AVC commonly refers to H. If you have any questions relating to wherever and how to use AVC file structure, you can speak to us at our own webpage. 264/AVC, a encoding method rather than a file container, and most videos you encounter are actually MP4, MKV, MOV, or TS containers that simply include an AVC-encoded track plus audio, which creates the habit of calling the entire file an "AVC file" even though the container is what defines the file type; when the extension is .avc or .h264/.264, it often signals a raw bitstream or device-specific output that VLC may play but with limited seeking, inaccurate timing, or no audio because true containers provide indexes and multiple streams.

Some CCTV/DVR units use strange extension schemes despite the content being standard, so renaming to .mp4 often works unless the file is genuinely proprietary and must be processed in the vendor’s export tool; the fastest approach is testing in VLC, checking codec details, or using MediaInfo to see if it’s a proper container format with audio, and if it’s actually a raw AVC stream you’ll usually need to wrap into an MP4 container for smoother playback and navigation.

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 wrong duration reports because essential container-level information is absent.

This is also why `.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 real container with indexing, and `.avc` usually means something proprietary, which explains missing audio, limited seeking, and compatibility problems.

Once you confirm what your "AVC file" actually represents—misnamed MP4, raw H.264, or proprietary—the next action is straightforward; if MediaInfo or VLC identifies it as a regular container like MP4 (showing "Format: MPEG-4" or smooth seeking), renaming `clip.avc` to `clip.mp4` usually works, provided you make a backup; if instead the file is raw AVC (often shown as "Format: AVC" with minimal metadata and clumsy navigation), you should embed it into an MP4 container without re-encoding to add the indexing and timing structure missing from raw streams.

If the footage originates from a CCTV/DVR or similar device using a custom container, the surest route is using the vendor tool to export to MP4 or AVI, since some proprietary formats won’t convert without errors without an official export; in those cases you’re transforming a proprietary structure into a standard container, and if the file still fails—corrupted playback, no opening, wrong duration post-remux—it typically means incomplete data or missing index files, so the remedy is re-exporting or finding the required companion metadata.