[FFmpeg-devel] todays swscale changes

Michael Niedermayer michaelni at gmx.at
Fri May 27 03:30:58 CEST 2011


Hi

I was unable to merge the swscale changes of todays libav as they
simply dont work and just segfault.
They have obviously neither been reviewed nor tested as the errors
are very obvious

        MOVNTQ(%%mm3, (%1, %%REGa))\
        "add                                 $8, %3         \n\t"\
        "cmp                                 %2, %3         \n\t"\
        "movq             "VROUNDER_OFFSET"(%0), %%mm3      \n\t"\
        "movq                             %%mm3, %%mm4      \n\t"\
        "lea                     " offset "(%0), %%"REG_d"  \n\t"\
        "mov                        (%%"REG_d"), %%"REG_S"  \n\t"\
        "jb                                  1b             \n\t"\
        :: "r" (&c->redDither),\
           "r" (dest), "g" ((x86_reg)(end)), "r"((x86_reg)(pos))\
        : "%"REG_d, "%"REG_S\

This uses REGa, but its not onn the clobber list, on the input nor on
the output
it writes into %3 while this is a input


another:
        MOVNTQ(%%mm4, (%1, %%REGa))\
        "add                                 $8, %3         \n\t"\
        "cmp                                 %2, %3         \n\t"\
        "lea                     " offset "(%0), %%"REG_d"  \n\t"\
        "pxor                             %%mm4, %%mm4      \n\t"\
        "pxor                             %%mm5, %%mm5      \n\t"\
        "pxor                             %%mm6, %%mm6      \n\t"\
        "pxor                             %%mm7, %%mm7      \n\t"\
        "mov                        (%%"REG_d"), %%"REG_S"  \n\t"\
        "jb                                  1b             \n\t"\
        :: "r" (&c->redDither),\
        "r" (dest), "g" ((x86_reg)(end)), "r"((x86_reg)(pos))\
        : "%"REG_a, "%"REG_d, "%"REG_S\

ive not checked further

ronald please fix this, thank you.

also i _strongly_ suggest
1. That developers post patches to ffmpeg-dev instead of libav-dev
   when the authors or maintainers of that code follow ffmpeg-dev but
   not libav-dev
2. That authors are given a chance to review patches to their code
3. That the bans and blocks of libav lists are removed
4. That people base their work on ffmpeg git and not libav. Fewer
   bugs make debuging new ones easier. (for example the merged libav+
   ffmpeg+bugfixes yesterday works but yesterdays libav segfaulted
   when i tried to use bisect to debug above)

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I have often repented speaking, but never of holding my tongue.
-- Xenocrates
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