add support for OpenBSD in ffmpeg

add support for OpenBSD in ffmpeg

add openbsd config files

ffmpeg.gyp:
  - use openbs config files
  - disable -fno-signed-zeros because our gcc does not support it.

BUG=
TEST=

Patch by Robert Nagy <robert.nagy@gmail.com>;
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=106959

[Mark Mentovai, 2011-10-13 19:11:50]

Is there anything interesting about how you generated these files that would
make sense to add to README.chromium?

[ilja, 2011-10-14 03:35:05]

Adding Andrew.

Along Mark's lines of thought. IMHO either "openbsd" files are a 1:1 copy of
some other config files (presumably Linux). In this case we don't need to check
them in and you could just change ffmpeg.gyp to share them. Or there is a
distinct need for openbsd configuration/directory. That would complicate things
as it would require
a) changes in build_ffmpeg.sh
b) a machine to run build_ffmpeg.sh on to get proper configuration (plus
buildbot machines)

My take is if you can limit your changes to ffmpeg.gyp then it might fly. But if
you need new config files they will probably rot over time as I don't know of
available infrastructure to support and test it.

[scherkus (not reviewing), 2011-10-14 04:03:46]

I agree -- if there's nothing special about the openbsd.h config files then we
should either:
  a) change ffmpeg.gyp to swap to use linux OSes
  b) check in openbsd configs that simply include linux configs

[Robert Nagy, 2011-10-14 07:42:27]

On 2011/10/14 04:03:46, scherkus wrote:
> I agree -- if there's nothing special about the openbsd.h config files then we
> should either:
>   a) change ffmpeg.gyp to swap to use linux OSes
>   b) check in openbsd configs that simply include linux configs

SSE3 is disabled in the headers since it's not supported.

[ilja, 2011-10-14 18:52:12]

On 2011/10/14 07:42:27, Robert Nagy wrote:
> SSE3 is disabled in the headers since it's not supported.

How about then you take a look at the ffmpeg/source/munge_config*.sh scripts. If
you hook disabling SSE3 into either ffmpeg/build_ffmpeg.sh or
ffmpeg/copy_config.sh so that the openbsd files are automatically updated from
Linux each time the Linux configs are generated you should be good.

[Robert Nagy, 2011-10-19 10:17:16]

On 2011/10/14 18:52:12, ilja wrote:
> On 2011/10/14 07:42:27, Robert Nagy wrote:
> > SSE3 is disabled in the headers since it's not supported.
> 
> How about then you take a look at the ffmpeg/source/munge_config*.sh scripts.
If
> you hook disabling SSE3 into either ffmpeg/build_ffmpeg.sh or
> ffmpeg/copy_config.sh so that the openbsd files are automatically updated from
> Linux each time the Linux configs are generated you should be good.
Even if that is going to be used, someone has to generate the files on OpenBSD,
and if that is being done sse3 will not be enabled.

[ilja, 2011-10-19 18:50:58]

On 2011/10/19 10:17:16, Robert Nagy wrote:
> Even if that is going to be used, someone has to generate the files on
OpenBSD,
> and if that is being done sse3 will not be enabled.

Please let me explain myself. We don't have OpenBSD machines to generate the
files. The next time ffmpeg gets updated the OpenBSD build *will* break. How
should this be resolved long term?

[Robert Nagy, 2011-10-19 18:52:55]

On 2011/10/19 18:50:58, ilja wrote:
> On 2011/10/19 10:17:16, Robert Nagy wrote:
> > Even if that is going to be used, someone has to generate the files on
> OpenBSD,
> > and if that is being done sse3 will not be enabled.
> 
> Please let me explain myself. We don't have OpenBSD machines to generate the
> files. The next time ffmpeg gets updated the OpenBSD build *will* break. How
> should this be resolved long term?

Well I am prepared to take maintainership for this and whenever it gets updated
I can always provide a patch if needed.

[ilja, 2011-10-19 18:58:34]

On 2011/10/19 18:52:55, Robert Nagy wrote:
> Well I am prepared to take maintainership for this and whenever it gets
updated
> I can always provide a patch if needed.

Then it is fine with me. But the final call should be made by Andrew or somebody
else in the video team.

[Robert Nagy, 2011-10-19 19:10:19]

On 2011/10/19 18:58:34, ilja wrote:
> On 2011/10/19 18:52:55, Robert Nagy wrote:
> > Well I am prepared to take maintainership for this and whenever it gets
> updated
> > I can always provide a patch if needed.
> 
> Then it is fine with me. But the final call should be made by Andrew or
somebody
> else in the video team.

Can you please add him as a reviewer?

[ilja, 2011-10-19 19:19:09]

On 2011/10/19 19:10:19, Robert Nagy wrote:
> Can you please add him as a reviewer?

Sorry, he is already there. Andrew = scherkus.

[Robert Nagy, 2011-10-20 22:02:15]

On 2011/10/19 19:19:09, ilja wrote:
> On 2011/10/19 19:10:19, Robert Nagy wrote:
> > Can you please add him as a reviewer?
> 
> Sorry, he is already there. Andrew = scherkus.

Thanks! Andrew can you review please?

[scherkus (not reviewing), 2011-10-24 17:51:54]

Did you generate these config files using build_ffmpeg.sh? For example there are
no Chrome config files, which means that (theoretically) someone attempting to
build a version of Chrome on OpenBSD will hit a compile failure

[Robert Nagy, 2011-10-24 18:09:53]

On 2011/10/24 17:51:54, scherkus wrote:
> Did you generate these config files using build_ffmpeg.sh? For example there
are
> no Chrome config files, which means that (theoretically) someone attempting to
> build a version of Chrome on OpenBSD will hit a compile failure

No I did not use that script, I never heard of it, but looking at the first
google hit (if that's the correct one) shows me that that script is so linux
specific that it won't work for me.

What I've done is that I've copied the linux files and hand edited the headers
to reflect reality on OpenBSD by comparing the headers from our ffmpeg port
which runs the configure script with all the OpenBSD specific stuff.

I did not add any Chrome headers because I would never expect that someone will
actually try to do that, but if you think it's possible, then we should add
those files too.

[scherkus (not reviewing), 2011-10-24 18:13:16]

cool -- just double checking :)

LGTM

[Mark Mentovai, 2011-10-24 19:56:57]

Committed r106959, but this will need a DEPS roll in Chromium to be picked up
there. DEPS is currently at r106016 but another change landed at r106599 and
DEPS has not yet been updated.