Thanks for the in depth response Tom. I appreciate that implementing zones might complicate further rate control changes demanded by your customers. Still I think theres many people (myself included) who would find support useful today.
Happy holidays! Adam > On 23 Dec 2014, at 20:50, Tom Vaughan <[email protected]> > wrote: > > Fair question. For everyone's benefit, especially Adam Marcus who > contributed the patch, I should explain what's going on in this section of > the code. > > Of course there is some "cost" to every new feature (in complexity and the > need to maintain it). x265's rate control is significantly more complex > than x264, due to WPP and frame parallelism. At any given point in time > there may be 5 or 6 frames in varying stages of completion, and typically > you don't want to change the base QP mid-frame. We've also added new > features we've added to handle special cases that arise due to frame > parallelism (ABR reset, etc.). We're also developing a new CBR variant of > ABR with VBV. It is challenging to deliver rock solid rate control under > all possible scenarios, and when rate control can't handle certain > material you run out of bits somewhere, QP goes through the roof and you > get visible distortion. We have a number of important customers who are > putting x265 into commercial production, and we get feedback (along with > content samples, steps to reproduce, etc.) when x265's rate control > doesn't handle a particular combination of settings and content optimally. > These customer requests have been driving a lot of the rate control > patches/improvements that you've seen over the past months. > > We weigh the cost against the benefit. We like the basic concept of this > patch - the ability to uniquely adapt x265 to different segments within > the video title. This type of capability fits in with our long-term > roadmap for x265. > > Let me discuss with the engineering team to figure out when and how we can > add this feature. Now might not be the best time to commit this patch, as > our rate control lead developer is still working to finish up the new CBR > mode. > > Tom > > > -----Original Message----- > From: x265-devel [mailto:[email protected]] On Behalf Of > Derek Buitenhuis > Sent: Tuesday, December 23, 2014 12:50 PM > To: [email protected] > Subject: Re: [x265] [PATCH] Basic support for tweaking rate control using > zones > > On 12/23/2014 6:03 AM, Deepthi Nandakumar wrote: >> Thanks for your patch. I'm not quite sure any of our regular users need > this as of now. We will keep this on standby though - until any requests > come in. > > Zones are fairly popular on e.g. Doom9 and within the the anime community. > > I don't really understand the point of keeping it on ice until you get a > request - is it going to hurt? > > Cheers, > - Derek > _______________________________________________ > x265-devel mailing list > [email protected] > https://mailman.videolan.org/listinfo/x265-devel > _______________________________________________ > x265-devel mailing list > [email protected] > https://mailman.videolan.org/listinfo/x265-devel _______________________________________________ x265-devel mailing list [email protected] https://mailman.videolan.org/listinfo/x265-devel
