Free online H264 to DAT converter

What the H.264 format is

H.264, also called AVC, is a video codec used in MP4, MKV, MOV, TS, and camera-recording files. Phones, cameras, screen recorders, security systems, video editors, and streaming applications commonly create H.264 video. A file ending in .h264 may contain only a raw H.264 video stream, so it may have no audio, timestamps, or container metadata.

What the DAT format is

For video applications, .dat usually refers to the MPEG-1 program stream stored by a Video CD, often as MPEGAV/AVSEQ01.DAT. It is designed for VCD players and authoring software, not modern playback efficiency. Standard VCD video uses MPEG-1 at 352×288 pixels and 25 fps for PAL or 352×240 pixels and approximately 29.97 fps for NTSC, with MPEG-1 Layer II audio at 44.1 kHz when audio is present.

DAT is useful when compatibility with VCD-era equipment or disc-authoring software matters. It does not provide a smaller or higher-quality result than H.264; conversion normally increases file size and reduces quality because it uses an older codec and fixed low resolution.

How to convert H.264 to DAT

For a desktop conversion, FFmpeg is suitable because its VCD presets set the required MPEG-1 video, frame size, frame rate, bitrate, and audio parameters.

1. Install FFmpeg and place the source file in an accessible folder.
2. Choose the television standard required by the player: use pal-vcd for PAL or ntsc-vcd for NTSC.
3. For a source that already contains audio, run one of these commands:

ffmpeg -i input.h264 -target pal-vcd output.dat
ffmpeg -i input.h264 -target ntsc-vcd output.dat

For a raw H.264 stream, explicitly identify the input format:

ffmpeg -f h264 -i input.h264 -target pal-vcd output.dat

A raw .h264 file generally has no audio. If a separate audio file is available, map the video and audio streams explicitly:

ffmpeg -f h264 -i video.h264 -i audio.wav -map 0:v:0 -map 1:a:0 -target pal-vcd output.dat

If FFmpeg does not accept the .dat extension, write output.mpg instead and rename it to AVSEQ01.DAT only after conversion. For a real Video CD, use disc-authoring software to create the required MPEGAV directory and filesystem structure; renaming a file alone does not create a playable VCD.

You can also convert the file for free on the 101convert.com website without installing software. Select the video conversion option, upload the H.264 file, choose DAT or the VCD-compatible output when available, convert it, and download the result.

Quality and compatibility limitations

The conversion is lossy twice if the source is already compressed: H.264 is decoded and then encoded as MPEG-1. Keep the original H.264 file for archival use. Match PAL or NTSC to the target player, and verify that the source has a compatible duration and aspect ratio because VCD output is limited to low fixed resolution. A DAT file made from H.264 is not automatically valid VCD media; older players may require a properly authored and finalized disc.