[vlc-devel] [RFC 6/6] libvlc:vout: add a custom vout window module that can change the display size

[Steve Lhomme]

The libvlc_video_set_rendering_size() set the width/height and the host_window
module receives the change and tell the display module about the new size to
render into.
---
 lib/media_player.c                 |   2 +-
 modules/video_output/Makefile.am   |   2 +
 modules/video_output/host_window.c | 103 +++++++++++++++++++++++++++++
 3 files changed, 106 insertions(+), 1 deletion(-)
 create mode 100644 modules/video_output/host_window.c

diff --git a/lib/media_player.c b/lib/media_player.c
index c38cb1f5fb..4426801920 100644
--- a/lib/media_player.c
+++ b/lib/media_player.c
@@ -1211,7 +1211,7 @@ int libvlc_video_set_rendering_callbacks( libvlc_media_player_t *mp,
                                         libvlc_video_control_cb control_cb,
                                         void* opaque )
 {
-    var_SetString( mp, "window", "wdummy");
+    var_SetString( mp, "window", "host_window");
 
     if ( engine == libvlc_video_rendering_direct3d11 )
     {
diff --git a/modules/video_output/Makefile.am b/modules/video_output/Makefile.am
index ff3648e7cb..65913a3818 100644
--- a/modules/video_output/Makefile.am
+++ b/modules/video_output/Makefile.am
@@ -465,6 +465,7 @@ vout_LTLIBRARIES += $(LTLIBcaca)
 libflaschen_plugin_la_SOURCES = video_output/flaschen.c
 libflaschen_plugin_la_LIBADD = $(SOCKET_LIBS)
 
+libhost_window_plugin_la_SOURCES = video_output/host_window.c
 libvdummy_plugin_la_SOURCES = video_output/vdummy.c
 libvideo_splitter_plugin_la_SOURCES = video_output/splitter.c
 libvmem_plugin_la_SOURCES = video_output/vmem.c
@@ -474,6 +475,7 @@ libvgl_plugin_la_SOURCES = video_output/vgl.c
 
 vout_LTLIBRARIES += \
 	libflaschen_plugin.la \
+	libhost_window_plugin.la \
 	libvdummy_plugin.la \
 	libvideo_splitter_plugin.la \
 	libvmem_plugin.la \
diff --git a/modules/video_output/host_window.c b/modules/video_output/host_window.c
new file mode 100644
index 0000000000..de1014a7ca
--- /dev/null
+++ b/modules/video_output/host_window.c
@@ -0,0 +1,103 @@
+/**
+ * @file host_window.c
+ * @brief Video window provider that can be resized externally
+ */
+/*****************************************************************************
+ * Copyright (C) 2019 VLC authors and VideoLAN
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+#include <vlc_vout_window.h>
+
+struct window_sys_t
+{
+    vlc_object_t *dimension_src;
+};
+
+static int Enable(vout_window_t *wnd, const vout_window_cfg_t *cfg)
+{
+    vout_window_ReportSize(wnd, cfg->width, cfg->height);
+    return VLC_SUCCESS;
+}
+
+static void Resize(vout_window_t *window, unsigned width, unsigned height)
+{
+    vout_window_ReportSize(window, width, height);
+}
+
+static int WindowSize( vlc_object_t *obj, char const *name,
+                        vlc_value_t oldvalue, vlc_value_t newvalue, void *p_wnd )
+{
+    VLC_UNUSED(name);
+    VLC_UNUSED(oldvalue);
+    VLC_UNUSED(newvalue);
+
+    vout_window_t *wnd = p_wnd;
+    int width  = var_GetInteger(obj, "width");
+    int height = var_GetInteger(obj, "height");
+    vout_window_ReportSize( wnd, width, height);
+    return 0;
+}
+
+static void Destroy(struct vout_window_t *wnd)
+{
+    struct window_sys_t *sys = wnd->sys;
+    var_DelCallback( sys->dimension_src, "window-size", WindowSize, wnd);
+}
+
+static const struct vout_window_operations ops = {
+    .enable = Enable,
+    .resize = Resize,
+    .destroy = Destroy,
+};
+
+static int Open(vout_window_t *wnd)
+{
+    struct window_sys_t *sys = vlc_obj_malloc(VLC_OBJECT(wnd), sizeof(struct window_sys_t));
+    if (unlikely(sys==NULL))
+        return VLC_ENOMEM;
+
+    sys->dimension_src = VLC_OBJECT(wnd);
+    while (sys->dimension_src != NULL && var_Type( sys->dimension_src, "window-size" ) == 0)
+        sys->dimension_src = vlc_object_parent( sys->dimension_src );
+
+    if (sys->dimension_src == NULL )
+    {
+        msg_Err(wnd, "missing size trigger");
+        return VLC_EGENERIC;
+    }
+
+    var_AddCallback( sys->dimension_src, "window-size", WindowSize, wnd);
+    wnd->type = VOUT_WINDOW_TYPE_DUMMY;
+    wnd->ops = &ops;
+    wnd->sys = sys;
+    return VLC_SUCCESS;
+}
+
+vlc_module_begin()
+    set_shortname(N_("Host window"))
+    set_description(N_("Host window"))
+    set_category(CAT_VIDEO)
+    set_subcategory(SUBCAT_VIDEO_VOUT)
+    set_capability("vout window", 0)
+    set_callbacks(Open, NULL)
+vlc_module_end()
-- 
2.17.1