Expressions like array[get_vlc2()] can be optimized by using a symbols
table if the array is always the same for a given VLC. This requirement
is fulfilled for the VLC used for VP3 motion vectors. The reason it
hasn't been done before is probably that the array in this case
contained entries in the range -31..31; but this is no problem with
ff_init_vlc_from_lengths(): Just apply an offset of 31 to the symbols
before storing them in the table used to initialize VP3 motion vectors
and apply an offset of -31 when initializing the actual VLC.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This is possible by switching to ff_init_vlc_from_lengths() because it
allows to replace codes of type uint16_t by symbols of type uint8_t; in
some cases (like here) it also allows to replace explicitly coded
codes by implicitly coded symbols.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
By switching to ff_init_vlc_from_lengths() one can apply both positive
as well as negative offsets for free; in this case it even saves space
because one replaces codes tables that don't fit into an uint8_t by
symbols tables that fit into an uint8_t or can even be completely
avoided as they are trivial.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Some of the VP3 arrays (namely vp31_intra_y_dequant, vp31_intra_c_dequant
and vp31_inter_dequant) are currently declared as array of (const) int8_t
despite them being only used to directly initialize an array of uint8_t.
vp31_inter_dequant even contains the value 128 which is not
representible in int8_t and might generate overflow warnings by
compilers.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Reviewed-by: Peter Ross <pross@xvid.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.' to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".
Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk
certain source code identifiers in line with official VP3 spec (well,
*my* VP3 spec, anyway)
Originally committed as revision 2856 to svn://svn.ffmpeg.org/ffmpeg/trunk
