FFmpeg Screen Recording Script - Linux Guide

#!/usr/bin/env bash

# Configuration - Set your USB mic device here
USB_MIC="alsa_input.usb-Jieli_Technology_UACDemoV1.0_F584CD1399EC5853-00.mono-fallback"
INTERNAL_MIC="alsa_input.pci-0000_00_1f.3.analog-stereo"

record() {
  # Toggle on mic
  amixer set Capture toggle

  # Get screen dimensions
  SCREEN_DIM=$(xdpyinfo | awk '/dimensions/{print $2}')
  
  # Check if USB mic is available, fallback to internal mic
  if pactl list short sources | grep -q "$USB_MIC"; then
    AUDIO_SOURCE="$USB_MIC"
    AUDIO_CHANNELS=1  # Mono
    echo "Using USB microphone"
  else
    AUDIO_SOURCE="$INTERNAL_MIC"
    AUDIO_CHANNELS=2  # Stereo
    echo "USB mic not found, using internal microphone"
  fi

  # Single file with both video and audio
  # Lossy compression (reasonable file size) with audio
  ffmpeg \
    -f x11grab -s "$SCREEN_DIM" -r 30 -i :0.0 \
    -f pulse -i "$AUDIO_SOURCE" \
    -c:v libx264 -preset veryfast -crf 23 \
    -c:a aac -ac "$AUDIO_CHANNELS" -ar 44100 -b:a 128k \
    -movflags +faststart \
    "$HOME/video_$(date '+%a__%b%d__%H_%M_%S').mkv" &
  
  echo $! > /tmp/recpid

  # Optional: Separate cleaned audio file (if you want it)
  ffmpeg \
    -f pulse -i "$AUDIO_SOURCE" \
    -af "afftdn=nf=-75" \
    "$HOME/audio_cleaned_$(date '+%a__%b%d__%H_%M_%S').wav" &
  
  echo $! > /tmp/audpid

  echo "Rec •" > /tmp/recordingicon && pkill -RTMIN+3 dwmblocks
  notify-send -t 500 -h string:bgcolor:#a3be8c "Recording started & mic toggled"
}

end() {
  kill -15 "$(cat /tmp/recpid)" 2>/dev/null
  kill -15 "$(cat /tmp/audpid)" 2>/dev/null
  rm -f /tmp/recpid /tmp/audpid

  amixer set Capture toggle

  echo "" > /tmp/recordingicon && pkill -RTMIN+3 dwmblocks

  # Optional: Combine files if you kept the separate recording approach
  # combine_audio_video
  
  notify-send -t 500 -h string:bgcolor:#bf616a "Recording ended & mic toggled"
}

# Optional function to combine separate audio/video files
combine_audio_video() {
  # Find the latest video and audio files
  LATEST_VIDEO=$(ls -t "$HOME"/video_*.mkv 2>/dev/null | head -1)
  LATEST_AUDIO=$(ls -t "$HOME"/audio_*.wav 2>/dev/null | head -1)
  
  if [[ -f "$LATEST_VIDEO" && -f "$LATEST_AUDIO" ]]; then
    OUTPUT="${LATEST_VIDEO%.mkv}_combined.mkv"
    ffmpeg -i "$LATEST_VIDEO" -i "$LATEST_AUDIO" -c copy "$OUTPUT"
    echo "Combined file created: $OUTPUT"
  fi
}

# If the recording pid exists, end recording. If not, start recording
([[ -f /tmp/recpid ]] && end && exit 0) || record

# In record() function:
# Record screen with reference audio track (low quality)
ffmpeg \
  -f x11grab -s "$SCREEN_DIM" -r 30 -i :0.0 \
  -f pulse -i "$AUDIO_SOURCE" \
  -c:v libx264 -preset veryfast -crf 23 \
  -c:a aac -ac "$AUDIO_CHANNELS" -ar 44100 -b:a 32k \
  "$HOME/video_$(date '+%a__%b%d__%H_%M_%S').mkv" &

# High quality cleaned audio separately
ffmpeg \
  -f pulse -i "$AUDIO_SOURCE" \
  -af "afftdn=nf=-75" \
  -c:a pcm_s16le \
  "$HOME/audio_$(date '+%a__%b%d__%H_%M_%S').wav" &

# Add to record() function for region recording:
region_record() {
  # Use slurp to select region
  REGION=$(slurp)
  ffmpeg -f x11grab -video_size "$REGION" -i ":0.0+${REGION%%+*}" ...
}

# Add recording timer:
show_timer() {
  while [[ -f /tmp/recpid ]]; do
    DURATION=$((SECONDS - START_TIME))
    printf "Rec %02d:%02d •" $((DURATION/60)) $((DURATION%60)) > /tmp/recordingicon
    pkill -RTMIN+3 dwmblocks
    sleep 1
  done
}
# Call show_timer & after starting ffmpeg