fix: detect Tencent SILK (\x02 prefix) in audio magic bytes to avoid ffmpeg failure (#8009)

* fix: detect Tencent SILK (\x02 prefix) in audio magic bytes to avoid ffmpeg failure

QQ official bot sends voice in Tencent SILK format (leading \x02 byte before
#!SILK_V3 magic). _get_audio_magic_type() had two off-by-one slice errors:

  1. Standard SILK:  header[:8]  vs b'#!SILK_V3' (8 != 9 bytes) — never matched
  2. Tencent SILK:   not detected at all

Fixes:
  - Standard SILK:  header[:9]  == b'#!SILK_V3'   (correct 9-byte slice)
  - Tencent SILK:   header[:1] == b"\x02" and header[1:10] == b'#!SILK_V3'
  - ensure_wav() routes detected silk to tencent_silk_to_wav()

Before: QQ voice → ffmpeg → 'Invalid data found'
After:  QQ voice → magic detects silk → tencent_silk_to_wav → WAV OK

* refactor: use startswith() for SILK magic byte detection

Replace manual slice comparisons with startswith() — cleaner, less
error-prone, and immune to off-by-one slice errors.

Suggested by: sourcery-ai

Author: Tom8266

astrbot/core/utils/media_utils.py

@@ -15,6 +15,7 @@
 
 from astrbot import logger
 from astrbot.core.utils.astrbot_path import get_astrbot_temp_path
+from astrbot.core.utils.tencent_record_helper import tencent_silk_to_wav
 
 IMAGE_COMPRESS_DEFAULT_MAX_SIZE = 1280
 IMAGE_COMPRESS_DEFAULT_QUALITY = 95
@@ -250,9 +251,17 @@ async def ensure_wav(audio_path: str, output_path: str | None = None) -> str:
     if not audio_path:
         return audio_path
 
-    if _get_audio_magic_type(audio_path) == "wav":
+    audio_type = _get_audio_magic_type(audio_path)
+    if audio_type == "wav":
         return audio_path
 
+    if audio_type == "silk":
+        if output_path is None:
+            temp_dir = get_astrbot_temp_path()
+            os.makedirs(temp_dir, exist_ok=True)
+            output_path = os.path.join(temp_dir, f"media_audio_{uuid.uuid4().hex}.wav")
+        return await tencent_silk_to_wav(audio_path, output_path)
+
     return await convert_audio_to_wav(audio_path, output_path)
 
 
@@ -291,7 +300,11 @@ def _get_audio_magic_type(audio_path: str) -> str:
     if header[:4] == b"ftyp" and b"mp4" in header[:8]:
         return "mp4"
 
-    if header[:8] == b"#!SILK_V3":
+    if header.startswith(b"#!SILK_V3"):
+        return "silk"
+
+    # Tencent SILK: leading \x02 byte before #!SILK_V3
+    if header.startswith(b"\x02#!SILK_V3"):
         return "silk"
 
     return ""