[Slackbuilds-users] Meaning of PKGARCH=$(uname -m)_custom in ffmpeg.SlackBuild

Andrzej Telszewski atelszewski at gmail.com
Sat May 21 16:52:46 UTC 2016

On 21/05/16 17:30, Erik Hanson wrote:
> On Sat, 21 May 2016 17:04:46 +0200
> Andrzej Telszewski <atelszewski at gmail.com> wrote:
>> On 21/05/16 16:53, Erik Hanson wrote:
>>> On Sat, 21 May 2016 12:18:53 +0200
>>> Andrzej Telszewski <atelszewski at gmail.com> wrote:
>>>> Hi,
>>>> ffmpeg.SlackBuild sets the package arch to $(uname -m)_custom
>>>> Why is that?
>>>> This is somehow in reference to my previous question:
>>>> https://lists.slackbuilds.org/pipermail/slackbuilds-users/2016-March/015772.html
>>>> So, can the ffmpeg package built on one machine be safely used on
>>>> another machine?
>>> The result is a non-portable package. It's optimized for the CPU
>>> it's been compiled with. If you're working in an environment that
>>> consists of modern hardware, it's probably not too relevant.
>>> Consider it a warning that using a newer/faster machine to build
>>> the package and then installing it on an older/slower machine might
>>> mean the binary won't run as expected.
>> Thanks. I haven't researched the topic yet and I'm just going to ask
>> here, but feel free not to answer, since the question probably does
>> not belong here:
>> Is it possible to have ffmpeg being built as any other Slackware
>> package is?
> I believe so, I seem to remember something (it's been a while, memory
> is fuzzy) but you either pass a single parameter, like
> "--no-optimizations" or several, such as "--no-sse --nosse2
> --no-mmx" ... etc. These flags are examples, you'd need to research,
> look at the output of 'configure --help' and determine how to do it.
> Knowing the destination hardware, you could tune it. I will say, it
> seems obvious that just gutting all the optimizations would give you
> an ffmpeg binary that's pointlessly slow. I doubt anyone wants this.

Thanks. Based on what you say, it's just gonna be easier to build on the 
target machine.

Best regards,
Andrzej Telszewski

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