[Libav-user] Building with MSVC toolchain resulting in seeking problem?

John Orr john.orr at scala.com
Fri Mar 22 21:44:04 CET 2013

On 3/22/2013 4:26 AM, Bjoern Drabeck wrote:
> So do these changes make sense? What can I improve? Anyone willing to 
> try it (maybe John?)

I tried this change against the 1.2 release, adding these to my typical 
configuration command line:


Note that I had to replace an option I had been using in my typical 
configuration command line, --optflags= -arch:SSE2', and use this 
instead: --extra-cflags='-arch:SSE2'.  --optflags overrides any 
optimization flags implied by --enable-small (or --enable-speed).

With that change, I can compile, run and debug the resulting DLLs.

There is a flag defined in the ffmpeg configuraton file, 
"omit-frame-pointer".  In VC10, that option is -Oy (frame pointer 
omission).  For optimized builds (-O1 and -O2), -Oy is implied 
(According to the VC10 docs at 
http://msdn.microsoft.com/en-us/library/2kxx5t2c%28v=vs.100%29.aspx). It 
seems the state of omit-frame-pointer may be out of sync with the flags 
you set for non-debug builds.

The use of the -Oy- option turns off the "frame pointer omission" 
feature, which you pretty much need if you want visual studio to build a 
stack backtrace.


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