diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/xine-engine/post.c | 4 | ||||
| -rw-r--r-- | src/xine-engine/post.h | 25 |
2 files changed, 22 insertions, 7 deletions
diff --git a/src/xine-engine/post.c b/src/xine-engine/post.c index c65e53400..40cb30aab 100644 --- a/src/xine-engine/post.c +++ b/src/xine-engine/post.c @@ -17,7 +17,7 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA * - * $Id: post.c,v 1.1 2002/12/01 14:52:55 mroi Exp $ + * $Id: post.c,v 1.2 2002/12/03 21:59:46 mroi Exp $ */ /* @@ -99,7 +99,7 @@ post_video_port_t *post_intercept_video_port(xine_video_port_t *original) { } -/* functions intercepting frame calls */ +/* dummy intercept functions for frames */ static void post_frame_free(vo_frame_t *vo_img) { post_video_port_t *port = (post_video_port_t *)vo_img->port; post_restore_video_frame(vo_img, port); diff --git a/src/xine-engine/post.h b/src/xine-engine/post.h index 373480c46..156347dc0 100644 --- a/src/xine-engine/post.h +++ b/src/xine-engine/post.h @@ -17,7 +17,7 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA * - * $Id: post.h,v 1.1 2002/12/01 14:52:56 mroi Exp $ + * $Id: post.h,v 1.2 2002/12/03 21:59:46 mroi Exp $ * * post plugin definitions * @@ -92,6 +92,17 @@ struct post_plugin_s { }; +/* Post plugins work by intercepting calls to video or audio ports + * in the sense of the decorator design pattern. They reuse the + * functions of a given target port, but add own functionality in + * front of that port by creating a new port structure and filling in + * the function pointers with pointers to own functions that + * would do something and then call the original port function. + * + * Much the same is done with video frames which have their own + * set of functions attached that you might need to decorate. + */ + /* helper structure for intercepting video port calls */ typedef struct post_video_port_s post_video_port_t; struct post_video_port_s { @@ -104,14 +115,18 @@ struct post_video_port_s { /* here you can keep information about the frames */ vo_frame_t original_frame; + + /* backward reference so that you have access to the post plugin + * when the call only gives you the port */ + xine_post_t *post; }; -/* use this to create a new video port in which port functions can - * be replaced with own implementation */ +/* use this to create a new, trivially decorated video port in which + * port functions can be replaced with own implementations */ post_video_port_t *post_intercept_video_port(xine_video_port_t *port); -/* use this to modify a frame to so that functions can be replaced - * with own implementations */ +/* use this to decorate and to undecorate a frame so that its functions + * can be replaced with own implementations */ void post_intercept_video_frame(vo_frame_t *frame, post_video_port_t *port); void post_restore_video_frame(vo_frame_t *frame, post_video_port_t *port); |