AVC commonly refers to H.264/AVC, a video codec 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 cameras create files with unexpected extensions even though the inner format is normal, so simply renaming to .mp4 may solve playback, but some recordings require the vendor’s player to convert; the quickest check is VLC playback plus codec info or a MediaInfo scan to confirm a standard container (MP4/MKV/TS), and if it appears as a raw AVC stream the common fix is to remux into an MP4 container for compatibility without re-encoding.

A `.mp4` file works as a full-featured MP4 *container*—with organized video, audio, indexes, timing data, and metadata—while a `.avc` file typically lacks these container elements and is simply a raw AVC stream or device-specific file; it can decode, but players may show odd starting behavior since crucial structural information isn’t included.

This is also why `.avc` files frequently have no built-in sound: audio might be stored separately or never included at all, while MP4 commonly bundles both streams; plus, some CCTV/DVR systems mislabel their exports, so a file that’s really MP4 or TS could appear as `. If you enjoyed this short article and you would like to get more facts pertaining to AVC file structure kindly see the webpage. avc` until renamed to `.mp4`, though certain devices use proprietary wrappers that require their own players; ultimately, `.mp4` tends to represent a fully structured file, whereas `.avc` often signals raw H.264 only, which explains missing audio, poor seeking, and playback quirks.

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 repackage it into an MP4 container without re-encoding, adding essential timing and indexing data for proper playback.

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.