[vlc-commits] v4l2: load libv4l2 dynamically where available
Rémi Denis-Courmont
git at videolan.org
Sun Mar 11 21:15:51 CET 2012
vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Sun Mar 11 22:14:38 2012 +0200| [1faaadfcd885357a7ccde457aa4a540bb90e2185] | committer: Rémi Denis-Courmont
v4l2: load libv4l2 dynamically where available
This removes the build-time and install-time dependency.
> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=1faaadfcd885357a7ccde457aa4a540bb90e2185
---
configure.ac | 5 --
modules/access/Modules.am | 5 +-
modules/access/v4l2/lib.c | 89 +++++++++++++++++++++++++++++++++++++++++++
modules/access/v4l2/v4l2.h | 21 +++-------
modules/access/v4l2/video.c | 29 ++------------
5 files changed, 103 insertions(+), 46 deletions(-)
diff --git a/configure.ac b/configure.ac
index 154ec80..4244dad 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1840,11 +1840,6 @@ AS_IF([test "$enable_v4l2" != "no"], [
])
])
AS_IF([test "$have_v4l2" = "yes"], [
- PKG_CHECK_MODULES(LIBV4L2, libv4l2, [
- AC_DEFINE(HAVE_LIBV4L2, 1, [Define to 1 if libv4l2 is available])
- ], [
- AC_MSG_WARN([${LIBV4L2_PKG_ERRORS}.])
- ])
AS_IF([test "${enable_pvr}" = "yes"], [
VLC_ADD_PLUGIN([pvr])
])
diff --git a/modules/access/Modules.am b/modules/access/Modules.am
index ce69e25..eee6276 100644
--- a/modules/access/Modules.am
+++ b/modules/access/Modules.am
@@ -162,9 +162,10 @@ libv4l2_plugin_la_SOURCES = \
v4l2/demux.c \
v4l2/access.c \
v4l2/controls.c \
+ v4l2/lib.c \
v4l2/v4l2.h
-libv4l2_plugin_la_CFLAGS = $(AM_CFLAGS) $(LIBV4L2_CFLAGS)
-libv4l2_plugin_la_LIBADD = $(AM_LIBADD) $(LIBV4L2_LIBS) $(LIBM)
+libv4l2_plugin_la_CFLAGS = $(AM_CFLAGS)
+libv4l2_plugin_la_LIBADD = $(AM_LIBADD) $(LIBDL) $(LIBM)
libv4l2_plugin_la_DEPENDENCIES =
if HAVE_V4L2
libvlc_LTLIBRARIES += libv4l2_plugin.la
diff --git a/modules/access/v4l2/lib.c b/modules/access/v4l2/lib.c
new file mode 100644
index 0000000..6bd3dfe
--- /dev/null
+++ b/modules/access/v4l2/lib.c
@@ -0,0 +1,89 @@
+/*****************************************************************************
+ * lib.c : libv4l2 run-time
+ *****************************************************************************
+ * Copyright (C) 2012 Rémi Denis-Courmont
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser 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.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <pthread.h>
+#include <dlfcn.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include "v4l2.h"
+
+static void *v4l2_handle = NULL;
+static int (*v4l2_fd_open_) (int, int);
+int (*v4l2_close) (int);
+int (*v4l2_ioctl) (int, unsigned long int, ...);
+ssize_t (*v4l2_read) (int, void *, size_t);
+void * (*v4l2_mmap) (void *, size_t, int, int, int, int64_t);
+int (*v4l2_munmap) (void *, size_t);
+
+static int fd_open (int fd, int flags)
+{
+ (void) flags;
+ return fd;
+}
+
+static void v4l2_lib_load (void)
+{
+ void *h = dlopen ("libv4l2.so", RTLD_LAZY | RTLD_LOCAL);
+ if (h == NULL)
+ goto fallback;
+
+ v4l2_fd_open_ = dlsym (h, "v4l2_fd_open");
+ v4l2_close = dlsym (h, "v4l2_close");
+ v4l2_ioctl = dlsym (h, "v4l2_ioctl");
+ v4l2_read = dlsym (h, "v4l2_read");
+ v4l2_mmap = dlsym (h, "v4l2_mmap");
+ v4l2_munmap = dlsym (h, "v4l2_munmap");
+
+ if (v4l2_fd_open_ != NULL && v4l2_close != NULL && v4l2_ioctl != NULL
+ && v4l2_read != NULL && v4l2_mmap != NULL && v4l2_munmap != NULL)
+ {
+ v4l2_handle = h;
+ return;
+ }
+
+ dlclose (h);
+fallback:
+ v4l2_fd_open_ = fd_open;
+ v4l2_close = close;
+ v4l2_ioctl = ioctl;
+ v4l2_read = read;
+ v4l2_mmap = mmap;
+ v4l2_munmap = munmap;
+}
+
+__attribute__((destructor))
+static void v4l2_lib_unload (void)
+{
+ if (v4l2_handle != NULL)
+ dlclose (v4l2_handle);
+}
+
+int v4l2_fd_open (int fd, int flags)
+{
+ static pthread_once_t once = PTHREAD_ONCE_INIT;
+
+ pthread_once (&once, v4l2_lib_load);
+ return v4l2_fd_open_ (fd, flags);
+}
diff --git a/modules/access/v4l2/v4l2.h b/modules/access/v4l2/v4l2.h
index 3d8cc1c..705b7f4 100644
--- a/modules/access/v4l2/v4l2.h
+++ b/modules/access/v4l2/v4l2.h
@@ -65,16 +65,13 @@
# define V4L2_CID_ROTATE (V4L2_CID_BASE+34)
#endif
-#ifdef HAVE_LIBV4L2
-# include <libv4l2.h>
-#else
-# define v4l2_close close
-# define v4l2_dup dup
-# define v4l2_ioctl ioctl
-# define v4l2_read read
-# define v4l2_mmap mmap
-# define v4l2_munmap munmap
-#endif
+/* libv4l2 functions */
+extern int v4l2_fd_open (int, int);
+extern int (*v4l2_close) (int);
+extern int (*v4l2_ioctl) (int, unsigned long int, ...);
+extern ssize_t (*v4l2_read) (int, void *, size_t);
+extern void * (*v4l2_mmap) (void *, size_t, int, int, int, int64_t);
+extern int (*v4l2_munmap) (void *, size_t);
#define CFG_PREFIX "v4l2-"
@@ -105,10 +102,6 @@ struct demux_sys_t
es_out_id_t *p_es;
vlc_v4l2_ctrl_t *controls;
-
-#ifdef HAVE_LIBV4L2
- bool b_libv4l2;
-#endif
};
struct buffer_t
diff --git a/modules/access/v4l2/video.c b/modules/access/v4l2/video.c
index eb577c5..7e24c0d 100644
--- a/modules/access/v4l2/video.c
+++ b/modules/access/v4l2/video.c
@@ -82,12 +82,6 @@
#define FPS_LONGTEXT N_( "Framerate to capture, if applicable " \
"(0 for autodetect)." )
-#ifdef HAVE_LIBV4L2
-#define LIBV4L2_TEXT N_( "Use libv4l2" )
-#define LIBV4L2_LONGTEXT N_( \
- "Force usage of the libv4l2 wrapper." )
-#endif
-
#define CTRL_RESET_TEXT N_( "Reset controls" )
#define CTRL_RESET_LONGTEXT N_( "Reset controls to defaults." )
#define BRIGHTNESS_TEXT N_( "Brightness" )
@@ -340,9 +334,7 @@ vlc_module_begin ()
change_safe()
add_float( CFG_PREFIX "fps", 0, FPS_TEXT, FPS_LONGTEXT, true )
change_safe()
-#ifdef HAVE_LIBV4L2
- add_bool( CFG_PREFIX "use-libv4l2", false, LIBV4L2_TEXT, LIBV4L2_LONGTEXT, true );
-#endif
+ add_obsolete_bool( CFG_PREFIX "use-libv4l2" ) /* since 2.1.0 */
set_section( N_( "Tuner" ), NULL )
add_integer( CFG_PREFIX "tuner", 0, TUNER_TEXT, TUNER_LONGTEXT,
@@ -807,25 +799,12 @@ int OpenVideo( vlc_object_t *obj, demux_sys_t *sys, bool b_demux )
return -1;
}
free( path );
-#ifdef HAVE_LIBV4L2
- if( !var_InheritBool( obj, CFG_PREFIX "use-libv4l2" ) )
- {
- msg_Dbg( obj, "trying kernel V4L2" );
- if( InitVideo( obj, fd, sys, b_demux ) == 0 )
- return fd;
- }
- msg_Dbg( obj, "trying library V4L2" );
- /* Note the v4l2_xxx functions are designed so that if they get passed an
- unknown fd, the will behave exactly as their regular xxx counterparts,
- so if v4l2_fd_open fails, we continue as normal (missing the libv4l2
- custom cam format to normal formats conversion). Chances are big we will
- still fail then though, as normally v4l2_fd_open only fails if the
- device is not a v4l2 device. */
+
int libfd = v4l2_fd_open( fd, 0 );
if( libfd == -1 )
goto error;
- fd = libfd;
-#endif
+ libfd = fd;
+
if( InitVideo( obj, fd, sys, b_demux ) )
goto error;
More information about the vlc-commits
mailing list