Free online FLV to DAT converter

Some older VCD players and authoring tools expect video stored as an MPEG program stream with a .dat filename, while FLV files are mainly legacy web-video files. Converting usually means transcoding the FLV to VCD-compatible MPEG-1 video and, when required, placing that stream in a VCD image.

What the FLV format is

FLV, or Flash Video, is a container created for Adobe Flash playback. Legacy websites, Adobe Flash Media Server, browser-based video platforms, screen-recording applications, and older editing or encoding tools commonly produced FLV files. An FLV can contain video encoded with Sorenson Spark, VP6, or H.264 and audio encoded with MP3, AAC, or other codecs.

Modern video players such as VLC and FFmpeg can usually read FLV directly, but many standalone disc players and VCD authoring applications cannot use its codecs or container structure.

What the DAT format is

For video files, DAT normally means the MPEG program-stream file used in the MPEGAV directory of a Video CD. It is not a separate video codec: a VCD DAT generally contains MPEG-1 video and MPEG-1 Layer II audio in a VCD-compliant program stream.

VCD DAT files are useful when compatibility with older VCD players, optical-disc software, or hardware that expects the standard AVSEQ##.DAT naming scheme is required. VCD encoding uses fixed limits, including 352×288 pixels for PAL or 352×240 pixels for NTSC, approximately 1,150 kbit/s MPEG-1 video, and 44.1 kHz audio. The format is widely compatible with legacy equipment but normally produces lower quality than the original FLV and is not an efficient modern archive format.

How to actually convert FLV to DAT

FFmpeg is the most controllable desktop method. Install FFmpeg, place the source file in an accessible folder, and run the command matching the video standard:

• PAL: ffmpeg -i input.flv -target pal-vcd -f mpeg output.dat
• NTSC: ffmpeg -i input.flv -target ntsc-vcd -f mpeg output.dat

The -target option applies the required VCD-oriented MPEG-1 video, audio, frame rate, resolution, bitrate, and muxing settings. The explicit -f mpeg option tells FFmpeg to write an MPEG program stream even though the output extension is .dat.

If a particular application rejects the DAT extension, create an MPEG file first and rename it afterward:

Then rename output.mpg to AVSEQ01.DAT. Renaming changes only the filename; it does not convert the data. The file must already contain a VCD-compatible MPEG-1 stream.

For an actual Video CD, a DAT file alone may not be enough. Use a VCD authoring tool such as VCDImager to build the disc image from the compliant MPEG stream, then burn the generated BIN/CUE image. The authoring process creates the required VCD directory and sector layout; copying a renamed DAT file to a data disc does not create a playable Video CD.

For a conversion without installing software, the built-in converter at 101convert.com can process the file for free. Select FLV as the input and DAT as the output, upload the source, start the conversion, and save the resulting file. Check the output against the requirements of the target player because generic DAT output may not include a complete VCD disc structure.

Quality and compatibility limits

VCD conversion is normally lossy. If the FLV is already low-resolution or highly compressed, MPEG-1 encoding can make blocking, ringing, and motion artifacts more visible. Increasing the output bitrate beyond the VCD specification can improve quality but may make the file incompatible with standard VCD players.

Choose PAL or NTSC according to the playback system, not merely the source filename. PAL output uses 25 frames per second and 352×288 resolution; NTSC output uses approximately 29.97 frames per second and 352×240 resolution. FFmpeg can convert frame rates, but motion may become less smooth when the source standard differs.

A file named .dat is not automatically a VCD file. Compatibility depends on the MPEG-1 stream parameters, program-stream muxing, and, for physical discs, the complete VCD filesystem and disc image.