From f1c6404e932673fbf9f0bd0d5e717f2527479fa2 Mon Sep 17 00:00:00 2001
From: kwy404 <thekaway404@gmail.com>
Date: Tue, 27 Oct 2026 11:31:47 -0300
Subject: [PATCH] Fix the Opus parser failing on mono Ogg streams

When reading the OpusHead packet, OpusParser stored the channel mode in
packet_count instead of channel_mode. For a mono stream this set
packet_count back to 0 (ChannelMode.MONO), so the OpusTags packet was
then checked as the identification header and the parser raised
"first packet is not OpusHead". Stereo streams only worked because
ChannelMode.STEREO happens to be 1, and channel_mode always stayed
STEREO.
---
 bumble/a2dp.py     |  2 +-
 tests/a2dp_test.py | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/bumble/a2dp.py b/bumble/a2dp.py
index b16de874..9be306da 100644
--- a/bumble/a2dp.py
+++ b/bumble/a2dp.py
@@ -923,7 +923,7 @@ async def generate_frames() -> AsyncGenerator[OpusPacket, None]:
                             logger.debug("first packet (header)")
                             if packet[:8] != b"OpusHead":
                                 raise ValueError("first packet is not OpusHead")
-                            packet_count = (
+                            channel_mode = (
                                 OpusPacket.ChannelMode.MONO
                                 if packet[9] == 1
                                 else OpusPacket.ChannelMode.STEREO
diff --git a/tests/a2dp_test.py b/tests/a2dp_test.py
index 54fb591c..a08a0a75 100644
--- a/tests/a2dp_test.py
+++ b/tests/a2dp_test.py
@@ -489,6 +489,33 @@ async def test_opus_parser():
         assert packet.payload == audio_data_packet
 
 
+# -----------------------------------------------------------------------------
+async def test_opus_parser_mono():
+    page_header = (
+        b'OggS'  # Capture pattern
+        + b'\x00'  # Version
+        + b'\x02'  # Header type
+        + struct.pack("<QIIIB", 0, 2, 2, 0, 3)
+    )
+    segment_table = b'\x0a\x08\x0a'
+    opus_head_packet_data = b'OpusHead' + b'\x01' + b'\x01'  # 1 channel
+    opus_tags_packet_data = b'OpusTags'
+    audio_data_packet = b'0123456789'
+
+    data = Data(
+        page_header
+        + segment_table
+        + opus_head_packet_data
+        + opus_tags_packet_data
+        + audio_data_packet
+    )
+
+    packets = [packet async for packet in a2dp.OpusParser(data.read).packets]
+    assert len(packets) == 1
+    assert packets[0].channel_mode == a2dp.OpusPacket.ChannelMode.MONO
+    assert packets[0].payload == audio_data_packet
+
+
 # -----------------------------------------------------------------------------
 async def test_opus_packet_source():
     packed_header_data_revised = struct.pack(