Ffmpeg Deinterlacing Telecine

CRITICAL GUIDELINES

Windows File Path Requirements

MANDATORY: Always Use Backslashes on Windows for File Paths

When using Edit or Write tools on Windows, you MUST use backslashes (\) in file paths, NOT forward slashes (/).

Quick Reference

When to Use This Skill

Use for interlaced and telecined content:

• Converting broadcast/TV content to progressive
• DVD and Blu-ray processing
• Legacy video digitization
• Professional video production
• Field order correction
• Telecine removal (3:2 pulldown)

FFmpeg Deinterlacing & Telecine (2025)

Comprehensive guide to deinterlacing, field processing, and telecine removal.

Understanding Interlaced Video

What is Interlacing?

Interlaced video stores two half-resolution fields per frame:

• Top Field (TFF): Odd lines (1, 3, 5, ...)
• Bottom Field (BFF): Even lines (2, 4, 6, ...)

Common interlaced formats:

• 1080i (1920x1080, 50i or 60i)
• 576i (720x576, 50i - PAL)
• 480i (720x480, 60i - NTSC)

Detecting Interlaced Content

# Use idet filter to detect interlacing
ffmpeg -i input.mp4 -vf "idet" -frames:v 500 -f null -

# Output shows field types:
# TFF = Top Field First
# BFF = Bottom Field First
# Progressive = Not interlaced
# Undetermined = Mixed or uncertain

Deinterlacing Filters

yadif - Yet Another DeInterlacing Filter

The most widely used deinterlacing filter. Good balance of speed and quality.

# Basic deinterlacing (output same frame rate)
ffmpeg -i interlaced.mp4 -vf "yadif" output.mp4

# Double frame rate (output both fields as frames)
ffmpeg -i interlaced.mp4 -vf "yadif=1" output.mp4

# Specify field parity (auto-detect by default)
ffmpeg -i interlaced.mp4 -vf "yadif=0:0:0" output.mp4  # TFF
ffmpeg -i interlaced.mp4 -vf "yadif=0:1:0" output.mp4  # BFF

# Only deinterlace if detected as interlaced
ffmpeg -i input.mp4 -vf "yadif=deint=interlaced" output.mp4

Parameters:

Mode options:

• 0 / send_frame - Output one frame per input frame
• 1 / send_field - Output one frame per field (double fps)
• 2 / send_frame_nospatial - Like 0, without spatial interlacing check
• 3 / send_field_nospatial - Like 1, without spatial interlacing check

bwdif - Bob Weaver Deinterlacing Filter

Higher quality than yadif, uses more frames for interpolation.

# Basic bwdif
ffmpeg -i interlaced.mp4 -vf "bwdif" output.mp4

# Double frame rate
ffmpeg -i interlaced.mp4 -vf "bwdif=1" output.mp4

# Specify parity
ffmpeg -i interlaced.mp4 -vf "bwdif=0:-1:1" output.mp4

Parameters: Same as yadif

w3fdif - Martin Weston 3-Field Deinterlacing

Uses three fields for even higher quality interpolation.

# Simple filter (faster)
ffmpeg -i interlaced.mp4 -vf "w3fdif=filter=simple" output.mp4

# Complex filter (better quality)
ffmpeg -i interlaced.mp4 -vf "w3fdif=filter=complex" output.mp4

Parameters:

kerndeint - Kernel Deinterlacing

Adaptive kernel-based deinterlacing.

# Basic kerndeint
ffmpeg -i interlaced.mp4 -vf "kerndeint" output.mp4

# With threshold adjustment
ffmpeg -i interlaced.mp4 -vf "kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0" output.mp4

Hardware-Accelerated Deinterlacing

yadif_cuda - NVIDIA CUDA

# Full GPU pipeline with CUDA deinterlacing
ffmpeg -hwaccel cuda -hwaccel_output_format cuda \
  -i interlaced.mp4 \
  -vf "yadif_cuda=0:-1:0" \
  -c:v h264_nvenc output.mp4

# Double framerate with CUDA
ffmpeg -hwaccel cuda -hwaccel_output_format cuda \
  -i interlaced.mp4 \
  -vf "yadif_cuda=1" \
  -c:v h264_nvenc output.mp4

bwdif_cuda - NVIDIA CUDA (FFmpeg 7.0+)

# Higher quality CUDA deinterlacing
ffmpeg -hwaccel cuda -hwaccel_output_format cuda \
  -i interlaced.mp4 \
  -vf "bwdif_cuda" \
  -c:v h264_nvenc output.mp4

bwdif_vulkan - Vulkan (FFmpeg 8.0+)

Cross-platform GPU deinterlacing.

# Vulkan deinterlacing (works on AMD, Intel, NVIDIA)
ffmpeg -init_hw_device vulkan \
  -hwaccel vulkan -hwaccel_output_format vulkan \
  -i interlaced.mp4 \
  -vf "bwdif_vulkan" \
  -c:v h264_vulkan output.mp4

deinterlace_vaapi - VAAPI (Linux)

# VAAPI deinterlacing
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 \
  -hwaccel_output_format vaapi \
  -i interlaced.mp4 \
  -vf "deinterlace_vaapi" \
  -c:v h264_vaapi output.mp4

# Specify deinterlace mode
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 \
  -hwaccel_output_format vaapi \
  -i interlaced.mp4 \
  -vf "deinterlace_vaapi=mode=motion_adaptive:rate=frame" \
  -c:v h264_vaapi output.mp4

VAAPI deinterlace modes:

• default - Use driver default
• bob - Simple bob (double rate)
• weave - Weave fields together
• motion_adaptive - Motion-adaptive (best quality)
• motion_compensated - Motion-compensated (highest quality)

deinterlace_qsv - Intel QSV

# QSV deinterlacing
ffmpeg -hwaccel qsv -hwaccel_output_format qsv \
  -i interlaced.mp4 \
  -vf "vpp_qsv=deinterlace=2" \
  -c:v h264_qsv output.mp4

VPP_QSV deinterlace modes:

• 0 - Off
• 1 - Bob
• 2 - Advanced (motion adaptive)

Inverse Telecine (IVTC)

Understanding Telecine (3:2 Pulldown)

Telecine converts 24fps film to 30fps video by duplicating fields:

Film:   A  B  C  D
Video:  AA AB BB BC CC CD DD DA

pullup - Pullup Filter

Removes 3:2 telecine by detecting and removing duplicate fields.

# Basic IVTC
ffmpeg -i telecined.mp4 -vf "pullup" -r 24000/1001 output.mp4

# With metric output
ffmpeg -i telecined.mp4 -vf "pullup=mp=y" -r 24000/1001 output.mp4

Parameters:

fieldmatch - Field Matching

More advanced telecine removal with field matching.

# Basic field matching
ffmpeg -i telecined.mp4 -vf "fieldmatch" output.mp4

# Full IVTC pipeline with decimation
ffmpeg -i telecined.mp4 -vf "fieldmatch,decimate" output.mp4

# Specify field order
ffmpeg -i telecined.mp4 -vf "fieldmatch=order=tff,decimate" output.mp4

Combined IVTC workflow:

# Complete telecine removal pipeline
ffmpeg -i telecined.mp4 \
  -vf "fieldmatch=order=auto:combmatch=full,decimate" \
  -r 24000/1001 \
  output.mp4

decimate - Frame Decimation

Removes duplicate frames (used after fieldmatch).

# Remove every 5th frame (30->24 fps)
ffmpeg -i input.mp4 -vf "decimate=cycle=5" output.mp4

# Detect duplicates
ffmpeg -i input.mp4 -vf "decimate=cycle=5:ppsrc=1" output.mp4

Field Processing

fieldorder - Change Field Order

Transforms field order between TFF and BFF.

# Convert BFF to TFF
ffmpeg -i bff_input.mp4 -vf "fieldorder=tff" output.mp4

# Convert TFF to BFF
ffmpeg -i tff_input.mp4 -vf "fieldorder=bff" output.mp4

separatefields - Separate Fields

Splits each frame into two fields.

# Separate fields (doubles frame count, halves height)
ffmpeg -i interlaced.mp4 -vf "separatefields" output.mp4

weave - Weave Fields Together

Combines two consecutive frames into one interlaced frame.

# Weave fields (opposite of separatefields)
ffmpeg -i progressive.mp4 -vf "weave" interlaced.mp4

# Specify first field
ffmpeg -i progressive.mp4 -vf "weave=first_field=top" interlaced.mp4

tinterlace - Temporal Interlacing

Create interlaced output from progressive or modify interlaced content.

# Create interlaced from progressive (merge adjacent frames)
ffmpeg -i progressive.mp4 -vf "tinterlace=merge" interlaced.mp4

# Bob deinterlace (simple doubling)
ffmpeg -i interlaced.mp4 -vf "tinterlace=4" bobbed.mp4

# Create interlaced at half frame rate
ffmpeg -i progressive.mp4 -vf "tinterlace=interleave_top" interlaced.mp4

Modes:

il - Interleave/Deinterleave Lines

Low-level line interleaving.

# Swap luma and chroma lines
ffmpeg -i input.mp4 -vf "il=l=s:c=s" output.mp4

Common Workflows

DVD to Progressive MP4

# Step 1: Detect interlacing
ffmpeg -i dvd_rip.vob -vf "idet" -frames:v 500 -f null -

# Step 2: Deinterlace (if interlaced)
ffmpeg -i dvd_rip.vob \
  -vf "yadif=1:-1:1" \
  -c:v libx264 -crf 18 \
  -c:a aac -b:a 192k \
  output.mp4

# For telecined content (film-based DVDs):
ffmpeg -i dvd_rip.vob \
  -vf "fieldmatch,decimate" \
  -r 24000/1001 \
  -c:v libx264 -crf 18 \
  output.mp4

Broadcast 1080i to 1080p

# High quality deinterlacing
ffmpeg -i broadcast_1080i.ts \
  -vf "bwdif=1:-1:0" \
  -c:v libx264 -crf 18 -preset slow \
  -c:a copy \
  output_1080p.mp4

# With GPU acceleration
ffmpeg -hwaccel cuda -hwaccel_output_format cuda \
  -i broadcast_1080i.ts \
  -vf "bwdif_cuda=1" \
  -c:v h264_nvenc -preset p4 \
  -c:a copy \
  output_1080p.mp4

Mixed Content Detection and Processing

#!/bin/bash
# Detect and process based on content type

INPUT="$1"

# Detect interlacing type
result=$(ffmpeg -i "$INPUT" -vf "idet" -frames:v 1000 -f null - 2>&1)

if echo "$result" | grep -q "Multi.*[1-9]"; then
  echo "Interlaced content detected - applying bwdif"
  ffmpeg -i "$INPUT" -vf "bwdif" -c:v libx264 -crf 18 output.mp4
elif echo "$result" | grep -q "Repeated.*[1-9]"; then
  echo "Telecined content detected - applying IVTC"
  ffmpeg -i "$INPUT" -vf "fieldmatch,decimate" -c:v libx264 -crf 18 output.mp4
else
  echo "Progressive content - no deinterlacing needed"
  ffmpeg -i "$INPUT" -c:v libx264 -crf 18 output.mp4
fi

Quality Comparison

Best Practices

1. Always detect first - Use idet to determine content type
2. Preserve frame rate - Use mode 0 for same fps, mode 1 for double
3. Match field order - Use auto-detection or specify correct parity
4. Use GPU when available - CUDA/VAAPI filters are much faster
5. IVTC for film content - Don't deinterlace telecined film, use pullup/fieldmatch
6. Test on sample - Check a short segment before processing full video

This guide covers deinterlacing and telecine for 2025. For hardware acceleration details, see ffmpeg-hardware-acceleration. For video analysis, see ffmpeg-video-analysis.