Re: pkg/35864: 2006Q4 multimedia/ffmpeg with MMX does not build on 4.99.9

["Matthew Mondor" <mm_lists%pulsar-zone.net@localhost>]

The following reply was made to PR pkg/35864; it has been noted by GNATS.

From: "Matthew Mondor" <mm_lists%pulsar-zone.net@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: pkg/35864: 2006Q4 multimedia/ffmpeg with MMX does not build on 
4.99.9
Date: Sat, 23 Feb 2008 13:16:37 -0500 (EST)

 I thought about checking out the latest source from their repository,
 test it and if all goes well, archive the source and date it, to
 possibly have it eventually hosted in netbsd distfiles.
 
 It did build fine using MMX support on NetBSD 4.0_STABLE/i386 and
 i686 optimizations.  However, ffplay then displays a warning about
 stack memory not being properly aligned and to upgrade to GCC >4.2.  I
 nevertheless give it a test with an application I wrote, and MJPEG
 generation was extremely low quality.  I don't intend to personally
 try with a more recent GCC, I exclusively use the toolchain provided
 with NetBSD.
 
 Building the same ffmpeg code without MMX optimizations solved the
 problem.  So although it does build fine, we can't really say that MMX
 support is functional.  Since I built mplayer and mencoder with MMX
 support, I'm not sure what could be different because I did not
 observe such problems with it.
 
 My guess is that this is a bug/feature of ffmpeg source more recent
 than that was used to statically include into the mplayer source. 
 Diffing the libavcodec directories of each did show some differences
 but I didn't investigate further.
 
 Since ffmpeg MJPEG image generation is still quite faster than
 libjpeg's despite no MMX optimizations, using either the old ffmpeg we
 have in pkgsrc or the new ffmpeg source with MMX optimizations
 disabled still solves my problem for now.
 -- 
 Matthew Mondor