[FFmpeg-devel] dvdsub encoder: respect palette when it makes sense
Mon Mar 2 10:32:07 CET 2009
Le duodi 12 vent?se, an CCXVII, Michael Niedermayer a ?crit?:
> dvdsubdec seems to support 8bit
I found some information here:
# 4 colors out of 16 color palette (4 colors are determined once per PGC).
# 4 out of 16 contrast values
In practice, that means:
- there is a 16-colors palette in the DVD title's IFO file or the VOBSUB idx
- each subpicture packet is a 4-color pixmap;
- each subpicture packet has two fields that give, for the four color cells,
the alpha value and the palette entry number (lines 164-167 of the current
The 8bit stuff is for HD-DVD subtitles, added by revision 9788. The encoder
does not support HD-DVD subtitles.
> also in the other mail you spoke about makin them playabe in mplayer, this
> actually is of almost no relevance, it rather matters if they ae playable
> on hardware dvd players / if they are compliant tto he specs
You are perfectly right in principle, and I did not express myself
correctly. I can make a VOBSUB file that mplayer can play with either the
current version of my patched version; supposedly, other compliant players
would play it too.
But the colors (or, in mplayer case, the gray levels) are randomly permuted.
This is both what I can see in mplayer and what I understand in the source
The purpose of my patch was to stop the random permutation of colors. I now
see a better way to do it, and will shortly submit a patch implementing it.
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