* modules/access/screen/*: added a win32 only --screen-fragment-size option to...

* modules/access/screen/*: added a win32 only --screen-fragment-size option to do a kind of progressive capture by splitting the screen in several fragments. This does help user interactivity while capturing but also produces artefacts when moving windows around.

modules/access/screen/screen.c

@@ -42,6 +42,13 @@
 #define FPS_LONGTEXT N_( \
     "Allows you to set the desired frame rate for the capture." )
 
+#ifdef WIN32
+#define FRAGS_TEXT N_("Capture fragement size")
+#define FRAGS_LONGTEXT N_( \
+    "Allows you optimize the capture by fragmenting the screen in chunks " \
+    "of predefined height (16 might be a good value, and 0 means disabled)." )
+#endif
+
 static int  Open ( vlc_object_t * );
 static void Close( vlc_object_t * );
 
@@ -58,6 +65,11 @@ vlc_module_begin();
         CACHING_TEXT, CACHING_LONGTEXT, VLC_TRUE );
     add_float( "screen-fps", SCREEN_FPS, 0, FPS_TEXT, FPS_LONGTEXT, VLC_TRUE );
 
+#ifdef WIN32
+    add_integer( "screen-fragment-size", 0, NULL, FRAGS_TEXT,
+        FRAGS_LONGTEXT, VLC_TRUE );
+#endif
+
     set_capability( "access_demux", 0 );
     add_shortcut( "screen" );
     set_callbacks( Open, Close );
@@ -84,6 +96,15 @@ static int Open( vlc_object_t *p_this )
     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
     memset( p_sys, 0, sizeof( demux_sys_t ) );
 
+    /* Update default_pts to a suitable value for screen access */
+    var_Create( p_demux, "screen-caching", VLC_VAR_INTEGER|VLC_VAR_DOINHERIT );
+
+    var_Create( p_demux, "screen-fps", VLC_VAR_FLOAT|VLC_VAR_DOINHERIT );
+    var_Get( p_demux, "screen-fps", &val );
+    p_sys->f_fps = val.f_float;
+    p_sys->i_incr = 1000000 / val.f_float;
+    p_sys->i_next_date = 0;
+
     if( screen_InitCapture( p_demux ) != VLC_SUCCESS )
     {
         free( p_sys );
@@ -96,15 +117,6 @@ static int Open( vlc_object_t *p_this )
 
     p_sys->es = es_out_Add( p_demux->out, &p_sys->fmt );
 
-    /* Update default_pts to a suitable value for screen access */
-    var_Create( p_demux, "screen-caching", VLC_VAR_INTEGER|VLC_VAR_DOINHERIT );
-
-    var_Create( p_demux, "screen-fps", VLC_VAR_FLOAT|VLC_VAR_DOINHERIT );
-    var_Get( p_demux, "screen-fps", &val );
-    p_sys->f_fps = val.f_float;
-    p_sys->i_incr = 1000000 / val.f_float;
-    p_sys->i_next_date = 0;
-
     return VLC_SUCCESS;
 }
 
@@ -136,7 +148,11 @@ static int Demux( demux_t *p_demux )
 
     mwait( p_sys->i_next_date );
     p_block = screen_Capture( p_demux );
-    if( !p_block ) return 0;
+    if( !p_block )
+    {
+        p_sys->i_next_date += p_sys->i_incr;
+        return 1;
+    }
 
     p_block->i_dts = p_block->i_pts = p_sys->i_next_date;
 

modules/access/screen/win32.c

@@ -41,6 +41,10 @@ struct screen_data_t
     HDC hdc_dst;
     BITMAPINFO bmi;
     HGDIOBJ hgdi_backup;
+
+    int i_fragment_size;
+    int i_fragment;
+    block_t *p_block;
 };
 
 int screen_InitCapture( demux_t *p_demux )
@@ -48,6 +52,7 @@ int screen_InitCapture( demux_t *p_demux )
     demux_sys_t *p_sys = p_demux->p_sys;
     screen_data_t *p_data;
     int i_chroma, i_bits_per_pixel;
+    vlc_value_t val;
 
     p_sys->p_data = p_data = malloc( sizeof( screen_data_t ) );
 
@@ -111,6 +116,19 @@ int screen_InitCapture( demux_t *p_demux )
     p_data->bmi.bmiHeader.biClrUsed = 0;
     p_data->bmi.bmiHeader.biClrImportant = 0;
 
+    var_Create( p_demux, "screen-fragment-size",
+                VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
+    var_Get( p_demux, "screen-fragment-size", &val );
+    p_data->i_fragment_size =
+        val.i_int > 0 ? val.i_int : p_sys->fmt.video.i_height;
+    p_data->i_fragment_size =
+        val.i_int > p_sys->fmt.video.i_height ? p_sys->fmt.video.i_height :
+        p_data->i_fragment_size;
+    p_sys->f_fps *= (p_sys->fmt.video.i_height/p_data->i_fragment_size);
+    p_sys->i_incr = 1000000 / p_sys->f_fps;
+    p_data->i_fragment = 0;
+    p_data->p_block = 0;
+
     return VLC_SUCCESS;
 }
 
@@ -119,6 +137,8 @@ int screen_CloseCapture( demux_t *p_demux )
     demux_sys_t *p_sys = p_demux->p_sys;
     screen_data_t *p_data = p_sys->p_data;
 
+    if( p_data->p_block ) block_Release( p_data->p_block );
+
     if( p_data->hgdi_backup)
         SelectObject( p_data->hdc_dst, p_data->hgdi_backup );
 
@@ -172,16 +192,6 @@ static block_t *CaptureBlockNew( demux_t *p_demux )
         return NULL;
     }
 
-    if( !BitBlt( p_data->hdc_dst, 0, 0,
-                 p_sys->fmt.video.i_width, p_sys->fmt.video.i_height,
-                 p_data->hdc_src, 0, 0,
-                 IS_WINNT ? SRCCOPY | CAPTUREBLT : SRCCOPY ) )
-    {
-        msg_Err( p_demux, "error during BitBlt()" );
-        DeleteObject( hbmp );
-        return NULL;
-    }
-
     /* Build block */
     if( !(p_block = malloc( sizeof( block_t ) + sizeof( block_sys_t ) )) )
     {
@@ -206,13 +216,39 @@ static block_t *CaptureBlockNew( demux_t *p_demux )
 
 block_t *screen_Capture( demux_t *p_demux )
 {
-    block_t *p_block;
+    demux_sys_t *p_sys = p_demux->p_sys;
+    screen_data_t *p_data = p_sys->p_data;
 
-    if( !( p_block = CaptureBlockNew( p_demux ) ) )
+    if( !p_data->i_fragment )
+    {
+        if( !( p_data->p_block = CaptureBlockNew( p_demux ) ) )
         {
             msg_Warn( p_demux, "cannot get block" );
             return 0;
         }
+    }
 
+    if( !BitBlt( p_data->hdc_dst, 0, p_data->i_fragment *
+                 p_data->i_fragment_size,
+                 p_sys->fmt.video.i_width, p_data->i_fragment_size,
+                 p_data->hdc_src, 0, p_data->i_fragment *
+                 p_data->i_fragment_size,
+                 IS_WINNT ? SRCCOPY | CAPTUREBLT : SRCCOPY ) )
+    {
+        msg_Err( p_demux, "error during BitBlt()" );
+        return NULL;
+    }
+
+    p_data->i_fragment++;
+
+    if( !( p_data->i_fragment %
+           (p_sys->fmt.video.i_height/p_data->i_fragment_size) ) )
+    {
+        block_t *p_block = p_data->p_block;
+        p_data->i_fragment = 0;
+        p_data->p_block = 0;
         return p_block;
+    }
+
+    return NULL;
 }