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fix(interop): implement frame-rate-carrying CreateSender in P/Invoke + fake

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The INdiInterop.CreateSender(frameRateN, frameRateD) overload landed without
either implementation, so main stopped compiling on Windows (CS0535) and a
tag push would have failed the release build. The NDI SDK carries frame rate
per-frame, not on send_create: the handle now remembers the configured
rational and SendFrame stamps it onto every outgoing frame instead of the
hardwired 60000/1001. Frame assembly is extracted to a pure BuildVideoFrame
so the stamping is unit-testable without an NDI runtime.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
Zac Gaetano 2026-07-06 21:25:57 -04:00
parent f11f2b947f
commit 97d7028a3a
5 changed files with 130 additions and 29 deletions
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66
src/Dragon-ISO.Engine.NdiInterop/NdiInteropPInvoke.cs
View file

@ -275,7 +275,7 @@ public sealed class NdiInteropPInvoke : INdiInterop, IDisposable
// ---- Send ----
public NdiSenderHandle CreateSender(string outputName, string? groups = null)
public NdiSenderHandle CreateSender(string outputName, string? groups = null, int frameRateN = 60000, int frameRateD = 1001)
{
var trimmedGroups = NormalizeGroups(groups);
var nameUtf8 = Marshal.StringToHGlobalAnsi(outputName);
@ -297,7 +297,7 @@ public sealed class NdiInteropPInvoke : INdiInterop, IDisposable
$"NDIlib_send_create returned null for output '{outputName}' on groups '{trimmedGroups ?? "<default>"}'.");
if (trimmedGroups is not null)
_logger.LogInformation("NDI sender '{Output}' created on groups: {Groups}", outputName, trimmedGroups);
return new NdiPInvokeSenderHandle(native, outputName);
return new NdiPInvokeSenderHandle(native, outputName, frameRateN, frameRateD);
}
finally
{
@ -310,6 +310,29 @@ public sealed class NdiInteropPInvoke : INdiInterop, IDisposable
{
var pInvokeSender = (NdiPInvokeSenderHandle)sender;
// Pin the managed buffer so the native call can read it directly.
var pixels = frame.Pixels.ToArray();
var handle = GCHandle.Alloc(pixels, GCHandleType.Pinned);
try
{
var nativeFrame = BuildVideoFrame(
frame, handle.AddrOfPinnedObject(),
pInvokeSender.FrameRateN, pInvokeSender.FrameRateD);
NdiNative.SendSendVideoV2(pInvokeSender.Native, ref nativeFrame);
}
finally
{
handle.Free();
}
}
/// <summary>
/// Pure assembly of the native frame descriptor — extracted so the stamping
/// (frame rate, stride, dimensions) is unit-testable without an NDI runtime.
/// </summary>
internal static NdiNative.VideoFrameV2 BuildVideoFrame(
ProcessedFrame frame, IntPtr data, int frameRateN, int frameRateD)
{
var fourcc = frame.Format switch
{
PixelFormat.Bgra => NdiNative.FourCC.BGRA,
@ -318,32 +341,21 @@ public sealed class NdiInteropPInvoke : INdiInterop, IDisposable
_ => NdiNative.FourCC.BGRA
};
// Pin the managed buffer so the native call can read it directly.
var pixels = frame.Pixels.ToArray();
var handle = GCHandle.Alloc(pixels, GCHandleType.Pinned);
try
return new NdiNative.VideoFrameV2
{
var nativeFrame = new NdiNative.VideoFrameV2
{
xres = frame.Width,
yres = frame.Height,
FourCC = fourcc,
frame_rate_N = 60000,
frame_rate_D = 1001, // 59.94 default; controller-supplied later
picture_aspect_ratio = 0.0f, // 0 = derive from xres/yres
frame_format_type = NdiNative.FrameFormatType.Progressive,
timecode = NdiTimecodeSynthesize, // synthesize
p_data = handle.AddrOfPinnedObject(),
line_stride_in_bytes = frame.Width * BytesPerPixel(frame.Format),
p_metadata = IntPtr.Zero,
timestamp = frame.TimestampTicks
};
NdiNative.SendSendVideoV2(pInvokeSender.Native, ref nativeFrame);
}
finally
{
handle.Free();
}
xres = frame.Width,
yres = frame.Height,
FourCC = fourcc,
frame_rate_N = frameRateN,
frame_rate_D = frameRateD,
picture_aspect_ratio = 0.0f, // 0 = derive from xres/yres
frame_format_type = NdiNative.FrameFormatType.Progressive,
timecode = NdiTimecodeSynthesize, // synthesize
p_data = data,
line_stride_in_bytes = frame.Width * BytesPerPixel(frame.Format),
p_metadata = IntPtr.Zero,
timestamp = frame.TimestampTicks
};
}
private const long NdiTimecodeSynthesize = unchecked((long)0x8000000000000000UL); // NDIlib_send_timecode_synthesize

10
src/Dragon-ISO.Engine.NdiInterop/NdiPInvokeHandles.cs
View file

@ -44,10 +44,18 @@ internal sealed class NdiPInvokeSenderHandle : NdiSenderHandle
public IntPtr Native { get; private set; }
public string OutputName { get; }
public NdiPInvokeSenderHandle(IntPtr native, string outputName)
// The NDI SDK carries frame rate per-frame (VideoFrameV2.frame_rate_N/D),
// not on send_create, so the handle remembers the configured rational and
// SendFrame stamps it onto every outgoing frame.
public int FrameRateN { get; }
public int FrameRateD { get; }
public NdiPInvokeSenderHandle(IntPtr native, string outputName, int frameRateN = 60000, int frameRateD = 1001)
{
Native = native;
OutputName = outputName;
FrameRateN = frameRateN;
FrameRateD = frameRateD;
}
public override void Dispose()

5
src/tests/Dragon-ISO.Engine.Tests/Fakes/FakeNdiInterop.cs
View file

@ -23,6 +23,8 @@ public sealed class FakeNdiInterop : INdiInterop
public string? LastFinderGroups { get; private set; }
/// <summary>Per-output <c>groups</c> string seen by <see cref="CreateSender"/>; null = default Public.</summary>
public Dictionary<string, string?> SenderGroups { get; } = new();
/// <summary>Per-output rational frame rate (N, D) seen by <see cref="CreateSender"/>.</summary>
public Dictionary<string, (int N, int D)> SenderFrameRates { get; } = new();
/// <summary>
/// Number of finders created so far (initial construction + every rebuild).
@ -77,10 +79,11 @@ public sealed class FakeNdiInterop : INdiInterop
return null; // no audio queued — simulate timeout
}
public NdiSenderHandle CreateSender(string outputName, string? groups = null)
public NdiSenderHandle CreateSender(string outputName, string? groups = null, int frameRateN = 60000, int frameRateD = 1001)
{
SenderCreatedCount[outputName] = SenderCreatedCount.GetValueOrDefault(outputName) + 1;
SenderGroups[outputName] = groups;
SenderFrameRates[outputName] = (frameRateN, frameRateD);
SentFrames.GetOrAdd(outputName, _ => new List<ProcessedFrame>());
return new FakeSenderHandle(outputName);
}

63
src/tests/Dragon-ISO.Engine.Tests/Interop/NdiInteropSendFrameTests.cs Normal file
View file

@ -0,0 +1,63 @@
using System.Runtime.Versioning;
using DragonISO.Engine.NdiInterop;
using DragonISO.Engine.Pipeline;
namespace DragonISO.Engine.Tests.Interop;
// NdiInteropPInvoke is [SupportedOSPlatform("windows")]; these tests exercise
// pure helpers that never touch native code, but inherit the platform tag.
// Same pattern as NdiInteropNormalizeGroupsTests.
[SupportedOSPlatform("windows")]
// NdiPInvokeSenderHandle and NdiInteropPInvoke.BuildVideoFrame are internal;
// the engine tests project has access via InternalsVisibleTo.
public class NdiInteropSendFrameTests
{
private static ProcessedFrame MakeFrame(int width, int height, PixelFormat format) =>
new(width, height, 42, new byte[width * height * 4], format);
[Fact]
public void SenderHandle_CarriesFrameRate()
{
// CreateSender stashes the configured rational on the handle so SendFrame
// can stamp every outgoing video frame without re-plumbing the settings.
var handle = new NdiPInvokeSenderHandle(IntPtr.Zero, "Dragon-ISO_01", 30000, 1001);
handle.FrameRateN.Should().Be(30000);
handle.FrameRateD.Should().Be(1001);
}
[Fact]
public void BuildVideoFrame_StampsConfiguredFrameRate()
{
var frame = MakeFrame(1280, 720, PixelFormat.Bgra);
var native = NdiInteropPInvoke.BuildVideoFrame(frame, IntPtr.Zero, 24000, 1001);
native.frame_rate_N.Should().Be(24000,
because: "advertising the wrong rational causes drift and A/V desync downstream");
native.frame_rate_D.Should().Be(1001);
}
[Fact]
public void BuildVideoFrame_PreservesDimensionsAndStride()
{
var frame = MakeFrame(1920, 1080, PixelFormat.Bgra);
var native = NdiInteropPInvoke.BuildVideoFrame(frame, IntPtr.Zero, 60000, 1001);
native.xres.Should().Be(1920);
native.yres.Should().Be(1080);
native.line_stride_in_bytes.Should().Be(1920 * 4, because: "BGRA is 4 bytes per pixel");
}
[Fact]
public void BuildVideoFrame_MapsUyvyStride()
{
var frame = MakeFrame(1280, 720, PixelFormat.Uyvy);
var native = NdiInteropPInvoke.BuildVideoFrame(frame, IntPtr.Zero, 60000, 1001);
native.line_stride_in_bytes.Should().Be(1280 * 2, because: "UYVY is 2 bytes per pixel");
}
}

15
src/tests/Dragon-ISO.Engine.Tests/Pipeline/NdiSenderTests.cs
View file

@ -12,6 +12,21 @@ public class NdiSenderTests
private static ProcessedFrame MakeFrame(long ts) =>
new(1920, 1080, ts, new byte[1920 * 1080 * 4], PixelFormat.Bgra);
[Fact]
public void Ctor_ForwardsFrameRate_ToCreateSender()
{
var interop = new FakeNdiInterop();
var input = Channel.CreateUnbounded<ProcessedFrame>();
using var sender = new NdiSender(
interop, Output, input.Reader, NullLogger<NdiSender>.Instance,
outputGroups: null, frameRateN: 30000, frameRateD: 1001);
interop.SenderFrameRates[Output].Should().Be((30000, 1001),
because: "the sender must hand the configured rational frame rate to the interop " +
"so the NDI stream advertises 29.97 rather than the 59.94 default");
}
[Fact]
public async Task SendNextAsync_FrameAvailable_ForwardsToInterop()
{