AVC usually means H.264/AVC compression, which is the codec behind the video rather than the file container, and common formats like MP4, MKV, MOV, or TS just include AVC video alongside audio, leading to mix-ups where users call an MP4 "an AVC file" even though MP4 is the container; when you see extensions like .avc or .h264/.264, they often represent raw streams or specific device exports that may open in VLC but can lack proper seeking, accurate timing, or audio because containers normally deliver indexing and multi-track support.

Some CCTV/DVR systems use odd or misleading extensions even when the contents are standard, so a clip may be misnamed and work once renamed to .mp4, though some files are truly proprietary and require the vendor’s player to re-export; the quickest way to check is to open it in VLC, inspect codec details, or run MediaInfo to see if it’s a real container like MP4/MKV/TS with audio, in which case renaming often helps, while raw AVC streams usually need to be wrapped into an MP4 container for better compatibility and seeking without re-encoding.

A `.mp4` file is normally a standard MP4 *container*, offering organized video, audio, timing, indexing, subtitles, and metadata, but a `.avc` file is frequently just a raw H.264/AVC stream or device-specific output with none of that structure; it can decode, yet players might show slow seeking because essential container-level information is absent.

This is also why `.avc` files commonly contain no accompanying soundtrack: audio may not be bundled and might live elsewhere, while MP4 typically includes both; further confusion comes from CCTV/DVR exports that use nonstandard extensions, meaning a mislabeled `.avc` might behave normally if renamed to `. Should you loved this article and you would like to receive more information concerning AVC file type kindly visit the site. mp4`, though some require proprietary exporters; overall, `.mp4` suggests complete multimedia packaging, while `.avc` often suggests vendor-specific wrapping, which leads to missing audio and poor seek accuracy.

Once you’ve determined whether the "AVC file" is mislabeled, raw H.264, or proprietary, you can pick the right fix; when VLC/MediaInfo shows a standard container—look for "Format: MPEG-4" or normal seek behavior—just renaming the `.avc` to `.mp4` often restores compatibility (after copying it), but if the file is a raw H.264 stream indicated by "Format: AVC" with sparse container details and erratic seeking, then the usual remedy is to wrap it into an MP4 container without re-encoding, adding essential timing and indexing data for proper playback.

If the recording was produced by a CCTV/DVR or any system with a unique wrapper, the dependable approach is running it through the vendor’s playback/export utility to produce an MP4 or AVI, because many proprietary formats won’t wrap properly unless exported through their own tools; that’s a real conversion rather than a rename, and if the file continues to show corruption, refuses to open, or retains an incorrect duration after remuxing, it usually signals an incomplete clip or missing index/metadata files, meaning you need to re-export or locate the associated data.