Snapshot module (dummy video output module keeping a configurable image cache).

It is chiefly used by the corba module.

configure.ac

@@ -3573,7 +3573,7 @@ if test "${enable_corba}" = "yes"; then
       AC_MSG_ERROR([Could not find corba development headers])
     ])
     if test "${ac_cv_corba_headers}" = "yes"; then
-      AX_ADD_PLUGINS(corba)
+      AX_ADD_PLUGINS([corba snapshot])
     fi
     CPPFLAGS="${CPPFLAGS_save}"
   fi

include/snapshot.h

+typedef struct snapshot_t {
+  char *p_data;  /* Data area */
+
+  int i_width;       /* In pixels */
+  int i_height;      /* In pixels */
+  int i_datasize;    /* In bytes */
+  mtime_t date;      /* Presentation time */
+} snapshot_t;

modules/video_output/snapshot.c

+/*****************************************************************************
+ * snapshot.c : snapshot plugin for vlc
+ *****************************************************************************
+ * Copyright (C) 2002 VideoLAN
+ * $Id: snapshot.c,v 1.5 2004/01/30 11:26:20 oaubert Exp $
+ *
+ * Authors: Olivier Aubert <oaubert@lisi.univ-lyon1.fr>
+ *      
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+#include <stdlib.h>
+
+#include <vlc/vlc.h>
+#include <vlc/vout.h>
+#include <vlc/intf.h>
+#include <snapshot.h>
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static int  Create    ( vlc_object_t * );
+static void Destroy   ( vlc_object_t * );
+
+static int  Init      ( vout_thread_t * );
+static void Display   ( vout_thread_t *, picture_t * );
+
+/*****************************************************************************
+ * Module descriptor
+ *****************************************************************************/
+#define WIDTH_TEXT N_("snapshot width")
+#define WIDTH_LONGTEXT N_("Set the width of the snapshot image")
+
+#define HEIGHT_TEXT N_("snapshot height")
+#define HEIGHT_LONGTEXT N_("Set the height of the snapshot image")
+
+#define CHROMA_TEXT N_("chroma")
+#define CHROMA_LONGTEXT N_("Set the desired chroma for the snapshot image (a 4 character string)")
+
+#define CACHE_TEXT N_("cache size (number of images)")
+#define CACHE_LONGTEXT N_("Set the cache size (number of images to keep)")
+
+
+vlc_module_begin();                                            
+    set_description( _("snapshot module") );
+    set_capability( "video output", 0 );
+
+    add_integer( "snapshot-width", 320, NULL, WIDTH_TEXT, WIDTH_LONGTEXT, VLC_FALSE );
+    add_integer( "snapshot-height", 200, NULL, HEIGHT_TEXT, HEIGHT_LONGTEXT, VLC_FALSE );
+    add_string ( "snapshot-chroma", "RV32", NULL, CHROMA_TEXT, CHROMA_LONGTEXT, VLC_TRUE );
+    add_integer( "snapshot-cache-size", 50, NULL, CACHE_TEXT, CACHE_LONGTEXT, VLC_TRUE );
+    
+    set_callbacks( Create, Destroy );
+vlc_module_end();
+
+/*****************************************************************************
+ * vout_sys_t: video output descriptor
+ *****************************************************************************/
+struct vout_sys_t
+{
+  snapshot_t **p_list; /* List of available snapshots */
+  int i_index;        /* Index of the next available list member */
+  int i_size;         /* Size of the cache */
+  int i_datasize;     /* Size of an image */
+  input_thread_t *    p_input;             /* The input thread */  
+};
+
+/*****************************************************************************
+ * Create: allocates video thread
+ *****************************************************************************
+ * This function allocates and initializes a vout method.
+ *****************************************************************************/
+static int Create( vlc_object_t *p_this )
+{
+    vout_thread_t *p_vout = (vout_thread_t *)p_this;
+
+    /* Allocate instance and initialize some members */
+    p_vout->p_sys = malloc( sizeof( vout_sys_t ) );
+    if(! p_vout->p_sys)
+        return VLC_ENOMEM;
+
+    var_Create (p_this, "snapshot-width", VLC_VAR_INTEGER);
+    var_Create (p_this, "snapshot-height", VLC_VAR_INTEGER);
+    var_Create (p_this, "snapshot-datasize", VLC_VAR_INTEGER);
+    var_Create (p_this, "snapshot-cache-size", VLC_VAR_INTEGER);
+    var_Create (p_this, "snapshot-list-pointer", VLC_VAR_ADDRESS);
+
+    p_vout->pf_init = Init;
+    p_vout->pf_end = NULL;
+    p_vout->pf_manage = NULL;
+    p_vout->pf_render = NULL;
+    p_vout->pf_display = Display;
+
+    return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * Init: initialize video thread
+ *****************************************************************************/
+static int Init( vout_thread_t *p_vout )
+{
+    int i_index;
+    picture_t *p_pic;
+    vlc_value_t         val;
+    char* psz_chroma;
+    int i_chroma;
+    int i_width;
+    int i_height;
+    int i_datasize;
+
+    i_width  = config_GetInt( p_vout, "snapshot-width" );
+    i_height = config_GetInt( p_vout, "snapshot-height" );
+    
+    psz_chroma = config_GetPsz( p_vout, "snapshot-chroma" );
+    if (psz_chroma)
+      {
+	if (strlen (psz_chroma) < 4)
+	  {
+	    msg_Err(p_vout, 
+		     "snapshot-chroma should be 4 characters long.\n");
+	    return VLC_EGENERIC;
+	  }
+	i_chroma = VLC_FOURCC (psz_chroma[0],
+			       psz_chroma[1],
+			       psz_chroma[2],
+			       psz_chroma[3]);
+	free (psz_chroma);
+      }
+    else
+      {
+	msg_Err (p_vout, "Cannot find chroma information.\n");
+	return VLC_EGENERIC;
+      }
+
+    I_OUTPUTPICTURES = 0;
+
+    /* Initialize the output structure */
+    p_vout->output.i_chroma = i_chroma;
+    p_vout->output.pf_setpalette = NULL;
+    p_vout->output.i_width = i_width;
+    p_vout->output.i_height = i_height;
+    p_vout->output.i_aspect = p_vout->output.i_width
+                               * VOUT_ASPECT_FACTOR / p_vout->output.i_height;
+
+
+    /* Define the bitmasks */
+    switch( i_chroma )
+      {
+      case VLC_FOURCC('R','V','1','5'):
+	p_vout->output.i_rmask = 0x001f;
+	p_vout->output.i_gmask = 0x03e0;
+	p_vout->output.i_bmask = 0x7c00;
+	break;
+	
+      case VLC_FOURCC('R','V','1','6'):
+	p_vout->output.i_rmask = 0x001f;
+	p_vout->output.i_gmask = 0x07e0;
+	p_vout->output.i_bmask = 0xf800;
+	break;
+	  
+      case VLC_FOURCC('R','V','2','4'):
+	p_vout->output.i_rmask = 0xff0000;
+	p_vout->output.i_gmask = 0x00ff00;
+	p_vout->output.i_bmask = 0x0000ff;
+	break;
+	
+      case VLC_FOURCC('R','V','3','2'):
+	p_vout->output.i_rmask = 0xff0000;
+	p_vout->output.i_gmask = 0x00ff00;
+	p_vout->output.i_bmask = 0x0000ff;
+	break;
+      }
+
+    /* 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_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 )
+    {
+        return VLC_SUCCESS;
+    }
+
+    vout_AllocatePicture( p_vout, p_pic, p_vout->output.i_chroma,
+                          p_vout->output.i_width, p_vout->output.i_height,
+                          p_vout->output.i_aspect );
+
+    if( p_pic->i_planes == 0 )
+    {
+        return VLC_EGENERIC;
+    }
+
+    p_pic->i_status = DESTROYED_PICTURE;
+    p_pic->i_type   = DIRECT_PICTURE;
+
+    PP_OUTPUTPICTURE[ I_OUTPUTPICTURES ] = p_pic;
+
+    I_OUTPUTPICTURES++;
+
+
+    /* Get datasize and set variables */
+    i_datasize = i_width * i_height * p_pic->p->i_pixel_pitch;
+
+    p_vout->p_sys->i_datasize = i_datasize;
+    p_vout->p_sys->i_index = 0;
+    p_vout->p_sys->i_size = config_GetInt( p_vout, "snapshot-cache-size" );
+
+    if (p_vout->p_sys->i_size < 2) 
+      {
+	msg_Err (p_vout, "snapshot-cache-size must be at least 1.");
+	return VLC_EGENERIC;
+      }
+
+    p_vout->p_sys->p_list = (snapshot_t **)malloc (p_vout->p_sys->i_size * sizeof (snapshot_t *));
+
+    if( p_vout->p_sys->p_list == NULL )
+      return VLC_ENOMEM;
+
+    /* Initialize the structures for the circular buffer */
+    for (i_index = 0 ; i_index < p_vout->p_sys->i_size ; i_index++)
+      {
+	snapshot_t *p_snapshot;
+	p_snapshot = (snapshot_t *)malloc (sizeof (snapshot_t));
+
+	if( p_snapshot == NULL )
+	  return VLC_ENOMEM;
+
+	p_snapshot->i_width = i_width;
+	p_snapshot->i_height = i_height;
+	p_snapshot->i_datasize = i_datasize;
+	p_snapshot->date = 0;
+	p_snapshot->p_data = (char*) malloc (i_datasize);
+	if( p_snapshot->p_data == NULL )
+	  return VLC_ENOMEM;
+	p_vout->p_sys->p_list[i_index] = p_snapshot;
+      }
+
+    val.i_int = i_width;
+    var_Set (p_vout, "snapshot-width", val);
+    val.i_int = i_height;
+    var_Set (p_vout, "snapshot-height", val);
+    val.i_int = i_datasize;
+    var_Set (p_vout, "snapshot-datasize", val);
+
+    val.i_int = p_vout->p_sys->i_size;
+    var_Set (p_vout, "snapshot-cache-size", val);
+
+    val.p_address = p_vout->p_sys->p_list;
+    var_Set (p_vout, "snapshot-list-pointer", val);
+
+    /* Get the p_input pointer (to access video times) */
+    p_vout->p_sys->p_input = vlc_object_find( p_vout, VLC_OBJECT_INPUT,
+					      FIND_PARENT );
+    
+    if (! p_vout->p_sys->p_input)
+      return VLC_ENOOBJ;
+
+    if (var_Create (p_vout->p_sys->p_input, "snapshot-id", VLC_VAR_INTEGER) != VLC_SUCCESS)
+      {
+	msg_Err (p_vout, "Cannot create snapshot-id variable in p_input (%d).", p_vout->p_sys->p_input->i_object_id);
+	return VLC_EGENERIC;
+      }
+
+    /* Register the snapshot vout module at the input level */
+    val.i_int = p_vout->i_object_id;
+
+    if (var_Set (p_vout->p_sys->p_input, "snapshot-id", val) != VLC_SUCCESS)
+      {
+	msg_Err (p_vout, "Cannot register snapshot-id in p_input (%d).", p_vout->p_sys->p_input->i_object_id);
+	return VLC_EGENERIC;
+      }
+
+    return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * Destroy: destroy video thread
+ *****************************************************************************
+ * 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;
+  vlc_object_t *p_vlc;
+  int i_index;
+
+  fprintf (stderr, "Destroying snapshot module\n");
+  vlc_object_release(p_vout->p_sys->p_input);
+  var_Destroy (p_this, "snapshot-width");
+  var_Destroy (p_this, "snapshot-height");
+  var_Destroy (p_this, "snapshot-datasize");
+
+  p_vlc = vlc_object_find(p_this, VLC_OBJECT_ROOT, FIND_PARENT);
+  if (p_vlc)
+    {
+      /* UnRegister the snapshot vout module at the root level */
+      /* var_Destroy (p_vlc, "snapshot-id"); */
+      var_Destroy (p_this->p_libvlc, "snapshot-id");
+      vlc_object_release(p_vlc);
+    }
+
+  for (i_index = 0 ; i_index < p_vout->p_sys->i_size ; i_index++)
+    {
+      free (p_vout->p_sys->p_list[i_index]->p_data);
+    }
+  free (p_vout->p_sys->p_list);
+  /* Destroy structure */
+  free( p_vout->p_sys );
+}
+
+/* Return the position in ms from the start of the movie */
+mtime_t get_movietime(vout_thread_t *p_vout)
+{
+  input_thread_t* p_input;
+  vlc_value_t val;
+  mtime_t result;
+
+  p_input = p_vout->p_sys->p_input;
+  if (! p_input)
+    return 0;
+
+  var_Get( p_input, "time", &val );
+
+  result = val.i_time;
+
+  if (result == 0)
+    {
+      /* Either we are at the start, or (more probably) the demuxer
+	 does not support the DEMUX_GET_TIME call. Try to fallback to
+	 another method. */
+      stream_position_t pos;
+
+      input_Tell (p_input, &pos);
+      result = pos.i_mux_rate * 50 * pos.i_tell;
+    }
+  return (result / 1000);
+}
+
+/*****************************************************************************
+ * Display: displays previously rendered output
+ *****************************************************************************
+ * This function copies the rendered picture into our circular buffer.
+ *****************************************************************************/
+static void Display( vout_thread_t *p_vout, picture_t *p_pic )
+{
+   int i_index;
+   mtime_t date;
+ 
+   i_index = p_vout->p_sys->i_index;
+ 
+   p_vout->p_vlc->pf_memcpy(
+ 			   p_vout->p_sys->p_list[i_index]->p_data,
+ 			   p_pic->p->p_pixels,
+ 			   p_vout->p_sys->i_datasize);
+ 
+   date = get_movietime(p_vout);
+
+   p_vout->p_sys->p_list[i_index]->date = date;
+
+   i_index++;
+ 
+   if (i_index >= p_vout->p_sys->i_size)
+     {
+       i_index = 0;
+     }
+ 
+   p_vout->p_sys->i_index = i_index;
+ 
+  return;
+}