Free online H265 to DAT converter

What the H.265 format is

H.265, also called HEVC, is a video compression standard designed to deliver similar visual quality to H.264 at lower bitrates. Phones, action cameras, CCTV systems, screen recorders, and video editors may create H.265 video in containers such as MP4, MKV, or MOV; some devices also save a raw `.h265` or `.hevc` elementary stream.

H.265 is not the same thing as a container. The extension identifies the file or container convention, while the codec determines how the video is encoded. A DAT file cannot normally contain H.265 when compatibility with a Video CD player is required.

What the DAT format is

For video, `.dat` usually means the MPEG-1 program stream used on a Video CD. It contains MPEG-1 video and commonly MPEG-1 Layer II audio, rather than defining a separate modern codec. Video CD specifications generally use 352×288 at 25 fps for PAL or 352×240 at approximately 29.97 fps for NTSC, with about 1,150 kbit/s video and 224 kbit/s audio.

DAT is useful for legacy VCD players, older set-top equipment, and authoring software that expects a VCD-compatible MPEG stream. It has wide compatibility with that hardware but substantially lower efficiency and resolution than H.265.

How to actually convert H.265 to DAT

You can use the free converter on 101convert.com without installing software. Select the H.265 input, choose DAT as the output, start the conversion, and download the generated file. Check the result on the intended player because some converters create a file with a `.dat` extension without enforcing the full Video CD specification.

For controlled, repeatable output, FFmpeg is the most practical desktop tool. Install FFmpeg, open a terminal in the folder containing the source, and use a PAL command such as:

ffmpeg -i input.mp4 -target pal-vcd output.dat

For NTSC output, use:

ffmpeg -i input.mp4 -target ntsc-vcd output.dat

The `-target` preset selects MPEG-1 video, the appropriate frame size and frame rate, VCD-compatible bitrate settings, and MPEG audio when a compatible audio stream exists. Replace `input.mp4` with the actual H.265-containing filename; the input can also be an MKV or MOV file.

A raw H.265 stream often has no audio and may not contain timing information. Convert it explicitly as PAL video with no audio:

ffmpeg -f hevc -i input.h265 -an -c:v mpeg1video -b:v 1150k -vf scale=352:288,fps=25 -f vcd output.dat

For a raw NTSC stream, use:

ffmpeg -f hevc -i input.h265 -an -c:v mpeg1video -b:v 1150k -vf scale=352:240,fps=30000/1001 -f vcd output.dat

If the source has audio, omit `-an` and use an audio-capable VCD preset instead. A source with unusual dimensions may need cropping or padding before scaling; automatic stretching can distort the picture.

Quality and compatibility limitations

This conversion is lossy twice: the original H.265 compression is decoded, then the video is re-encoded as lower-efficiency MPEG-1. Converting to DAT cannot recover detail, and increasing the output resolution provides no quality improvement.

Choose PAL or NTSC to match the target player. The `.dat` extension alone does not guarantee VCD compliance; verify the codec, frame size, frame rate, bitrate, audio format, and MPEG program-stream structure when authoring a physical disc. A DAT file made for VCD playback is unsuitable for modern streaming workflows unless it is converted again to a current container and codec.