[XviD-devel] Memory leak and access violations

[Christoph Lampert]

Hi,

maybe it's time that we fix the many illegal memory accesses which
we constantly ignored for a long time:

First routines are definitely  interpolate8x8_halfpel_hv and halpel_v
in  /src/image/interpolate8x8.c

which accesses (at least) one image row too much in the end _and_
in the beginning. 

Also, we have lots of memory access to uninitialized memory with
image_mad, that disappear if image memory is zeroes after xvid_alloc.
So it seems that MAD is done for undefined memory (first frame?) 
This is ugly, too.

Other routine sometimes have problems, too. E.g. there is a message for
get_inter_block():

==1998== Use of uninitialised value of size 4
==1998==    at 0x8050C52: get_inter_block
(../../src/bitstream/vlc_codes.h:1284)
==1998==
==1998== Use of uninitialised value of size 4
==1998==    at 0x8050C5E: get_inter_block
(../../src/bitstream/vlc_codes.h:1289)
==1998==
==1998== Use of uninitialised value of size 4
==1998==    at 0x8050C89: get_inter_block
(../../src/bitstream/vlc_codes.h:1291)
==1998==
==1998== Use of uninitialised value of size 4
==1998==    at 0x8050CA8: get_inter_block
(../../src/bitstream/vlc_codes.h:1293)

(This logfile was done with "valgrind":
http://sourceforge.net/projects/valgrind/ )

Could someone please have a look what possibly goes wrong there?

gruel

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