vo_x11, vo_xv: XShmCompletion event support

This fixes OSD flicker with vo_xv at high frame rates.

video/out/vo_x11.c

@@ -49,6 +49,7 @@
 #define MODE_BGR  0x2
 
 #include "core/mp_msg.h"
+#include "osdep/timer.h"
 
 extern int sws_flags;
 
@@ -92,10 +93,10 @@ struct priv {
 
 #ifdef HAVE_SHM
     int Shmem_Flag;
+    int Shm_Warned_Slow;
 
     XShmSegmentInfo Shminfo[1];
     int gXErrorFlag;
-    int CompletionType;
 #endif
 };
 
@@ -120,15 +121,15 @@ static void getMyXImage(struct priv *p)
 {
     struct vo *vo = p->vo;
 #ifdef HAVE_SHM
-    if (vo->x11->display_is_local && XShmQueryExtension(vo->x11->display))
+    if (vo->x11->display_is_local && XShmQueryExtension(vo->x11->display)) {
         p->Shmem_Flag = 1;
-    else {
+        vo->x11->ShmCompletionEvent = XShmGetEventBase(vo->x11->display)
+                                    + ShmCompletion;
+    } else {
         p->Shmem_Flag = 0;
         mp_msg(MSGT_VO, MSGL_WARN,
                "Shared memory not supported\nReverting to normal Xlib\n");
     }
-    if (p->Shmem_Flag)
-        p->CompletionType = XShmGetEventBase(vo->x11->display) + ShmCompletion;
 
     if (p->Shmem_Flag) {
         p->myximage =
@@ -409,6 +410,7 @@ static void Display_Image(struct priv *p, XImage *myximage, uint8_t *ImageData)
         XShmPutImage(vo->x11->display, vo->x11->window, vo->x11->vo_gc,
                      p->myximage, 0, 0, x, y, p->dst_width, p->myximage->height,
                      True);
+        vo->x11->ShmCompletionWaitCount++;
     } else
 #endif
     {
@@ -458,6 +460,25 @@ static mp_image_t *get_screenshot(struct vo *vo)
     return res;
 }
 
+static void wait_for_completion(struct vo *vo, int max_outstanding)
+{
+#ifdef HAVE_SHM
+    struct priv *ctx = vo->priv;
+    struct vo_x11_state *x11 = vo->x11;
+    if (ctx->Shmem_Flag) {
+        while (x11->ShmCompletionWaitCount > max_outstanding) {
+            if (!ctx->Shm_Warned_Slow) {
+                mp_msg(MSGT_VO, MSGL_WARN, "[VO_X11] X11 can't keep up! Waiting"
+                                           " for XShm completion events...\n");
+                ctx->Shm_Warned_Slow = 1;
+            }
+            usec_sleep(1000);
+            check_events(vo);
+        }
+    }
+#endif
+}
+
 static void flip_page(struct vo *vo)
 {
     struct priv *p = vo->priv;
@@ -471,6 +492,8 @@ static void draw_image(struct vo *vo, mp_image_t *mpi)
     uint8_t *dst[MP_MAX_PLANES] = {NULL};
     int dstStride[MP_MAX_PLANES] = {0};
 
+    wait_for_completion(vo, 0);
+
     if ((p->old_vo_dwidth != vo->dwidth || p->old_vo_dheight != vo->dheight)
         /*&& y==0 */ && p->zoomFlag)
     {
@@ -635,9 +658,6 @@ const struct vo_driver video_out_x11 = {
         .srcH = -1,
         .old_vo_dwidth = -1,
         .old_vo_dheight = -1,
-#ifdef HAVE_SHM
-        .CompletionType = -1,
-#endif
     },
     .preinit = preinit,
     .query_format = query_format,

video/out/vo_xv.c

@@ -55,6 +55,7 @@
 #include "aspect.h"
 #include "video/csputils.h"
 #include "core/subopt-helper.h"
+#include "osdep/timer.h"
 
 static const vo_info_t info = {
     "X11/Xv",
@@ -83,9 +84,10 @@ struct xvctx {
     struct mp_rect dst_rect;
     uint32_t max_width, max_height; // zero means: not set
     int mode_switched;
+    int Shmem_Flag;
 #ifdef HAVE_SHM
     XShmSegmentInfo Shminfo[2];
-    int Shmem_Flag;
+    int Shm_Warned_Slow;
 #endif
 };
 
@@ -255,9 +257,11 @@ static void allocate_xvimage(struct vo *vo, int foo)
     // align it for faster OSD rendering (draw_bmp.c swscale usage)
     int aligned_w = FFALIGN(ctx->image_width, 32);
 #ifdef HAVE_SHM
-    if (x11->display_is_local && XShmQueryExtension(x11->display))
+    if (x11->display_is_local && XShmQueryExtension(x11->display)) {
         ctx->Shmem_Flag = 1;
-    else {
+        x11->ShmCompletionEvent = XShmGetEventBase(x11->display)
+                                + ShmCompletion;
+    } else {
         ctx->Shmem_Flag = 0;
         mp_tmsg(MSGT_VO, MSGL_INFO, "[VO_XV] Shared memory not supported\nReverting to normal Xv.\n");
     }
@@ -325,7 +329,8 @@ static inline void put_xvimage(struct vo *vo, XvImage *xvi)
         XvShmPutImage(x11->display, x11->xv_port, x11->window, x11->vo_gc, xvi,
                       src->x0, src->y0, sw, sh,
                       dst->x0, dst->y0, dw, dh,
-                      False);
+                      True);
+        x11->ShmCompletionWaitCount++;
     } else
 #endif
     {
@@ -388,6 +393,25 @@ static void draw_osd(struct vo *vo, struct osd_state *osd)
     osd_draw_on_image(osd, res, osd->vo_pts, 0, &img);
 }
 
+static void wait_for_completion(struct vo *vo, int max_outstanding)
+{
+#ifdef HAVE_SHM
+    struct xvctx *ctx = vo->priv;
+    struct vo_x11_state *x11 = vo->x11;
+    if (ctx->Shmem_Flag) {
+        while (x11->ShmCompletionWaitCount > max_outstanding) {
+            if (!ctx->Shm_Warned_Slow) {
+                mp_msg(MSGT_VO, MSGL_WARN, "[VO_XV] X11 can't keep up! Waiting"
+                                           " for XShm completion events...\n");
+                ctx->Shm_Warned_Slow = 1;
+            }
+            usec_sleep(1000);
+            check_events(vo);
+        }
+    }
+#endif
+}
+
 static void flip_page(struct vo *vo)
 {
     struct xvctx *ctx = vo->priv;
@@ -395,16 +419,15 @@ static void flip_page(struct vo *vo)
 
     /* remember the currently visible buffer */
     ctx->visible_buf = ctx->current_buf;
-
     ctx->current_buf = (ctx->current_buf + 1) % ctx->num_buffers;
-    XFlush(vo->x11->display);
-    return;
+
+    if (!ctx->Shmem_Flag)
+        XSync(vo->x11->display, False);
 }
 
 static mp_image_t *get_screenshot(struct vo *vo)
 {
     struct xvctx *ctx = vo->priv;
-
     if (!ctx->original_image)
         return NULL;
 
@@ -417,6 +440,8 @@ static void draw_image(struct vo *vo, mp_image_t *mpi)
 {
     struct xvctx *ctx = vo->priv;
 
+    wait_for_completion(vo, ctx->num_buffers - 1);
+
     struct mp_image xv_buffer = get_xv_buffer(vo, ctx->current_buf);
     mp_image_copy(&xv_buffer, mpi);
 

video/out/x11_common.c

@@ -903,6 +903,11 @@ int vo_x11_check_events(struct vo *vo)
                     Event.xclient.data.l[0] == x11->XAWM_DELETE_WINDOW)
                     mplayer_put_key(vo->key_fifo, KEY_CLOSE_WIN);
                 break;
+        default:
+                if (Event.type == x11->ShmCompletionEvent)
+                    if (x11->ShmCompletionWaitCount > 0)
+                        x11->ShmCompletionWaitCount--;
+                break;
         }
     }
     return ret;

video/out/x11_common.h

@@ -80,6 +80,13 @@ struct vo_x11_state {
     unsigned int oldfuncs;
     XComposeStatus compose_status;
 
+    /* XShm stuff */
+    int ShmCompletionEvent;
+    /* Number of outstanding XShmPutImage requests */
+    /* Decremented when ShmCompletionEvent is received */
+    /* Increment it before XShmPutImage */
+    int ShmCompletionWaitCount;
+
     Atom XA_NET_SUPPORTED;
     Atom XA_NET_WM_STATE;
     Atom XA_NET_WM_STATE_FULLSCREEN;