A .dav file is the recording format of Dahua recorders and cameras, and of the many recorders
built on Dahua's platform and sold under other names. Every frame is wrapped in a Dahua header
with the recorder's date and a millisecond counter, so ordinary players, phones and upload forms
can't open it.
How to convert DAV to MP4
- Upload the
.davfile, several of them, or a ZIP of the export folder. - Keep the settings as they are, or choose Join the clips into one video when the recorder split the export into several files.
- Download the MP4. It is named after the recording start, for example
2019-02-13_19-24-22.mp4.
What is kept
- The picture, unchanged. The H.264 video inside the DAV is copied into the MP4, not re-encoded, so the conversion is quick and loses nothing.
- The sound. G.711 sound, which MP4 players don't accept, becomes AAC; AAC sound is converted too, so every result plays the same way.
- The timing. Each frame keeps its time from the recorder's millisecond counter instead of being snapped to the whole seconds of the date stamp, so motion stays smooth. The frame rate is measured, and the report says what it was.
- The date and time. The MP4's creation time is the recording start, and an optional subtitle track shows the recorder's clock for every second.
Damaged and awkward exports
DAV exports are often cut out of a longer recording. When a file starts in the middle of a group of pictures, the frames before the first keyframe can't be decoded; the video starts at the keyframe and the report counts what was left out. A file cut off during copying loses only its last, incomplete frame, and unreadable stretches in the middle are skipped and reported.
Password-protected (encrypted) exports can't be converted: export the footage again without a password. For WhatsApp or an upload portal that refuses the original picture, choose Make it play everywhere to get H.264 at up to 1080p.
More about what this tool reads and writes: CCTV Footage to MP4.