feat(ads/seo/release): v1.2.0 with live Google Ads, isolated ad profile, ads.txt, and SEO/AEO/GEO optimization

src/Paca.Core/Platform/AudioNormalizer.cs

@@ -0,0 +1,102 @@
+using System.Globalization;
+using System.Text.Json;
+
+namespace Paca.Core.Platform;
+
+public sealed record LoudnessSpec(double TargetLufs = -14.0, double TruePeak = -1.0, double LoudnessRange = 11.0)
+{
+    public static LoudnessSpec WebStandard => new(-14.0, -1.0, 11.0);
+    public static LoudnessSpec EbuR128 => new(-23.0, -1.0, 7.0);
+}
+
+public sealed record MeasuredLoudness(double MeasuredI, double MeasuredTp, double MeasuredLra, double MeasuredThresh);
+
+/// <summary>
+/// 29차: EBU R128 2-pass 오디오 라우드니스 정규화 및 무음 트리밍 엔진.
+/// </summary>
+public sealed class AudioNormalizer
+{
+    private readonly IProcessRunner _runner;
+
+    public AudioNormalizer(IProcessRunner runner)
+    {
+        _runner = runner ?? throw new ArgumentNullException(nameof(runner));
+    }
+
+    public async Task<string> NormalizeAudioAsync(string ffmpeg, string inputFile, string outputFile, LoudnessSpec spec, CancellationToken ct)
+    {
+        // Pass 1: Measure loudness
+        var iStr = spec.TargetLufs.ToString("F1", CultureInfo.InvariantCulture);
+        var tpStr = spec.TruePeak.ToString("F1", CultureInfo.InvariantCulture);
+        var lraStr = spec.LoudnessRange.ToString("F1", CultureInfo.InvariantCulture);
+
+        var pass1Filter = $"loudnorm=I={iStr}:TP={tpStr}:LRA={lraStr}:print_format=json";
+        var pass1Args = new[]
+        {
+            "-hide_banner", "-i", inputFile,
+            "-af", pass1Filter,
+            "-f", "null", "-"
+        };
+
+        var pass1Res = await _runner.RunAsync(new ProcessSpec(ffmpeg, pass1Args), null, ct);
+        if (pass1Res.ExitCode != 0)
+            throw new InvalidOperationException($"오디오 라우드니스 1-pass 측정 실패 (ExitCode: {pass1Res.ExitCode}): {pass1Res.Stderr}");
+        var stats = ParseLoudnessStats(pass1Res.Stdout.Length > 0 ? pass1Res.Stdout : pass1Res.Stderr);
+
+        // Pass 2: Apply normalized audio
+        var pass2Filter = stats != null
+            ? $"loudnorm=I={iStr}:TP={tpStr}:LRA={lraStr}:measured_I={stats.MeasuredI.ToString("F2", CultureInfo.InvariantCulture)}:measured_TP={stats.MeasuredTp.ToString("F2", CultureInfo.InvariantCulture)}:measured_LRA={stats.MeasuredLra.ToString("F2", CultureInfo.InvariantCulture)}:measured_thresh={stats.MeasuredThresh.ToString("F2", CultureInfo.InvariantCulture)}:linear=true"
+            : $"loudnorm=I={iStr}:TP={tpStr}:LRA={lraStr}";
+
+        var pass2Args = new[]
+        {
+            "-y", "-hide_banner", "-loglevel", "error",
+            "-i", inputFile,
+            "-af", pass2Filter,
+            "-c:v", "copy",
+            "-c:a", "aac", "-b:a", "192k",
+            outputFile
+        };
+
+        var pass2Res = await _runner.RunAsync(new ProcessSpec(ffmpeg, pass2Args), null, ct);
+        if (pass2Res.ExitCode != 0)
+            throw new InvalidOperationException($"오디오 정규화 실패: {pass2Res.Stderr}");
+
+        return outputFile;
+    }
+
+    public static MeasuredLoudness? ParseLoudnessStats(string text)
+    {
+        if (string.IsNullOrWhiteSpace(text)) return null;
+
+        var startIdx = text.IndexOf('{');
+        var endIdx = text.LastIndexOf('}');
+        if (startIdx < 0 || endIdx <= startIdx) return null;
+
+        var json = text.Substring(startIdx, endIdx - startIdx + 1);
+        try
+        {
+            using var doc = JsonDocument.Parse(json);
+            var root = doc.RootElement;
+
+            double i = 0, tp = 0, lra = 0, thresh = 0;
+            if (root.TryGetProperty("input_i", out var iEl)) double.TryParse(iEl.GetString(), NumberStyles.Any, CultureInfo.InvariantCulture, out i);
+            if (root.TryGetProperty("input_tp", out var tpEl)) double.TryParse(tpEl.GetString(), NumberStyles.Any, CultureInfo.InvariantCulture, out tp);
+            if (root.TryGetProperty("input_lra", out var lraEl)) double.TryParse(lraEl.GetString(), NumberStyles.Any, CultureInfo.InvariantCulture, out lra);
+            if (root.TryGetProperty("input_thresh", out var thEl)) double.TryParse(thEl.GetString(), NumberStyles.Any, CultureInfo.InvariantCulture, out thresh);
+
+            return new MeasuredLoudness(i, tp, lra, thresh);
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
+    public static string BuildSilenceRemoveFilter(double thresholdDb = -50.0, double minDurationSec = 0.5)
+    {
+        var thStr = thresholdDb.ToString("0.##", CultureInfo.InvariantCulture);
+        var durStr = minDurationSec.ToString("0.##", CultureInfo.InvariantCulture);
+        return $"silenceremove=start_periods=1:start_duration={durStr}:start_threshold={thStr}dB:stop_periods=1:stop_duration={durStr}:stop_threshold={thStr}dB";
+    }
+}