doc: modify style for texi2html 1.78+

The generated HTML files are similar to the ones generated with
texi2html 1.56k used on the website.

Tested with texi2html 1.78 and 5.0. 1.78 is the minimal recommended
version.

The removed @sp from the titlepage section were ignored until
texi2html 5.0. If not removed the pages generated by 5.0 will have ugly
empty space around the title.

10 files changed, 54 insertions, 18 deletions

diff --git a/Makefile b/Makefile
index c5e74f062c..2658a30dc5 100644
--- a/Makefile
+++ b/Makefile
@@ -123,8 +123,8 @@ doc/ffprobe.pod doc/ffprobe.html: doc/demuxers.texi doc/indevs.texi doc/protocol
 doc/libavfilter.html: doc/filters.texi
 
 doc/%.html: TAG = HTML
-doc/%.html: doc/%.texi
-	$(M)cd doc && texi2html -monolithic -number $(<:doc/%=%)
+doc/%.html: doc/%.texi $(SRC_PATH_BARE)/doc/t2h.init
+	$(M)cd doc && texi2html -monolithic --init-file $(SRC_PATH_BARE)/doc/t2h.init $(<:doc/%=%)
 
 doc/%.pod: TAG = POD
 doc/%.pod: doc/%.texi
diff --git a/doc/developer.texi b/doc/developer.texi
index 89bc3392e4..b9e246f214 100644
--- a/doc/developer.texi
+++ b/doc/developer.texi
@@ -2,11 +2,12 @@
 
 @settitle Developer Documentation
 @titlepage
-@sp 7
 @center @titlefont{Developer Documentation}
-@sp 3
 @end titlepage
 
+@top
+
+@contents
 
 @chapter Developers Guide
 
diff --git a/doc/faq.texi b/doc/faq.texi
index c03a2e1efe..100adff312 100644
--- a/doc/faq.texi
+++ b/doc/faq.texi
@@ -2,11 +2,12 @@
 
 @settitle FFmpeg FAQ
 @titlepage
-@sp 7
 @center @titlefont{FFmpeg FAQ}
-@sp 3
 @end titlepage
 
+@top
+
+@contents
 
 @chapter General Questions
 
diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index 98f2031f75..047444ab62 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -2,11 +2,13 @@
 
 @settitle FFmpeg Documentation
 @titlepage
-@sp 7
 @center @titlefont{FFmpeg Documentation}
-@sp 3
 @end titlepage
 
+@top
+
+@contents
+
 @chapter Synopsis
 
 The generic syntax is:
diff --git a/doc/ffplay.texi b/doc/ffplay.texi
index c03905c3e0..e0518b859e 100644
--- a/doc/ffplay.texi
+++ b/doc/ffplay.texi
@@ -2,11 +2,13 @@
 
 @settitle FFplay Documentation
 @titlepage
-@sp 7
 @center @titlefont{FFplay Documentation}
-@sp 3
 @end titlepage
 
+@top
+
+@contents
+
 @chapter Synopsis
 
 @example
diff --git a/doc/ffprobe.texi b/doc/ffprobe.texi
index bc96bd561e..de65eee664 100644
--- a/doc/ffprobe.texi
+++ b/doc/ffprobe.texi
@@ -2,11 +2,13 @@
 
 @settitle FFprobe Documentation
 @titlepage
-@sp 7
 @center @titlefont{FFprobe Documentation}
-@sp 3
 @end titlepage
 
+@top
+
+@contents
+
 @chapter Synopsis
 
 The generic syntax is:
diff --git a/doc/ffserver.texi b/doc/ffserver.texi
index 77deb85317..0cab3c8a98 100644
--- a/doc/ffserver.texi
+++ b/doc/ffserver.texi
@@ -2,11 +2,13 @@
 
 @settitle FFserver Documentation
 @titlepage
-@sp 7
 @center @titlefont{FFserver Documentation}
-@sp 3
 @end titlepage
 
+@top
+
+@contents
+
 @chapter Synopsys
 
 The generic syntax is:
diff --git a/doc/general.texi b/doc/general.texi
index c1fecef580..950159f1b3 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -2,11 +2,12 @@
 
 @settitle General Documentation
 @titlepage
-@sp 7
 @center @titlefont{General Documentation}
-@sp 3
 @end titlepage
 
+@top
+
+@contents
 
 @chapter external libraries
 
diff --git a/doc/libavfilter.texi b/doc/libavfilter.texi
index 8745928d40..f0b448259a 100644
--- a/doc/libavfilter.texi
+++ b/doc/libavfilter.texi
@@ -2,11 +2,12 @@
 
 @settitle Libavfilter Documentation
 @titlepage
-@sp 7
 @center @titlefont{Libavfilter Documentation}
-@sp 3
 @end titlepage
 
+@top
+
+@contents
 
 @chapter Introduction
 
diff --git a/doc/t2h.init b/doc/t2h.init
new file mode 100644
index 0000000000..cd38a3ec9e
--- /dev/null
+++ b/doc/t2h.init
@@ -0,0 +1,24 @@
+# no horiz rules between sections
+$end_section = \&FFMPEG_end_section;
+sub FFMPEG_end_section($$)
+{
+}
+
+$print_page_foot = \&FFMPEG_print_page_foot;
+sub FFMPEG_print_page_foot($$)
+{
+    my $fh = shift;
+    print $fh "$SMALL_RULE\n";
+    T2H_DEFAULT_print_page_foot($fh);
+}
+
+# no navigation elements
+$SECTION_NAVIGATION = 0;
+# the same for texi2html 5.0
+$HEADERS = 0;
+
+# TOC and Chapter headings link
+$TOC_LINKS = 1;
+
+# print the TOC where @contents is used
+$INLINE_CONTENTS = 1;