[vlc-devel] [PATCH v2 1/3] lib: Add libvlc_picture API
Hugo Beauzée-Luyssen
hugo at beauzee.fr
Mon Oct 15 16:32:06 CEST 2018
This API is mostly meant to simplify thumbnailing management, by
exposing a simple picture type, that can be probed for its buffer or
saved to a file
---
include/vlc/libvlc_picture.h | 127 ++++++++++++++++++++++++++++++++
lib/Makefile.am | 5 +-
lib/libvlc.sym | 9 +++
lib/picture.c | 137 +++++++++++++++++++++++++++++++++++
lib/picture_internal.h | 46 ++++++++++++
5 files changed, 323 insertions(+), 1 deletion(-)
create mode 100644 include/vlc/libvlc_picture.h
create mode 100644 lib/picture.c
create mode 100644 lib/picture_internal.h
diff --git a/include/vlc/libvlc_picture.h b/include/vlc/libvlc_picture.h
new file mode 100644
index 0000000000..a421d30a92
--- /dev/null
+++ b/include/vlc/libvlc_picture.h
@@ -0,0 +1,127 @@
+/*****************************************************************************
+ * libvlc_picture.h: libvlc external API
+ *****************************************************************************
+ * Copyright (C) 1998-2018 VLC authors and VideoLAN
+ *
+ * Authors: Hugo Beauzée-Luyssen <hugo at beauzee.fr>
+ *
+ * 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.
+ *****************************************************************************/
+
+#ifndef VLC_LIBVLC_PICTURE_H
+#define VLC_LIBVLC_PICTURE_H 1
+
+# ifdef __cplusplus
+extern "C" {
+# endif
+
+typedef struct libvlc_picture_t libvlc_picture_t;
+
+typedef enum libvlc_picture_type_t
+{
+ libvlc_picture_Argb,
+ libvlc_picture_Png,
+ libvlc_picture_Jpg,
+} libvlc_picture_type_t;
+
+/**
+ * Increment the reference count of this picture.
+ *
+ * \see libvlc_picture_release()
+ * \param p_pic A picture object
+ */
+LIBVLC_API void
+libvlc_picture_retain( libvlc_picture_t* p_pic );
+
+/**
+ * Decrement the reference count of this picture.
+ * When the reference count reaches 0, the picture will be released.
+ * The picture must not be accessed after calling this function.
+ *
+ * \see libvlc_picture_retain
+ * \param p_pic A picture object
+ */
+LIBVLC_API void
+libvlc_picture_release( libvlc_picture_t* p_pic );
+
+/**
+ * Saves this picture to a file. The image format is the same as the one
+ * returned by \link libvlc_picture_type \endlink
+ *
+ * \param p_pic A picture object
+ * \param psz_path The path to the generated file
+ * \return 0 in case of success, -1 otherwise
+ */
+LIBVLC_API int
+libvlc_picture_save( const libvlc_picture_t* p_pic, const char* psz_path );
+
+/**
+ * Returns the image internal buffer, including potential padding.
+ * The libvlc_picture_t owns the returned buffer, which must not be modified nor
+ * freed.
+ *
+ * \param p_pic A picture object
+ * \param p_size A pointer to a size_t that will hold the size of the buffer [required]
+ * \return A pointer to the internal buffer.
+ */
+LIBVLC_API const unsigned char*
+libvlc_picture_get_buffer( const libvlc_picture_t* p_pic, size_t *p_size );
+
+/**
+ * Returns the picture type
+ *
+ * \param p_pic A picture object
+ * \see libvlc_picture_type_t
+ */
+LIBVLC_API libvlc_picture_type_t
+libvlc_picture_type( const libvlc_picture_t* p_pic );
+
+/**
+ * Returns the image stride, ie. the number of bytes per line.
+ * This can only be called on images of type libvlc_Argb
+ *
+ * \param p_pic A picture object
+ */
+LIBVLC_API unsigned int
+libvlc_picture_get_stride( const libvlc_picture_t* p_pic );
+
+/**
+ * Returns the width of the image in pixels
+ *
+ * \param p_pic A picture object
+ */
+LIBVLC_API unsigned int
+libvlc_picture_get_width( const libvlc_picture_t* p_pic );
+
+/**
+ * Returns the height of the image in pixels
+ *
+ * \param p_pic A picture object
+ */
+LIBVLC_API unsigned int
+libvlc_picture_get_height( const libvlc_picture_t* p_pic );
+
+/**
+ * Returns the time at which this picture was generated, in milliseconds
+ * \param p_pic A picture object
+ */
+LIBVLC_API libvlc_time_t
+libvlc_picture_get_time( const libvlc_picture_t* p_pic );
+
+# ifdef __cplusplus
+}
+# endif
+
+#endif // VLC_LIBVLC_PICTURE_H
diff --git a/lib/Makefile.am b/lib/Makefile.am
index b605cd6549..8dbbaf9d2a 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -19,6 +19,7 @@ pkginclude_HEADERS = \
../include/vlc/libvlc_media_list_player.h \
../include/vlc/libvlc_media_player.h \
../include/vlc/libvlc_renderer_discoverer.h \
+ ../include/vlc/libvlc_picture.h \
../include/vlc/vlc.h
nodist_pkginclude_HEADERS = ../include/vlc/libvlc_version.h
@@ -34,6 +35,7 @@ libvlc_la_SOURCES = \
media_internal.h \
media_list_internal.h \
media_player_internal.h \
+ picture_internal.h \
renderer_discoverer_internal.h \
core.c \
dialog.c \
@@ -50,7 +52,8 @@ libvlc_la_SOURCES = \
media_list_path.h \
media_list_player.c \
media_library.c \
- media_discoverer.c
+ media_discoverer.c \
+ picture.c
EXTRA_DIST = libvlc.pc.in libvlc.sym ../include/vlc/libvlc_version.h.in
libvlc_la_LIBADD = ../src/libvlccore.la ../compat/libcompat.la $(LIBM)
diff --git a/lib/libvlc.sym b/lib/libvlc.sym
index 9a896ce7b2..67cd40b69c 100644
--- a/lib/libvlc.sym
+++ b/lib/libvlc.sym
@@ -262,3 +262,12 @@ libvlc_set_exit_handler
libvlc_audio_filter_list_get
libvlc_video_filter_list_get
libvlc_module_description_list_release
+libvlc_picture_retain
+libvlc_picture_release
+libvlc_picture_save
+libvlc_picture_get_buffer
+libvlc_picture_type
+libvlc_picture_get_stride
+libvlc_picture_get_width
+libvlc_picture_get_height
+libvlc_picture_get_time
diff --git a/lib/picture.c b/lib/picture.c
new file mode 100644
index 0000000000..e8d7d4fd4a
--- /dev/null
+++ b/lib/picture.c
@@ -0,0 +1,137 @@
+/*****************************************************************************
+ * picture.c: libvlc API picture management
+ *****************************************************************************
+ * Copyright (C) 1998-2018 VLC authors and VideoLAN
+ *
+ * Authors: Hugo Beauzée-Luyssen <hugo at beauzee.fr>
+ *
+ * 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 <vlc/libvlc.h>
+#include <vlc/libvlc_picture.h>
+
+#include <vlc_atomic.h>
+#include <vlc_picture.h>
+#include <vlc_block.h>
+#include <vlc_fs.h>
+
+#include "picture_internal.h"
+
+struct libvlc_picture_t
+{
+ vlc_atomic_rc_t rc;
+ libvlc_picture_type_t i_type;
+ block_t* p_converted;
+ video_format_t fmt;
+ libvlc_time_t i_time;
+};
+
+libvlc_picture_t* libvlc_picture_new( vlc_object_t* p_obj, picture_t* p_input,
+ libvlc_picture_type_t i_type,
+ unsigned int i_width, unsigned int i_height )
+{
+ libvlc_picture_t *p_pic = malloc( sizeof( *p_pic ) );
+ if ( unlikely( p_pic == NULL ) )
+ return NULL;
+ vlc_atomic_rc_init( &p_pic->rc );
+ p_pic->i_type = i_type;
+ p_pic->i_time = MS_FROM_VLC_TICK( p_input->date );
+ vlc_fourcc_t format;
+ switch ( i_type )
+ {
+ case libvlc_picture_Argb:
+ format = VLC_CODEC_ARGB;
+ break;
+ case libvlc_picture_Jpg:
+ format = VLC_CODEC_JPEG;
+ break;
+ case libvlc_picture_Png:
+ format = VLC_CODEC_PNG;
+ break;
+ }
+ if ( picture_Export( p_obj, &p_pic->p_converted, &p_pic->fmt,
+ p_input, format, i_width, i_height ) != VLC_SUCCESS )
+ {
+ free( p_pic );
+ return NULL;
+ }
+
+ return p_pic;
+}
+
+void libvlc_picture_retain( libvlc_picture_t* p_pic )
+{
+ vlc_atomic_rc_inc( &p_pic->rc );
+}
+
+void libvlc_picture_release( libvlc_picture_t* p_pic )
+{
+ if ( vlc_atomic_rc_dec( &p_pic->rc ) == false )
+ return;
+ video_format_Clean( &p_pic->fmt );
+ if ( p_pic->p_converted )
+ block_Release( p_pic->p_converted );
+ free( p_pic );
+}
+
+int libvlc_picture_save( const libvlc_picture_t* p_pic, const char* psz_path )
+{
+ FILE* p_file = vlc_fopen( psz_path, "wb" );
+ if ( !p_file )
+ return -1;
+ size_t res = fwrite( p_pic->p_converted->p_buffer,
+ p_pic->p_converted->i_buffer, 1, p_file );
+ fclose( p_file );
+ return res == 1 ? 0 : -1;
+}
+
+const unsigned char* libvlc_picture_get_buffer( const libvlc_picture_t* p_pic,
+ size_t *p_size )
+{
+ assert( p_size != NULL );
+ *p_size = p_pic->p_converted->i_buffer;
+ return p_pic->p_converted->p_buffer;
+}
+
+libvlc_picture_type_t libvlc_picture_type( const libvlc_picture_t* p_pic )
+{
+ return p_pic->i_type;
+}
+
+unsigned int libvlc_picture_get_stride( const libvlc_picture_t *p_pic )
+{
+ assert( p_pic->i_type == libvlc_picture_Argb );
+ return p_pic->fmt.i_width * p_pic->fmt.i_bits_per_pixel / 8;
+}
+
+unsigned int libvlc_picture_get_width( const libvlc_picture_t* p_pic )
+{
+ return p_pic->fmt.i_visible_width;
+}
+
+unsigned int libvlc_picture_get_height( const libvlc_picture_t* p_pic )
+{
+ return p_pic->fmt.i_visible_height;
+}
+
+libvlc_time_t libvlc_picture_get_time( const libvlc_picture_t* p_pic )
+{
+ return p_pic->i_time;
+}
diff --git a/lib/picture_internal.h b/lib/picture_internal.h
new file mode 100644
index 0000000000..3ad68b46f5
--- /dev/null
+++ b/lib/picture_internal.h
@@ -0,0 +1,46 @@
+/*****************************************************************************
+ * picture_internal.h: libvlc API picture management
+ *****************************************************************************
+ * Copyright (C) 1998-2018 VLC authors and VideoLAN
+ *
+ * Authors: Hugo Beauzée-Luyssen <hugo at beauzee.fr>
+ *
+ * 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.
+ *****************************************************************************/
+
+#ifndef PICTURE_INTERNAL_H
+#define PICTURE_INTERNAL_H
+
+#include <vlc_picture.h>
+
+
+/**
+ * \brief libvlc_picture_new Wraps a libvlccore's picture_t to a libvlc_picture_t
+ * \param p_obj A vlc object
+ * \param p_input Input picture
+ * \param i_type Desired converted picture type
+ * \param i_width Converted picture width
+ * \param i_height Converted picture height
+ * \return An opaque libvlc_picture_t
+ *
+ * The picture refcount is left untouched by this function, but is converted to
+ * the required format and stored as a block_t
+ * The returned picture must be released through libvlc_picture_release
+ */
+libvlc_picture_t* libvlc_picture_new( vlc_object_t* p_obj, picture_t* p_pic,
+ libvlc_picture_type_t i_format,
+ unsigned int i_width, unsigned int i_height );
+
+#endif // PICTURE_INTERNAL_H
--
2.19.1
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