Correct AV1 distortion cost scaling

1 month ago · 43035256d7
2 changed files with 4 additions and 4 deletions
--- a/src/ImageSharp/Formats/Heif/Av1/Entropy/Av1RateDistortion.cs
+++ b/src/ImageSharp/Formats/Heif/Av1/Entropy/Av1RateDistortion.cs
@ -19,6 +19,6 @@ internal static class Av1RateDistortion
    {
        long weightedRate = (long)rate * rateMultiplier;
        long roundedRate = (weightedRate + (1 << (Av1ProbabilityCost.CostShift - 1))) >> Av1ProbabilityCost.CostShift;
-        return roundedRate + distortion;
+        return roundedRate + (distortion << 7);
    }
 }
--- a/tests/ImageSharp.Tests/Formats/Heif/Av1/Av1EntropyTests.cs
+++ b/tests/ImageSharp.Tests/Formats/Heif/Av1/Av1EntropyTests.cs
@ -522,9 +522,9 @@ public class Av1EntropyTests
    [Theory]
    [InlineData(1, 255, 0L, 0L)]
    [InlineData(1, 256, 0L, 1L)]
-    [InlineData(128, 512, 1000L, 1128L)]
+    [InlineData(128, 512, 1000L, 128_128L)]
-    [InlineData(512, 512, 1000L, 1512L)]
+    [InlineData(512, 512, 1000L, 128_512L)]
-    [InlineData(64, 1024, 4_000_000_000L, 4_000_000_128L)]
+    [InlineData(64, 1024, 4_000_000_000L, 512_000_000_128L)]
    public void RateDistortionCostMatchesCurrentLibaom(
        int rateMultiplier,
        int rate,