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
This commit is contained in:
Mark Michelson 2009-02-17 21:40:09 +00:00
parent 57b89131a3
commit 6d60de7efa
1 changed files with 11 additions and 3 deletions

View File

@ -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? */