[FFmpeg-devel] [PATCH] Use av_clip_uint8 in swscale.

Måns Rullgård mans
Tue Aug 18 03:34:18 CEST 2009


Jason Garrett-Glaser <darkshikari at gmail.com> writes:

> 2009/8/17 M?ns Rullg?rd <mans at mansr.com>:
>> Jason Garrett-Glaser <darkshikari at gmail.com> writes:
>>
>>> 2009/8/17 M?ns Rullg?rd <mans at mansr.com>:
>>>> Jason Garrett-Glaser <darkshikari at gmail.com> writes:
>>>>
>>>>>> But not on x86-64 or most other modern CPUs.
>>>>>
>>>>> Yes you can. ?It's only prohibited in shared libraries.
>>>>
>>>> Assuming you can arrange for the address to fit in 32 bits, yes.
>>>> There are no 64-bit immediate address operands IIRC.
>>>
>>> Which is generally not a problem, since the ffmpeg binary still fits
>>> in 4 gigabytes ;)
>>
>> Fitting in 4G doesn't guarantee it will be loaded at a virtual address
>> lower than 4G.
>
> Hence the reason it doesn't work in shared libraries, but does work in
> static libraries.
>
> Claiming that it doesn't work *period* is rather silly, given that
> both ffmpeg and x264 make widespread usage of exactly what you're
> saying doesn't work.

I didn't say it never works, only that it doesn't *always* work.  You
have to be careful to make it work.

-- 
M?ns Rullg?rd
mans at mansr.com



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