AgentSkillsCN

ffmpeg-shapes-graphics

完备的形状与图形叠加系统。主动启用以下功能:(1) 绘制矩形(drawbox);(2) 绘制网格叠加层(drawgrid);(3) 绘制圆形与椭圆(geq);(4) 添加图像水印与标志;(5) 添加下三分之一区域的图形元素;(6) 创建进度条与指示器;(7) 添加动画叠加层;(8) 使用混合模式与合成效果;(9) 提供安全区域引导线;(10) 生成各类图案(渐变、噪点、棋盘格)。本指南提供:滤波器语法参考、位置表达式、色彩格式指南、混合模式示例以及性能优化技巧。确保在视频中呈现专业级的图形叠加与视觉特效。

SKILL.md
--- frontmatter
name: ffmpeg-shapes-graphics
description: Complete shape and graphics overlay system. PROACTIVELY activate for: (1) Drawing rectangles (drawbox), (2) Grid overlays (drawgrid), (3) Circles and ellipses (geq), (4) Image watermarks and logos, (5) Lower third graphics, (6) Progress bars and indicators, (7) Animated overlays, (8) Blend modes and compositing, (9) Safe area guides, (10) Generated patterns (gradients, noise, checkerboards). Provides: Filter syntax reference, position expressions, color format guide, blend mode examples, performance optimization tips. Ensures: Professional graphics overlays and visual effects on video.

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 (/).

Documentation Guidelines

NEVER create new documentation files unless explicitly requested by the user.


Quick Reference

ShapeFilterCommand Example
Rectangledrawbox-vf "drawbox=x=100:y=100:w=200:h=150:color=red:t=fill"
Griddrawgrid-vf "drawgrid=w=iw/3:h=ih/3:t=2:color=white"
Textdrawtext-vf "drawtext=text='Hello':x=10:y=10:fontsize=24"
Watermarkoverlay[0:v][1:v]overlay=W-w-10:10
PositionExpression
Centeredx=(iw-200)/2:y=(ih-150)/2
Bottom-rightx=iw-w-10:y=ih-h-10
Full-width barx=0:y=0:w=iw:h=80

When to Use This Skill

Use for graphics and shape overlays:

  • Drawing rectangles, boxes, borders
  • Adding watermarks and logos
  • Lower third graphics
  • Progress bars and indicators
  • Grid overlays and safe area guides

FFmpeg Shapes and Graphics (2025)

Complete guide to drawing shapes, graphics overlays, and geometric patterns using FFmpeg.

Shape Drawing Filters

Available Drawing Filters

FilterPurposeShapes
drawboxDraw rectangles/boxesRectangles, squares
drawgridDraw grid patternsLines, grids
drawtextDraw textText, numbers
geqGeometric equationAny (via expressions)
overlayComposite imagesAny image/shape
blendBlend layersComposite effects

Drawing Boxes (drawbox)

Basic Rectangle

bash
# Draw red box
ffmpeg -i video.mp4 \
  -vf "drawbox=x=100:y=100:w=200:h=150:color=red:t=3" \
  output.mp4

# Filled rectangle
ffmpeg -i video.mp4 \
  -vf "drawbox=x=100:y=100:w=200:h=150:color=red:t=fill" \
  output.mp4

# Semi-transparent rectangle
ffmpeg -i video.mp4 \
  -vf "drawbox=x=100:y=100:w=200:h=150:color=red@0.5:t=fill" \
  output.mp4

Position Options

bash
# Centered box
ffmpeg -i video.mp4 \
  -vf "drawbox=x=(iw-200)/2:y=(ih-150)/2:w=200:h=150:color=blue:t=fill" \
  output.mp4

# Box at bottom right
ffmpeg -i video.mp4 \
  -vf "drawbox=x=iw-210:y=ih-160:w=200:h=150:color=green:t=3" \
  output.mp4

# Full-width bar at top
ffmpeg -i video.mp4 \
  -vf "drawbox=x=0:y=0:w=iw:h=80:color=black@0.7:t=fill" \
  output.mp4

# Full-width bar at bottom
ffmpeg -i video.mp4 \
  -vf "drawbox=x=0:y=ih-80:w=iw:h=80:color=black@0.7:t=fill" \
  output.mp4

Letterbox/Pillarbox

bash
# Add letterbox bars (16:9 to 2.35:1)
ffmpeg -i video_16x9.mp4 \
  -vf "drawbox=x=0:y=0:w=iw:h=ih*0.12:color=black:t=fill,\
       drawbox=x=0:y=ih-ih*0.12:w=iw:h=ih*0.12:color=black:t=fill" \
  letterbox.mp4

# Add pillarbox bars (4:3 in 16:9 frame)
ffmpeg -i video_4x3.mp4 \
  -vf "scale=-1:1080,pad=1920:1080:(ow-iw)/2:0:black" \
  pillarbox.mp4

Animated Boxes

bash
# Growing box
ffmpeg -i video.mp4 \
  -vf "drawbox=x=100:y=100:w='min(t*50,300)':h='min(t*30,200)':color=red:t=fill" \
  growing_box.mp4

# Moving box
ffmpeg -i video.mp4 \
  -vf "drawbox=x='mod(t*100,iw)':y=100:w=100:h=100:color=blue:t=fill" \
  moving_box.mp4

# Pulsing opacity
ffmpeg -i video.mp4 \
  -vf "drawbox=x=100:y=100:w=200:h=150:color=red@'0.3+0.3*sin(t*3)':t=fill" \
  pulsing_box.mp4

# Box appears at specific time
ffmpeg -i video.mp4 \
  -vf "drawbox=x=100:y=100:w=200:h=150:color=yellow:t=fill:enable='between(t,2,5)'" \
  timed_box.mp4

Multiple Boxes

bash
# Border/frame effect
ffmpeg -i video.mp4 \
  -vf "drawbox=x=0:y=0:w=iw:h=20:color=white:t=fill,\
       drawbox=x=0:y=ih-20:w=iw:h=20:color=white:t=fill,\
       drawbox=x=0:y=0:w=20:h=ih:color=white:t=fill,\
       drawbox=x=iw-20:y=0:w=20:h=ih:color=white:t=fill" \
  bordered.mp4

# Grid of boxes
ffmpeg -i video.mp4 \
  -vf "drawbox=x=0:y=0:w=iw/3:h=ih/3:color=red@0.3:t=fill,\
       drawbox=x=iw/3:y=0:w=iw/3:h=ih/3:color=green@0.3:t=fill,\
       drawbox=x=2*iw/3:y=0:w=iw/3:h=ih/3:color=blue@0.3:t=fill" \
  color_grid.mp4

Drawing Grids (drawgrid)

Basic Grid

bash
# Simple grid overlay
ffmpeg -i video.mp4 \
  -vf "drawgrid=w=100:h=100:t=1:color=white@0.5" \
  grid.mp4

# Rule of thirds grid
ffmpeg -i video.mp4 \
  -vf "drawgrid=w=iw/3:h=ih/3:t=2:color=white@0.7" \
  thirds.mp4

# Fine grid
ffmpeg -i video.mp4 \
  -vf "drawgrid=w=50:h=50:t=1:color=cyan@0.3" \
  fine_grid.mp4

Crosshair/Center Marker

bash
# Center crosshair
ffmpeg -i video.mp4 \
  -vf "drawbox=x=iw/2-1:y=0:w=2:h=ih:color=red:t=fill,\
       drawbox=x=0:y=ih/2-1:w=iw:h=2:color=red:t=fill" \
  crosshair.mp4

# Center circle marker (using multiple points)
ffmpeg -i video.mp4 \
  -vf "drawbox=x=iw/2-5:y=ih/2-5:w=10:h=10:color=red:t=2" \
  center_marker.mp4

Drawing Circles and Ellipses (geq)

Using geq Filter for Circles

bash
# Draw circle outline
ffmpeg -i video.mp4 \
  -vf "geq=lum='if(between(sqrt(pow(X-iw/2,2)+pow(Y-ih/2,2)),100,105),255,lum(X,Y))':cb='cb(X,Y)':cr='cr(X,Y)'" \
  circle_outline.mp4

# Filled circle (white)
ffmpeg -i video.mp4 \
  -filter_complex "\
    color=c=white:s=1920x1080[c];\
    [c]geq=lum='if(lt(sqrt(pow(X-W/2,2)+pow(Y-H/2,2)),200),255,0)':cb=128:cr=128[mask];\
    [0:v][mask]overlay[v]" \
  -map "[v]" \
  filled_circle.mp4

Using Overlay with Circle Images

bash
# More practical: overlay a circle image
# First create circle image
ffmpeg -f lavfi \
  -i "color=c=red:s=200x200" \
  -vf "geq=lum='if(lt(sqrt(pow(X-100,2)+pow(Y-100,2)),100),255,0)':cb=128:cr=128,format=rgba,colorchannelmixer=aa='if(lt(sqrt(pow(X-100,2)+pow(Y-100,2)),100),1,0)'" \
  -frames:v 1 \
  circle.png

# Overlay circle on video
ffmpeg -i video.mp4 -i circle.png \
  -filter_complex "[0:v][1:v]overlay=100:100" \
  video_with_circle.mp4

Generate Shape Patterns

bash
# Radial gradient
ffmpeg -f lavfi \
  -i "color=c=black:s=500x500,geq=lum='255*sqrt(pow(X-W/2,2)+pow(Y-H/2,2))/(W/2)':cb=128:cr=128" \
  -frames:v 1 \
  radial_gradient.png

# Checkerboard pattern
ffmpeg -f lavfi \
  -i "color=c=white:s=800x800,geq=lum='if(mod(floor(X/100)+floor(Y/100),2),255,0)':cb=128:cr=128" \
  -frames:v 1 \
  checkerboard.png

# Diagonal stripes
ffmpeg -f lavfi \
  -i "color=c=black:s=800x600,geq=lum='if(mod(X+Y,100)<50,255,0)':cb=128:cr=128" \
  -frames:v 1 \
  stripes.png

Image Overlays

Basic Overlay

bash
# Overlay logo at top-right corner
ffmpeg -i video.mp4 -i logo.png \
  -filter_complex "[0:v][1:v]overlay=W-w-10:10" \
  watermarked.mp4

# Overlay at bottom-left
ffmpeg -i video.mp4 -i logo.png \
  -filter_complex "[0:v][1:v]overlay=10:H-h-10" \
  watermarked.mp4

# Centered overlay
ffmpeg -i video.mp4 -i overlay.png \
  -filter_complex "[0:v][1:v]overlay=(W-w)/2:(H-h)/2" \
  centered.mp4

Overlay with Transparency

bash
# Scale and position logo with transparency
ffmpeg -i video.mp4 -i logo.png \
  -filter_complex "\
    [1:v]format=rgba,colorchannelmixer=aa=0.5[logo];\
    [0:v][logo]overlay=W-w-20:H-h-20" \
  watermark_50.mp4

# Fade in logo
ffmpeg -i video.mp4 -i logo.png \
  -filter_complex "\
    [1:v]format=rgba,fade=t=in:st=0:d=1:alpha=1[logo];\
    [0:v][logo]overlay=W-w-10:10:enable='gte(t,1)'" \
  fade_logo.mp4

Animated Overlays

bash
# Moving logo across screen
ffmpeg -i video.mp4 -i logo.png \
  -filter_complex "\
    [0:v][1:v]overlay=x='mod(t*100,W+w)-w':y=10" \
  scrolling_logo.mp4

# Bouncing logo
ffmpeg -i video.mp4 -i logo.png \
  -filter_complex "\
    [0:v][1:v]overlay=x='abs(mod(t*100,2*(W-w))-(W-w))':y='abs(mod(t*80,2*(H-h))-(H-h))'" \
  bouncing_logo.mp4

# Rotating overlay (using rotate filter)
ffmpeg -i video.mp4 -i logo.png \
  -filter_complex "\
    [1:v]rotate=t*PI/4:c=none:ow=200:oh=200[rot];\
    [0:v][rot]overlay=(W-200)/2:(H-200)/2" \
  rotating_logo.mp4

Multiple Overlays

bash
# Multiple logos/watermarks
ffmpeg -i video.mp4 -i logo1.png -i logo2.png \
  -filter_complex "\
    [0:v][1:v]overlay=10:10[tmp];\
    [tmp][2:v]overlay=W-w-10:10" \
  multi_logo.mp4

# Grid of thumbnails
ffmpeg -i main.mp4 -i thumb1.png -i thumb2.png -i thumb3.png -i thumb4.png \
  -filter_complex "\
    [1:v]scale=200:150[t1];[2:v]scale=200:150[t2];\
    [3:v]scale=200:150[t3];[4:v]scale=200:150[t4];\
    [0:v][t1]overlay=10:10[a];\
    [a][t2]overlay=220:10[b];\
    [b][t3]overlay=10:170[c];\
    [c][t4]overlay=220:170" \
  thumbnail_grid.mp4

Text Graphics (drawtext)

Styled Text

bash
# Text with background box
ffmpeg -i video.mp4 \
  -vf "drawtext=text='LIVE':x=10:y=10:fontsize=36:fontcolor=white:\
       box=1:boxcolor=red:boxborderw=10" \
  live_badge.mp4

# Text with shadow
ffmpeg -i video.mp4 \
  -vf "drawtext=text='Title':x=(w-tw)/2:y=50:fontsize=72:fontcolor=white:\
       shadowcolor=black:shadowx=3:shadowy=3" \
  title.mp4

# Text with outline
ffmpeg -i video.mp4 \
  -vf "drawtext=text='Outlined':x=100:y=100:fontsize=64:fontcolor=yellow:\
       borderw=3:bordercolor=black" \
  outlined.mp4

Lower Thirds

bash
# Professional lower third
ffmpeg -i video.mp4 \
  -vf "drawbox=x=0:y=ih-120:w=400:h=100:color=0x1a1a2e@0.9:t=fill,\
       drawbox=x=0:y=ih-120:w=5:h=100:color=0x00ff88:t=fill,\
       drawtext=text='John Smith':x=20:y=ih-110:fontsize=32:fontcolor=white,\
       drawtext=text='Senior Developer':x=20:y=ih-70:fontsize=24:fontcolor=0xaaaaaa" \
  lower_third.mp4

# Animated lower third (slide in)
ffmpeg -i video.mp4 \
  -vf "drawbox=x='if(lt(t,1),-400+t*400,0)':y=ih-120:w=400:h=100:color=blue@0.8:t=fill:\
       enable='gte(t,0.5)',\
       drawtext=text='Guest Speaker':x='if(lt(t,1.2),-400+t*333,20)':y=ih-100:\
       fontsize=28:fontcolor=white:enable='gte(t,0.7)'" \
  animated_lower.mp4

Timecode Display

bash
# Timecode overlay
ffmpeg -i video.mp4 \
  -vf "drawtext=timecode='00\:00\:00\:00':rate=30:x=10:y=10:\
       fontsize=32:fontcolor=white:box=1:boxcolor=black@0.6" \
  with_timecode.mp4

# Frame counter
ffmpeg -i video.mp4 \
  -vf "drawtext=text='Frame\: %{frame_num}':x=10:y=10:fontsize=24:fontcolor=white:\
       box=1:boxcolor=black@0.5" \
  frame_counter.mp4

Progress Bars and Indicators

Progress Bar

bash
# Horizontal progress bar
ffmpeg -i video.mp4 \
  -vf "drawbox=x=50:y=ih-30:w=iw-100:h=10:color=gray@0.5:t=fill,\
       drawbox=x=50:y=ih-30:w='(iw-100)*t/10':h=10:color=red:t=fill" \
  progress_bar.mp4

# Circular progress (approximate with boxes)
# Note: True circular progress requires more complex expressions

Loading Spinner (Approximation)

bash
# Rotating indicator using drawbox
ffmpeg -i video.mp4 \
  -vf "drawbox=x='iw/2+50*cos(t*3)':y='ih/2+50*sin(t*3)':w=10:h=10:color=white:t=fill" \
  spinner.mp4

Color Correction Overlays

Vignette Effect

bash
# Dark vignette
ffmpeg -i video.mp4 \
  -vf "vignette=PI/4" \
  vignette.mp4

# Custom vignette intensity
ffmpeg -i video.mp4 \
  -vf "vignette=angle=PI/4:mode=backward" \
  soft_vignette.mp4

Color Tint Overlay

bash
# Warm tint using blend
ffmpeg -i video.mp4 \
  -f lavfi -i "color=c=0xFF8800:s=1920x1080" \
  -filter_complex "[0:v][1:v]blend=all_mode=softlight:all_opacity=0.3" \
  warm_tint.mp4

# Cool tint
ffmpeg -i video.mp4 \
  -f lavfi -i "color=c=0x0088FF:s=1920x1080" \
  -filter_complex "[0:v][1:v]blend=all_mode=softlight:all_opacity=0.2" \
  cool_tint.mp4

Blend Modes

Available Blend Modes

ModeEffect
additionAdd pixel values
multiplyMultiply (darken)
screenScreen (lighten)
overlayOverlay blend
softlightSoft light
hardlightHard light
differenceDifference
exclusionExclusion
darkenDarken only
lightenLighten only

Blend Mode Examples

bash
# Multiply blend (darken)
ffmpeg -i video.mp4 -i texture.png \
  -filter_complex "[0:v][1:v]blend=all_mode=multiply" \
  multiply.mp4

# Screen blend (lighten)
ffmpeg -i video.mp4 -i light_leak.png \
  -filter_complex "[0:v][1:v]blend=all_mode=screen" \
  light_leak.mp4

# Overlay blend
ffmpeg -i video.mp4 -i texture.png \
  -filter_complex "[0:v][1:v]blend=all_mode=overlay:all_opacity=0.5" \
  textured.mp4

Safe Areas and Guides

Broadcast Safe Areas

bash
# Title safe (90%) and action safe (80%) guides
ffmpeg -i video.mp4 \
  -vf "drawbox=x=iw*0.05:y=ih*0.05:w=iw*0.9:h=ih*0.9:color=red:t=1,\
       drawbox=x=iw*0.1:y=ih*0.1:w=iw*0.8:h=ih*0.8:color=yellow:t=1" \
  safe_areas.mp4

Aspect Ratio Guides

bash
# 16:9 guide on 4:3 content
ffmpeg -i video_4x3.mp4 \
  -vf "drawbox=x=(iw-iw*0.75)/2:y=0:w=iw*0.75:h=ih:color=green:t=1" \
  aspect_guide.mp4

# 2.35:1 cinematic guide
ffmpeg -i video.mp4 \
  -vf "drawbox=x=0:y=ih*0.12:w=iw:h=ih*0.76:color=red:t=1" \
  cinematic_guide.mp4

Masking

Rectangle Mask

bash
# Blur outside rectangle
ffmpeg -i video.mp4 \
  -filter_complex "\
    [0:v]split[a][b];\
    [a]boxblur=20[blur];\
    [b]crop=400:300:100:100[crop];\
    [blur][crop]overlay=100:100" \
  spotlight.mp4

Using Alpha Mask

bash
# Apply effect only to masked area
ffmpeg -i video.mp4 -i mask.png \
  -filter_complex "\
    [0:v]split[a][b];\
    [a]curves=preset=lighter[light];\
    [1:v]format=gray[mask];\
    [light][b][mask]maskedmerge" \
  masked_effect.mp4

Generating Graphics Programmatically

Color Bars and Test Patterns

bash
# SMPTE color bars
ffmpeg -f lavfi -i "smptebars=size=1920x1080:duration=10" \
  -c:v libx264 -pix_fmt yuv420p \
  colorbars.mp4

# Test pattern with grid
ffmpeg -f lavfi -i "testsrc=size=1920x1080:duration=10" \
  -c:v libx264 -pix_fmt yuv420p \
  testpattern.mp4

# Solid color
ffmpeg -f lavfi -i "color=c=red:s=1920x1080:d=5" \
  -c:v libx264 -pix_fmt yuv420p \
  red.mp4

Gradient Backgrounds

bash
# Horizontal gradient
ffmpeg -f lavfi -i "gradients=s=1920x1080:c0=0x000033:c1=0x003366:duration=5" \
  -c:v libx264 -pix_fmt yuv420p \
  gradient.mp4

# Radial gradient (using geq)
ffmpeg -f lavfi \
  -i "color=c=black:s=1920x1080:d=5,geq=lum='255-255*sqrt(pow(X-W/2,2)+pow(Y-H/2,2))/sqrt(pow(W/2,2)+pow(H/2,2))':cb=128:cr=128" \
  -c:v libx264 -pix_fmt yuv420p \
  radial.mp4

Noise and Texture

bash
# Noise overlay
ffmpeg -f lavfi -i "nullsrc=size=1920x1080:duration=5,geq=lum='random(1)*255':cb=128:cr=128" \
  -c:v libx264 -pix_fmt yuv420p \
  noise.mp4

# Film grain effect
ffmpeg -i video.mp4 -f lavfi -i "nullsrc=size=1920x1080,geq=lum='random(1)*20+lum(X,Y)':cb=128:cr=128" \
  -filter_complex "[0:v][1:v]blend=all_mode=addition:all_opacity=0.1" \
  grainy.mp4

Performance Tips

Optimize Drawing Operations

bash
# Use enable parameter to limit processing
ffmpeg -i video.mp4 \
  -vf "drawbox=x=100:y=100:w=200:h=150:color=red:t=fill:enable='between(t,5,10)'" \
  optimized.mp4

# Pre-render static graphics
# Instead of complex real-time drawing, overlay pre-made images
ffmpeg -i video.mp4 -i prerendered_graphic.png \
  -filter_complex "[0:v][1:v]overlay=10:10" \
  faster.mp4

Hardware Acceleration

bash
# Use hardware encoding for graphics-heavy output
ffmpeg -i video.mp4 \
  -vf "drawbox=x=100:y=100:w=200:h=150:color=red:t=fill" \
  -c:v h264_nvenc -preset fast \
  output.mp4

Troubleshooting

Common Issues

"Expression syntax error"

bash
# Escape special characters properly
# Use single quotes around expression values
ffmpeg -i video.mp4 \
  -vf "drawbox=x='iw/2':y='ih/2':w=100:h=100:color=red:t=fill" \
  output.mp4

Overlay not visible

bash
# Check PNG has alpha channel
ffprobe -v error -select_streams v -show_entries stream=pix_fmt overlay.png

# Convert to RGBA if needed
ffmpeg -i overlay.png -pix_fmt rgba overlay_rgba.png

Text not rendering

bash
# Specify font file explicitly
ffmpeg -i video.mp4 \
  -vf "drawtext=text='Hello':fontfile=/path/to/font.ttf:fontsize=24:fontcolor=white" \
  output.mp4

# List available fonts
fc-list : family | sort | uniq

Performance issues with complex filters

bash
# Reduce filter chain complexity
# Pre-render graphics
# Use lower resolution for preview
ffmpeg -i video.mp4 \
  -vf "scale=640:360,drawbox=..." \
  -preset ultrafast \
  preview.mp4

Best Practices

Design

  1. Use transparency (RGBA) for overlays
  2. Match overlay resolution to video
  3. Use appropriate colors for visibility
  4. Test on various backgrounds

Performance

  1. Pre-render complex graphics as images
  2. Use enable parameter for timed effects
  3. Limit filter chain length
  4. Use hardware encoding for final output

Accessibility

  1. Ensure sufficient contrast for text
  2. Avoid flashing/blinking elements
  3. Keep important content within safe areas
  4. Test at multiple resolutions

This guide covers FFmpeg shape and graphics operations. For subtitle and caption overlays, see the captions-subtitles skill.