From 29e0719680ddad2895bff544a9e77c64cfc84af9 Mon Sep 17 00:00:00 2001
From: Mr-Neutr0n <64578610+Mr-Neutr0n@users.noreply.github.com>
Date: Tue, 10 Feb 2026 00:06:41 +0530
Subject: [PATCH] Handle non-UTF-8 metadata in audio file stream info

Some audio files (e.g. Opus files from the MLS dataset) contain
metadata with non-UTF-8 bytes (such as Latin-1 encoded artist names),
which causes a UnicodeDecodeError when the metadata is parsed during
audio loading.

This adds try/except guards around the AudioDecoder construction and
the metadata.sample_rate access so that files with non-decodable
metadata bytes produce a clear RuntimeError instead of an unhandled
UnicodeDecodeError.

Fixes #3821
---
 src/torchaudio/_torchcodec.py | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/torchaudio/_torchcodec.py b/src/torchaudio/_torchcodec.py
index a785fe50ad..9341f1d31c 100644
--- a/src/torchaudio/_torchcodec.py
+++ b/src/torchaudio/_torchcodec.py
@@ -112,13 +112,25 @@ def load_with_torchcodec(
         warnings.warn("The 'format' parameter is not supported by TorchCodec AudioDecoder.", UserWarning, stacklevel=2)
 
     # Create AudioDecoder
+    # Some audio files (e.g. Opus from MLS dataset) contain metadata
+    # with non-UTF-8 bytes, which can cause UnicodeDecodeError during
+    # initialization or when accessing stream metadata.
     try:
         decoder = AudioDecoder(uri)
+    except UnicodeDecodeError as e:
+        raise RuntimeError(
+            f"Failed to create AudioDecoder for {uri}: "
+            f"file metadata contains non-decodable bytes: {e}"
+        ) from e
     except Exception as e:
         raise RuntimeError(f"Failed to create AudioDecoder for {uri}: {e}") from e
 
-    # Get sample rate from metadata
-    sample_rate = decoder.metadata.sample_rate
+    # Get sample rate from metadata.
+    # Guard against UnicodeDecodeError from non-UTF-8 metadata tags.
+    try:
+        sample_rate = decoder.metadata.sample_rate
+    except UnicodeDecodeError:
+        sample_rate = None
     if sample_rate is None:
         raise RuntimeError("Unable to determine sample rate from audio metadata")