Harden movie playback lifecycle and diagnostics

engine/Age.Engine.Tests/MovieCorpusGateTests.cs

@@ -0,0 +1,102 @@
+using Age.Engine.Sys4;
+
+public class MovieCorpusGateTests
+{
+    private sealed class FakeFrameSource(FfmpegMovieInfo info,
+                                         params FfmpegVideoFrame[] frames) : IFfmpegFrameSource
+    {
+        private readonly Queue<FfmpegVideoFrame> _frames = new(frames);
+        public FfmpegMovieInfo Info { get; } = info;
+        public bool Disposed { get; private set; }
+        public bool TryDecodeNextVideoFrame(out FfmpegVideoFrame frame)
+            => _frames.TryDequeue(out frame!);
+        public void Dispose() => Disposed = true;
+    }
+
+    [Fact]
+    public void SequenceHeaderProbeReadsIndependentDimensions()
+    {
+        byte[] payload = SyntheticPayload(320, 240);
+
+        Assert.True(MovieCorpusDiscovery.TryReadSequenceDimensions(payload, out int width, out int height));
+        Assert.Equal(320, width);
+        Assert.Equal(240, height);
+        Assert.False(MovieCorpusDiscovery.TryReadSequenceDimensions(new byte[] { 0, 0, 1, 0xba }, out _, out _));
+    }
+
+    [Fact]
+    public void GateReportsFramesMetadataTimingAndTeardown()
+    {
+        var source = new FakeFrameSource(new FfmpegMovieInfo(16, 16, 100, 20, 1, false),
+            Frame(16, 16, 1, 0), Frame(16, 16, 2, 50));
+        var input = new MovieCorpusInput(0x2bc2, "SYNTH.AGF", () =>
+            new MoviePayload("SYNTH.AGF", SyntheticPayload(16, 16)));
+
+        MovieCorpusReport report = new MovieCorpusGate(_ => source).Run([input], 1, 1000);
+
+        Assert.True(report.Passed);
+        var item = Assert.Single(report.Movies);
+        Assert.True(item.Passed);
+        Assert.Equal("0x2bc2", item.PackedIdHex);
+        Assert.Equal(16, item.ExpectedWidth);
+        Assert.Equal(2, item.FrameCount);
+        Assert.Equal(0, item.FirstPresentationTimeMs);
+        Assert.Equal(50, item.LastPresentationTimeMs);
+        Assert.True(item.FramesChanged);
+        Assert.True(source.Disposed);
+    }
+
+    [Fact]
+    public void GateContinuesAfterValidationFailureAndReportsCountMismatch()
+    {
+        var badDimensions = new FakeFrameSource(new FfmpegMovieInfo(8, 16, 100, 20, 1, false),
+            Frame(8, 16, 1, 0));
+        var decreasingTimestamps = new FakeFrameSource(new FfmpegMovieInfo(16, 16, 100, 20, 1, false),
+            Frame(16, 16, 1, 50), Frame(16, 16, 2, 40));
+        var sources = new Queue<IFfmpegFrameSource>([badDimensions, decreasingTimestamps]);
+        MovieCorpusInput[] inputs =
+        [
+            new(1, "BAD-DIMS.AGF", () => new MoviePayload("BAD-DIMS.AGF", SyntheticPayload(16, 16))),
+            new(2, "BAD-PTS.AGF", () => new MoviePayload("BAD-PTS.AGF", SyntheticPayload(16, 16))),
+        ];
+
+        MovieCorpusReport report = new MovieCorpusGate(_ => sources.Dequeue()).Run(inputs, 3, 1000);
+
+        Assert.False(report.Passed);
+        Assert.Equal(2, report.FailedCount);
+        Assert.Contains("expected 3", Assert.Single(report.SelectionErrors));
+        Assert.Contains("differ", report.Movies[0].Error);
+        Assert.Contains("timestamp", report.Movies[1].Error);
+        Assert.True(badDimensions.Disposed);
+        Assert.True(decreasingTimestamps.Disposed);
+    }
+
+    [Fact]
+    public void GateRejectsInvalidFrameRateMetadata()
+    {
+        var source = new FakeFrameSource(new FfmpegMovieInfo(16, 16, 100, 0, 1, false),
+            Frame(16, 16, 1, 0));
+        var input = new MovieCorpusInput(1, "BAD-RATE.AGF", () =>
+            new MoviePayload("BAD-RATE.AGF", SyntheticPayload(16, 16)));
+
+        MovieCorpusReport report = new MovieCorpusGate(_ => source).Run([input], 1, 1000);
+
+        Assert.False(report.Passed);
+        Assert.Contains("rate 0/1", Assert.Single(report.Movies).Error);
+        Assert.True(source.Disposed);
+    }
+
+    private static byte[] SyntheticPayload(int width, int height) =>
+    [
+        0, 0, 1, 0xba,
+        0, 0, 1, 0xb3,
+        (byte)(width >> 4),
+        (byte)(((width & 0x0f) << 4) | (height >> 8)),
+        (byte)height,
+        0,
+    ];
+
+    private static FfmpegVideoFrame Frame(int width, int height, byte value, long timestamp)
+        => new(new RgbaImage(width, height,
+            Enumerable.Repeat(value, checked(width * height * 4)).ToArray()), timestamp);
+}