To all that have input lag and picture quality questions...

Over the past 3 years I (at least "believe") have grown from a flaming young idiot to more understanding of the uses of YCbCr (compressed media) and RGB (uncompressed media or where ever processing power is abundant). So I apologize to all that I have argued
with when they were correct in some aspect.

That being said, RGB is still the native colorspace for everything playing on your Xbox 360 (and One) except for DVD/Blu-rays. Even apps are outputting RGB and some (like Xfinity TV and Netflix) that I have seen convert the RGB range to limited even if you
have Expanded set in the dashboard. This is compensated by switching HDMI black level to Low.

There is a darker gamma ramp due to the extra conversion that the 360 does after sRGB correction, but its stated that its what TVs expect and I don't think Microsoft realized TV's would evolve into providing capabilities that a PC monitor has (ability to
process RGB natively/PC mode. Also, switching Black Level for full/limited content).

That is why we see the darker images more evident than on a correct console like the Playstation 3+4 and Xbox One.

As an added caveat, I'll say the best settings if your TV has a PC mode input label that changes the signal processing are:

HDTV resolution - 720p (why I say 720p is that most Xbox 360 games are obviously 720p. It depends on whether your TV scales faster than the 360 and in PC mode on my 1080p LG LN5300, 720p had
less lag, but a blurrier image. If I disable PC mode, edges were as sharp as 1080p, but that is because PC mode would disable extra scaling processing to leave the original image blurry as intended.)

RGB - Expanded (High TV Black level. All PC mode TV's should have a black level setting)

Digital Output - Digital Stereo (This one is a big sacrifice for someone who has surround headphones or conventional speakers like myself. Using Dolby Digital before, I noticed in one of the
Guitar Hero games I had it would change the "audio response" if I enabled DD ingame. Well, audio doesn't have a "response" like video and "response time" so I wondered if the Xbox 360 itself delays "input response" when DD is enabled to compensate for the
audio delay. Well it did for my observation and using stereo had less lag [due to it being uncompressed PCM].)

For those without PC mode on their TV's, its best to use (only works if using HDMI or VGA) the PC formatted resolution (1360x768, 1024x768, 1280x768, etc.) because it will tell your TV to start processing RGB instead of YCbCr because that's what "PC's" output
(and Xbox 360 is a type of a "PC").

RGB - Expanded (Even if you don't have a black level setting, If you choose the proper PC resolution it will put the TV into expecting Full range content)

Digital Output - same as above
(otherwise use Dolby Digital in sacrifice for more input delay)

So basically, this was a colorspace/input delay explanation from my observations. Think of the resolutions beyond 720p and Dolby Digital as "demo's" for what the eight generation of consoles can now do easily in every game. It wasn't ment to be consistent,
but upscaled 1080p + 5.1 surround is there to give a glimpse at what next-gen gaming would be.

The downside is the generous amount of input delay that presents itself when using these features and many people don't know there are console settings that produce the input delay and not just their TV. I believe it comes down to the games not knowing they
need to send an "upscaled" resolution of its internal target.

The Xbox 360 just takes the game's internal resolution and upscales it itself using the hardware upscaling that produces some delay. If both software and hardware in the 360 agreed, then the delay wouldn't be substantial if any at all.

:)

 

What tvs are the best for xb1 picture and input lag ?

Looking to buy a new tv , which ones do you think have best input lag , picture quality and hertz rate

 

Is there an Alternative setup?

Hi All, Just got a Samsung UN55D8000, great picture but it comes with the dreaded input lag. The game mode is very helpful at reducing lag but unfortunately it also has a noticeable loss in picture quality. I was wondering if anyone knows of an alternative
to game mode or some setting that will reduce lag without affecting picture quality a noticeable amount.

Also, I currently have my bd player and xbox going into the receiver and my receiver going out to my TV, all VIA HDMI. Is there an alternative (such as bd player and xbox to the tv and the tv out to the receiver) that will possibly improve the lag without
sacrificing the Surround Sound?

 

What delay times are you thinking of because all the image scaling and audio processing is takes very very little time. Big reason the original designs of the 360 had dedicated image scaling encoder chips and after the slim still have dedicated hardware
image scaling encoders. Playing a game rendering a solid 60 FPS the frame will be color translated and scaled and waiting for the TV for the next frame refresh. I would think because of this it's better to let the 360 handle scaling than selecting a lower
resolution closer to the games rendering resolution which for a lot of games was a non standard resolution that had to be scaled anyways than for your TV to then upscale if you select 720 and have a 1080 TV which is a TV and doesn't put as high a priority
on scaling. In your case the TV still has to generate all the extra pixels that don't exist when it receives a 720 frame, but is a 1080 display even if you disable image post processing. As for audio all games are required to use the XMA audio format and
support Dolby surround so the audio processing wouldn't take any longer if you choose Dolby 5.1 or stereo.

There are issues with color space conversions that produced noticeable image artifacts, but that is because of the way the 360 GPU handles rendering and the secondary image scaling and encoding trying to compensate.

I would say almost anyone that has issues with input delay is probably some post processing effects on their TV or routing through an AV receiver.

 

The buffer needed for scaling doesn't need to be very large, only as many lines as the maximum vertical distance between taps in the scaling kernel. It does not rescale the entire source image and buffer it in its entirety before it's output.

Rather, the display controller of the GPU (Xenos) continuously reads out pixels from the front buffer to the scaler, which buffers up maybe 5 or so many lines of the source data, calculates the output pixels from the source pixels, and buffers the result
briefly for feeding to the TV encoder (HANA) as the latter requests the data. I imagine that the scaling is also parallelized, processing multiple output pixels simultaneously.

I imagine that the delay added by the scaling step is a few hundred microseconds at most.

The display in turn syncs to the incoming signal. It might buffer several frames of video before display for reference in performing noise reduction and motion compensation, with or without the ability to bypass the buffering depending on which features
are enabled. That's why the input lag can differ so much between different brands and models.

 

@Smiling Cat. So I was on vacation in North Carolina about a month and brought my 360 with me for entertainment when I wasn't at the beach or sightseeing. The room I was staying in at the beach house still only had a Crt (which of course virtually
has no delay. We've gotten rid of all our CRT tv's back at home by the way).

When I was playing some Gears of war (1) it felt like there was still a slight delay in turning (I notice pretty easily being a person who use to play twitch fps games). Nothing could be done video-wise as 480I was the highest (composite cable) allowed,
but moving on my audio theory I changed my audio settings from DD to Digital Stereo (since I have never used it long enough to notice) and the input right away felt less like molasses and more like the analog stick moved in sync with the screen highlighted
option.

So there doesn't even need to be a receiver or HDTV present for the delay to happen. Once it is enabled in the dashboard, it affects all delay, not just video. All I could say is try it yourself and if you don't experience anything, that is fine. I'm just
telling what worked best for me (the most BASIC settings...)

@Zacabeb I think it was Icestorm III that i saw say it first, but you could have as well: which ever does the scaling faster (the Xbox 360 or your TV) is what should be kept. The reason crt's are obviously a quick choice is that they are limited to 480I
(not referring to crt RPTV's) so they aren't prone to scaling by the 360 (and just downscaling from the 360 is all that happens). That and the technology they utilize allows for immediate display (obviously to the technical minded like yourself). But remember,
1080p was never included in "hardware" but a later software update. It could take longer than any other resolution for the scaler to upscale to 1080p than any other resolution and that might be the way I notice a delay rather than just selecting 720p (what
most xbox 360 games are rendered at of course).

Maybe it has to do also with the fact that 720p shows up as a second detailed timing in my TV's EDID when using moninfo where as my last HDTV showed 1366x768 instead as a second detailing timing. So maybe my display knows what to do with 720p quick enough
if it was the one doing the scaling.

 

Also, apologize for not including "X360" or "Xbox 360" in the title.

I understand that this sub-forum is for A/V Hardware that has users with Xbox One consoles viewing these threads as well so I hope no one gets too confused...