invmem fake video codec module

This module make possible uses libvlc as output (not input as vmem) for
video stream rendering in aplication ... motivation to create this patch can
find at http://forum.videolan.org/viewtopic.php?f=32&t=53256

Usage is similar to vmem output module. We need next vlc_argv[] options:
   "--codec", "invmem",
   "--invmem-width", width,
   "--invmem-height", height,
   "--invmem-lock", clock,
   "--invmem-unlock", cunlock,
   "--invmem-data", cdata,
and calling libvlc_media_new with "fake://" access string:
   libvlc_media_new(libvlc, "fake://", &ex);
Signed-off-by: Rémi Denis-Courmont <rdenis@simphalempin.com>

modules/codec/Modules.am

@@ -25,6 +25,7 @@ SOURCES_png = png.c
 SOURCES_svcdsub = svcdsub.c
 SOURCES_cvdsub = cvdsub.c
 SOURCES_fake = fake.c
+SOURCES_invmem = invmem.c
 SOURCES_realaudio = realaudio.c
 SOURCES_realvideo = realvideo.c
 SOURCES_sdl_image = sdl_image.c
@@ -53,4 +54,5 @@ libvlc_LTLIBRARIES += \
 	libmpeg_audio_plugin.la \
 	librawvideo_plugin.la \
 	libsvcdsub_plugin.la \
+	libinvmem_plugin.la \
 	$(NULL)

modules/codec/invmem.c

+/*****************************************************************************
+ * invmem_decoder.c: memory video driver for vlc
+ *****************************************************************************
+ * Copyright (C) 2008 the VideoLAN team
+ * $Id$
+ *
+ * Authors: Robert Paciorek <robert@opcode.eu.org> <http://opcode.eu.org/bercik>
+ * based on:
+ *  - vmem video output module (Gildas Bazin <gbazin@videolan.org>)
+ *  - png video decodec module (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_common.h>
+#include <vlc_plugin.h>
+#include <vlc_codec.h>
+
+#include <vlc_image.h>
+#include <vlc_filter.h>
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static int  OpenDecoder   ( vlc_object_t * );
+static void CloseDecoder  ( vlc_object_t * );
+
+static picture_t *DecodeBlock  ( decoder_t *, block_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_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" )
+
+#define INVMEM_HELP N_( "This module make possible making video stream from raw-image " \
+                        "generating (to memory) from rendering program uses libvlc. " \
+                        "To use this module from libvlc set --codec to invmem, "\
+                        "set all --invmem-* options in vlc_argv an use " \
+                        "libvlc_media_new(libvlc, \"fake://\", &ex);. " \
+                        "Besides is simillar to vmem video output module." )
+vlc_module_begin();
+    set_category( CAT_INPUT );
+    set_subcategory( SUBCAT_INPUT_VCODEC );
+    set_shortname( N_("Memory video decoder") );
+    set_description( N_("Memory video decoder") );
+    set_help( INVMEM_HELP );
+    set_capability( "decoder", 50 );
+    set_callbacks( OpenDecoder, CloseDecoder );
+    add_shortcut( "invmem" );
+
+    add_integer( "invmem-width", "0", NULL, T_WIDTH, LT_WIDTH, false );
+    add_integer( "invmem-height", "0", NULL, T_HEIGHT, LT_HEIGHT, false );
+    add_string( "invmem-lock", "0", NULL, T_LOCK, LT_LOCK, true );
+    add_string( "invmem-unlock", "0", NULL, T_UNLOCK, LT_UNLOCK, true );
+    add_string( "invmem-data", "0", NULL, T_DATA, LT_DATA, true );
+vlc_module_end();
+
+
+struct decoder_sys_t
+{
+    void * (*pf_lock) (void *);
+    void (*pf_unlock) (void *);
+    void *p_data;
+
+    int i_width;
+    int i_height;
+    int i_pitch;
+
+    picture_t *p_pic;
+};
+
+
+/*****************************************************************************
+ * OpenDecoder: probe the decoder and return score
+ *****************************************************************************/
+static int OpenDecoder( vlc_object_t *p_this )
+{
+    decoder_t *p_dec = (decoder_t*)p_this;
+    decoder_sys_t *p_sys;
+    char *psz_tmp;
+
+    if( p_dec->fmt_in.i_codec != VLC_FOURCC('f','a','k','e'))
+    {
+        return VLC_EGENERIC;
+    }
+
+    /* Allocate the memory needed to store the decoder's structure */
+    if( ( p_dec->p_sys = p_sys =
+          (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
+        return VLC_ENOMEM;
+
+    // get parametrs
+    p_sys->i_width = var_CreateGetInteger( p_this, "invmem-width" );
+    p_sys->i_height = var_CreateGetInteger( p_this, "invmem-height" );
+    if (p_sys->i_width == 0 || p_sys->i_height == 0) {
+        msg_Err( p_dec, "--vmem-width and --vmem-height must be > 0" );
+        return VLC_EGENERIC;
+    }
+
+    psz_tmp = var_CreateGetString( p_dec, "invmem-lock" );
+    p_sys->pf_lock = (void * (*) (void *))(intptr_t)atoll( psz_tmp );
+    free( psz_tmp );
+
+    psz_tmp = var_CreateGetString( p_dec, "invmem-unlock" );
+    p_sys->pf_unlock = (void (*) (void *))(intptr_t)atoll( psz_tmp );
+    free( psz_tmp );
+
+    psz_tmp = var_CreateGetString( p_dec, "invmem-data" );
+    p_sys->p_data = (void *)(intptr_t)atoll( psz_tmp );
+    free( psz_tmp );
+
+    if( !p_sys->pf_lock || !p_sys->pf_unlock )
+    {
+        msg_Err( p_dec, "Invalid lock or unlock callbacks" );
+        return VLC_EGENERIC;
+    }
+
+    /* Set output properties */
+    p_dec->fmt_out.i_cat = VIDEO_ES;
+    //p_dec->fmt_out.i_codec = VLC_FOURCC('R','G','B','A');
+    p_dec->fmt_out.i_codec = VLC_FOURCC('R','V','2','4');
+    p_dec->fmt_out.video.i_width = p_dec->p_sys->i_width;
+    p_dec->fmt_out.video.i_height = p_dec->p_sys->i_height;
+    p_dec->fmt_out.video.i_aspect = VOUT_ASPECT_FACTOR * p_dec->p_sys->i_width / p_dec->p_sys->i_height;
+    p_dec->fmt_out.video.i_rmask = 0xff0000;
+    p_dec->fmt_out.video.i_gmask = 0x00ff00;
+    p_dec->fmt_out.video.i_bmask = 0x0000ff;
+    p_dec->fmt_out.i_cat = VIDEO_ES;
+
+    p_sys->i_pitch = p_sys->i_width*3 + p_sys->i_width%4;
+
+    // create new picture
+    p_sys->p_pic = p_dec->pf_vout_buffer_new( p_dec );
+
+    /* Set callbacks */
+    p_dec->pf_decode_video = DecodeBlock;
+
+    return VLC_SUCCESS;
+}
+
+/****************************************************************************
+ * DecodeBlock: the whole thing
+ ****************************************************************************
+ * This function must be fed with a complete compressed frame.
+ ****************************************************************************/
+static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
+{
+    decoder_sys_t *p_sys = p_dec->p_sys;
+
+    if( !pp_block || !*pp_block ) return NULL;
+
+    // create new picture
+    picture_Release( p_sys->p_pic );
+    p_sys->p_pic = p_dec->pf_vout_buffer_new( p_dec );
+    p_sys->p_pic->b_force = true;
+    p_sys->p_pic->p->i_pitch = p_dec->p_sys->i_pitch;
+
+   // lock input and copy to picture
+    p_sys->p_pic->p->p_pixels = p_sys->pf_lock( p_dec->p_sys->p_data );
+
+    // unlock input
+    p_sys->pf_unlock( p_dec->p_sys->p_data );
+
+    block_Release( *pp_block ); *pp_block = NULL;
+    return p_sys->p_pic;
+}
+
+/*****************************************************************************
+ * CloseDecoder: invmem decoder destruction
+ *****************************************************************************/
+static void CloseDecoder( vlc_object_t *p_this )
+{
+    decoder_t *p_dec = (decoder_t *)p_this;
+    decoder_sys_t *p_sys = p_dec->p_sys;
+
+    free( p_sys );
+}