Progressive vs Interlaced Video Encoding: Key Differences Explained

Video quality is one of the most important factors in OTT and streaming platforms. However, quality is not just about resolution like 1080p or 4K. It also depends on how frames are displayed.

Two fundamental video encoding methods are:

• Progressive scan

• Interlaced scan

These formats determine how video frames are transmitted and displayed on screens.

Understanding the difference between them is essential for:

• Streaming platform owners

• Video engineers

• Content creators

Progressive encoding displays all lines of a video frame in a single pass.

Each frame is shown completely, from top to bottom, without splitting.

How It Works

• A full frame is captured and displayed at once

• Every refresh shows a complete image

Example

• 1080p means 1080 horizontal lines displayed progressively

Interlaced encoding splits each frame into two fields:

• Odd-numbered lines

• Even-numbered lines

These fields are displayed alternately.

How It Works

• First, odd lines are displayed

• Then, even lines follow

• Together, they form one frame

Example

• 1080i means interlaced video with 1080 lines

Interlaced video was developed for older television systems to:

• Reduce bandwidth usage

• Improve motion perception

• Work with hardware limitations

It allowed smoother motion without requiring full frame transmission.

However, modern technology has reduced the need for this approach.

Progressive Video

• Clear and sharp images

• No flickering

• Better for fast motion

Interlaced Video

• May show “combing” artifacts

• Slight flicker on modern screens

• Lower perceived clarity

For OTT platforms, progressive encoding is the standard.

Why Progressive Is Preferred

1. Better User Experience
Modern devices like smartphones and smart TVs are designed for progressive video.

2. Improved Compression Efficiency
Progressive frames compress more efficiently with modern codecs.

3. No Deinterlacing Required
Interlaced video needs conversion before playback, which can reduce quality.

4. Compatible with Adaptive Streaming
Works better with streaming technologies like HLS and DASH.

Although less common, interlaced video is still used in:

• Traditional broadcast TV

• Live sports production (in some regions)

• Legacy video systems

However, most platforms convert interlaced video into progressive format before streaming.

1080p vs 1080i: Practical Example

Key Insight

Even though both have 1080 lines:

• 1080p delivers a full frame every cycle

• 1080i splits the frame into two parts

This makes 1080p significantly better for modern viewing.

Progressive Encoding

• Better compression with modern codecs

• Higher bandwidth usage initially

• More efficient in streaming pipelines

Interlaced Encoding

• Designed to save bandwidth in older systems

• Less efficient with modern codecs

• Requires additional processing

Role in OTT Encoding Pipelines

A typical OTT video workflow includes:

1. Content ingestion

2. Encoding and transcoding

3. Packaging for streaming

4. Delivery via CDN

Where Progressive Fits

• Used in encoding stage

• Preferred for all output formats

Where Interlaced Fits

• May appear in source content

• Usually converted during transcoding

Deinterlacing: Why It Matters

Deinterlacing is the process of converting interlaced video into progressive format.

Why It’s Needed

• Modern screens are progressive

• Interlaced video does not display properly

Challenges

• Quality loss

• Processing overhead

• Motion artifacts

1. Always Use Progressive Encoding for Output

Ensure all final streams are progressive.

2. Convert Interlaced Sources Early

Handle interlaced input during ingestion or transcoding.

3. Use Modern Codecs

Codecs like H.264 and H.265 perform better with progressive video.

4. Optimize for Devices

Focus on mobile and smart TV compatibility.

5. Maintain High Frame Rates

Use progressive formats like 60fps for smoother motion.

Common Mistakes to Avoid

• Streaming interlaced content without conversion

• Ignoring deinterlacing quality

• Mixing formats inconsistently

• Assuming 1080i equals 1080p

Vodlix simplifies video delivery by:

• Supporting progressive encoding formats

• Automatically handling transcoding workflows

• Optimizing streams for all devices

• Ensuring high-quality playback

This ensures that content is delivered in the best possible format without manual effort.

Progressive and interlaced encoding represent two different approaches to video delivery.

Interlaced video was designed for older broadcast systems, while progressive video is built for modern digital platforms.

For OTT platforms, the choice is clear:

• Progressive encoding delivers better quality

• It works seamlessly across devices

• It supports modern streaming technologies

Understanding this difference helps ensure better video quality, improved user experience, and efficient streaming performance.