Once an audiohook is attached to a channel, we continue to transcode all of the

frames, even after all of the hooks are detached.  This patch short-cicuits us
out before we transcode unnecessarily.
........

Merged revisions 349144 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 349145 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@349146 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/audiohook.c

@@ -783,6 +783,12 @@ static struct ast_frame *audio_audiohook_write_list(struct ast_channel *chan, st
 	int middle_frame_manipulated = 0;
 	int removed = 0;
 
+	/* Don't translate our frame if we aren't going to bother to use it */
+	if (AST_LIST_EMPTY(&audiohook_list->spy_list)
+		&& AST_LIST_EMPTY(&audiohook_list->whisper_list)
+		&& AST_LIST_EMPTY(&audiohook_list->manipulate_list))
+		return end_frame;
+
 	/* ---Part_1. translate start_frame to SLINEAR if necessary. */
 	if (!(middle_frame = audiohook_list_translate_to_slin(audiohook_list, direction, start_frame))) {
 		return frame;