NS_E_NO_REPEAT_PREPROCESS (0XC00D1B8D) two-pass loop fix

Most common cause: The source is set to loop while using two-pass encoding

This error shows up when you're encoding with something like Windows Media Encoder (WME) or a tool that uses its pipeline. The exact text is: "It is not possible to use two-pass encoding when the source is set to loop." That's your clue.

Two-pass encoding needs to analyze the whole source file from start to finish on the first pass, then encode on the second. If the source is set to loop (meaning it plays over and over), the encoder can't figure out where the file ends. It gets confused and throws error 0XC00D1B8D.

This happens a lot when you're encoding video for a website or a kiosk display and you checked "loop" on the source properties. Or you're using a screen capture that loops, like a webcam feed or a repeating video clip.

Fix: Disable looping on the source

1. Open Windows Media Encoder (or your encoding app that uses the same engine).
2. Go to the Source tab (or Properties for the video input).
3. Look for a checkbox that says Loop or Repeat.
4. Uncheck it. If you don't see it, look under Source Properties > Advanced.
5. Click Apply then OK.
6. After you apply, the encoder should show the source duration now (like 0:00:15 for a 15-second clip). That means it knows the endpoint.
7. Try the two-pass encoding again. It should work now.

If the loop option is grayed out, it means the source itself is a live feed (like a capture card). In that case, skip to the second fix below.

Second cause: The source is a live or continuously streaming input

Some sources just don't have an end. Think: a webcam, a screen capture that records the desktop live, or a network stream that keeps playing. Two-pass encoding can't work on these because the first pass never ends — it would run forever.

The error code is the same: 0XC00D1B8D. But here the loop checkbox might not even be visible. The source is inherently endless.

Fix: Switch to one-pass encoding

1. In Windows Media Encoder, go to the Session Properties window.
2. Click the Compression tab (or Encoding Options in newer versions).
3. Find the Encoding mode dropdown. It probably says Two-pass CBR or Two-pass VBR.
4. Change it to One-pass CBR or One-pass VBR. One-pass CBR is the safest bet for live sources — it keeps the bitrate steady and doesn't need to guess the file length.
5. Click Apply then OK.
6. After you apply, you should see the encoder start immediately (if the source is live). No more error.

One-pass encoding trades a bit of quality for compatibility with live sources. For most webcam streams or screen recordings, you won't notice the difference.

Third cause: The source file path points to a playlist or repeating sequence

Less common but it happens. You might have set the source to a playlist file (like a .wpl or .asx) that repeats itself, or you're using a batch script that feeds the same file in a loop. The encoder sees the repetition and flags it as looping.

This can also occur if you drag a video file into a timeline that's set to repeat in an editing tool before exporting to WME.

Fix: Point to a single, non-repeating file

1. Confirm the source is a single file, not a playlist. In the Source tab, check the File name field. If it ends in .wpl, .asx, .m3u, or .pls, that's a playlist.
2. Replace it with the direct path to a single video file (like C:\Videos\clip.mp4).
3. If you're using a command-line tool like WMEnc.exe, make sure the -input parameter points to one file, not a folder or a playlist.
4. Also check if the file itself has a loop tag embedded. In Windows Media Player, right-click the file > Properties > Details. Look for a "Loop" attribute. If it's set to True, remove it using a metadata editor or re-encode the file first.
5. Click Apply then OK. The source duration should show a finite length. Run the two-pass encode again.

Quick-reference summary table

If none of these fixes work, check the Event Viewer for related errors under Windows Media Encoder logs. But honestly, 9 times out of 10 it's the loop checkbox or the live source issue. Start there and you'll save yourself the headache.