Free online MP4 to DAT converter

Video CD players and VCD authoring software may require an MPEG-1 program stream with a .dat extension instead of a modern MP4. The conversion is therefore a compatibility step for legacy VCD playback or disc creation, not a way to improve image quality.

What the MP4 format is

MP4 is the MPEG-4 Part 14 multimedia container. It commonly contains H.264 or H.265 video and AAC audio, but it can also store other codecs, subtitles, metadata, and multiple streams.

Phones, cameras, screen-recording applications, video editors, streaming software, and tools such as Adobe Premiere Pro, DaVinci Resolve, and FFmpeg create MP4 files. Computers, televisions, browsers, and mobile devices support MP4 widely because it can provide good image quality at relatively small file sizes.

What the DAT format is

For video, .dat most commonly identifies the MPEG-1 program-stream files used by Video CDs. A VCD normally stores video in a path such as MPEGAV\AVSEQ01.DAT, using MPEG-1 video and MPEG-1 Layer II audio.

VCD DAT files are useful when an older VCD player, set-top player, or authoring program expects the disc format. Their fixed MPEG-1 specifications improve compatibility with that equipment, but they provide much lower resolution and compression efficiency than modern MP4 files. The extension alone does not define the contents: renaming an MP4 to .dat changes only its name.

Convert with FFmpeg

FFmpeg provides the most reliable control when the destination is a VCD-compatible DAT file. First determine whether the target uses PAL or NTSC; use PAL for equipment designed for most European regions and NTSC for equipment designed for North America, Japan, and other NTSC regions.

1. Install FFmpeg and open a terminal or command prompt in the folder containing the source file.
2. For a PAL VCD, run:
   ffmpeg -i input.mp4 -target pal-vcd -f mpeg output.dat
3. For an NTSC VCD, run:
   ffmpeg -i input.mp4 -target ntsc-vcd -f mpeg output.dat
4. Play output.dat in an MPEG-compatible player or import it into VCD-authoring software.
5. When creating a physical disc, let the authoring program build the VCD filesystem and directory structure; do not copy the DAT file to a disc as an ordinary data file.

The pal-vcd and ntsc-vcd presets select the usual MPEG-1 video, Layer II audio, frame rate, resolution, bitrate, and program-stream settings. If the MP4 contains multiple streams, select the intended video and audio explicitly, for example -map 0:v:0 -map 0:a:0.

Convert without installing software

You can convert the file for free on 101convert.com by selecting the MP4, choosing DAT as the output format, starting the conversion, and downloading the result. If the file will be used for a physical VCD, verify that the output is a VCD-compatible MPEG-1 program stream; a generic file with a .dat extension may not satisfy the player or authoring software.

Quality and compatibility limits

Standard VCD video is approximately 352×288 pixels at 25 fps for PAL or 352×240 pixels at 29.97 fps for NTSC. MPEG-1 video is commonly encoded near 1.15 Mb/s, with MPEG-1 Layer II audio commonly at 224 kb/s. High-resolution MP4 footage must therefore be downscaled and re-encoded, which removes detail and can introduce blocking or blur.

Use the television standard required by the player; some hardware rejects the opposite standard. Variable-frame-rate phone recordings may need frame-rate conversion, and damaged, DRM-protected, or unsupported source codecs can prevent decoding. Conversion also does not preserve modern MP4 features such as H.265 compression, multiple audio tracks, or advanced subtitles when the VCD target has no support for them.