[FFmpeg-devel] [PATCH] Add dvdsub workaround for some players

Oliver Fromme oliver at fromme.com
Thu Jul 10 19:41:08 CEST 2014

Michael Niedermayer wrote:
 > On Wed, Jul 09, 2014 at 10:58:55PM +0200, Oliver Fromme wrote:
 > > Michael Niedermayer wrote:
 > > > [...]
 > > > can you also post one that adds "even_rows_fix" to the docs ?
 > > 
 > > Yes, but I'm not sure where exactly.  So far, the ffmpeg
 > > man page doesn't have a section about subtitle encoders
 > > at all, it only has one for decoders.
 > > 
 > > Should I add such a section and a short description of the
 > > dvdsub encoder?  Then I can put the text for "even_rows_fix"
 > > there.
 > probably, yes

Ok, I have done that.  This patch adds a "subtitles encoders"
chapter to the bottom of encoders.texi.

Best regards

--- a/doc/encoders.texi	2014-06-15 19:20:05.000000000 +0200
+++ b/doc/encoders.texi	2014-07-10 19:30:16.000000000 +0200
@@ -2147,3 +2147,27 @@
 recommended value) and do not set a size constraint.
 @c man end VIDEO ENCODERS
+ at chapter Subtitles Encoders
+ at c man begin SUBTITLES ENCODERS
+ at section dvdsub
+This codec encodes the bitmap subtitle format that is used in DVDs.
+Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
+and they can also be used in Matroska files.
+ at subsection Options
+ at table @option
+ at item even_rows_fix
+When set to 1, enable a work-around that makes the number of pixel rows
+even in all subtitles.  This fixes a problem with some players that
+cut off the bottom row if the number is odd.  The work-around just adds
+a fully transparent row if needed.  The overhead is low, typically
+one byte per subtitle on average.
+By default, this work-around is disabled.
+ at end table

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