From: Mark Michelson Date: Tue, 17 Feb 2009 21:40:09 +0000 (+0000) Subject: Clear up documentation of AST_FRIENDLY_OFFSET in frame.h X-Git-Tag: 1.6.2.0-beta1~194 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=6d60de7efad8e4d8adb5d2f9f6e3c5981c4d855d;p=thirdparty%2Fasterisk.git Clear up documentation of AST_FRIENDLY_OFFSET in frame.h git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@176697 65c4cc65-6c06-0410-ace0-fbb531ad65f3 --- diff --git a/include/asterisk/frame.h b/include/asterisk/frame.h index 4a18bdbacd..bb547962c7 100644 --- a/include/asterisk/frame.h +++ b/include/asterisk/frame.h @@ -194,9 +194,17 @@ struct ast_frame { for this purpose instead of having to declare one on the stack */ extern struct ast_frame ast_null_frame; -#define AST_FRIENDLY_OFFSET 64 /*! It's polite for a a new frame to - have this number of bytes for additional - headers. */ +/*! \brief Offset into a frame's data buffer. + * + * By providing some "empty" space prior to the actual data of an ast_frame, + * this gives any consumer of the frame ample space to prepend other necessary + * information without having to create a new buffer. + * + * As an example, RTP can use the data from an ast_frame and simply prepend the + * RTP header information into the space provided by AST_FRIENDLY_OFFSET instead + * of having to create a new buffer with the necessary space allocated. + */ +#define AST_FRIENDLY_OFFSET 64 #define AST_MIN_OFFSET 32 /*! Make sure we keep at least this much handy */ /*! Need the header be free'd? */