Interlaced video
Interlaced video is a display method that draws each frame in two halves, called fields, one with the odd lines and one with the even lines, shown one after another. It was designed for older TV broadcasts to make motion look smooth while saving bandwidth. Formats such as 1080i and 480i use interlacing.
Why it matters
Interlaced footage still turns up in broadcast feeds and older archives. If it is streamed without conversion, moving edges show jagged comb lines on phones and computers. Teams licensing TV content or digitizing archives must plan for deinterlacing, or viewers see a visibly flawed picture.
How it works
- Each frame is split into two fields: one with the odd lines, one with the even lines.
- The fields are captured and shown one after the other, for example 60 fields per second.
- Older TVs blended the two fields, so motion looked smooth.
- Modern screens need a deinterlacer to merge or rebuild fields into full progressive frames.
Interlaced vs progressive: which is better?
Progressive is better for modern screens and online video. It draws every line in each frame, giving cleaner motion without comb lines. Interlaced was a bandwidth-saving method for older TV broadcasts. Phones, computers and web players all expect progressive video, so interlaced footage should be converted.
How do you fix interlaced video?
You fix interlaced video by deinterlacing it, which converts the two fields into full progressive frames. Editing tools and encoders such as FFmpeg include deinterlacing filters. For example, 1080i at 60 fields per second is commonly converted to 1080p at 30 frames per second.
Where it's used
Broadcasters, OTT services and video platforms handling TV feeds or old archives must convert interlaced footage, otherwise moving edges show jagged comb-like lines on phones and computers.
By the numbers
- YouTube asks for interlaced content to be deinterlaced before upload, for example converting 1080i60 to 1080p30. (YouTube recommended upload encoding settings)
