[MPlayer-advusers] mplayer fails to build on non-sse2 x86 cpu

[Ivan Kalvatchev]

--- On Thu, 9/6/12, Andrew Savchenko <bircoph at gmail.com> wrote:

> From: Andrew Savchenko <bircoph at gmail.com>
> Subject: [MPlayer-advusers] mplayer fails to build on non-sse2 x86 cpu
> To: mplayer-advusers at mplayerhq.hu
> Date: Thursday, September 6, 2012, 3:14 PM
> Hello,
> 
> mplayer-r35150 fails to link on non-sse2 x86 cpu
> (Athlon-XP):
> 
> ffmpeg/libavcodec/libavcodec.a(ac3dsp_init.o): In function
> `ff_ac3dsp_init_x86': ac3dsp_init.c:(.text.unlikely+0x6c):
> undefined
> reference to `ff_ac3_exponent_min_sse2'
> ac3dsp_init.c:(.text.unlikely
> +0x88): undefined reference to
> `ff_ac3_extract_exponents_sse2'
> collect2: ld returned 1 exit status
> 
> The same stand-alone version of ffmpeg (as fetched by
> configure
> script in mplayer) builds fine.
> 
> The problem is in different definition of 
> HAVE_${INSTRUCTION_SET}_EXTERNAL
> flags in ffmpeg and mplayer: ffmpeg defines them
> unconditionally
> (for a whole target architecture), while mplayer defines
> them
> conditionally — only in an appropriate instruction set is
> present in
> the target cpu.
> 
> For the issue I encountered libavcodec/x86/ac3dsp.asm
> contains:
> %if HAVE_SSE2_EXTERNAL
> INIT_XMM
> AC3_EXPONENT_MIN sse2
> %endif
> 
> This code is compiled by ffmpeg, used during linking, but
> not during
> runtime, because of the following check in ac3dsp_init.c:
> if (mm_flags & AV_CPU_FLAG_SSE2 && HAVE_SSE)
> 
> As a solution mplayer should mimic ffmpeg's behaviour for
> defining
> HAVE_*_EXTERNAL cpu flags.

Is this still an issue?

The current ffmpeg git have explicit checks for the HAVE_SSE2_EXTERNAL, through the EXTERNAL_SSE2() macro.