lavc: add teletext decoder using libzvbi

Based on a patch by Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>.
http://lists.ffmpeg.org/pipermail/ffmpeg-devel/2012-December/136677.html

The original patch was rebased by Tudor SUCIU <tudor.suciu@gmail.com>.

Lots of additional features and fixes are made by me.

Fixes ticket #2086.

Changes since last version:
- change default page to all pages
Signed-off-by: Marton Balint <cus@passwd.hu>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Changelog

@@ -15,6 +15,7 @@ version <next>
   data read from an input file
 - incomplete Voxware MetaSound decoder
 - read EXIF metadata from JPEG
+- DVB teletext decoder
 
 
 version 2.0:

configure

@@ -242,6 +242,7 @@ External library support:
   --enable-libxvid         enable Xvid encoding via xvidcore,
                            native MPEG-4/Xvid encoder exists [no]
   --enable-libzmq          enable message passing via libzmq [no]
+  --enable-libzvbi         enable teletext support via libzvbi [no]
   --enable-openal          enable OpenAL 1.1 capture support [no]
   --enable-opencl          enable OpenCL code
   --enable-openssl         enable openssl [no]
@@ -1205,6 +1206,7 @@ EXTERNAL_LIBRARY_LIST="
     libxavs
     libxvid
     libzmq
+    libzvbi
     openal
     opencl
     openssl
@@ -2044,6 +2046,7 @@ libxavs_encoder_deps="libxavs"
 libxvid_encoder_deps="libxvid"
 libutvideo_decoder_deps="libutvideo"
 libutvideo_encoder_deps="libutvideo"
+libzvbi_teletext_decoder_deps="libzvbi"
 
 # demuxers / muxers
 ac3_demuxer_select="ac3_parser"
@@ -3767,6 +3770,7 @@ die_license_disabled gpl libvidstab
 die_license_disabled gpl libx264
 die_license_disabled gpl libxavs
 die_license_disabled gpl libxvid
+die_license_disabled gpl libzvbi
 die_license_disabled gpl x11grab
 
 die_license_disabled nonfree libaacplus
@@ -4245,6 +4249,7 @@ enabled libx264           && require libx264 x264.h x264_encoder_encode -lx264 &
 enabled libxavs           && require libxavs xavs.h xavs_encoder_encode -lxavs
 enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
 enabled libzmq            && require_pkg_config libzmq zmq.h zmq_ctx_new
+enabled libzvbi           && require libzvbi libzvbi.h vbi_decoder_new -lzvbi
 enabled openal            && { { for al_libs in "${OPENAL_LIBS}" "-lopenal" "-lOpenAL32"; do
                                check_lib 'AL/al.h' alGetError "${al_libs}" && break; done } ||
                                die "ERROR: openal not found"; } &&
@@ -4635,6 +4640,7 @@ echo "threading support         ${thread_type-no}"
 echo "safe bitstream reader     ${safe_bitstream_reader-no}"
 echo "SDL support               ${sdl-no}"
 echo "opencl enabled            ${opencl-no}"
+echo "libzvbi enabled           ${libzvbi-no}"
 echo "texi2html enabled         ${texi2html-no}"
 echo "perl enabled              ${perl-no}"
 echo "pod2man enabled           ${pod2man-no}"

doc/decoders.texi

@@ -158,4 +158,45 @@ ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
 7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b}.
 @end table
 
+@section libzvbi-teletext
+
+Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
+subtitles. Requires the presence of the libzvbi headers and library during
+configuration. You need to explicitly configure the build with
+@code{--enable-libzvbi}.
+
+@subsection Options
+
+@table @option
+@item txt_page
+List of teletext page numbers to decode. You may use the special * string to
+match all pages. Pages that do not match the specified list are dropped.
+Default value is *.
+@item txt_chop_top
+Discards the top teletext line. Default value is 1.
+@item txt_format
+Specifies the format of the decoded subtitles. The teletext decoder is capable
+of decoding the teletext pages to bitmaps or to simple text, you should use
+"bitmap" for teletext pages, because certain graphics and colors cannot be
+expressed in simple text. You might use "text" for teletext based subtitles if
+your application can handle simple text based subtitles. Default value is
+bitmap.
+@item txt_left
+X offset of generated bitmaps, default is 0.
+@item txt_top
+Y offset of generated bitmaps, default is 0.
+@item txt_chop_spaces
+Chops leading and trailing spaces and removes empty lines from the generated
+text. This option is useful for teletext based subtitles where empty spaces may
+be present at the start or at the end of the lines or empty lines may be
+present between the subtitle lines because of double-sized teletext charactes.
+Default value is 1.
+@item txt_duration
+Sets the display duration of the decoded teletext pages or subtitles in
+miliseconds. Default value is 30000 which is 30 seconds.
+@item txt_transparent
+Force transparent background of the generated teletext bitmaps. Default value
+is 0 which means an opaque (black) background.
+@end table
+
 @c man end SUBTILES DECODERS

doc/general.texi

@@ -133,6 +133,20 @@ Go to @url{https://github.com/dekkers/libilbc} and follow the instructions for
 installing the library. Then pass @code{--enable-libilbc} to configure to
 enable it.
 
+@section libzvbi
+
+libzvbi is a VBI decoding library which can be used by FFmpeg to decode DVB
+teletext pages and DVB teletext subtitles.
+
+Go to @url{http://sourceforge.net/projects/zapping/} and follow the instructions for
+installing the library. Then pass @code{--enable-libzvbi} to configure to
+enable it.
+
+@float NOTE
+libzvbi is licensed under the GNU General Public License Version 2 or later
+(see @url{http://www.gnu.org/licenses/old-licenses/gpl-2.0.html} for details),
+you must upgrade FFmpeg's license to GPL in order to use it.
+@end float
 
 
 @chapter Supported File Formats, Codecs or Features
@@ -947,6 +961,7 @@ performance on systems without hardware floating point support).
 @item 3GPP Timed Text  @tab   @tab   @tab X @tab X
 @item AQTitle          @tab   @tab X @tab   @tab X
 @item DVB              @tab X @tab X @tab X @tab X
+@item DVB teletext     @tab   @tab X @tab   @tab E
 @item DVD              @tab X @tab X @tab X @tab X
 @item JACOsub          @tab X @tab X @tab   @tab X
 @item MicroDVD         @tab X @tab X @tab   @tab X
@@ -969,6 +984,8 @@ performance on systems without hardware floating point support).
 
 @code{X} means that the feature is supported.
 
+@code{E} means that support is provided through an external library.
+
 @section Network Protocols
 
 @multitable @columnfractions .4 .1

libavcodec/Makefile

@@ -727,6 +727,7 @@ OBJS-$(CONFIG_LIBWAVPACK_ENCODER)         += libwavpackenc.o
 OBJS-$(CONFIG_LIBX264_ENCODER)            += libx264.o
 OBJS-$(CONFIG_LIBXAVS_ENCODER)            += libxavs.o
 OBJS-$(CONFIG_LIBXVID_ENCODER)            += libxvid.o
+OBJS-$(CONFIG_LIBZVBI_TELETEXT_DECODER)   += libzvbi-teletextdec.o
 
 # parsers
 OBJS-$(CONFIG_AAC_PARSER)              += aac_parser.o aac_ac3_parser.o \

libavcodec/allcodecs.c

@@ -505,6 +505,7 @@ void avcodec_register_all(void)
     REGISTER_ENCODER(LIBX264RGB,        libx264rgb);
     REGISTER_ENCODER(LIBXAVS,           libxavs);
     REGISTER_ENCODER(LIBXVID,           libxvid);
+    REGISTER_DECODER(LIBZVBI_TELETEXT,  libzvbi_teletext);
     REGISTER_ENCODER(LIBAACPLUS,        libaacplus);
 
     /* text */

libavcodec/version.h

@@ -29,7 +29,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVCODEC_VERSION_MAJOR 55
-#define LIBAVCODEC_VERSION_MINOR  30
+#define LIBAVCODEC_VERSION_MINOR  31
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \