added readmeHEADmain

1 files changed, 124 insertions, 0 deletions

diff --git a/record-output b/record-output
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+++ b/record-output
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+#!/usr/bin/env bash
+set -euo pipefail
+
+OUTPUT="voice"
+FORMAT="mp3"
+BITRATE="128k"
+SOURCE=""
+GAIN="6dB"
+NORMALIZE=1
+PROBE=0
+
+usage() {
+    cat <<EOF
+Usage: $0 -o name [-f mp3|wav] [-b bitrate] [-s source] [-g gain] [-n] [-p]
+
+Records the currently active audio output (whatever is playing through the
+default sink). Auto-detects the correct monitor source.
+
+Options:
+  -o NAME       Output basename (without extension)
+  -f FORMAT     mp3 (default) or wav
+  -b BITRATE    MP3 bitrate (default 128k)
+  -s SOURCE     Override monitor source (default: auto-detect from default sink)
+  -g GAIN       Pre-normalization gain (default 8dB; set 0dB to disable)
+  -n            No normalization (raw capture)
+  -p            Probe mode: 5s test recording, print levels, exit
+  -h            Help
+
+Notes:
+  Pre-gain default (8dB) is tuned for an attenuated chain (e.g. Bluetooth sink
+  at ~0.35 + app-level stream attenuation). Run -p after any sink or headphone
+  change; chain attenuation is device-specific.
+
+Examples:
+  $0 -o lecture
+  $0 -o music -f wav -g 6dB
+  $0 -p                  # check levels before committing to a long recording
+EOF
+    exit 0
+}
+
+while getopts "o:f:b:s:g:nph" opt; do
+    case "$opt" in
+        o) OUTPUT="$OPTARG" ;;
+        f) FORMAT="$OPTARG" ;;
+        b) BITRATE="$OPTARG" ;;
+        s) SOURCE="$OPTARG" ;;
+        g) GAIN="$OPTARG" ;;
+        n) NORMALIZE=0 ;;
+        p) PROBE=1 ;;
+        h) usage ;;
+        *) usage ;;
+    esac
+done
+
+# Auto-detect monitor of the default sink (what the user is actually hearing)
+if [ -z "$SOURCE" ]; then
+    DEFAULT_SINK=$(pactl get-default-sink)
+    SOURCE="${DEFAULT_SINK}.monitor"
+fi
+
+# Verify the source exists before invoking ffmpeg
+if ! pactl list sources short | awk '{print $2}' | grep -Fxq "$SOURCE"; then
+    echo "Error: monitor source not found: $SOURCE" >&2
+    echo "Available sources:" >&2
+    pactl list sources short | awk '{print "  " $2}' >&2
+    exit 1
+fi
+
+# Build audio filter chain
+FILTER=""
+if [ "$NORMALIZE" -eq 1 ]; then
+    FILTER="volume=${GAIN},loudnorm=I=-16:TP=-1.5:LRA=11"
+elif [ "$GAIN" != "0dB" ]; then
+    FILTER="volume=${GAIN}"
+fi
+
+FORMAT=$(echo "$FORMAT" | tr '[:upper:]' '[:lower:]')
+
+# Probe mode: short capture, report levels, exit
+if [ "$PROBE" -eq 1 ]; then
+    echo "Probing $SOURCE for 5 seconds..."
+    PROBE_OUT=$(ffmpeg -hide_banner -nostats -loglevel info \
+        -f pulse -i "$SOURCE" -t 5 -af "volumedetect" -f null - 2>&1) || true
+    LEVELS=$(echo "$PROBE_OUT" | grep -E "mean_volume|max_volume" || true)
+    if [ -z "$LEVELS" ]; then
+        echo "No level data — source emitted silence or ffmpeg failed."
+        echo
+        echo "ffmpeg output (last 20 lines):"
+        echo "$PROBE_OUT" | tail -20
+    else
+        echo "$LEVELS"
+        echo
+	echo "Current gain: -g ${GAIN}"
+	echo
+        echo "Reference:"
+        echo "  mean_volume near -16 dB        good for voice"
+        echo "  mean_volume below -25 dB       increase -g or raise sink volume"
+        echo "  max_volume above -1 dB         reduce -g (risk of clipping)"
+    fi
+    exit 0
+fi
+
+# Assemble ffmpeg invocation
+FILE="${OUTPUT}.${FORMAT}"
+ARGS=(-f pulse -i "$SOURCE" -ac 2)
+[ -n "$FILTER" ] && ARGS+=(-af "$FILTER")
+
+case "$FORMAT" in
+    mp3) ARGS+=(-c:a libmp3lame -b:a "$BITRATE") ;;
+    wav) : ;;
+    *)
+        echo "Error: unsupported format '$FORMAT' (use mp3 or wav)" >&2
+        exit 1
+        ;;
+esac
+
+echo "Recording: $SOURCE"
+echo "Filter:    ${FILTER:-(none)}"
+echo "Output:    $FILE"
+echo "Press Ctrl+C to stop."
+echo
+
+ffmpeg "${ARGS[@]}" "$FILE"