Why Do I Need to Deinterlace?
If you’re going to be ripping any significant amount of your personal DVDs, you’re going to come across interlaced video at some point. Many DVDs, usually older DVDs and TV series on DVD have interlaced video content. I’ve noticed this to be the case frequently with animated TV shows. If you do not take steps to deinterlace the video, you can wind up with a video file that seems to have strange horizontal lines in it during motion and action sequences. Most modern Hollywood film DVDs aren’t interlaced anymore, but I’ve encountered this problem frequently all the same.
While it’s beyond the scope of this article to explain interlacing, I will walk you step-by-step through a time-tested and proven deinterlacing process in HandBrake.
NOTE: I’ve never seen interlacing on HD sourced videos, whether DVR sourced or Blu-Ray.
How to Tell if Your Video is Interlaced
You can often tell if a show is interlaced and needs to be deinterlaced by using the Preview Window in HandBrake. If viewing a still in the Preview Window isn’t helping, you can use the slider to find a sequence with motion, and click the Live Preview button. This will encode a short 10 second video preview from the segment you chose. You should be able to see the horizontal lines if you’re looking for them – they appear like the teeth of a comb, horizontally. The screenshot below is from Seinfeld, Season 8, disc 1. You can see it even in this still.
In this still in the Preview Window, we can clearly see the horizontal lines that give this source DVD away as interlaced video. Look closely at edges of objects to see them. A Live Preview confirms it even more clearly.
It’s frustrating when you don’t check beforehand, and realize it only after you’ve ripped the video. It’s good practice to check this before you start the rip. It can be difficult to see in the Preview Window, so I recommend trying several spots and using the Live Preview button to be sure.
Deinterlacing the Video
Deinterlacing is slow and reduces picture quality. It’s often not even necessary. It can waste time and produce lower quality videos when used unnecessarily. If a video is interlaced, you should definitely deinterlace it.
Use the Decomb feature instead of Deinterlace to have HandBrake examine frames individually and only deinterlace those that need it.
Use the Decomb feature instead of Deinterlace to have HandBrake examine frames individually and only deinterlace those that need it.
Decomb vs. Deinterlace
Fortunately, there’s a way to tell HandBrake to only deinterlace when necessary. It’s the Decomb feature. Decomb tells HandBrake to only deinterlace frames that are interlaced. That way you don’t unnecessarily reduce quality of normal frames, and you don’t slow down the encode by deinterlacing the entire video.
So let’s take advantage of HandBrake’s built-in deinterlacing filters to eliminate this nastiness. Within the Picture Settings pane, just slide the Decomb button to Decomb, and select “Default” as the Decomb setting, as shown in the screenshot to the right.
M4 Power Tip: If you insist on using the Deinterlace setting instead of Decomb, keep in mind that a Fast setting results in poorer quality video, but speeds up the encode. Slow or Slower will result in a higher quality, deinterlaced video, but will slow down the encode, taking longer to finish the file.
Preview the Setting
After adjusting the Picture Filters, close and reopen the Preview Window. You may be able to see the filter applied and tell that it is going to work. If you can’t tell from the stills, use the Live Preview feature, which will encode a 10 second segment using the Decombing filter. Notice the difference in the screenshot below, compared to the untreated screenshot shown previously.
With Decomb set to Default, a Live Preview shows that the interlacing has has been removed.
After a successful preview, go ahead and rip it! Please Like this article if you found it helpful.
Pertinent References: HandBrake Picture Settings Wiki
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A clear explanation, thanks.
I just purchased a dvd containing a bbc 1979 tv series transferred from vhs. Interlacing throughout the movie with movement provides a poor viewing experience. Can I decomb the dvd using a good quality dvd player or must I use a computer dvd player and software?
Peter,
Unfortunately, DVD players won’t “decomb” the video for you. If you’re seeing the interlacing on your TV when you play this back, you will definitely have to rip the DVD and decomb it. You’ll be able to create a new disc sans interlacing, if you wish. Check our other posts for tips and tutorials on ripping the DVD.
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