AVC generally means H.264/AVC video compression, which is how the video is squeezed down, while the actual file format is usually a container like MP4, MKV, MOV, or TS that can hold AVC video along with audio tracks such as AAC, so people sometimes mix things up and label an MP4 as “an AVC file” despite the container defining the type; files ending in .avc or .h264/.264 usually contain raw AVC streams or custom exports that VLC may handle but often with weak seeking, incorrect duration, or no audio due to missing container-level indexing.

Some CCTV/DVR systems assign nonstandard file types though the video may still be standard, allowing a rename to .mp4 to work, while others need the manufacturer’s software to re-export; to identify the type quickly, open in VLC, check codec info, or run MediaInfo to see if it’s a normal container with audio, and if it shows as a raw AVC stream you typically remux it into an MP4 container to improve seeking and compatibility without recompression.

A `.mp4` file is almost always a true MP4 *container* holding compressed video plus audio, subtitle tracks, metadata, and seek/timing structure, whereas a `.avc` file is often merely a raw H.264/AVC stream or vendor-specific output; although playable, it commonly leads to strange initial playback because container elements aren’t present.

This is also why `. Here is more in regards to AVC file online tool look at our own web site. avc` recordings often have video-only streams: audio wasn’t packaged or lives separately, whereas MP4 generally combines video and audio; plus, many CCTV/DVR systems output bizarre extensions, so a file might actually be MP4/TS but mislabeled and fixed by renaming, while others rely on proprietary wrappers needing vendor software; put simply, `.mp4` means a standard structured file, and `.avc` usually means something proprietary, which explains missing audio, limited seeking, and compatibility problems.

Once you know whether the “AVC file” is simply mislabeled, a raw stream, or something proprietary, you can choose the right fix; if tools like VLC or MediaInfo report a standard container such as MP4—e.g., “Format: MPEG-4” or normal playback—renaming `.avc` to `.mp4` often restores compatibility (copy the file first), but if it’s a raw H.264 bitstream, usually indicated by “Format: AVC” with little structural info and shaky seeking, the standard solution is to remux an MP4 container without re-encoding to supply proper timing and indexing.

If the file originated from a CCTV/DVR or another system using a proprietary wrapper, the most dependable method is running it through the vendor’s export tool to MP4 or AVI, because certain closed formats don’t wrap correctly without a proper export; in those cases you’re converting from a special structure to a standard one rather than renaming, and if playback still fails, won’t open, or shows incorrect duration after remuxing, it usually signals corruption or missing sidecar/index files, meaning you must re-export from the source or retrieve the matching metadata.