What is the AVC file format?
The .avc file extension is used by MPEG-4 AVC (Advanced Video Coding, standardized as H.264) encoded video files. .avc files store video data only - most are raw H.264 elementary streams structured as a sequence of NAL units with Annex B start-code prefixes (00 00 00 01), carrying no audio, no duration, and no container wrapper. Multimedia containers, such as .m2ts or .mts, typically carry AVC video data alongside audio inside a proper container - a bare .avc file does not. A minority of .avc files are actually .mp4 or MOV files renamed with the .avc extension; those begin with an ftyp box at byte offset 4 and can be played normally by renaming them back to .mp4.
Advantages of the AVC standard
MPEG-4 AVC offers higher compression rates and better image quality while maintaining lower bandwidth requirements than its predecessors (MPEG-2, H.263, etc.). The AVC standard is considered universal, supported by a wide range of applications, systems, and technologies, including Blu-ray, .mkv-based streaming, broadcast TV, digital streaming, and VoIP. Because .avc is a raw stream, however, many standard media players will refuse to open it; tools such as VLC and ffmpeg handle it reliably.
Security & safety
RISK: LOWA raw .avc stream is inert video data, not executable, so it's safe to play and remux. Two practical notes: crafted streams have occasionally triggered decoder bugs, so keep VLC/ffmpeg updated; and if the footage is evidence (CCTV/capture), remux with '-c copy' (lossless) rather than re-encoding to preserve the original frames. Online converters upload your video to a third party - remux locally with ffmpeg for anything private. Note that a Kaspersky .avc database file is not video; don't try to play or convert it.
Format details
in a nutshell- Kaspersky Anti-Virus Database - Some Kaspersky products store virus-definition update data in .avc files; these are not video and open only inside the antivirus.
- Avid Media Composer Script - Avid editing software can save a script/transcript file with the .avc extension, unrelated to the video codec.
Programs that open AVC files
Windows2 apps
VLC media player
Open-source Drag the .avc onto VLC; if it won't play, set Preferences > Input/Codecs > Demuxers > 'H264 video demuxer'. 
FFmpeg
Open-source Remux losslessly: 'ffmpeg -i in.avc -c copy out.mp4' (add '-framerate 25' if there's no timing). Use out.mkv if MP4 errors. 
macOS2 apps
FFmpeg
Open-source 'ffmpeg -i in.avc -c copy out.mp4' wraps the stream in a container without re-encoding. 
Linux2 apps
Android1 app
VLC for Android
Open-source Open the .avc in VLC; it handles H.264 streams most other Android players reject. Technical details
deep spec| File structure | Raw H.264 Annex B elementary stream; no container wrapper, no audio track, and no duration metadata |
| Video codec | H.264 / MPEG-4 Part 10 (AVC) |
| MIME type | `video/h264` |
| File signature | NAL unit start-code `00 00 00 01` at offset 0, typically followed by SPS byte `0x67` then PPS byte `0x68` |
| Audio support | None - `.avc` carries video data only; audio requires a container format such as `.mp4` or `.mkv` |
| H.264 profiles | Baseline, Main, High, High 10, High 4:2:2, High 4:4:4 Predictive |
| Chroma subsampling | 4:2:0 in standard profiles; up to 4:4:4 in High 4:4:4 Predictive profile |
| Bit depth | 8-bit (standard); up to 14-bit in High 10 and High 4:4:4 profiles |
| NAL start-code variant | 3-byte (`00 00 01`) or 4-byte Annex B (`00 00 00 01`) prefix; 4-byte form is most common in `.avc` files |
| Maximum resolution | Up to 8192×4320 at Level 6.2; commonly used at 1080p (Level 4.1) and 4K UHD (Level 5.1) |
| Maximum bitrate | Up to ~300 Mbit/s at Level 6.2 High profile; Blu-ray disc streams use up to 40 Mbit/s |
| Frame types | I-frames (intra-coded), P-frames (predictive) and B-frames (bi-directional); B-frame support improves compression over MPEG-2 |
| Lossy/lossless | Lossy by default; lossless encoding possible via QP=0 in High 4:4:4 Predictive profile |
| Renamed-file caveat | A minority of `.avc` files are renamed `.mp4` or `.mov`; these begin with an `ftyp` box at byte offset 4 and play normally if renamed back |
| Player compatibility | Raw `.avc` elementary streams are rejected by many players; VLC and `ffmpeg` handle them reliably; most OS-native players require a container |
| Released | H.264/AVC standard finalized 2003 (ITU-T Rec. H.264 / ISO/IEC 14496-10) |
| Open standard | Yes · royalty-free |
| Specification | www.itu.int |
AVC conversions
Community Q&A
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