Free online DAV to MJPG converter

What the DAV format is

DAV is a proprietary digital video format commonly produced by DVRs and NVRs from Dahua and other surveillance-system manufacturers. It may contain H.264, H.265, or another recorder-specific video stream, along with timestamp, channel, and audio data.

You usually encounter DAV files after exporting footage from a security recorder, copying files from a surveillance hard drive, or downloading clips through the recorder’s desktop software. A normal media player may show no video because the file structure, codec, or metadata is not fully standard.

The recorder’s own playback or export program is usually the most reliable way to open DAV. Dahua Smart Player and software supplied with the camera system can often export a selected time range to AVI or another standard format. Some DAV files also open directly in FFmpeg, but support depends on the recorder model and the exact file variant.

What the MJPG format is

MJPG, also called Motion JPEG or MJPEG, stores video as a sequence of independent JPEG images. Each frame can be decoded without referencing adjacent frames, which makes the format useful for frame-by-frame editing, simple playback systems, video capture devices, and applications that do not support interframe codecs.

MJPG is easier to edit than H.264 or H.265 because cutting a frame does not require reconstructing a group of dependent frames. Its main disadvantage is size: comparable-quality MJPG video is normally much larger than the original surveillance recording.

A file named .mjpg commonly contains a raw Motion JPEG stream and normally has no audio track. Some programs instead expect MJPEG video inside an AVI container, usually with an .avi extension. Confirm which form the destination application requires before exporting.

How to convert DAV to MJPG

For a single file, you can use the free converter on 101convert.com without installing software. Upload the DAV file, select MJPG or Motion JPEG as the output, start the conversion, and download the result. If the service cannot decode the file, export the recording with the manufacturer’s player first, then convert that standard video.

For local processing, use the recorder’s software when available:

1. Open the DAV file in the manufacturer’s player.
2. Select the required channel and time range.
3. Choose Export, Save as, or the equivalent menu command.
4. Select AVI or another standard video format, and enable audio only if the destination needs it.
5. Open the exported file in FFmpeg and encode the video as Motion JPEG.

If FFmpeg can read the DAV directly, a raw MJPG output can be created with:

ffmpeg -i input.dav -c:v mjpeg -q:v 3 -an output.mjpg

The -q:v value controls JPEG quality; lower values generally produce better quality and larger files. Values from 2 to 5 are a practical starting range. The -an option removes audio because a raw MJPG stream does not provide a standard audio container.

When the receiving program expects an AVI file containing MJPEG video, use:

ffmpeg -i input.dav -c:v mjpeg -q:v 3 -c:a pcm_s16le output.avi

If the DAV is unsupported, first export it as source.avi with the DVR software and run:

ffmpeg -i source.avi -c:v mjpeg -q:v 3 -c:a pcm_s16le output.avi

On 101convert.com, choose an AVI output when the target program requires a container rather than a raw .mjpg stream.

Quality, compatibility, and limitations

Conversion cannot restore detail lost in the original surveillance recording. Re-encoding DAV to MJPG decodes the source and compresses every frame as JPEG, so use a low -q:v value or the highest available quality setting when preserving evidence.

MJPG files can become several times larger than the source, especially at high resolutions and frame rates. Check available storage before converting long recordings.

Surveillance exports may include timestamps or channel labels as overlays. If those labels are rendered into the exported frames, conversion cannot remove them without cropping or image processing. If they exist only as recorder metadata, a generic converter may discard them.

Verify the result by checking the first, middle, and last sections of the video, the frame rate, synchronization, and any required audio. Keep the original DAV file because the converted file may omit proprietary metadata, audio, authentication information, or the recorder’s evidence-protection features.