ASF to MPEG Converter

Convert ASF to MPEG Online

ASF (Advanced Systems Format) is Microsoft's media container — the wrapper behind .asf, .wmv, and .wma files, first released proprietarily in 1996 and published on 26 February 1998. Inside it you almost always find Windows Media Video and Windows Media Audio, which is why an .asf opens on a Windows PC with the right codecs installed and stalls almost everywhere else. This page rebuilds that clip as an MPEG program stream: MPEG-2 video with MP2 audio by default, the pairing that legacy players, DVD-authoring suites, and set-top hardware were built around.

How to Convert ASF to MPEG

1. Upload Your ASF File: Drag and drop the file onto the page or click "+ Add Files" to browse for .asf or .wmv clips — Windows Media exports, archived webcasts, old screen recordings. Queue several and they all convert with the same settings.
2. Choose Video Codec and Audio Codec: Video Codec offers MPEG-2 (the default, and what DVD-era hardware expects) and MPEG-1. Audio Codec defaults to MP2, with MP3, AC3, and DTS (DCA) also selectable for the program stream.
3. Set Quality, Resolution, or Trim: Under File Compression the Quality Preset starts on "Very High (Recommended)"; switch to Specific file size, Constant Bitrate, Variable Bitrate, Constant Quality, or Constraint Quality instead. On this page the Constant Quality slider is a 1–31 scale (MPEG-2's qscale, where lower is better), not the 16–51 CRF that H.264 pages use. Video resolution stays on Keep original unless you pick a Preset Resolution or type a Width x Height, and Trim → Time Range takes a Start time and Duration in seconds or HH:MM:SS.sss.
4. Convert and Download: Click Convert and save the .mpeg. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared or made public.

ASF at a Glance

MPEG Program Stream at a Glance

MPEG-2 or MPEG-1 — Which Codec Should You Pick?

Leave Video Codec on MPEG-2 for anything modern-ish: it is the DVD-Video codec, it handles full standard-definition and HD frame sizes, and every player that reads a .mpeg reads it. MPEG-1 exists on this page for the narrow case where a device only understands VCD-era streams — its ceiling is much lower, and DVD-Video allows MPEG-1 video only up to 1.856 Mbit/s versus 9.8 Mbit/s for MPEG-2. If your .asf is standard definition, keeping the source frame size and letting the Quality Preset choose the bitrate produces a clean MPEG-2 stream without hand-tuning anything.

The one thing neither codec can do is undo the first encode. Windows Media Video is lossy, MPEG-2 is lossy, and the two share no common bitstream, so the picture is fully decoded and re-encoded. That is a one-way trip through a second generation of compression — worth it for compatibility, pointless if the file already plays where you need it.

Frequently Asked Questions

Does converting ASF to MPEG lose quality?

Yes — this is a lossy-to-lossy transcode, and it cannot be anything else. ASF carries Windows Media Video and WMA; the MPEG output carries MPEG-2 video and MP2 audio. Nothing in those two bitstreams is interchangeable, so our converter decodes the Windows Media streams and runs a fresh MPEG-2 encode over the decoded frames. Detail the original WMV encoder discarded is gone for good and will not come back. Keeping the Quality Preset on "Very High (Recommended)" and leaving the resolution at Keep original holds the second-generation loss to something you have to look for; converting the same file back and forth repeatedly is what makes damage obvious.

Why is my MPEG file larger than the ASF I started with?

Because MPEG-2 is a 1995-era codec being asked to match a much newer one. WMV 9 / VC-1 was designed roughly a decade later and needs fewer bits for the same perceived quality, so re-encoding a Windows Media clip into MPEG-2 at a comparable quality target usually grows the file. This is expected, not a bug: you are trading bytes for hardware compatibility. If size matters more than legacy playback, ASF to MP4 gives you H.264 at a fraction of the size, or you can shrink the finished stream with Compress MPEG.

Is .mpeg the same file as .mpg?

Yes. Both name an MPEG program stream — the multiplex that interleaves one video and one audio elementary stream into a single file. The three-letter .mpg spelling is a holdover from operating systems that limited extensions to three characters; .m2p and .ps show up occasionally for the same thing. This page writes the four-letter .mpeg name; if a DVD-authoring or disc-burning tool insists on the shorter one, either rename the file or use ASF to MPG, which produces the same program stream under that extension.

What happens to the audio track inside the ASF?

It is decoded from WMA and re-encoded — by default to MP2, MPEG-1 Audio Layer II, which is the audio every MPEG-aware player and DVD-authoring tool accepts. Video and audio are re-multiplexed together, so sync is preserved. If your target specifically wants Dolby Digital, set Audio Codec to AC3; MP3 and DTS (DCA) are also on the list. Multichannel WMA Pro sources are folded down for a standard stereo program stream.

Can I burn this MPEG straight to a DVD?

Not as-is — a .mpeg file is the video, not a finished disc. DVD-Video requires MPEG-2 at 720×480 (NTSC) or 720×576 (PAL) with video peaking at 9.8 Mbit/s, audio as AC-3, MP2, LPCM, or DTS, and all of it authored into a VIDEO_TS structure before burning. Convert here with Width x Height set to 720 x 480 or 720 x 576 (the Preset Resolutions list sets height only, so it cannot pin a DVD raster), then run the result through an authoring tool such as DVDStyler to build the disc. Most disc-free media players and smart TVs will simply play the .mpeg from a USB stick with no authoring step at all.

Do subtitles, scripts, or metadata inside the ASF survive?

Mostly no. A program stream is deliberately narrow: it multiplexes one video and one audio program, and everything else — ASF script commands, marker/index objects, embedded metadata, DRM headers — has no equivalent slot in it. Subtitle text carried as an ASF script stream is not converted into an MPEG subtitle track. If you need captions on the far side, keep them as a separate .srt and load them alongside the file in your player.

Why does a DRM-protected .asf or .wmv fail to convert?

ASF was built with a digital-rights-management framework baked into the container, and older Windows Media stores used it heavily. A protected file's streams are encrypted and unlocked only by a licence tied to the original account or machine, so no converter can decode them — the job fails, or produces a black or silent result. The fix is to obtain an unprotected copy from the original source; there is no setting on this page that changes it.

How large a file can I upload, and how are my files handled?

There is no per-file cap tied to your own hardware here, because the encode happens on our servers rather than on your machine — the practical limit is how much you can upload and how long you are willing to wait for it. Batch several clips and download them individually or as a ZIP. Every upload travels over an encrypted (TLS) connection, is processed on our servers, and is deleted automatically after a few hours; nothing is shared, made public, or kept beyond that window, and no account is required.