If the framebuffer hardware doesn't support double buffering in hardware, then...

If the framebuffer hardware doesn't support double buffering in hardware, then do this in software. It will increase vout memory consumption by at least one output picture size, but will guarantee smooth subpictures in the video output.

modules/video_output/fb.c

@@ -57,12 +57,17 @@ static int  Manage    ( vout_thread_t * );
 static void Display   ( vout_thread_t *, picture_t * );
 static int  Control   ( vout_thread_t *, int, va_list );
 
+static int  NewPicture     ( vout_thread_t *, picture_t * );
+static void FreePicture    ( vout_thread_t *, picture_t * );
+
 static int  OpenDisplay    ( vout_thread_t * );
 static void CloseDisplay   ( vout_thread_t * );
 static void SwitchDisplay  ( int i_signal );
 static void TextMode       ( int i_tty );
 static void GfxMode        ( int i_tty );
 
+#define MAX_DIRECTBUFFERS 1
+
 /*****************************************************************************
  * Module descriptor
  *****************************************************************************/
@@ -90,6 +95,12 @@ static void GfxMode        ( int i_tty );
     "Select the resolution for the framebuffer. Currently it supports " \
     "the values 0=QCIF 1=CIF 2=NTSC 3=PAL, 4=auto (default 4=auto)" )
 
+#define HW_ACCEL_TEXT N_("Framebuffer uses hw acceleration.")
+#define HW_ACCEL_LONGTEXT N_( \
+    "If your framebuffer supports hardware acceleration or does double buffering " \
+    "in hardware then you must disable this option. It then does double buffering " \
+    "in software." )
+
 vlc_module_begin();
     set_shortname( "Framebuffer" );
     set_category( CAT_VIDEO );
@@ -103,6 +114,8 @@ vlc_module_begin();
                 ASPECT_RATIO_LONGTEXT, VLC_TRUE );
     add_integer( "fb-mode", 4, NULL, FB_MODE_TEXT, FB_MODE_LONGTEXT,
                  VLC_TRUE );
+    add_bool( "fb-hw-accel", VLC_TRUE, NULL, HW_ACCEL_TEXT, HW_ACCEL_LONGTEXT,
+              VLC_TRUE );
     set_description( _("GNU/Linux console framebuffer video output") );
     set_capability( "video output", 30 );
     set_callbacks( Create, Destroy );
@@ -133,6 +146,7 @@ struct vout_sys_t
     vlc_bool_t                  b_pan;     /* does device supports panning ? */
     struct fb_cmap              fb_cmap;                /* original colormap */
     uint16_t                    *p_palette;              /* original palette */
+    vlc_bool_t                  b_hw_accel;          /* has hardware support */
 
     /* Video information */
     uint32_t i_width;
@@ -147,6 +161,11 @@ struct vout_sys_t
     size_t      i_page_size;                                    /* page size */
 };
 
+struct picture_sys_t
+{
+    byte_t *    p_data;                                       /* base adress */
+};
+
 /*****************************************************************************
  * Create: allocates FB video thread output method
  *****************************************************************************
@@ -179,6 +198,9 @@ static int Create( vlc_object_t *p_this )
     p_vout->pf_display = Display;
     p_vout->pf_control = Control;
 
+    /* Does the framebuffer uses hw acceleration? */
+    p_sys->b_hw_accel = p_sys->b_tty = var_CreateGetBool( p_vout, "fb-hw-accel" );
+
     /* Set tty and fb devices */
     p_sys->i_tty = 0; /* 0 == /dev/tty0 == current console */
     p_sys->b_tty = var_CreateGetBool( p_vout, "fb-tty" );
@@ -354,6 +376,102 @@ static int Create( vlc_object_t *p_this )
     return VLC_SUCCESS;
 }
 
+
+/*****************************************************************************
+ * Destroy: destroy FB video thread output method
+ *****************************************************************************
+ * Terminate an output method created by Create
+ *****************************************************************************/
+static void Destroy( vlc_object_t *p_this )
+{
+    vout_thread_t *p_vout = (vout_thread_t *)p_this;
+
+    CloseDisplay( p_vout );
+
+    if( p_vout->p_sys->b_tty )
+    {
+        /* Reset the terminal */
+        ioctl( p_vout->p_sys->i_tty, VT_SETMODE, &p_vout->p_sys->vt_mode );
+
+        /* Remove signal handlers */
+        sigaction( SIGUSR1, &p_vout->p_sys->sig_usr1, NULL );
+        sigaction( SIGUSR2, &p_vout->p_sys->sig_usr2, NULL );
+
+        /* Reset the keyboard state */
+        tcsetattr( 0, 0, &p_vout->p_sys->old_termios );
+
+        /* Return to text mode */
+        TextMode( p_vout->p_sys->i_tty );
+    }
+
+    /* Destroy structure */
+    free( p_vout->p_sys );
+}
+
+/*****************************************************************************
+ * NewPicture: allocate a picture
+ *****************************************************************************
+ * Returns 0 on success, -1 otherwise
+ *****************************************************************************/
+static int NewPicture( vout_thread_t *p_vout, picture_t *p_pic )
+{
+    /* We know the chroma, allocate a buffer which will be used
+     * directly by the decoder */
+    p_pic->p_sys = malloc( sizeof( picture_sys_t ) );
+    if( p_pic->p_sys == NULL )
+    {
+        return VLC_ENOMEM;
+    }
+
+    /* Fill in picture_t fields */
+    vout_InitPicture( VLC_OBJECT(p_vout), p_pic, p_vout->output.i_chroma,
+                      p_vout->output.i_width, p_vout->output.i_height,
+                      p_vout->output.i_aspect );
+
+    p_pic->p_sys->p_data = malloc( p_vout->p_sys->i_page_size );
+    if( !p_pic->p_sys->p_data )
+    {
+        free( p_pic->p_sys );
+        p_pic->p_sys = NULL;
+        return VLC_ENOMEM;
+    }
+
+    p_pic->p->p_pixels = (uint8_t*) p_pic->p_sys->p_data;
+
+    p_pic->p->i_pixel_pitch = p_vout->p_sys->i_bytes_per_pixel;
+    p_pic->p->i_lines = p_vout->p_sys->var_info.yres;
+    p_pic->p->i_visible_lines = p_vout->p_sys->var_info.yres;
+
+    if( p_vout->p_sys->var_info.xres_virtual )
+    {
+        p_pic->p->i_pitch = p_vout->p_sys->var_info.xres_virtual
+                             * p_vout->p_sys->i_bytes_per_pixel;
+    }
+    else
+    {
+        p_pic->p->i_pitch = p_vout->p_sys->var_info.xres
+                             * p_vout->p_sys->i_bytes_per_pixel;
+    }
+
+    p_pic->p->i_visible_pitch = p_vout->p_sys->var_info.xres
+                                 * p_vout->p_sys->i_bytes_per_pixel;
+    p_pic->i_planes = 1;
+
+    return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * FreePicture: destroy a picture allocated with NewPicture
+ *****************************************************************************
+ * Destroy Image AND associated data.
+ *****************************************************************************/
+static void FreePicture( vout_thread_t *p_vout, picture_t *p_pic )
+{
+    free( p_pic->p_sys->p_data );
+    free( p_pic->p_sys );
+    p_pic->p_sys = NULL;
+}
+
 /*****************************************************************************
  * Init: initialize framebuffer video thread output method
  *****************************************************************************/
@@ -361,7 +479,7 @@ static int Init( vout_thread_t *p_vout )
 {
     vout_sys_t *p_sys = p_vout->p_sys;
     int i_index;
-    picture_t *p_pic;
+    picture_t *p_pic = NULL;
 
     I_OUTPUTPICTURES = 0;
 
@@ -425,52 +543,86 @@ static int Init( vout_thread_t *p_vout )
     /* Clear the screen */
     memset( p_sys->p_video, 0, p_sys->i_page_size );
 
-    /* Try to initialize 1 direct buffer */
-    p_pic = NULL;
-
-    /* Find an empty picture slot */
-    for( i_index = 0 ; i_index < VOUT_MAX_PICTURES ; i_index++ )
+    if( !p_sys->b_hw_accel )
     {
-        if( p_vout->p_picture[ i_index ].i_status == FREE_PICTURE )
+        /* Try to initialize up to MAX_DIRECTBUFFERS direct buffers */
+        while( I_OUTPUTPICTURES < MAX_DIRECTBUFFERS )
         {
-            p_pic = p_vout->p_picture + i_index;
-            break;
+            p_pic = NULL;
+
+            /* Find an empty picture slot */
+            for( i_index = 0 ; i_index < VOUT_MAX_PICTURES ; i_index++ )
+            {
+            if( p_vout->p_picture[ i_index ].i_status == FREE_PICTURE )
+                {
+                    p_pic = p_vout->p_picture + i_index;
+                    break;
+                }
+            }
+
+            /* Allocate the picture */
+            if( p_pic == NULL || NewPicture( p_vout, p_pic ) )
+            {
+                break;
+            }
+
+            p_pic->i_status = DESTROYED_PICTURE;
+            p_pic->i_type   = DIRECT_PICTURE;
+
+            PP_OUTPUTPICTURE[ I_OUTPUTPICTURES ] = p_pic;
+
+            I_OUTPUTPICTURES++;
         }
     }
-
-    /* Allocate the picture */
-    if( p_pic == NULL )
+    else
     {
-        return VLC_EGENERIC;
-    }
+        /* Try to initialize 1 direct buffer */
+        p_pic = NULL;
 
-    /* We know the chroma, allocate a buffer which will be used
-     * directly by the decoder */
-    p_pic->p->p_pixels = p_vout->p_sys->p_video;
-    p_pic->p->i_pixel_pitch = p_vout->p_sys->i_bytes_per_pixel;
-    p_pic->p->i_lines = p_vout->p_sys->var_info.yres;
-    p_pic->p->i_visible_lines = p_vout->p_sys->var_info.yres;
+        /* Find an empty picture slot */
+        for( i_index = 0 ; i_index < VOUT_MAX_PICTURES ; i_index++ )
+        {
+            if( p_vout->p_picture[ i_index ].i_status == FREE_PICTURE )
+            {
+                p_pic = p_vout->p_picture + i_index;
+                break;
+            }
+        }
 
-    if( p_vout->p_sys->var_info.xres_virtual )
-    {
-        p_pic->p->i_pitch = p_vout->p_sys->var_info.xres_virtual
-                             * p_vout->p_sys->i_bytes_per_pixel;
-    }
-    else
-    {
-        p_pic->p->i_pitch = p_vout->p_sys->var_info.xres
-                             * p_vout->p_sys->i_bytes_per_pixel;
-    }
+        /* Allocate the picture */
+        if( p_pic == NULL )
+        {
+            return VLC_EGENERIC;
+        }
 
-    p_pic->p->i_visible_pitch = p_vout->p_sys->var_info.xres
-                                 * p_vout->p_sys->i_bytes_per_pixel;
-    p_pic->i_planes = 1;
-    p_pic->i_status = DESTROYED_PICTURE;
-    p_pic->i_type   = DIRECT_PICTURE;
+        /* We know the chroma, allocate a buffer which will be used
+        * directly by the decoder */
+        p_pic->p->p_pixels = p_vout->p_sys->p_video;
+        p_pic->p->i_pixel_pitch = p_vout->p_sys->i_bytes_per_pixel;
+        p_pic->p->i_lines = p_vout->p_sys->var_info.yres;
+        p_pic->p->i_visible_lines = p_vout->p_sys->var_info.yres;
+
+        if( p_vout->p_sys->var_info.xres_virtual )
+        {
+            p_pic->p->i_pitch = p_vout->p_sys->var_info.xres_virtual
+                                * p_vout->p_sys->i_bytes_per_pixel;
+        }
+        else
+        {
+            p_pic->p->i_pitch = p_vout->p_sys->var_info.xres
+                                * p_vout->p_sys->i_bytes_per_pixel;
+        }
+
+        p_pic->p->i_visible_pitch = p_vout->p_sys->var_info.xres
+                                    * p_vout->p_sys->i_bytes_per_pixel;
+        p_pic->i_planes = 1;
+        p_pic->i_status = DESTROYED_PICTURE;
+        p_pic->i_type   = DIRECT_PICTURE;
 
-    PP_OUTPUTPICTURE[ I_OUTPUTPICTURES ] = p_pic;
+        PP_OUTPUTPICTURE[ I_OUTPUTPICTURES ] = p_pic;
 
-    I_OUTPUTPICTURES++;
+        I_OUTPUTPICTURES++;
+    }
 
     return VLC_SUCCESS;
 }
@@ -480,39 +632,20 @@ static int Init( vout_thread_t *p_vout )
  *****************************************************************************/
 static void End( vout_thread_t *p_vout )
 {
-    /* Clear the screen */
-    memset( p_vout->p_sys->p_video, 0, p_vout->p_sys->i_page_size );
-}
-
-/*****************************************************************************
- * Destroy: destroy FB video thread output method
- *****************************************************************************
- * Terminate an output method created by Create
- *****************************************************************************/
-static void Destroy( vlc_object_t *p_this )
-{
-    vout_thread_t *p_vout = (vout_thread_t *)p_this;
-
-    CloseDisplay( p_vout );
-
-    if( p_vout->p_sys->b_tty )
+    if( !p_vout->p_sys->b_hw_accel )
     {
-        /* Reset the terminal */
-        ioctl( p_vout->p_sys->i_tty, VT_SETMODE, &p_vout->p_sys->vt_mode );
-
-        /* Remove signal handlers */
-        sigaction( SIGUSR1, &p_vout->p_sys->sig_usr1, NULL );
-        sigaction( SIGUSR2, &p_vout->p_sys->sig_usr2, NULL );
+        int i_index;
 
-        /* Reset the keyboard state */
-        tcsetattr( 0, 0, &p_vout->p_sys->old_termios );
+        /* Free the direct buffers we allocated */
+        for( i_index = I_OUTPUTPICTURES ; i_index ; )
+        {
+            i_index--;
+            FreePicture( p_vout, PP_OUTPUTPICTURE[ i_index ] );
+        }
 
-        /* Return to text mode */
-        TextMode( p_vout->p_sys->i_tty );
     }
-
-    /* Destroy structure */
-    free( p_vout->p_sys );
+    /* Clear the screen */
+    memset( p_vout->p_sys->p_video, 0, p_vout->p_sys->i_page_size );
 }
 
 /*****************************************************************************
@@ -609,6 +742,12 @@ static int panned=0;
             panned++;
         }
     }
+
+    if( !p_vout->p_sys->b_hw_accel )
+    {
+        p_vout->p_libvlc->pf_memcpy( p_vout->p_sys->p_video, p_pic->p->p_pixels,
+                                     p_vout->p_sys->i_page_size );
+    }
 }
 
 #if 0
@@ -835,7 +974,7 @@ static void CloseDisplay( vout_thread_t *p_vout )
  * This function activates or deactivates the output of the thread. It is
  * called by the VT driver, on terminal change.
  *****************************************************************************/
-static void SwitchDisplay(int i_signal)
+static void SwitchDisplay( int i_signal )
 {
 #if 0
     vout_thread_t *p_vout;