diff options
Diffstat (limited to 'libavfilter/avfilter.h')
| -rw-r--r-- | libavfilter/avfilter.h | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h index bcc1fd9c75..bdacfcabf1 100644 --- a/libavfilter/avfilter.h +++ b/libavfilter/avfilter.h @@ -29,6 +29,29 @@ typedef struct AVFilterContext AVFilterContext; typedef struct AVFilterLink AVFilterLink; typedef struct AVFilterPad AVFilterPad; +/** + * A linked list of filters which reference this picture and the permissions + * they each have. This is needed for the case that filter A requests a buffer + * from filter B. Filter B gives it a buffer to use with the permissions it + * requested, while reserving more permissions for itself to use when filter A + * eventually passes the buffer to filter B. However, filter A does not know + * what these permissions are to reinsert them in the reference passed to B, + * filter B can't assume that any picture it is passed is one that it allocated. + * + * Rather than have each filter implement their own code to check for this + * case, we store all the permissions here in the picture structure. + * + * Because the number of filters holding references to any one picture should + * be rather low, this should not be a major source of performance problems. + */ +typedef struct AVFilterPicPerms +{ + AVFilterContext *filter; ///< the filter + int perms; ///< the permissions that filter has + + struct AVFilterPicPerms *next; +} AVFilterPicPerms; + /* TODO: look for other flags which may be useful in this structure (interlace * flags, etc) */ @@ -44,6 +67,7 @@ typedef struct AVFilterPic enum PixelFormat format; ///< colorspace unsigned refcount; ///< number of references to this image + AVFilterPicPerms *perms; ///< list of permissions held by filters /** private data to be used by a custom free function */ void *priv; @@ -81,15 +105,25 @@ typedef struct AVFilterPicRef #define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times } AVFilterPicRef; +/** Get the permissions the filter has to access the picture. */ +int avfilter_get_pic_perms(AVFilterPicRef *pic, AVFilterContext *filter); + +/** Give the filter more permissions to access the picture */ +void avfilter_add_pic_perms(AVFilterPicRef *pic, AVFilterContext *filter, + int perms); + /** * Add a new reference to a picture. * @param ref An existing reference to the picture + * @param ref If non-NULL, a pointer to the filter to which the permissions + * to the picture are to be given * @param pmask A bitmask containing the allowable permissions in the new * reference * @return A new reference to the picture with the same properties as the * old, excluding any permissions denied by pmask */ -AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, int pmask); +AVFilterPicRef *avfilter_ref_pic(AVFilterPicRef *ref, AVFilterContext *filter, + int pmask); /** * Remove a reference to a picture. If this is the last reference to the @@ -222,6 +256,8 @@ int *avfilter_default_query_output_formats(AVFilterLink *link); AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms); +/** handler for get_video_buffer() which forwards the request down the chain */ +AVFilterPicRef *avfilter_next_get_video_buffer(AVFilterLink *link, int perms); /** * Filter definition. This defines the pads a filter contains, and all the * callback functions used to interact with the filter. |