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Old 06 October 2013, 22:18   #21
ajk
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Probably a PAL/NTSC thing in this case. It's meant to be 60fps no doubt.
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Old 07 October 2013, 11:50   #22
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Quote:
Originally Posted by ancalimon View Post
So why doesn't having a 24fps video of Amiga gameplay produce smooth scrolling? I looks like every second frame is skipped. It seems like we are missing something in this logic.
Guys you are confused with two things:

First Amiga have to video timings modes (numbers for PAL):
- progressive 312 OR 313 lines (in total 624 OR 626 lies),
- interlace 625 lines (average 312.5 lines per field)

second, coders usually don't care about video timing except V-BLANK - i.e. they force to change video content each field not frame (thus 50 times per second).

To code correctly they should check V-BLANK and Top/Bottom Field Flag.

Side effect of this is that all captures from Amiga shall be performed with all lines i.e. 576 lines and 720 pixels and 50 times per second.
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Old 07 October 2013, 14:02   #23
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The Amiga has a progressive display, so 25 is losing half of the action.
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Old 08 October 2013, 18:45   #24
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@ancalimon

That site has kept the video at 50 fps, nice find. Hopefully it remains that way.
They have closed down shop
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Old 08 October 2013, 20:10   #25
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Doh!
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Old 08 October 2013, 20:57   #26
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There are some enemies of smoothness, one is turning off Vsync in WinUAE before recording.

Once a perfect 50 fps recording is made, you can save it as a 50 or 25fps .mp4 that you can play on your computer. 50fps requires a good media player to not skip a single frame.

Your screen can then show it smoothly if you set it to a 50Hz mode. And reasonably smoothly, with shadowing (LCD)/slight stutter (CRT) if it has a 100Hz mode (same for a 75Hz playing the 25fps version).

On top of this, LCD screens add pixel shadowing if there is movement in the picture, causing the movement to be slightly blurry. With cheap LCDs and fast movement, quite noticably blurry.

And finally, standard codecs actively degrade picture quality in general (it's its job) and are made to compress movement within the picture. They have an especially tough time with the high contrast and high saturation colors used in games etc.

These are the steps you have to overcome (or, in most cases, find the best compromise with). The first step is to use a suitable codec (not a standard one) in WinUAE running at 320x256. Else it doesn't really matter what you do afterwards. ("Crap in, crap out")

If you google Recorded Amiga Games, you can download their video files and compare with their (newer) Youtube videos. They get pretty good results.

I looked at streaming video a few years ago, and 50 fps MP4 .ogg seemed quite OK then.
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Old 09 October 2013, 00:57   #27
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I think they recommended using the Techsmith codec (comes with Camtasia) for recording Amiga games, as it records in lossless quality.

I remember reading that in their forums and trying it out, and the quality of my videos improved dramatically.

I had no idea how to get smooth scrolling on Youtube though, so even the better quality videos (as compared to my old ones that is) still have very choppy and ugly scrolling.
The video files had much smoother scrolling, but when uploading them they degraded a lot in that regard... I wish I had looked up how to get better scrolling on there as I had no clue, I just uploaded the clips and that was it.

It's especially annoying in games like Shadow of the Beast, that is known for its silky smooth parallax scrolling.

EDIT - here is an example, I recorded Shadow of the Beast twice (a few years in between) as the old recording had such poor quality... I must have used something like xvid or so to record that one, I don't remember.
[ Show youtube player ]

When I switched to the Techsmith codec, the picture quality became a lot better, but the scrolling still ended up horrible on Youtube, as I said.
[ Show youtube player ]

Last edited by laffer; 09 October 2013 at 01:06.
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Old 09 October 2013, 01:55   #28
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Youtube should support shit like PNG Codec, which is by far the best one for this kind of application, in my opinion.
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Old 15 October 2013, 20:12   #29
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Compare frames per second: which looks better?
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Old 15 October 2013, 21:39   #30
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Shk: not relevant, partly because we're talking encoding to video clips and partly because the author of the movement code didn't check if the graphics perform at the fps he wants

It's a motion blur test without vsync and no fps checking. Maybe it works in some mobile web browser on a specific phone? I dunno. It's still not video though, and that's the point. Anyway.
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Old 15 October 2013, 21:51   #31
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I think the first problem is that we are trying to save the 50Hz game video and then play it at the 60Hz lcd. It can't be a smooth scrolling like that.
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Old 16 October 2013, 06:55   #32
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No it can't, but 50fps video would still look closer to the original than a 25fps one (assuming of course that the game runs at 50fps). But it doesn't seem like there are many web services that allow you to maintain 50fps.
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Old 16 October 2013, 08:23   #33
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http://hometheater.about.com/od/tele...evsrefresh.htm

Quote:
Frame Rate vs Refresh Rate

What makes things confusing is the concept of how many separate and discreet frames are displayed every second, verses how many times the frame is repeated every 1/24th, 1/25, or 1/30th of a second to match the refresh rate of the Television display.

TVs have their own screen refresh capabilities. A television's screen refresh rate is usually listed in the user manual or on the manufacturer's product web page.

The most common refresh rate for today's Televisions are 60hz for NTSC-based systems and 50hz for PAL-based systems. However, with the introduction of some Blu-ray Disc and HD-DVD players that can actually output a 24 frame per second video signal, instead of the traditional 30 frame per second video signal, new refresh rates are being implemented by some television display makers to accommodate these signals in the correct mathematical ratio.

If you have a TV with a 120hz refresh rate that is 1080p/24 compatible (1920 pixels across the screen vs 1080 pixels down the screen, with a 24 frame per second rate). The TV ends up displaying 24 separate frames every second, but repeats each frame according to the refresh rate of the TV. In the case of 120hz each frame would be displayed 5 times within each 24th of a second.

In other words, even with higher refresh rates, there are still only 24 separate frames displayed every second, but they may need to be displayed multiple times, depending on the refresh rate.

To display 24 frames per second on a TV with a 120hz refresh rate, each frame is repeated 5 times every 24th of a second.

To display 24 frames per second on a TV with a 72hz refresh rate, each frame is repeated 3 times every 24th of a second.

To display 30 frames per second on a TV with a 60 hz refresh rate, each frame is repeated 2 times every 30th of a second.

To display 25 frames per second on a TV with a 50 hz refresh rate (PAL Countries), each frame is repeated 2 times every 25th of a second.

To display 25 frames per second on a TV with a 100 hz refresh rate (PAL Countries), each frame is repeated 4 times every 25th of a second.
Based on this, the best results will be when we capture games in the 60hz NTSC mode and deinterlaced recordings by 60i-to-60p method (double deinterlacing). Playback will be smooth with common 60Hz PC-displays. But, yes, you still need the web services that allow you to playback 60fps videos.
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Old 17 October 2013, 02:50   #34
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Quote:
Originally Posted by ShK View Post
http://hometheater.about.com/od/tele...evsrefresh.htm



Based on this, the best results will be when we capture games in the 60hz NTSC mode and deinterlaced recordings by 60i-to-60p method (double deinterlacing). Playback will be smooth with common 60Hz PC-displays. But, yes, you still need the web services that allow you to playback 60fps videos.
I'm guessing there are no web service that supports 50 or 60fps video upload and playback since the one I found closed down
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Old 25 April 2014, 18:40   #35
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My files after uploading to youtube have lower resolution and quality. I'm not using some exotic codec, it's Xvid.
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Old 25 April 2014, 19:03   #36
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a videogame to be smooth need at least 50 or 60 fps, for example on the Amiga putty squad ,chaos engine and Aladdin run at 25fps are not smooth
while Turrican series, assasin,zool 1 and 2 run at 50fps are smooth
I play some PC games at 120 fps on my monitor, some games allow it and that is great, super smooth,

videogames on youtube don't look smooth because despite you upload the video at 60fps they convert it degrading performance and quality, example you upload a DIVX video at 60fps they convert it to FLASH 30fps
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Old 25 April 2014, 19:10   #37
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What I tend to do is use overkill on the bitrates when uploading to youtube, taking into account youtube will always degrade the video somewhat. Another tip is to stick to constant bitrates rather than using minimum/maximum averages. You can give the illusion of having smooth scrolling using a blur effect on the motion but the trade off is the after images it leaves behind.
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Old 25 April 2014, 20:43   #38
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My files after uploading to youtube have lower resolution and quality. I'm not using some exotic codec, it's Xvid.
Encode uploads as HD (1080) - or at least 720p - YT anyway recode files thus your upload can be encoded as H.264 with fast or very fast preset (x264) to save encode time.


https://support.google.com/youtube/a...1722171?hl=en\

as a principle, all vides need to be deinterlaced (progressive as google deosn't do deinterlace and recode everything as interlace - this with resize create nasty pattern on video ) - Amiga can produce both types of video thus only one safe capture mode is 50/60fps full resolution (such as 736x568 for PAL, twice H res for SHires) - a bit overkill but... unavoidable as Amiga screen can have multiple resolution and different framerates and frame update speed.
btw you can cosnsider to upsacle video from Amiga even to 2160p: 3840x2160 or 1440p: 2560x1440 - sounds weird but this only way to obey google limitations (increase resolution by modulo 2 - remain area pad to fill resolution).
There is no need to loose time on encode quality.

ffmpeg -i input -c:v libx264 -preset ultrafast -crf 18 -strict experimental -c:a aac -b:a 384k -ac 2 -shortest -movflags faststart -pix_fmt yuv420p output.mp4
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Old 25 April 2014, 21:28   #39
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Here is some [ Show youtube player ]. I think the game segments look good enough, apart from the occasional blurring issues due to the 30 fps limit. I capture at the standard PAL resolution of 720x576 and then process depending on the type of game, but always bringing the FPS down to 25 before uploading.
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Old 27 April 2014, 02:01   #40
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Apart from my general information about what is going on, pandy71's advice is correct, or at least Youtube will mangle your video less if it's at least 720p. Getting that out of WinUAE is not possible I think, which is why I use Free Screen To Video and screen capture it instead. The alternative is to use the Recorded Amiga Games method I mention, but I'm not saying there's a guarantee your video won't get mangled.

You won't get Youtube to display a video with > 30 fps until something wonderful happens, i.e. Youtube webdevs must put in some work to support some 1980s quality 50/60Hz format and so will be able to encode to something other than the standard "something like 25 fps" FLV or 25/30 FPS MP4. Either way you'll be going with H264 for best results I think.
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