diff --git a/src/Dragon-ISO.Engine/Pipeline/AudioPeakComputer.cs b/src/Dragon-ISO.Engine/Pipeline/AudioPeakComputer.cs
index c011ff8..fc7b599 100644
--- a/src/Dragon-ISO.Engine/Pipeline/AudioPeakComputer.cs
+++ b/src/Dragon-ISO.Engine/Pipeline/AudioPeakComputer.cs
@@ -5,29 +5,34 @@ namespace DragonISO.Engine.Pipeline;
 /// <summary>
 /// Computes a single peak amplitude (in [0.0, 1.0]) from one NDI audio frame.
 ///
-/// NDI 6's preferred audio format is <c>NDIlib_FourCC_audio_type_FLTP</c> —
+/// NDI 6's preferred audio format is <c>NDIlib_FourCC_audio_type_FLTP</c> —
 /// 32-bit IEEE float, planar (one contiguous chunk per channel). Values are
 /// nominally normalized to [-1, 1]; brief excursions past 1 during transient
 /// clipping are clamped here. We compute a max-absolute peak across every
 /// sample of every channel rather than RMS so the UI VU bar reads
-/// "loudest part of the buffer" — the same convention OBS / Resolve / Studio
+/// "loudest part of the buffer" — the same convention OBS / Resolve / Studio
 /// Monitor use for their meters.
 ///
 /// Pulled out of <see cref="NdiReceiver"/> so the math is unit-testable
 /// without an NDI runtime; the heavy work (FLTP decode) runs entirely on
 /// managed memory the caller has already copied across the P/Invoke
 /// boundary, so tests exercise the same code path that production does.
+///
+/// FourCC values are packed little-endian, matching the NDI SDK and
+/// <see cref="DragonISO.Engine.NdiInterop"/>'s video FourCCs: the first ASCII
+/// character occupies the least-significant byte. So <c>'P','C','M','s'</c>
+/// is <c>0x73</c>('s')<c>4D</c>('M')<c>43</c>('C')<c>50</c>('P') = 0x734D4350.
 /// </summary>
 public static class AudioPeakComputer
 {
-    /// <summary>FourCC for FLTP — 32-bit float, planar layout. <c>'F','L','T','p'</c>.</summary>
+    /// <summary>FourCC for FLTP — 32-bit float, planar layout. <c>'F','L','T','p'</c>.</summary>
     public const uint FourCC_FLTP = 0x70544c46;
 
-    /// <summary>FourCC for FLT — 32-bit float, interleaved. <c>'F','L','T',' '</c>. Rarely seen but cheap to handle.</summary>
+    /// <summary>FourCC for FLT — 32-bit float, interleaved. <c>'F','L','T',' '</c>. Rarely seen but cheap to handle.</summary>
     public const uint FourCC_FLT = 0x20544c46;
 
     /// <summary>FourCC for PCM 16-bit signed integer, interleaved. Some legacy senders use this. <c>'P','C','M','s'</c>.</summary>
-    public const uint FourCC_PCMs16 = 0x73334d50;
+    public const uint FourCC_PCMs16 = 0x734D4350;
 
     /// <summary>
     /// Returns the largest absolute sample value found in the buffer,
@@ -38,7 +43,7 @@ public static class AudioPeakComputer
     /// <param name="fourCC">The NDI audio FourCC (see the constants on this class).</param>
     /// <param name="totalSamples">
     /// Total sample count across all channels (e.g. <c>no_samples * no_channels</c>
-    /// for FLTP — channels are concatenated planes, but every sample contributes).
+    /// for FLTP — channels are concatenated planes, but every sample contributes).
     /// </param>
     public static double ComputePeak(ReadOnlySpan<byte> data, uint fourCC, int totalSamples)
     {
@@ -48,7 +53,7 @@ public static class AudioPeakComputer
         {
             FourCC_FLTP or FourCC_FLT => ComputePeakFloat32(data, totalSamples),
             FourCC_PCMs16 => ComputePeakInt16(data, totalSamples),
-            _ => 0.0, // unknown format — surface silence rather than throw
+            _ => 0.0, // unknown format — surface silence rather than throw
         };
     }
 
@@ -56,7 +61,7 @@ public static class AudioPeakComputer
     {
         // 4 bytes per sample. Cap by what's actually in the buffer in case
         // the caller's totalSamples disagrees with the byte length (defensive
-        // — a misreporting source shouldn't take down the receiver loop).
+        // — a misreporting source shouldn't take down the receiver loop).
         var available = Math.Min(totalSamples, data.Length / 4);
         if (available <= 0) return 0.0;