Re: [libdv-dev] Re: libdv for AMD64

[Roman S. <rv...@su...>]

On Wed, Oct 13, 2004 at 07:03:35AM -0400, Dan Dennedy wrote:
> Thank you. I downloaded it, and will work on making sure it merges
> nicely into my CVS working copy and test. Then, hopefully we get some
> others to test.

 ffmpeg has got and AMD64 boost recently as well, so it'll be interesting to
 compare results w.r.t. speed of decoding/encoding.

Thanks,
Roman.
 
> On Tue, 2004-10-12 at 00:32 -0700, Dean Kolosiek wrote:
> > Hello,
> > 
> > I ported the assembly language of libdv-0.103 to AMD64. I left a copy of it 
> > at http://www.users.qwest.net/~kdean6/libdv-0.103-AMD64.tar.gz if you want 
> > it. There's no web page for it, just that file, so go directly to it.
> > 
> > I also found a bug with multi-threading when I ran 
> > enctest.  _dv_prepare_reorder_tables gets called by each thread during 
> > initialization, but it's not written to run multiple times. I got 
> > segmentation faults at random times because the time slicing was random, 
> > but many times it worked fine. I did not try to fix it.
> > 
> > I created a definition ARCH_X86_64 that parallels ARCH_X86 nearly 
> > everywhere. I added x86_64 to make new routine names and new .S file names.
> > 
> > Most of the changes were due to pointers changing to 64 bits, and the ABI 
> > changing for AMD64. I used documents at http://www.x86-64.org/ for the ABI 
> > and they have a translation hints page. There were some cases where there 
> > is no equivalent 64 bit instruction to handle 8 bit data, or the ABI calls 
> > for passing parameters in a register that was being used, so it takes a few 
> > more instructions in a few places. Another big change is that relocatable 
> > libraries use a different relocation mechanism on AMD64, so (%rip) is added 
> > to many instructions to generate PC-relative addresses.
> > 
> > I did not bother translating the use_mmx parts because it is my 
> > understanding that AMD64 chips will always have mmx functionality. This 
> > should be double-checked, and it may not be true for Intel chips.
> > 
> > I made no attempt to rewrite anything to make use of  AMD64 features like 
> > 64 bit registers.
> > 
> > It needs more testing before distribution. I've only tested it with enctest 
> > and playdv, and in kino (linking the new code) I played one .avi file made 
> > by grabdv. playdv plays the pond.dv example. I'm not really a video person, 
> > so I don't know how to come up with tests for it. I'm running it on a 
> > Fedora Core 2 x86-64 Opteron system.
> > 
> > Dean Kolosiek
> > 
> 
> 
> 
> -------------------------------------------------------
> This SF.net email is sponsored by: IT Product Guide on ITManagersJournal
> Use IT products in your business? Tell us what you think of them. Give us
> Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more
> http://productguide.itmanagersjournal.com/guidepromo.tmpl
> _______________________________________________
> libdv-dev mailing list
> lib...@li...
> https://lists.sourceforge.net/lists/listinfo/libdv-dev