[x264-devel] Question armv7e-m

[Janne Grunau]

Hi,

On 2015-09-26 05:43:36 +0000, sarah at hederstierna.com wrote:
> 
> Have anyone looked into optimizing x264 for armv7e-m like Cortex 
> M4/M7?

you probably want to look at this thread: 
http://thread.gmane.org/gmane.comp.video.x264.devel/10273

> I believe these processors have some SIMD capabilities called DSC, but 
> not as powerful as NEON.

I think it has some instructions which are more powerful than NEON.  The 
problem is they operate only on 32-bit registers.

> Would it be feasible to possibly speed-up stuff adding an armv7e-m asm 
> port?

Probably although I would be surprised over speedup larger than 2 for 
individual functions unless the compiler generates stupid code which is 
not that unlikely.

> I'm trying to estimate to probable FPS and memory requirements on an 
> Cortex M4/M7 for encoding VGA at low bitrate.

I wouldn't expect realtime encoding with 25fps at VGA resolution.

> If required we might be able to contribute some on such a port if its 
> likely to be done.

I don't think anyone is working on it so you would meed to write it 
yourself.

Janne