Emulation vs the Real Thing

[Dot77]

Originally Posted by Hewitson

Not true at all. Besides, if the image is tearing, it's obviously not moving smoothly is it?


Absolute bullshit.

Tearing does not cause a jerk in scrolling. It just causes that visible horizontal anomaly due to seeing two (perhaps even more) different frames on the screen at the same time. I'm starting to think that we are talking about slightly different things. You focus more on the overall visual quality of what you are seeing on the screen, and i'm just talking about whether scrolling has jerks/hickups/framedrops (whatever you want to call them) or not.

A very short video of 1280x720p Pinball Dreams, recorded with Fraps at 50fps, full size and lossless RGB compression. Compressed using H264 compression with CRF setting of 18:

Dropbox link

In order to see what i saw during gameplay, you need a 50Hz desktop, Period. There's no way around that (and VLC is good for playback - for example my MPH-HC + ffdshow setup with all its tweaks caused some hickups here and there on its own during video playback). In 60Hz desktop, the steady subtle jerkyness is caused by the difference between video framerate and desktop refresh rate. Graphics are a bit fuzzy due to bilinear filtering for null filter in WinUAE. VSync was not used.

[Christian]

Originally Posted by Hewitson

There is many more factors to consider than just frames being dropped.

Saying vsync should be avoided proves you don't have a clue what you're talking about. How the hell is anything going to scroll smoothly when it's not synchronised to the refresh rate of the monitor?

Um, In my experience, in WinUAE, Double-Buffering is enough to eliminate screen tearing. V-sync should be avoided as it (again for me) creates more of a lag/delay from key presses to results on the screen.

And yes, you can get perfectly smooth scrolling without v-sync. And no, you do NOT need a CRT. Who the f*ck wants one of those on their desk nowadays! I mean really???!

[Leffmann]

Originally Posted by Christian

Um, In my experience, in WinUAE, Double-Buffering is enough to eliminate screen tearing. V-sync should be avoided as it (again for me) creates more of a lag/delay from key presses to results on the screen.

And yes, you can get perfectly smooth scrolling without v-sync. And no, you do NOT need a CRT. Who the f*ck wants one of those on their desk nowadays! I mean really???!

Double buffering in itself never removes screen tearing, but V-syncing always has the purpose of removing screen tearing. If double buffering removes screen tearing then it's understood that some vertical syncing is also taking place.

One reason to use a CRT is to avoid the small lag/delay introduced by flat screens due to how they work. This delay is only the duration of a single image frame so it's pretty negligible.

[Hewitson]

Thanks for the video, unfortunately my monitor doesn't seem to sync down to 50hz but I'd be interested to see one done in 60hz.

I still believe that if you were to run something like this:

http://ftp.amigascne.org/pub/amiga/G...Band-CrTrBeast

That you would certainly notice jerking in the scrolling.

[Dot77]

Challenge accepted

I used 60fps in WinUAE this time, for 60Hz people to see smooth scrolling (once again i recommend VLC for playback). Audio was disabled, but emulated. It sounds hideous when sped up. Also appears to cause some "crackling".

WinUAE was running in 1280x720 fullscreen (no VSync). Fraps was recording in 60fps, fullsize and lossless RGB compression. Recording was done to RAM disk to minimize the chance of frame drops in the recorded video.

During recording i watched the screen like a hawk and didn't spot ANY jerks. You might see one or two in the video, BUT those jerks don't seem to have any fixed locations in the video timeframe. That would suggest oddities in video playback, not problems in WinUAE delivering smoothness

Dropbox-link

[s2325]

The thing is you can have scrolling with same or even better quality without modern PC but with 25-years old hardware.

[Dot77]

Originally Posted by s2325

The thing is you can have scrolling with same or even better quality without modern PC but with 25-years old hardware.

Of course you can. The debate i was having with Hewitson was whether emulation is at all capable of achieving smooth scrolling or not. This should interest people who prefer emulation due to whatever reasons.

[s2325]

I think you can not have same quality because it's software emulation and with heavy OS working in background.

[Dot77]

Originally Posted by s2325

I think you can not have same quality because it's software emulation and with heavy OS working in background.

For me the audiovisual experience so far has been ok enough for me in WinUAE (to make me not bother myself with my real A500), but i admit the problems in input response (i.e. in WB the mouse cursor is not as responsive as it is in the real thing).

Modern computers with their multiple cores have helped with the background OS burden. You saw my latest video? It had 64-bit Win7 + Fraps recording process running in the background. Still pretty good result i think.

[Dot77]

One final video, showing Turrican II gameplay. WinUAE output was 1920x1080 fullscreen @ 60fps (no VSync). Audio was disabled but emulated again. In-game graphics were resized (scaled) to fit the screen more efficiently (null filter used point sampling). Fraps recorded half-size only and without "force lossless RGB compression" switch. Due to these settings in Fraps, the game naturally looked better in actual gameplay. Once again i didn't notice any jerks in gameplay, but the video does show some. Those are either playback oddities or dropped frames by Fraps during recording.

Dropbox-link

[Hewitson]

Thanks for the videos, amazingly I couldn't spot any jerking at all. I still wouldn't say it's as smooth as a real machine, but it's much better than I was expecting.

Sorry for being rude to you earlier in the thread, I have well and truly been proven wrong!

[seuden]

How much does Toni charge for WinUAE?

[r.cade]

Originally Posted by Dot77

Challenge accepted

I used 60fps in WinUAE this time, for 60Hz people to see smooth scrolling (once again i recommend VLC for playback). Audio was disabled, but emulated. It sounds hideous when sped up. Also appears to cause some "crackling".

WinUAE was running in 1280x720 fullscreen (no VSync). Fraps was recording in 60fps, fullsize and lossless RGB compression. Recording was done to RAM disk to minimize the chance of frame drops in the recorded video.

During recording i watched the screen like a hawk and didn't spot ANY jerks. You might see one or two in the video, BUT those jerks don't seem to have any fixed locations in the video timeframe. That would suggest oddities in video playback, not problems in WinUAE delivering smoothness

Dropbox-link

The trick is the sound. I get nice smooth video without VSYNC also, but only with sound disabled. For that reason I run AutoVSync, which is a good compromise. It skips here and there, but not badly, and the sound is correct.

[Dot77]

Originally Posted by r.cade

The trick is the sound. I get nice smooth video without VSYNC also, but only with sound disabled. For that reason I run AutoVSync, which is a good compromise. It skips here and there, but not badly, and the sound is correct.

I didn't know AutoVSync can prevent the audio speedup in 60fps + 60Hz output That's just reveals how much i've ignored it. I'm lucky to be able to run at 50fps + 50Hz, so i don't need VSync to keep audio at normal speed. It means good video and audio at the same time

I'll admit that in 60fps + 60Hz + AutoVSync, the good video smoothness is gone (and i didn't like the audio either tbh - i was hearing subtle out-of-tune problems). I'm loving my 50Hz desktop possibility more and more.

[Dot77]

Originally Posted by Hewitson

...

Sorry for being rude to you earlier in the thread, I have well and truly been proven wrong!

In the world of LCD displays where 50Hz desktop is a rarity, your statement of non-smooth scrolling is actually very valid. You can't get jerk-free scrolling AND normal sounding audio at the same time in a 60Hz environment. From my experience it's either close-to-normal-but-not-quite-there audio with jerky scrolling, or too fast and therefore unusable audio with jerk-free scrolling. Both are poor choices imo (my 60fps videos ended up being bad examples as they represented the latter case).

And now that i did some further testing, i noticed that while audio is normal (i.e. no speed or out-of-tune/fluctuation problems), i was able to hear occasional audio anomalies (skip/crackle) in 50fps + 50Hz + VSync-off configuration where scrolling is jerk-free. Enabling VSync might help audio, but definitely causes jerks in scrolling. So in the end it's not possible to get the absolute best from both worlds under 50Hz environment either.

Audio sample from Turrican II gameplay. WinUAE output was 50fps / 1920x1080 / 50Hz / VSync off. I didn't notice any jerks in scrolling Audio is from Fraps recording:

Yet another Dropbox-link

It should also be noted that i used WinUAE sound buffer size 1 here. Perhaps if i raise it higher, it could help with those skips/crackles, but i don't like sound lagging behind screen events.

[Christian]

Hey Dot77, have you seen this thread?

http://eab.abime.net/showthread.php?t=58900

Toni explains some stuff there.

[Dot77]

Originally Posted by Christian

Hey Dot77, have you seen this thread?

http://eab.abime.net/showthread.php?t=58900

Toni explains some stuff there.

Some very technical stuff there But now it's obvious why i haven't seen any tearing and my input response can be lacking. I've been using triple-buffering all the time

I'm definitely going to try this chipset_refreshrate calibrating process.


[EDIT]: Man it's hard to try and keep the tear in place. I think i'll keep using buffering and live with the slight input delay. I learned new things from WinUAE. It's a shame it doesn't have any proper documentation itself. You have to figure things out by lurking in forums or reading (mostly) out-of-date guides for setting up WinUAE.

[Christian]

That thread has been updated again and Toni has come up with a new vsync method (no need to "calibrate" your refresh rate).

Works great and will be included in the next beta I believe

Also, you're using a 1080p tv like me I think? I've recently switched to using no filter at all and no aspect correction. Just Horizontal Size to 2x, and Vertical Size to 4x. This ensures that there are no scaling artifacts at all for a very, very clear picture. The amiga screen fits quite nicely on a 1080p TV. Not all games will fill the screen vertically of course (same as on a real Amiga) but the "automatic center" option can be quite nice in these cases.

Scanlines & bilinear can still be turned on if that's your thing

[Retro-Nerd]

Originally Posted by Christian

Also, you're using a 1080p tv like me I think? I've recently switched to using no filter at all and no aspect correction. Just Horizontal Size to 2x, and Vertical Size to 4x. This ensures that there are no scaling artifacts at all for a very, very clear picture. The amiga screen fits quite nicely on a 1080p TV. Not all games will fill the screen vertically of course (same as on a real Amiga) but the "automatic center" option can be quite nice in these cases.

Scanlines & bilinear can still be turned on if that's your thing

This doesn't work for me on my 37" HD-Ready TV with a 1280x720 resolution. The zoom was too big and the D3D scanlines caused garbage. Anyway, i've changed

gfx_filter_vert_zoom_mult=350
gfx_filter_horiz_zoom_mult=700

which is a 1.43/2.86 zoom and it looks pretty nice now. No scaling artefacts (ugly lines) anymore, just a little bit of noise which can you can soften with the bilinear filter.

Edti: Forget it. Now i know (on my PC!) what causes this annoying vertical/horizontal lines. It's a combination of scaling and D3D Scanlines/PNG overlay Scanlines. Without scanlines (but scaling enabled) it looks like the mentioned image noise.

[Christian]

Ah ok mate, yeah those settings were for 1920x1080 resolution only.

Is the native res of your tv 1280x720 then? We have another screen in the house that is not full hd and it's resolution is 1366x768 (or something). Also the tv will need to have some sort of 1:1 pixel mode turned on. I think on my Sony it's called "full pixel" or something.