Countdown Video Generator

This project generates countdown videos with FFmpeg. The primary tool is the Go CLI in main.go, which builds the FFmpeg filter graph from presets and command-line flags.

Watch the demo: CountdownNow on YouTube

The video includes:

• Static radial gradient background, or a custom image/video background
• Large MM:SS countdown timer
• Shrinking bottom progress bar
• Optional logo overlay with configurable position
• Final outro where the timer/logo fade and the title/subtitle appear
• Hardware encoder attempts when available, with automatic libx264 fallback
• Responsive layout sizing for landscape, vertical, square, ultrawide, 4K, and custom dimensions
• Themes, outro modes, progress styles, preview frames, and optional audio

Requirements

Install a full FFmpeg build before running CountdownNow.

macOS:

brew install ffmpeg-full

Windows and Linux users should install a full FFmpeg package from their package manager or from the official FFmpeg builds. After installing FFmpeg, verify the runtime with:

./countdownnow --check

Quick Start

Download the release archive for your platform from the latest GitHub Release, extract it, and run the binary.

Run the default 5-minute landscape countdown:

./countdownnow

./countdownnow --version
./countdownnow --help

To run an unsigned or unnotarized macOS download, remove the quarantine attribute after extracting the archive:

xattr -dr com.apple.quarantine ./countdownnow-macos-universal-unsigned
./countdownnow-macos-universal-unsigned/countdownnow --help

Default output:

countdown_300s.mp4

Short Test Renders

Use short renders while tuning layout:

./countdownnow --duration 0.5 --output /tmp/countdown-test.mp4 --encoder software

Print the generated FFmpeg command without rendering:

./countdownnow --duration 0.5 --dry-run

Check the runtime FFmpeg installation before rendering:

./countdownnow --check

The check verifies the FFmpeg executable, required video/audio filters, libx264, listed hardware encoders, and a tiny drawtext render.

Generate one preview frame without rendering a video:

./countdownnow --preview preview.png --preview-time 120

Use a custom image or video background:

./countdownnow --background background.png
./countdownnow --background background.mp4
./countdownnow --background background.mp4 --width 1920 --height 1080 --background-fit cover
./countdownnow --background poster.png --width 1080 --height 1920 --background-fit contain

When --background is provided without --width and --height, the output video uses the background's first video stream dimensions. If you provide dimensions, pass both --width and --height; those values override the background size.

Image backgrounds are looped for the full countdown. Video backgrounds are looped and trimmed to --duration.

Background fit modes:

• cover: fill the output canvas and crop overflow. This is the default.
• contain: show the whole background with black padding when aspect ratios differ.
• stretch: resize exactly to the output size, even if that distorts the background.

Presets And Sizes

Landscape, 1280x720:

./countdownnow --preset landscape

Vertical, 1080x1920:

./countdownnow --preset vertical --output vertical-countdown.mp4

Square, 1080x1080:

./countdownnow --preset square --output square-countdown.mp4

Ultrawide, 2560x1080:

./countdownnow --preset ultrawide --output ultrawide-countdown.mp4

4K landscape, 3840x2160:

./countdownnow --preset 4k --output countdown-4k.mp4

You can also override dimensions directly. The timer, logo, progress bar, title, subtitle, margins, and bitrate scale from the selected canvas size:

./countdownnow --width 1920 --height 1080 --output custom.mp4
./countdownnow --width 1080 --height 1350 --output social-4x5.mp4
./countdownnow --width 2160 --height 3840 --output vertical-4k.mp4
./countdownnow --width 3440 --height 1440 --output wide-monitor.mp4

Text Options

Set duration:

./countdownnow --duration 600

By default, --outro-seconds is part of the duration. To add the outro after the countdown, keep the timer duration unchanged and extend the final video:

./countdownnow --duration 10 --outro-seconds 6 --outro-over-duration

Set title:

./countdownnow --title "Sunday Gathering"

Set outro subtitle:

./countdownnow --subtitle "We are glad you are here."

Use a custom font file for all text:

./countdownnow --font ./fonts/Passion_One/PassionOne-Bold.ttf

Advanced font overrides:

./countdownnow --font-title ./title.ttf --font-subtitle ./subtitle.ttf
./countdownnow --font-timer ./timer.ttf

Disable the final title and subtitle:

./countdownnow --title none --subtitle none

The timer and logo still fade out during the outro.

Visual Options

Set a color theme:

./countdownnow --theme midnight
./countdownnow --theme warm
./countdownnow --theme sunrise
./countdownnow --theme minimal

Override the timer font color:

./countdownnow --timer-color "#ffcc00"
./countdownnow --timer-color white

Set the outro reveal style:

./countdownnow --outro slide
./countdownnow --outro fade
./countdownnow --outro typewriter
./countdownnow --outro none

Set the progress indicator:

./countdownnow --progress bottom-bar
./countdownnow --progress none

bottom-bar is the default shrinking bar. It runs through the countdown and finishes just before the end so the final moment is clean. Use none to hide the progress indicator.

Add extra padding for screens that crop edges:

./countdownnow --safe-area 80

Logo Options

Default logo path is auto-detected from:

logo.png
default.png
Round Icon Design.png

If no local logo file is available, the Go binary uses its embedded logo.png.

Use a specific logo:

./countdownnow --logo logo.png

Disable the logo:

./countdownnow --logo none
./countdownnow --logo-position none

Set logo position:

./countdownnow --logo-position top-right
./countdownnow --logo-position top-left
./countdownnow --logo-position bottom-right
./countdownnow --logo-position bottom-left
./countdownnow --logo-position center

Resize or adjust margins:

./countdownnow --logo-width 160 --logo-margin-x 30 --logo-margin-y 40

The app warns when ffprobe reports a low-resolution logo or a logo pixel format that may not include transparency.

Audio Options

Add background audio:

./countdownnow --audio worship-pad.mp3 --audio-volume 0.35

Fade background audio during the outro:

./countdownnow --audio worship-pad.mp3 --fade-audio

Mix in a short sound effect near the end:

./countdownnow --end-sound chime.wav

Encoder Options

Default mode is auto:

./countdownnow --encoder auto

Auto mode tries hardware encoders first for the current OS, then falls back to software:

• macOS: h264_videotoolbox, then libx264
• Windows: h264_nvenc, h264_qsv, h264_amf, then libx264
• Linux: h264_nvenc, h264_qsv, then libx264

Force software:

./countdownnow --encoder software

Use a specific FFmpeg encoder:

./countdownnow --encoder h264_nvenc

Set hardware bitrate:

./countdownnow --bitrate 8M

Set software quality:

./countdownnow --encoder software --crf 20 --preset-x264 veryfast

Developer Build

Build from source:

make build
./countdownnow

The Makefile builds with -trimpath -buildvcs=false and -ldflags="-s -w" so the binary omits local source paths, VCS metadata, and debug symbols.

Build metadata is injected at build time. If HEAD is on a git tag, that tag is used as the version; otherwise the short commit SHA is used.