require a tool made for that game's format. Follow the extractor's documentation and do not bypass encryption or access controls unless you have the necessary rights.

1. Extract the USM into separate video and audio streams. Typical output files are .h264, .m2v, .adx, .hca, or .wav.
2. If the audio is ADX or HCA, decode it with a compatible audio decoder such as vgmstream, producing audio.wav or a lossless format supported by your muxer.
3. Inspect the extracted streams with ffprobe video.h264 and ffprobe audio.wav.
4. If the video and audio codecs are already supported by Matroska, mux them without re-encoding:

ffmpeg -i video.h264 -i audio.wav -map 0:v:0 -map 1:a:0 -c:v copy -c:a copy output.mkv

For an MPEG-2 elementary video stream, replace video.h264 with the relevant .m2v filename. Add additional audio files with more -i options and map each track, for example -map 2:a:0.

If the extracted video or audio is not suitable for Matroska, re-encode only that stream:

ffmpeg -i video.h264 -i audio.wav -map 0:v:0 -map 1:a:0 -c:v libx264 -crf 18 -preset medium -c:a flac output.mkv

You can also use the free converter on 101convert.com without installing software. Proprietary or encrypted USM files may fail there and with other generic converters because conversion requires USM extraction before normal video conversion.

Quality, compatibility, and limitations

Use -c:v copy whenever the extracted video is already H.264 or another Matroska-compatible codec; this avoids generation loss and is faster. Re-encoding with libx264 changes the video and may alter frame timing, so retain the original USM for archival purposes.

Audio synchronization can fail if the extractor does not preserve the original timestamps, loop points, or stream delay. Check the beginning and end of the MKV, especially for cutscenes with separate voice, music, and effects tracks. A USM may contain multiple video segments or interleaved streams, in which case the extractor must reconstruct them before FFmpeg can create a correct MKV.