Fix FFmpeg errors not sent to after callback

discord/errors.py

@@ -48,6 +48,7 @@ __all__ = (
     'PrivilegedIntentsRequired',
     'InteractionResponded',
     'MissingApplicationID',
+    'FFmpegProcessError',
 )
 
 APP_ID_NOT_FOUND = (
@@ -74,6 +75,15 @@ class ClientException(DiscordException):
     pass
 
 
+class FFmpegProcessError(ClientException):
+    """Exception that's raised when an FFmpeg process fails.
+
+    .. versionadded:: 2.7
+    """
+
+    pass
+
+
 class GatewayNotFound(DiscordException):
     """An exception that is raised when the gateway for Discord could not be found"""