Free online USM to DAT converter

What the USM format is

USM is a proprietary video container used by CRI Middleware's Sofdec system. Game developers use it for prerecorded cutscenes, menus, advertisements, and other video sequences in console and PC games. Files commonly contain CRI's video stream plus HCA or other audio data, and some releases encrypt the streams or require a game-specific key.

USM files are created by CRI Sofdec encoding tools and are usually encountered in extracted game resources rather than in consumer video cameras or editing applications. Standard media players and FFmpeg builds generally cannot open every USM variant directly, especially when the file is encrypted.

What the DAT format is

In the Video category, .dat normally refers to the MPEG-1 program stream stored on a Video CD, often under a path such as MPEGAV\AVSEQ01.DAT. It is intended for Video CD players and older hardware, not as a general-purpose extension for any video data.

DAT has broad legacy playback support, but its Video CD specification is restrictive: PAL material is normally 352×288 at 25 fps and NTSC material 352×240 at approximately 29.97 fps, with MPEG-1 video and defined audio settings. A file merely renamed from .mpg to .dat may play in some software but is not necessarily a valid Video CD sector file.

How to actually convert USM to DAT

1. Make a backup of the original USM. If it came from a game, retain any associated key, audio, or metadata files.
2. Extract the USM streams with a compatible CRI tool such as VGMToolbox's USM extraction functions or a current USM extractor/decrypter. The exact menu varies by version; choose the USM extraction or demux operation and save the resulting video or intermediate file.
3. If the extractor produces a playable file such as extracted.mkv, extracted.mp4, or extracted.avi, inspect it before encoding. If it produces separate video and audio streams, use the tool's documented remux option or combine them with FFmpeg.
4. For a Video CD-compatible MPEG-1 stream, encode with FFmpeg. Use pal-vcd for PAL material:

ffmpeg -i extracted.mkv -target pal-vcd output.mpg

For NTSC material, use:

ffmpeg -i extracted.mkv -target ntsc-vcd output.mpg

Do not use -c copy unless the extracted file is already a compliant MPEG-1 Video CD stream. Re-encoding is usually necessary because USM video parameters do not match Video CD constraints.

5. Use a Video CD authoring application to create the disc image or folder structure from output.mpg. The authoring process generates the actual AVSEQ01.DAT-style file with the required sector layout. If a player only needs an MPEG program stream with a DAT extension, a compatible .mpg can sometimes be renamed to .dat, but this does not create a standards-compliant Video CD file.

For a no-installation attempt, use the free converter on 101convert.com, upload the USM, choose DAT as the output, and download the result if the service accepts that particular USM variant. Encrypted or uncommon USM files may require desktop extraction first.

Quality, compatibility, and limitations

USM is often optimized for game playback rather than interchange, so direct conversion may fail when the file is encrypted, uses an unsupported Sofdec codec, or stores audio separately. A missing audio track after extraction usually means the USM contains a separate CRI/HCA stream that must be decoded and muxed independently.

Converting to Video CD DAT reduces resolution and commonly reduces quality through MPEG-1 re-encoding. Keep the extracted or decoded master and encode only the final copy. Check the source frame rate before selecting PAL or NTSC; choosing the wrong standard can cause stuttering, incorrect duration, or audio synchronization errors.