test: retire Metal frontend recordings on viewport changes

Wrap the existing changing-color/audio core with an opt-in geometry change at frame 90. Require direct and threaded native frontend recording to finalize before later frames and independently decode the resulting file after playback continues.

.github/workflows/MacOS-videotoolbox-encode.yml

@@ -176,7 +176,7 @@ jobs:
         run: |
           set -eu
           command -v ffmpeg >/dev/null && command -v ffprobe >/dev/null || brew install ffmpeg
-          cc -dynamiclib -std=gnu89 -Ilibretro-common/include samples/record/nvenc_frontend/core.c -o "$RUNNER_TEMP/metal-record-core.dylib" -lm
+          cc -dynamiclib -std=gnu89 -Ilibretro-common/include samples/record/metal_frontend/core.c -o "$RUNNER_TEMP/metal-record-core.dylib" -lm
           python3 samples/record/metal_frontend/run.py --retroarch ./retroarch --core "$RUNNER_TEMP/metal-record-core.dylib" --output-dir "$RUNNER_TEMP/metal-frontend-recordings"
       - uses: actions/upload-artifact@v6
         if: always()

samples/record/metal_frontend/core.c

@@ -0,0 +1,18 @@
+/* Copyright (C) 2026 The RetroArch team. SPDX-License-Identifier: GPL-3.0-or-later */
+#define retro_run metal_fixture_run
+#include "../nvenc_frontend/core.c"
+#undef retro_run
+void retro_run(void)
+{
+   if (frames==90 && getenv("NATIVE_RECORD_VIEWPORT_CHANGE"))
+   {
+      struct retro_game_geometry geometry;
+      memset(&geometry,0,sizeof(geometry));
+      geometry.base_width=256; geometry.base_height=HEIGHT;
+      geometry.max_width=WIDTH; geometry.max_height=HEIGHT;
+      geometry.aspect_ratio=4.0f/3.0f;
+      if (!environment(RETRO_ENVIRONMENT_SET_GEOMETRY,&geometry)) abort();
+      fprintf(stderr,"[fixture] viewport geometry changed at frame 90\n");
+   }
+   metal_fixture_run();
+}

samples/record/metal_frontend/run.py

@@ -127,3 +127,20 @@ for control in ('early', 'exists'):
         assert destination.read_bytes()==b'preserve existing output',log
         assert '[Metal recording] Failed' in log,log
     print(f'PASS: real frontend {control}: bounded shutdown and output preservation',flush=True)
+
+for threaded in ('false','true'):
+    changed=root/f'viewport-{threaded}.mp4'
+    changed_config=root/f'viewport-{threaded}.cfg'
+    changed_config.write_text(config.read_text(encoding='utf-8').replace(
+        'video_threaded = "true"',f'video_threaded = "{threaded}"'),encoding='utf-8')
+    changed_env=dict(env,NATIVE_RECORD_VIEWPORT_CHANGE='1')
+    result=subprocess.run([exe,'-v','--config',str(changed_config),'-L',core,
+        '--record',str(changed),'--recordconfig',str(record),'--max-frames','180'],
+        cwd=case,env=changed_env,stdout=subprocess.PIPE,stderr=subprocess.STDOUT,timeout=60)
+    log=result.stdout.decode(errors='replace')
+    (root/f'viewport-{threaded}.log').write_text(log,encoding='utf-8')
+    assert result.returncode==0 and '[fixture] viewport geometry changed' in log,log[-8000:]
+    done=re.search(r'Finalized (\d+) GPU frames, (\d+) PCM frames',log)
+    assert done and 0<int(done[1])<100 and '[Metal recording] Failed' not in log,log[-8000:]
+    subprocess.run([ffmpeg,'-v','error','-i',str(changed),'-f','null','-'],check=True,timeout=30)
+    print(f'PASS: real frontend viewport change threaded={threaded}: retired playable recording',flush=True)