fix(video): ship FFmpeg DLLs as loose files, not inside single-file exe

src/OpenIPC.Viewer.Devices/Onvif/OnvifClientBuilder.cs

@@ -97,6 +97,15 @@ private static async Task<DeviceClient> CreatePreAuthDeviceAsync(Uri uri)
         {
             shift = await probe.GetDeviceTimeShift().ConfigureAwait(false);
         }
+        catch (CommunicationException)
+        {
+            // Some firmwares answer GetSystemDateAndTime with an empty/truncated
+            // body ("Unexpected end of file"), which used to abort the whole add
+            // flow. The shift only compensates camera clock skew for the
+            // WS-UsernameToken digest — assume zero and proceed; if the camera
+            // truly rejects the digest, the next call surfaces the real error.
+            shift = TimeSpan.Zero;
+        }
         finally
         {
             CloseQuietly(probe);

src/OpenIPC.Viewer.Video/OpenIPC.Viewer.Video.csproj

@@ -25,30 +25,42 @@
     the directory not existing, so contributors without a given RID's binaries
     aren't blocked. Linux/macOS users can alternatively rely on system
     apt/brew-installed FFmpeg — FfmpegRuntime falls back to the loader path.
+
+    ExcludeFromSingleFile keeps these out of the PublishSingleFile bundle.
+    Bundled (IncludeNativeLibrariesForSelfExtract) they extract to a temp dir
+    under their runtimes\<rid>\native\ subpath, which is NOT on the host's
+    native search path — and AppContext.BaseDirectory still points at the exe
+    dir, so FfmpegRuntime.ResolveNativeDir finds nothing and every av_* call
+    throws NotSupportedException. Loose files next to the exe also keep the
+    LGPL DLLs user-replaceable.
   -->
   <ItemGroup>
     <Content Include="..\..\runtimes\win-x64\native\*.dll"
              Condition="Exists('..\..\runtimes\win-x64\native')">
       <Link>runtimes\win-x64\native\%(Filename)%(Extension)</Link>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      <ExcludeFromSingleFile>true</ExcludeFromSingleFile>
       <Visible>false</Visible>
     </Content>
     <Content Include="..\..\runtimes\linux-x64\native\*.so*"
              Condition="Exists('..\..\runtimes\linux-x64\native')">
       <Link>runtimes\linux-x64\native\%(Filename)%(Extension)</Link>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      <ExcludeFromSingleFile>true</ExcludeFromSingleFile>
       <Visible>false</Visible>
     </Content>
     <Content Include="..\..\runtimes\osx-arm64\native\*.dylib"
              Condition="Exists('..\..\runtimes\osx-arm64\native')">
       <Link>runtimes\osx-arm64\native\%(Filename)%(Extension)</Link>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      <ExcludeFromSingleFile>true</ExcludeFromSingleFile>
       <Visible>false</Visible>
     </Content>
     <Content Include="..\..\runtimes\osx-x64\native\*.dylib"
              Condition="Exists('..\..\runtimes\osx-x64\native')">
       <Link>runtimes\osx-x64\native\%(Filename)%(Extension)</Link>
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      <ExcludeFromSingleFile>true</ExcludeFromSingleFile>
       <Visible>false</Visible>
     </Content>
   </ItemGroup>

src/OpenIPC.Viewer.Video/Pipeline/FfmpegRuntime.cs

@@ -9,11 +9,21 @@ namespace OpenIPC.Viewer.Video.Pipeline;
 internal static class FfmpegRuntime
 {
     private static int _initialized;
+    private static Exception? _initFailure;
 
     public static void EnsureInitialized()
     {
         if (Interlocked.CompareExchange(ref _initialized, 1, 0) != 0)
+        {
+            // Replay a failed first init instead of returning success — otherwise
+            // every later session walks straight into uninitialized bindings and
+            // dies mid-stream with a bare "Specified method is not supported"
+            // (what the field logs showed: one descriptive crash, then an endless
+            // reconnect loop of cryptic av_dict_set failures).
+            if (_initFailure is not null)
+                throw _initFailure;
             return;
+        }
 
         if (OperatingSystem.IsAndroid())
         {
@@ -54,13 +64,15 @@ public static void EnsureInitialized()
             // message is preserved.
             var (rid, _) = RuntimeIds.Current();
             var probe = string.IsNullOrEmpty(nativeDir) ? "(loader path)" : nativeDir;
-            throw new FfmpegNativeLibsMissingException(
+            _initFailure = new FfmpegNativeLibsMissingException(
                 $"FFmpeg native libraries failed to load for runtime '{rid ?? "unknown"}'. " +
                 $"Probed: {probe}. " +
                 $"Android: ensure runtimes/android-{{arm64,x64}}/native/*.so are populated " +
                 $"(run tools/build-ffmpeg-android.sh via WSL or pull .so from a CI APK artifact). " +
-                $"Desktop: tools/fetch-ffmpeg.ps1 (Windows) or apt/brew. " +
+                $"Desktop: keep the runtimes/ folder from the release archive next to the exe, " +
+                $"or tools/fetch-ffmpeg.ps1 (Windows) / apt/brew. " +
                 $"Underlying: {DescribeChain(ex)}", ex);
+            throw _initFailure;
         }
     }
 
@@ -70,6 +82,11 @@ private static bool IsNativeLoadFailure(Exception ex)
         {
             if (cur is DllNotFoundException) return true;
             if (cur is BadImageFormatException) return true;
+            // FFmpeg.AutoGen's DynamicallyLoadedBindings doesn't throw on a
+            // failed library load — it leaves the function vector pointing at a
+            // stub that throws NotSupportedException on first call. Within this
+            // init scope that's always a load failure, not a real capability gap.
+            if (cur is NotSupportedException) return true;
         }
         return ex is TypeInitializationException;
     }