Free online DAV to MP4 converter

Footage exported from a DVR or NVR may be saved as a .dav file that ordinary players, editors, case-management systems, and mobile devices cannot open. Converting a viewing or sharing copy to MP4 provides wider playback and editing support while the original surveillance export remains intact.

What the DAV format is

DAV is a proprietary surveillance-video format used mainly by Dahua Technology DVRs, NVRs, and related client software. Some other surveillance products also use the .dav extension, so the extension alone does not identify the video codec, audio codec, metadata, encryption, or required playback utility.

A DAV export can contain H.264/AVC, H.265/HEVC, or older video streams, optional audio, timestamps, camera information, and recorder-specific verification data. Dahua Smart Player and SmartPSS can open DAV files created by supported Dahua systems, but VLC, HandBrake, and FFmpeg may not recognize every DAV variant. Renaming recording.dav to recording.mp4 changes only the filename; it does not convert the container or video streams.

What the MP4 format is

MP4 is a standardized multimedia container. For the broadest compatibility, an MP4 should contain H.264 video and AAC audio; this combination is widely supported by current Windows and macOS software, phones, browsers, media players, and video editors.

MP4 can also contain H.265/HEVC, but HEVC playback is less consistent on older devices, browsers, televisions, and editing systems. Converting HEVC footage to H.264 improves compatibility but requires re-encoding and creates a larger file at a comparable visual quality.

Convert the DAV file online

1. Keep the original DAV export unchanged and work from a copy.
2. Upload the copy to the DAV-to-MP4 converter on 101convert.com.
3. Select MP4 as the output format, start the conversion, and download the converted file.
4. Open the MP4 in the intended player or editor and check its beginning, middle, and end.

The converter can be used free without installing software. Do not upload security footage containing identifiable people, private locations, access details, or evidence material unless online processing complies with the applicable privacy, retention, and evidence-handling requirements.

Use the recorder software when available

The recorder manufacturer’s software is the best first option for a proprietary or rejected DAV file because it understands the recorder-specific layout and metadata. In Dahua Smart Player or SmartPSS, open the DAV copy, verify the camera channel, date, time, image, and audio, then use the available Export, Save As, or conversion function to create MP4. Exact menu names and output choices vary by software release and recorder model.

If the software cannot export MP4, export to a standard playable format such as AVI or ASF, then convert that intermediate file to H.264/AAC MP4. Preserve the source resolution and frame rate unless a smaller delivery copy is required; upscaling cannot add camera detail.

Use FFmpeg for recognized files

FFmpeg is useful only when it can identify and decode the DAV file, or after vendor software has exported a standard intermediate file. Inspect the file first:

ffprobe input.dav

If FFmpeg recognizes MP4-compatible streams and reports valid timestamps, try remuxing without re-encoding:

ffmpeg -i input.dav -c copy output.mp4

Stream copying is fast and does not alter the encoded video or audio, but it fails when the DAV structure is unsupported or when its codecs, timestamps, or streams are unsuitable for MP4. If the output does not play reliably, re-encode a vendor-exported AVI or other supported file:

ffmpeg -i input.avi -map 0:v:0 -map 0:a? -c:v libx264 -crf 18 -preset medium -c:a aac -b:a 128k -movflags +faststart output.mp4

-crf 18 retains more detail and produces a larger file; values around 20 to 23 reduce file size with more compression. Do not force a guessed frame rate: an incorrect value can change playback speed, create time drift, or duplicate and drop frames.

Quality and evidence limitations

Re-encoding cannot restore detail absent from the camera recording and may reduce fine detail in faces, plates, or motion. Test for missing audio, incorrect aspect ratio, dropped frames, time drift, and playback failures in the destination application.

An MP4 may omit proprietary camera identifiers, motion data, authentication information, multi-camera layout data, and watermark-verification data. A timestamp burned into the image remains visible, but its original verification status may not survive conversion.

Keep the untouched DAV file and its associated export metadata as the master. For legal or investigative material, retain the original export, document the recorder and software versions and export settings, and follow the organization’s hashing and chain-of-custody procedure. Treat the MP4 as a derivative viewing or editing copy.