x264 development

[ajp_anton]

Why does it feel like the development of the actual encoder has kind of stopped...
Are there still improvements planned?

[Dark Shikari]

Currently there's about 25-30 MBAFF patches queued up waiting for final review. Patience is a virtue!

[simonhorlick]

Other things to look out for are hopefully Trellis ME (summer of code) and energy preserving quant. Both of which look like they'll be really good for compression.

[LoRd_MuldeR]

Originally Posted by simonhorlick

Other things to look out for are hopefully Trellis ME (summer of code) and energy preserving quant. Both of which look like they'll be really good for compression.

I can't see those on the list of projects palnned for SoC 2011
http://wiki.videolan.org/SoC_x264_2011

[Mr VacBob]

Trellis ME is "Non-local RD optimization". Energy-preserving quant is a side project by saintdev (psy-trellis already behaves sort of like this).

[jpsdr]

It seems that bluray-compat put weigthp to 1 ? If i add a command line to put weightp to 2, will it work ?
I don't understand this choice. I thought weigthp 2 was bluray compliant according the specs, and problem was only because of some broken chipset ?
In the same good way, bluray-compat seems to put pict-struct only on interlaced content, and not on progressive content, wich seems to be strictly compliant to the spec, even if some people suggest to always put pict-struct, because some authoring software required it.
So, why chose to strictly follow the spec in one case, and not in the other ?
(Unless i am mistaken and understood things wrongly).

[skampy]

Has anyone ever had problems with the --zones function when the beginning frame is set to when the screen is blank (black)? Say at the very beginning of a video/movie (frame 0), or a few frames after a fade-to-black?

The problem is that, when that beginning frame of the set zone is reached, there is a 'gray' screen displayed for about a second or two, then the video resumes normally. The gray screen doesn't flash, it's simply static gray screen displayed in lieu of what is meant to be, in this case, a black screen.

This has happened with two seperate encodes with two different video sources, with x264 revisions of r1913 and r1924 respectively. Both gray screens occurred when the zone started during a black screen (intro/credits). The zones in this case were nothing special; the only setting used was a bitrate multiplier. I've used zones successfully many times without any problems, but now that I think about it, the start frame for the zone didn't happen to start on a black screen.

I am using the x264 CLI with the lastest x264 revision. The 1st and 2nd passes used exactly the same settings (I am aware that unless --slow-firstpass is specified, the 2nd pass settings aren't used for the 1st pass), and that includes the zone settings. The decoder I use is ffdshow w/ mpc-hc.

Any ideas? Is this a bug, or have I done something wrong?

PS- I don't think posting my x264 cl is relevant in this case, as I cannot fathom how any setting could cause such a weird bug.

[shon3i]

Originally Posted by jpsdr

It seems that bluray-compat put weigthp to 1 ? If i add a command line to put weightp to 2, will it work ?
I don't understand this choice. I thought weigthp 2 was bluray compliant according the specs, and problem was only because of some broken chipset ?
In the same good way, bluray-compat seems to put pict-struct only on interlaced content, and not on progressive content, wich seems to be strictly compliant to the spec, even if some people suggest to always put pict-struct, because some authoring software required it.
So, why chose to strictly follow the spec in one case, and not in the other ?
(Unless i am mistaken and understood things wrongly).

It seems that bluray compat is executed after user params, and all non bd compatible switches are reduced, so weightp 2 is not possible anymore with blu-ray.

pic-struct is not mandatory for progressive content in specs, only for (fake)interlaced and pulldown. But verifiers complain about (probably due bad interpretation of specs)

D_S already update x264 to use pic-struct on (fake)interlaced and pulldown in case bluray compat, we now just wait for next revision.

[Sharc]

Originally Posted by shon3i

It seems that bluray compat is executed after user params, and all non bd compatible switches are reduced, so weightp 2 is not possible anymore with blu-ray.

Good to know. That's different then compared to the earlier strategy when later settings in the command line overwrote the preceeding ones.

[Dark Shikari]

weightp 2 gives relatively little compression benefit over 1 (since the modification I made). If you really want to force it, modifying the code is trivial.

[Sharc]

Originally Posted by Dark Shikari

weightp 2 gives relatively little compression benefit over 1 (since the modification I made). If you really want to force it, modifying the code is trivial.

Little compression benefit yes, but I had in mind that the main benefit of weightp 2 was an improvement for fading scenes.

[Dark Shikari]

Originally Posted by Sharc

Little compression benefit yes, but I had in mind that the main benefit of weightp 2 was an improvement for fading scenes.

weightp 1 does that now.

[Sharc]

Originally Posted by Dark Shikari

weightp 1 does that now.

Excellent, thanks.

[Sharc]

Originally Posted by shon3i

It seems that bluray compat is executed after user params, and all non bd compatible switches are reduced, so weightp 2 is not possible anymore with blu-ray.

Will it also overwrite the --slices parameter?
I am asking because the --slices are still included here

[shon3i]

no just reduce bframes=3, ref=4 for 1080, ref=6 for 720/576/480, bpyramid=strict, weightp=1, aud=1, nalhrd=vbr

[Sharc]

Thank you. All clear now.

[Dark Shikari]

It doesn't force anything that isn't global to all Blu-ray profiles.

[Sharc]

Originally Posted by Dark Shikari

It doesn't force anything that isn't global to all Blu-ray profiles.

I see. And because it is executed after user parameters it does a clean up of non-compliant user settings

[jpsdr]

Originally Posted by shon3i

It seems that bluray compat is executed after user params, and all non bd compatible switches are reduced, so weightp 2 is not possible anymore with blu-ray.

So, does it mean that finaly weightp 2 was not bluray compliant strictly speaking of bluray spec, leaving aside all problem concerning crapy broken chipset ??

[sneaker_ger]

Originally Posted by jpsdr

So, does it mean that finaly weightp 2 was not bluray compliant strictly speaking of bluray spec, leaving aside all problem concerning crapy broken chipset ??

No. There's even a comment in the source that this is only to care for broken player, not for Blu-Ray compliance.