From e2ee76a3197169cae6c1cf2d341204c997eddbf1 Mon Sep 17 00:00:00 2001 From: Tilghman Lesher Date: Tue, 30 Nov 2010 22:32:20 +0000 Subject: Add a comment on why the reserved bit is reserved. Came up when reviewing discussion on the CODEC PREFS IE in IAX2. git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@296826 65c4cc65-6c06-0410-ace0-fbb531ad65f3 --- include/asterisk/frame.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/include/asterisk/frame.h b/include/asterisk/frame.h index c16a3c150..b9eb75bd1 100644 --- a/include/asterisk/frame.h +++ b/include/asterisk/frame.h @@ -300,7 +300,13 @@ extern struct ast_frame ast_null_frame; #define AST_FORMAT_SPEEX16 (1ULL << 33) /*! Raw mu-law data (G.711) */ #define AST_FORMAT_TESTLAW (1ULL << 47) -/*! Reserved bit - do not use */ +/*! Reserved bit - do not use + * \warning We use this bit internally for iteration. Additionally, using this + * bit will severely break the implementation of codec prefs within IAX2, as we + * rely on the equivalence of UTF-8 and ASCII. The codec represented by this + * bit should use the first two-byte encoding of UTF-8, which is not presently + * accounted for. Hence, we reserve this bit as unused. + */ #define AST_FORMAT_RESERVED (1ULL << 63) enum ast_control_frame_type { -- cgit v1.2.3