Most modern systems can play these natively. On Windows, you can right-click the file and select "Open with" to choose your preferred media player .
While every system is different, strings like this usually contain: 38501-90 901531473174_Sub_f_1532163041.mp4
Deciphering the Mystery: What is "38501-90 901531473174_Sub_f_1532163041.mp4"? Most modern systems can play these natively
The _Sub_f often denotes a "Sub-stream"—a lower-resolution version of a video meant for mobile viewing or faster remote streaming. 2. How to Open These Files Security systems record two versions of every event:
If your file contains the _Sub tag, it is likely a . Security systems record two versions of every event: a high-definition "Main stream" for evidence and a "Sub-stream" for quick previews. If the footage looks pixelated, look for a corresponding file in your storage that might have _Main or a larger file size—that will be the high-quality version.
If you hear audio but see no video, you may need a codec pack like K-Lite Codec Pack to help your computer "decode" the specific compression used. 3. Why Is My Video Low Quality?
The initial numbers (like 38501-90 ) often identify the specific camera or hardware source.