[x265] How does x265 handle the memory allocation?

[Mario *LigH* Rohkrämer]

Am 04.08.2015, 18:00 Uhr, schrieb Steve Borho <steve at borho.org>:

> On 08/04, fangzhen wrote:
>> Hi all, I am a video encoder developer. And X265 is a fantastic
>> implementation of HEVC. I am studying it right now.  During this
>> process, I find a very interesting situation.  I use some large
>> resolution sequences to test x265, such as 2560x1600. If the memory is
>> sufficient, x265 will get about 1GB memory. Howerver, if more programs
>> are running and the left memory is less than 1GB, x265 will still run
>> normally and use the left memory. Here is the question, in my opinion,
>> if the memory is not enough, some program will crash, so how x265 do
>> that? How x265 handle the memory allocation adaptively?
>
> We're not doing anything special about allocating memory, my guess is
> that the O/S is simply paging away your other applications to make room
> for x265

 From my experience on 64-bit Windows 7, x265 can allocate about 12 (in  
words: twelve) GB of *virtual* memory to compress 8K UHD video. That  
means, if your system does not have as much *physical* RAM installed, the  
operating system will probably keep exchanging data between RAM and swap  
file on the harddisk. The result is an incredibly low encoding speed.

-- 

Fun and success!
Mario *LigH* Rohkrämer
mailto:contact at ligh.de