feat(video): alias "av1" to "libsvtav1" for backward compat

src/lerobot/datasets/video_utils.py

@@ -138,6 +138,12 @@ class VideoEncoderConfig:
         also silently rewritten to ``libsvtav1`` so encoding never hard-fails on
         a host missing the requested encoder.
         """
+        # Backward compatibility: older datasets persist ``vcodec="av1"`` in
+        # ``info.json``. Rewrite to the canonical encoder name *before* the
+        # validation check below so loading those datasets keeps working.
+        if self.vcodec == "av1":
+            self.vcodec = "libsvtav1"
+
         if self.vcodec not in VALID_VIDEO_CODECS:
             raise ValueError(f"Invalid vcodec '{self.vcodec}'. Must be one of: {sorted(VALID_VIDEO_CODECS)}")
         if self.vcodec == "auto":

tests/datasets/test_video_encoding.py

@@ -311,6 +311,18 @@ class TestEncoderDetection:
         assert "h264_videotoolbox" in VALID_VIDEO_CODECS
         assert "h264_nvenc" in VALID_VIDEO_CODECS
 
+    def test_av1_alias_resolves_to_libsvtav1(self):
+        """Older datasets persist ``vcodec="av1"``; backward-compat alias must keep them loadable."""
+        cfg = VideoEncoderConfig(vcodec="av1")
+        assert cfg.vcodec == "libsvtav1"
+
+    def test_av1_alias_persisted_after_resolve(self):
+        """Repeated calls to ``resolve_vcodec`` should be idempotent (alias only fires once)."""
+        cfg = VideoEncoderConfig(vcodec="av1")
+        assert cfg.vcodec == "libsvtav1"
+        cfg.resolve_vcodec()
+        assert cfg.vcodec == "libsvtav1"
+
 
 ARTIFACTS = Path(__file__).parent.parent / "fixtures" / "artifacts" / "videos"