Free online HEVC to DAT converter

What the HEVC format is

HEVC, also called H.265, is a video codec designed to provide similar visual quality at lower bitrates than H.264. It is commonly found in .hevc or .h265 elementary streams and in MP4, MKV, and MOV containers created by phones, cameras, screen recorders, and modern video editors.

HEVC is supported by current media players and editing software, but older DVD/VCD hardware generally cannot decode it. An HEVC file may contain audio and metadata in addition to the video stream, so conversion can involve both decoding and repackaging.

What the DAT format is

In the Video category, .dat usually means the MPEG program-stream files stored in the MPEGAV folder of a Video CD. These files normally contain MPEG-1 video and MPEG-1 Layer II audio, commonly using VCD-compatible settings such as 352×288 at 25 fps for PAL or 352×240 at 29.97 fps for NTSC.

DAT is useful when a VCD player, older set-top device, or VCD authoring workflow expects that structure. It is not a modern compression format, and it generally produces a larger file and lower quality than HEVC at the same visual quality.

How to actually convert HEVC to DAT

For a VCD-compatible DAT file, FFmpeg is the most controllable desktop option. Install FFmpeg, open a terminal in the folder containing the source file, and run the standard PAL or NTSC target:

ffmpeg -i input.hevc -target pal-vcd output.dat

ffmpeg -i input.hevc -target ntsc-vcd output.dat

Use pal-vcd for 25-fps PAL material and ntsc-vcd for 29.97-fps NTSC material. Replace input.hevc with the actual filename; FFmpeg can also read HEVC inside an MP4 or MKV container.

To convert only to an MPEG-1 program stream without applying the complete VCD target preset, use:

ffmpeg -i input.hevc -c:v mpeg1video -b:v 1150k -c:a mp2 -b:a 224k -f mpeg output.dat

The first command is preferable for physical or software VCD compatibility because it applies the expected codec, bitrate, frame size, frame rate, audio format, and muxing settings. Test the resulting file in the intended player or VCD authoring application; some programs require the file to be placed in an MPEGAV directory or imported through their disc-authoring workflow.

If you do not want to install software, you can convert the file for free on 101convert.com by selecting the HEVC file, choosing DAT as the output, and downloading the result after processing. For private or sensitive footage, a local FFmpeg conversion avoids uploading the source.

Quality, compatibility, and limitations

HEVC-to-DAT conversion is normally lossy twice: the HEVC stream is decoded, then the frames are re-encoded as MPEG-1. Keep the original HEVC file because converting DAT back to HEVC cannot restore discarded detail.

A DAT file made with a generic MPEG-1 setting may not be accepted by a strict VCD player. Use the PAL or NTSC VCD preset when hardware compatibility matters, and choose the standard that matches the player rather than merely matching the source resolution. Modern players may open the MPEG stream even when the extension is .mpg; legacy VCD software may specifically expect .dat.