Question / Help Having a Difficult Time :(

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ToastyPillow

New Member
There's just so much conflicting information out there that I don't know what to do anymore. So I've finally decided to just make my own thread. I will keep this post as clear and concise as I can. I will split it into two halves.

I will start by simply posting some info about my rig.

Processor: i7 3930k CPU @ 3.20GHz
GPU: x2 GeForce GTX 770s
RAM: 15.94 GB
Monitor: x2 1920x1080, 60Hz LG

Okay, so as far as I'm aware, my rig (although starting to show its age) is still more than capable of great quality recordings. The key word there is recordings; right now I am *only* trying to do local recordings to upload to YouTube. No streaming right now. Specifically, I am doing gameplay videos for games such as Battlefield or Assassin's Creed. It's just for fun, a hobby, but if I'm going to do it, I want to make sure that they're good quality, HD, and meet my own standards.

Unfortunately I have run into a LOT of confusion, and I have many questions. Please note that while I am more than willing to learn, I am not an extremely tech-savvy guy, so I'd appreciate it if you could do your best to explain everything as simply as you can. Or at least include an additional explanation / answer in lay-man's terms.

1. Many say that, when using the x264 Encoder, lowering the "CPU Usage Preset" will result in better quality at the cost of more CPU usage. However, I've come across numerous people saying the exact opposite for *local recordings*. These people say that a higher preset will result in better quality for local recordings only. What's up with that? Who is correct, and why?

2. What does deblocking mean? What does it do, or look like? For example, what does a video with good deblocking look like, in comparison to a video with poor deblocking?

3. What is a good CRF tuner for gameplay?

4. Why is bitrate important for local recordings? I thought bitrate and buffer size were only for live-streaming, not recording gameplay footage offline? Having asked that: what exactly *is* bitrate?

5. Why does it force me to set a Downscale Filter if I'm not downscaling?

6. Lastly, I'm absolutely lost when it comes to the color settings under the Advanced tab. How do I know what Color Format to use? What does YUV Color Space / Range mean? What do I set these to, and why?

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Now, the second half of my post. After I give some background information, I will list my settings.

Using CBR for "Rate Control", with Bitrate and Buffer Size both set to 2500, I was getting weird footage. The game in question was Assassin's Creed 1, so not a very demanding game for my PC. During scenes of high-movement, like when running around and parkour sequences, textures - and really the gameplay in general - would get even more "blockier" and "pixelly". That's the best way I can describe it: blocky and pixellated. I tested with Rocket League, another game that isn't very demanding, with the same results and general poor image quality. Can anybody explain what was causing this, and / or how to fix it?

Since then I changed Rate Control to CRF. I have it set to 10, because I was told the lower the better (just like with the CPU Usage Preset). While the general image quality seems to have improved with Rocket League (haven't retested Assassin's Creed yet), the footage does not look smooth. I don't know how else to explain it, other than by saying it doesn't look smooth. I mean, it doesn't look like an old silent-film either, but a lot of YouTubers have video quality so smooth that it looks exactly like you're playing the game yourself.

And *this* is when some confusion happened. I read several threads where people were saying to put the preset back to veryfast or even superfast. So I did that, and it appears smoother. But now I'm not sure if it's just all in my head and I'm tripping myself out. Maybe I'll need to privately upload some test footage of both games, and link the videos here to see what other people think. Guess it won't really matter what I think, if 100 other people think it looks fine.

My settings as promised. I'm running the latest update for OBS Studio, the 0.16.4 update on Windows 7.

-Output-

Mode: Advanced
Type: Standard

Format: mp4

Encoder: x264
Rate Control: CRF (value set to 10)
CPU Usage Preset: veryfast
Profile: high
Tune: None.
VFR: unchecked
x264 Options: N/A

-Video-
Base Resolution: 1920x1080
Output Resolution: 1920x1080
Downscale Filter: Bicubic (Sharpened scaling, 16 samples)
FPS: 60
Aero: Disabled

-Advanced-

Process Priority: Above Normal

Renderer: Direct3D 11

Color Format: NV12
YUV Color Space: 601
YUV Color Range: Partial

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My ultimately goal here is to try and get these questions answered. If more information, such as a log file or test recording, are needed then please just let me know. Help is greatly appreciated, and I'll try to be equally as helpful in getting my issues resolved.
 
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RytoEX

Forum Admin
Forum Moderator
Developer
Hi! Please post a log from recording session where you experience issues. Bonus points if you can include a link to an uploaded video from that session. Logs are incredibly useful to us here, they provide basically all of the system and settings info that you posted, without you having to manually type it.

There are also some wonderful guides on these forums. One such guide that would be useful for you is this guide on high quality recordings.
 
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ToastyPillow

New Member
RytoEX said:
Hi! Please post a log from recording session where you experience issues. Bonus points if you can include a link to an uploaded video from that session. Logs are incredibly useful to us here, they provide basically all of the system and settings info that you posted, without you having to manually type it.

There are also some wonderful guides on these forums. One such guide that would be useful for you is this guide on high quality recordings.
Click to expand...

https://gist.github.com/025ff0276931bad8767531d2faf64778

There's the link OBS gives me for my current log. Towards the bottom is the last recorded test session for Assassin's Creed 1, which was 15 minutes long.

Unfortunately I don't have it uploaded to show you. But during fight scenes and also when running around, the video lags. I was also noticing a little bit of lag when playing as well, but I had my task manager opened on my second monitor the entire time, and CPU usage never exceeded 50-60% range. My memory was also fine.

I think the bottleneck here must be the write speed of my HDD, no? Should I try recording to my SSD (C drive)?

The good news is that image quality looks good otherwise! Its sharp, colors aren't washed or anything. It looks good. Now the matter is getting smooth footage; getting rid of that lag. Not sure if those lost frames have anything to do with it. Only counted 9 lagged frames over a 15 minute timeframe, so I highly doubt that it's connected.
 
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RytoEX

Forum Admin
Forum Moderator
Developer
Hard disk write speeds are 80-160 MB/s. Unless you're churning out 80000 Kbps videos, it's unlikely that your hard disk is the bottleneck.

From your log:
23:40:19.481: Output 'adv_file_output': Number of skipped frames due to encoding lag: 90 (1.4%)
23:40:19.481: Output 'adv_file_output': Number of lagged frames due to rendering lag/stalls: 64 (1.0%)
[...]
00:10:16.398: Output 'adv_file_output': Number of skipped frames due to encoding lag: 10 (0.0%)
00:10:16.398: Output 'adv_file_output': Number of lagged frames due to rendering lag/stalls: 91 (0.3%)
[...]
00:33:46.032: Output 'adv_file_output': Number of lagged frames due to rendering lag/stalls: 9 (0.0%)
Click to expand...

You were skipping and lagging frames throughout your tests, but not much, so you were just hitting the limits of your CPU and GPU. If I recall correctly... Rendering lag is caused by the GPU not getting the frame to the encoder in time. Encoding lag is caused by the encoder not finishing the frame in time for output to the file. In this case, the encoder being x264, that's CPU resource strain/shortage.

CRF 10 is overkill. CRF 15-18 is probably your sweetspot, given what you want. It seems you've already settled on CRF 16 and x264 ultrafast, which should be fine for the most part, though you'll probably still lag a few frames (1% or less). If having absolutely zero lagged/skipped frames is a priority, then you'll have to reduce something (resolution, FPS, game settings, etc.).

From what I can see in the log, there's not hardly any skipped/lagged frames, so it's possible your game is actually what is stuttering.
 
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ToastyPillow

New Member
RytoEX said:
Hard disk write speeds are 80-160 MB/s. Unless you're churning out 80000 Kbps videos, it's unlikely that your hard disk is the bottleneck.

From your log:


You were skipping and lagging frames throughout your tests, but not much, so you were just hitting the limits of your CPU and GPU. If I recall correctly... Rendering lag is caused by the GPU not getting the frame to the encoder in time. Encoding lag is caused by the encoder not finishing the frame in time for output to the file. In this case, the encoder being x264, that's CPU resource strain/shortage.

CRF 10 is overkill. CRF 15-18 is probably your sweetspot, given what you want. It seems you've already settled on CRF 16 and x264 ultrafast, which should be fine for the most part, though you'll probably still lag a few frames (1% or less). If having absolutely zero lagged/skipped frames is a priority, then you'll have to reduce something (resolution, FPS, game settings, etc.).

From what I can see in the log, there's not hardly any skipped/lagged frames, so it's possible your game is actually what is stuttering.
Click to expand...

Thanks for the quick reply!

Yeah I figured the same thing about a CRF of 10, so I put it at sweet 16. I'll try a CRF of 21, although I'm skeptical it'll make a noticeable difference.

It's not so much the lagged frames, as there were only 9 out of over ~55k. I'm more than satisfied with 1% or less lagged frames!

Regarding my CPU and GPU, I guess I'm just confused. Is an i7 3930k and SLI 770s really not powerful enough? I mean, there are people with rigs equal or lower than mine who record beautiful, smooth HD footage. I'm referring to the raw footage of course, not anything additionally done in programs like Sony Vegas.

Another question: by lower the resolution, do you mean downscaling? Would downscaling in OBS from 1080p (native) to 720p help?

Thanks! :)

In the meantime I'll run another test and see what happens.
 
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ToastyPillow

New Member
Osiris said:
Try with SLI disabled
Click to expand...

I don't have a problem doing this, but may I ask why?

I always like learning the reasons behind these things. So the more information and knowledge I can glean, the better! :D

My guess: perhaps trying to split the load between running the game and doing the rendering, is potentially causing efficiency issues?
 
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ToastyPillow

New Member
Wow, thank-you so much, both of you! Disabling SLI did the trick! The game and footage is smooth as a baby's bottom. I'll be sure to either leave an update here, or make a new thread, if I experience any new issues. :)

So now I know that when I want to record with OBS, I should disable SLI.

Quick question though: does OBS plan on supporting SLI in the future?
 
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