[x265] x265 on Linux , yuv input , "Floating point exception"

[Steve Borho]

On Wed, Jul 24, 2013 at 9:44 PM, 王康 <scateu at gmail.com> wrote:

> Hi ,
>
>    I just checkout the latest code version from bitbucket, and compile
> yasm-1.2.0, and make. It seems all right so far on both x86 and x64 Debian
> Linux.
>
> $ uname -a
> Linux 3.2.0-4-686-pae #1 SMP Debian 3.2.35-2 i686 GNU/Linux
>
> $ uname -a
> Linux 3.2.0-2-amd64 #1 SMP Mon Jun 11 17:24:18 UTC 2012 x86_64 GNU/Linux
>
> $ gcc -v
> gcc version 4.7.2 (Debian 4.7.2-4)
>
> $ yasm --version
> yasm 1.2.0
> Compiled on Jul 24 2013.
> Copyright (c) 2001-2011 Peter Johnson and other Yasm developers.
> Run yasm --license for licensing overview and summary.
>
>
> $ x265 -V
> x265 [info]: HEVC encoder version 0.3+24-fd4954d7c2ac
> x265 [info]: build info [Linux][GCC 4.7.2][32 bit] 8bpp
> x265 [info]: detected SIMD architectures SSE2 SSE3 SSSE3
> x265 [info]: performance primitives: intrinsic assembly
>
>    Then I generate yuv and y4m file using ffmpeg:
>
>  $ ffmpeg -i charlie.mp4 charlie.yuv
>  $ ffmpeg -i charlie.mp4 charlie.y4m
>
>    And x265 on yuv file :
>  $ x265 charlie.yuv -o charlie.hevc
>  Floating point exception
>


I'm surprised this tried to do anything.  When you use a YUV input file you
need to provide input height width and rate.  it must have crashed trying
to use zero dimensions somewhere.  This can be fixed easily.



>    x265 on y4m file, the size of output file is zero.
>
> $ x265 charlie.y4m -o charlie.hevc
> y4m  [info]: 1280x720 23Hz, frames 0 - 2397 of 2398
> x265 [info]: detected SIMD architectures SSE2 SSE3 SSSE3
> x265 [info]: performance primitives: intrinsic assembly
> x265 [info]: Main profile, Level-3.1 (Main tier)
> x265 [info]: Parallelism disabled, single thread mode
> x265 [info]: CU size                      : 64
> x265 [info]: Max RQT depth inter / intra  : 3 / 3
> x265 [info]: ME method / range / maxmerge : star / 64 / 5
> x265 [info]: Keyframe Interval            : 24
> x265 [info]: QP                           : 32
> x265 [info]: enabled coding tools: rect rdo rdoq sign-hide tskip
> tskip-fast rdoqts
> Illegal instruction 0.00 kb/s
>

But this is not cool.  Can you build with debug and get a traceback for
this?  I have a suspicion that GCC is using some SSE4 instructions in the
SSE3 files.

On your x64 Debian system, the CPU supports SSE4 so it's not a problem.

-- 
Steve Borho
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