New video output driver: "vmem", for direct memory access.
authorSam Hocevar <sam@zoy.org>
Fri, 21 Mar 2008 14:26:30 +0000 (14:26 +0000)
committerSam Hocevar <sam@zoy.org>
Fri, 21 Mar 2008 14:26:30 +0000 (14:26 +0000)
Sometimes our list of video output modules is still not enough for an
external libvlc application with specific requirements. For instance, an
SDL application running in full screen cannot open a new window on Linux
(this is a known libSDL limitation). This vmem video output allows it to
asynchronously render the video into an SDL_Surface, with full locking.

Resolution or pitch changes are not supported yet. I'd advise against
them however, since they often require a full chroma unload/reload
operation, which is quite expensive.

I also believe this feature should be directly integrated into libvlc,
but I don't want to be too intrusive yet.

configure.ac
modules/video_output/Modules.am
modules/video_output/vmem.c [new file with mode: 0644]

index 6a4b298..5ae665a 100644 (file)
@@ -1205,7 +1205,7 @@ VLC_ADD_PLUGINS([converter_fixed mono])
 VLC_ADD_PLUGINS([trivial_resampler ugly_resampler])
 VLC_ADD_PLUGINS([trivial_channel_mixer trivial_mixer])
 VLC_ADD_PLUGINS([playlist export nsc xtag])
-VLC_ADD_PLUGINS([i420_rgb grey_yuv rawvideo blend scale image logo magnify puzzle colorthres])
+VLC_ADD_PLUGINS([i420_rgb grey_yuv rawvideo blend scale image vmem logo magnify puzzle colorthres])
 VLC_ADD_PLUGINS([wav araw subtitle vobsub adpcm a52sys dtssys au ty voc xa nuv smf])
 VLC_ADD_PLUGINS([access_directory access_file access_udp access_tcp])
 VLC_ADD_PLUGINS([access_http access_mms access_ftp access_rtmp])
index 6cfe1e0..49c4954 100644 (file)
@@ -17,3 +17,5 @@ SOURCES_opengl = opengl.c
 SOURCES_opengllayer = opengllayer.m
 SOURCES_image = image.c
 SOURCES_directfb = directfb.c
+SOURCES_vmem = vmem.c
+
diff --git a/modules/video_output/vmem.c b/modules/video_output/vmem.c
new file mode 100644 (file)
index 0000000..80eb9cc
--- /dev/null
@@ -0,0 +1,290 @@
+/*****************************************************************************
+ * vmem.c: memory video driver for vlc
+ *****************************************************************************
+ * Copyright (C) 2008 the VideoLAN team
+ * $Id$
+ *
+ * Authors: Sam Hocevar <sam@zoy.org>
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <vlc/vlc.h>
+#include <vlc_vout.h>
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static int  Create    ( vlc_object_t * );
+static void Destroy   ( vlc_object_t * );
+
+static int  Init          ( vout_thread_t * );
+static int  LockPicture   ( vout_thread_t *, picture_t * );
+static int  UnlockPicture ( vout_thread_t *, picture_t * );
+
+/*****************************************************************************
+ * Module descriptor
+ *****************************************************************************/
+#define T_WIDTH N_( "Width" )
+#define LT_WIDTH N_( "Video memory buffer width." )
+
+#define T_HEIGHT N_( "Height" )
+#define LT_HEIGHT N_( "Video memory buffer height." )
+
+#define T_PITCH N_( "Pitch" )
+#define LT_PITCH N_( "Video memory buffer pitch in bytes." )
+
+#define T_CHROMA N_( "Chroma" )
+#define LT_CHROMA N_( "Output chroma for the memory image as a 4-character " \
+                      "string, eg. \"RV32\"." )
+
+#define T_LOCK N_( "Lock function" )
+#define LT_LOCK N_( "Address of the locking callback function. This " \
+                    "function must return a valid memory address for use " \
+                    "by the video renderer." )
+
+#define T_UNLOCK N_( "Unlock function" )
+#define LT_UNLOCK N_( "Address of the unlocking callback function" )
+
+#define T_DATA N_( "Callback data" )
+#define LT_DATA N_( "Data for the locking and unlocking functions" )
+
+vlc_module_begin( );
+    set_description( _( "Video memory module" ) );
+    set_shortname( _("Video memory") );
+
+    set_category( CAT_VIDEO );
+    set_subcategory( SUBCAT_VIDEO_VOUT );
+    set_capability( "video output", 0 );
+
+    add_integer( "vmem-width", 320, NULL, T_WIDTH, LT_WIDTH, VLC_FALSE );
+    add_integer( "vmem-height", 200, NULL, T_HEIGHT, LT_HEIGHT, VLC_FALSE );
+    add_integer( "vmem-pitch", 640, NULL, T_PITCH, LT_PITCH, VLC_FALSE );
+    add_string( "vmem-chroma", "RV16", NULL, T_CHROMA, LT_CHROMA, VLC_TRUE );
+    add_string( "vmem-lock", "0", NULL, T_LOCK, LT_LOCK, VLC_TRUE );
+    add_string( "vmem-unlock", "0", NULL, T_UNLOCK, LT_UNLOCK, VLC_TRUE );
+    add_string( "vmem-data", "0", NULL, T_DATA, LT_DATA, VLC_TRUE );
+
+    set_callbacks( Create, Destroy );
+vlc_module_end();
+
+/*****************************************************************************
+ * vout_sys_t: video output descriptor
+ *****************************************************************************/
+struct vout_sys_t
+{
+    int i_width, i_height, i_pitch;
+
+    void * (*pf_lock) (void *);
+    void (*pf_unlock) (void *);
+    void *p_data;
+};
+
+/*****************************************************************************
+ * 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;
+
+    p_vout->pf_init = Init;
+    p_vout->pf_end = NULL;
+    p_vout->pf_manage = NULL;
+    p_vout->pf_render = NULL;
+    p_vout->pf_display = NULL;
+
+    return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * Init: initialize video thread
+ *****************************************************************************/
+static int Init( vout_thread_t *p_vout )
+{
+    int i_index;
+    picture_t *p_pic;
+    char *psz_chroma, *psz_tmp;
+    int i_width, i_height, i_pitch, i_chroma;
+
+    i_width = config_GetInt( p_vout, "vmem-width" );
+    i_height = config_GetInt( p_vout, "vmem-height" );
+    i_pitch = config_GetInt( p_vout, "vmem-pitch" );
+
+    psz_chroma = config_GetPsz( p_vout, "vmem-chroma" );
+    if( psz_chroma )
+    {
+        if( strlen( psz_chroma ) < 4 )
+        {
+            msg_Err( p_vout, "vmem-chroma should be 4 characters long" );
+            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." );
+        return VLC_EGENERIC;
+    }
+
+    psz_tmp = config_GetPsz( p_vout, "vmem-lock" );
+    p_vout->p_sys->pf_lock = (void * (*) (void *))(intptr_t)atoll( psz_tmp );
+    free( psz_tmp );
+
+    psz_tmp = config_GetPsz( p_vout, "vmem-unlock" );
+    p_vout->p_sys->pf_unlock = (void (*) (void *))(intptr_t)atoll( psz_tmp );
+    free( psz_tmp );
+
+    psz_tmp = config_GetPsz( p_vout, "vmem-data" );
+    p_vout->p_sys->p_data = (void *)(intptr_t)atoll( psz_tmp );
+    free( psz_tmp );
+
+    if( !p_vout->p_sys->pf_lock || !p_vout->p_sys->pf_unlock )
+    {
+        msg_Err( p_vout, "Invalid lock or unlock callbacks" );
+        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_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->i_pitch = i_pitch;
+
+    p_pic->pf_lock = LockPicture;
+    p_pic->pf_unlock = UnlockPicture;
+
+    p_pic->i_status = DESTROYED_PICTURE;
+    p_pic->i_type   = DIRECT_PICTURE;
+
+    PP_OUTPUTPICTURE[ I_OUTPUTPICTURES ] = p_pic;
+
+    I_OUTPUTPICTURES++;
+
+    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;
+
+    /* Destroy structure */
+    free( p_vout->p_sys );
+}
+
+/*****************************************************************************
+ * LockPicture: lock a picture
+ *****************************************************************************
+ * This function locks the picture and prepares it for direct pixel access.
+ *****************************************************************************/
+static int LockPicture( vout_thread_t *p_vout, picture_t *p_pic )
+{
+    p_pic->p->p_pixels = p_vout->p_sys->pf_lock( p_vout->p_sys->p_data );
+
+    return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * UnlockPicture: unlock a picture
+ *****************************************************************************
+ * This function unlocks a previously locked picture.
+ *****************************************************************************/
+static int UnlockPicture( vout_thread_t *p_vout, picture_t *p_pic )
+{
+    p_vout->p_sys->pf_unlock( p_vout->p_sys->p_data );
+
+    (void)p_pic;
+
+    return VLC_SUCCESS;
+}
+