sub: always go through sub.c for OSD rendering

Before this commit, vf_vo.c and vf_ass.c were manually calling the
subtitle decoder to retrieve images to render. In particular, this
circumvented the sub-bitmap conversion & caching layer in sub.c.

Change this so that subtitle decoding isn't special anymore, and draws
all subtitles with the normal OSD drawing API.

This is also a step towards removing the need for vf_ass auto-insertion.
In fact, if auto-insertion would be disabled now, VOs with "old" OSD
rendering could still render ASS subtitles in monochrome, because
there is still ASS -> old-OSD bitmap conversion in the sub.c mechanism.

The code is written with the assumption that the subtitle rendering
filter (vf_ass) can render all subtitle formats. Since vf_ass knows the
ASS format only, rendering image subs (i.e. RGBA subs) with it simply
fails. This means that with vo_xv (vf_ass auto-inserted), image subs
wouldn't be rendered. Use a dumb hack to disable rendering subs with a
filter, if we detect that the subs are not in ASS format. (Trying to
render the subs first would probably result in purging the conversion
cache on every frame.)

1 files changed, 1 insertions, 2 deletions

diff --git a/libmpcodecs/vf.h b/libmpcodecs/vf.h
index ec8144b22f..8b18470e62 100644
--- a/libmpcodecs/vf.h
+++ b/libmpcodecs/vf.h
@@ -104,8 +104,7 @@ struct vf_ctrl_screenshot {
 #define VFCTRL_SKIP_NEXT_FRAME 12  // For encoding - drop the next frame that passes thru
 #define VFCTRL_FLUSH_FRAMES    13  // For encoding - flush delayed frames
 #define VFCTRL_SCREENSHOT      14  // Take screenshot, arg is vf_ctrl_screenshot
-#define VFCTRL_INIT_EOSD       15  // Select EOSD renderer
-#define VFCTRL_DRAW_EOSD       16  // Render EOSD */
+#define VFCTRL_INIT_OSD        15  // Filter OSD renderer present?
 #define VFCTRL_SET_DEINTERLACE 18  // Set deinterlacing status
 #define VFCTRL_GET_DEINTERLACE 19  // Get deinterlacing status
 /* Hack to make the OSD state object available to vf_expand and vf_ass which