Free online DAV to M2T converter

What the DAV format is

DAV is a proprietary surveillance-video container commonly created by Dahua DVRs, NVRs, and compatible security cameras. It can contain recorded video, audio, timestamps, and other recorder-specific data, and may use encoding or metadata that ordinary media players do not recognize.

You typically encounter DAV files after exporting incident footage from a CCTV recorder or downloading recordings through Dahua management software. Dahua Smart Player and some recorder utilities can open the files; VLC, FFmpeg, and video editors may not read every DAV variant directly.

What the M2T format is

M2T is a filename extension commonly used for an MPEG-2 transport stream, especially HDV recordings. The container carries MPEG-2 video and usually MPEG-1 Layer II audio in a stream structure designed for transport, broadcast, and camcorder workflows.

M2T is useful when a receiving application expects MPEG-2 transport-stream media rather than a proprietary surveillance file. It is broadly documented and easier to process than DAV, but it normally produces larger files than modern H.264 or H.265 formats at comparable visual quality.

How to convert DAV to M2T

Using the built-in online converter

You can convert the file on 101convert.com for free without installing software:

1. Open the DAV-to-M2T conversion page.
2. Upload the DAV recording and select M2T as the output format.
3. Start the conversion and download the resulting .m2t file when processing finishes.

Proprietary DAV variants are not universally supported by online converters. If the upload is rejected or the output has no video, first export the recording to a standard intermediate format with the recorder manufacturer's software.

Using Dahua Smart Player and FFmpeg

1. Open the DAV file in Dahua Smart Player or the playback utility supplied with the recorder.
2. Use the program's Convert, Export, or Save as function to create an AVI or MP4 file. Menu names vary between Smart Player releases; export the original time range and retain the source frame rate.
3. Check the intermediate file with a standard player. If it contains the required footage, run FFmpeg:

ffmpeg -i exported.mp4 -c:v mpeg2video -b:v 25M -minrate 25M -maxrate 25M -bufsize 1780k -c:a mp2 -b:a 384k -f mpegts output.m2t

Replace exported.mp4 with the actual intermediate filename. The command encodes MPEG-2 video, MP2 audio, and an MPEG transport stream; the .m2t extension identifies the output for applications that use that convention.

For a smaller surveillance clip, replace -b:v 25M -minrate 25M -maxrate 25M with a suitable lower bitrate, such as -b:v 8M. The receiving system may require a specific resolution, frame rate, audio format, or constant bitrate, so use its specification instead of assuming HDV settings.

Quality and compatibility limitations

Conversion cannot recover detail that was absent from the DAV recording. Re-encoding the exported video to MPEG-2 introduces another generation of compression and can enlarge a short CCTV clip substantially.

Some DAV files contain recorder authentication, proprietary timestamps, multiple camera channels, or encryption. A normal M2T file generally preserves only the decoded audio and video, not the original surveillance database, search index, watermark metadata, or recorder controls. Keep the original DAV file when evidentiary integrity or later verification matters.

M2T is a container label rather than a guarantee of one exact profile. Test the result in the target editor or device; an MPEG-2 transport stream with H.264 video, unusual audio, or unsupported dimensions may still be rejected even though its extension is .m2t.