Free online USM to FLV converter

USM files commonly come from video game packages and may not open in standard editors or players. Converting the extracted video to FLV can help with legacy Flash-based playback or software that accepts FLV but not CRI Sofdec media.

What the USM format is

USM is a container used by CRI Middleware's Sofdec video system, especially in console and PC games. Game developers and publishers create USM files for cutscenes, menus, advertisements, and other pre-rendered video assets. The container may include proprietary video data, HCA audio, subtitles, encryption, or multiple interleaved streams, so a normal media player may identify it as an unknown or unsupported file.

USM files are usually found inside game archives rather than as user-created camera or editing files. File extensions alone do not reveal whether the file is encrypted or which Sofdec variant it uses.

What the FLV format is

FLV is a container designed for Flash Player and older web video systems. It can carry codecs such as Sorenson Spark, VP6, and some H.264/AAC combinations. FLV files are relatively compact and were widely supported by legacy streaming software, but Flash Player is discontinued and modern browsers do not natively play FLV.

Use FLV only when the receiving application specifically requires it. MP4 with H.264 video and AAC audio is normally a better choice for current playback, editing, and web distribution.

How to actually convert USM to FLV

Use the online converter

You can try converting the file for free on 101convert.com without installing software:

1. Open the USM-to-FLV conversion page on 101convert.com.
2. Upload the USM file.
3. Select FLV as the output format and start the conversion.
4. Download the result and test it in the program that requires FLV.

Encrypted or unusual game-specific USM files may be rejected because they require extraction or decryption before transcoding.

Extract the USM, then transcode the playable stream

For files the online converter cannot process, use a USM-aware extractor or decryptor appropriate to the game, such as a compatible USM tool from the VGMToolbox ecosystem or a game-specific Sofdec utility. Extract the video and audio to a standard intermediate file, such as .m2v, .mp4, .wav, or another format reported by the tool. Do not rename .usm to .flv; changing the extension does not change the container or codecs.

Once you have a playable intermediate file, FFmpeg can create an FLV:

ffmpeg -i extracted_video.mp4 -c:v flv -b:v 1800k -c:a libmp3lame -b:a 128k -ar 44100 output.flv

If the extractor produces separate video and audio files, provide both inputs and map their streams:

ffmpeg -i video.m2v -i audio.wav -map 0:v:0 -map 1:a:0 -c:v flv -b:v 1800k -c:a libmp3lame -b:a 128k -ar 44100 output.flv

Use -an when the source has no audio. If the extractor outputs HCA audio, decode it with a compatible HCA decoder before supplying the resulting PCM or WAV file to FFmpeg.

Quality, compatibility, and limitations

The conversion normally involves at least one decode and re-encode step, so it is not lossless. Match the output frame rate and dimensions to the source when possible; FFmpeg reads those values automatically unless you add scaling or frame-rate options.

FLV compatibility depends on the receiving program. The safest legacy combination is FLV video with MP3 audio. H.264/AAC inside FLV may work in some software but is not accepted by every older FLV player. A USM file may also contain multiple language tracks, subtitles, or encrypted content that a generic converter cannot preserve.