[FFmpeg-devel] DVD subtitles

Erik Slagter erik
Wed Feb 27 13:35:05 CET 2008

Hi, it's me again ;-)

As the AVFilter framework got merged recently, it looks to me a perfect 
basis for a hardsub filter, it looks like there doesn't exist something 
like that yet(?). Although I am ehrm... not too enthusiastic about 
hardcoding subtitles in video, encoding to mp4 with subtitles and 
playing on non-mplayer "equipment" seems to leave me no choice :-/

Anyway for this to work I'd reckon all (DVD) subtitles need to be 
detected correctly. At this moment it doesn't. In the past I had a 
workaround, forcing the probe routines to dive further into the file 
than it normally does, but it seems that this knob (#define) is no 
longer used.

So, my question: is there a (known) method/workaround to have 
ffmpeg/libav* detect all DVD subtitles in a vob? Or is this simply a 

I already tried this:

Index: libavformat/utils.c
--- libavformat/utils.c (revision 12216)
+++ libavformat/utils.c (working copy)
@@ -1792,7 +1792,7 @@

  /* absolute maximum size we read until we abort */
-#define MAX_READ_SIZE        5000000
+#define MAX_READ_SIZE        50000000

  #define MAX_STD_TIMEBASES (60*12+5)
  static int get_std_framerate(int i){

But it doesn't help.


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